Infectious Diseases Flashcards
Bacteria for septicemia in neonates under 1 month?
Group B strep, E. Coli, streptococcus pneumoniae (pneumococcus), staph aureus
Bacteria for septicemia in infants 1-12 months?
Group B strep, E. Coli, streptococcus pneumoniae (pneumococcus), staph aureus, and salmonella
Bacteria for septicemia in immunocompromised patients?
Gram negative bacilli (pseudomonas, E. Coli, and Klebsiella) and Staph
Bacteria for septicemia in asplenic patients?
Streptococcus pneumoniae
Remember sickle cell disease is functional asplenia, they won’t note this outright
Petechiae or purpura on skin, patient with a non blanching rash
Neisseria meningitidis
If you are told a patient has received the meningococcal vaccine, is meningococcemia still a possible diagnosis?
Yes, this doesn’t confer 100% immunity
Bacteria presenting with pustules on the skin?
Staph aureus
Bacteria presenting with ecthyma gangrenosum (large pustules on an indurated, inflamed base)?
Pseudomonas
Bacteria presenting with rose spots on the skin?
Salmonella typhosa
Is neonatal meningitis usually bacterial or viral?
Usually bacterial, but can sometimes be enteroviral (especially in the spring or summer)
What are the most common bacteria causing neonatal meningitis?
Group B strep, Listeria monocytogenes, E. Coli
What are the most common bacteria causing meningitis in young children?
Streptococcus pneumoniae, Neisseria meningitidis, enteroviruses, Borrelia burgdorferi, Rickettsia rickettsii
What are neurological sequelae of meningitis?
Seizures and focal deficits (aphasia, visual field deficits, hemiparesis)
What has to be considered as a complication of meningitis (neuro problem)?
Subdural hematoma
How is a subdural hematoma managed in the setting of meningitis?
Only supportive (in absence of increased intracranial pressure)
Why do you have to monitor urine output, serum electrolytes, and osmolality so closely in a patient who has meningitis?
Because of the risk of SIADH
If you need to do an LP to diagnose meningitis, when should you get a CT scan first?
If there are focal signs
If you have a kid from a developing country, what 3 things should you look for?
- Something US kids are immunized against
- Chronic condition that wasn’t previously diagnosed
- Infectious diseases that are more common in developing world
What are some examples of diseases that they might describe in children from developing countries?
TB, HIV, typhoid fever, invasive H. flu, and sickle cell disease
What are the 3 species of Chlamydia that are pathological to humans?
- Chlamydia trachomatis
- Chlamydophilia pneumoniae
- Chlamydophilia psittaci
What is the most common reportable STD in the US?
Chlamydia trachomatis
How can chlamydia trachomatis be transmitted?
Sexually
Mothers to infants (mostly via vaginal birth)
Can be transmitted with C-section delivery even with intact membranes
Newborn (first 2 months of life) with an afebrile “staccato cough”, tachypnea, possible eye discharge?
Chlamydia trachomatis
“Intracytoplasmic inclusion bodies” in scrapings?
Chlamydia trachomatis
How is chlamydia trachomatis definitively diagnosed?
PCR
How is chlamydia conjunctivitis treated?
ORAL erythromycin (or sulfonamides if erythromycin isn’t tolerated)
*Topical treatment will be the wrong choice
What are lab findings for chlamydia conjunctivitis?
Eosinophilia
remember erythromycin is treatment…both start with E
What is the memory aid for chlamydia conjunctivitis?
“Clams” instead of eyes with discharge and coughing… cold clams have no fever. If you put eye drops in there, they gobble it up and the rest of the body gets none (so systemic antibiotics are needed)
What antibiotic use has been associated with increased incidence of infantile hypertrophic pyloric stenosis?
Oral erythromycin use in infants younger than 6 weeks
What are treatment options for uncomplicated chlamydia genital infections?
Doxycycline for 7 days
Azithromycin single 1g PO dose
*Erythromycin, ofloxacin, or levofloxacin for 7 days are also acceptable alternatives for uncomplicated genital infections
What does silver nitrate prophylaxis prevent against?
GC conjunctivitis (not Chlamydia conjunctivitis)
What is the preferred prophylaxis immediately after birth for the eyes?
0.5% erythromycin
Because the silver nitrate only protects against GC conjunctivitis, not Chlamydia conjunctivitis
If you have an adolescent with a low-grade fever and infiltrates and mycoplasma isn’t an answer choice, what is it?
Chlamydia pneumoniae
How is C. pneumoniae diagnosed?
With immunofluorescent antibodies
Picture glow in the dark clams
How is chlamydia pneumonia treated?
Azithromycin for 5 days
Erythromycin for 14 days
What is the most common fatal tick-borne disease in the US?
Rocky Mountain Spotted Fever
What bacteria causes RMSF?
Rickettsia rickettsii
What are the peak times for infection with RMSF?
May and June
If they present symptoms during the winter, it is unlikely to be RMSF
What % of cases of RMSF occur in the Rocky Mountain states?
Less than 2%
Describe the rash in RMSF
“Mac pap” or “Purpuric Macular Rash” which becomes petechial
Rash starts on wrists/ankles, palms/soles and spreads centrally
What are other symptoms of RMSF besides the rash?
Headache, fevers, myalgias, CNS symptoms (confusion and lethargy)
Around 1/4 of affected individuals have the CNS symptoms
What is the memory aid for RMSF?
Think of a Rocky Mountain climber who develops a rash on his hands and feet from climbing the Rocky Mountains. His hands come into contact with tiny microscopic stones, which form tiny red dots (petechiae).
What % of cases with RMSF present without a rash?
About 20%
If RMSF presents without a rash, what can you watch out for as clues to the diagnosis?
Hyponatremia along with depression of 1 or all 3 cell lines of the CBC
Patient with classic signs of RMSF…most important immediate step and treatment?
Patients should receive treatment if the index of suspicion is high (treat first and ask questions later)…waiting for test result is never answer with suspected RMSF.
Doxycycline (even in kids)
Despite treatment, what is the mortality rate for RMSF?
4%…quick diagnosis based on acute clinical assessment is key
During the acute phase of RMSF, what is the only reliable test for diagnosis?
Direct immunofluorescence of a skin biopsy
This isn’t very sensitive…treat if index of suspicion is high
What is the current preferred treatment for RMSF?
Doxycycline (even if under 8…risk of teeth staining from a single course is low)
Chloramphenicol used to be treatment of choice
How long do you treat for RMSF?
Doxycycline for 7 days or until fever has resolved for at least 3 days
What are symptoms of ehrlichiosis?
Fever, headache, myalgias (can be clinically indistinguishable from RMSF)
What lab values will distinguish RMSF from Ehrlichiosis?
Both can present with thrombocytopenia and hyponatremia
Human ehrlichiosis is more likely to present with leukopenia and elevated LFTs
What has the Hib vaccine decreased?
The amount of H. flu, type B meningitis, and invasive disease
What can H. Flu type B cause?
Neonatal sepsis, childhood meningitis, periorbital cellulitis, pyogenic arthritis, and epiglottitis
Mortality and morbidity rates from these infections are high
What bug should you think of if you have a kid coming from a developing country or a kid whose parents are against immunizations?
Hib
If they describe a gram-negative pleomorphic organism on gram stain, what should you think?
Hib
Where is Hib’s natural habitat?
Human respiratory tract
How is Hib transmitted?
Person to person transmission occurs via inhalation of respiratory droplets or by direct contact with respiratory secretions
What is the treatment of an infection caused by Hib?
Ceftriaxone or cefotaxime
Alternatives are meropenem or chloramphenicol (watching and waiting isn’t appropriate because it is an aggressive organism)
What does the Hib vaccine not protect against?
Vaccine doesn’t provide protection from non-typeable H. flu…this is a cause of otitis media in kids and pneumonia in older patients
Name 3 encapsulated organisms
- Strep pneumo
- Neisseria meningitidis
- H. flu
Which patient do you have to worry about encapsulated organisms?
Splenectomized patients
In a house with someone under 12 months who hasn’t gotten primary series of Hib vaccine, what is given for chemoprophylaxis following Hib exposure?
All household members should receive rifampin
In a house with someone under 4 who is incompletely immunized against Hib, what is given for chemoprophylaxis following Hib exposure?
All household contacts regardless of age should get rifampin
If there is an immunocompromized child in the household,what is given for chemoprophylaxis following Hib exposure?
All members of household need rifampin prophylaxis
Even if the kid is older than 4 and completely immunized because of the possibility that immunization may not have been effective
When is chemoprophylaxis after Hib exposure not recommended?
For occupants of households where all members are immunocompetent and have been fully immunized
What kind of chemoprophylaxis is given if the index case has non-typeable H. flu?
None…this is a trick and nobody needs rifampin
What is done if there are 2+ cases of invasive Hib infection occurring within 60 days and there are unimunized or incompletely immunized children in the child care facility or preschool?
Rifampin prophylaxis is indicated for ALL attendees and child care providers
What type of Hib chemoprophylaxis is needed for nursery school or childcare children older than 2 who have only been exposed to 1 index case?
Decided on a case-by-case basis
What else should unimmunized or incompletely immunized kids get besides post-exposure chemoprophylaxis for Hib?
Hib vaccine and proceed with regular vaccine series
What are the 3 phases of pertussis?
- Catarrhal
- Paroxysmal
- Recovery
When does an asymptomatic incubation period occur in Pertussis?
One week prior to the catarrhal stage
Describe the typical catarrhal stage of pertussis?
Indistinguishable from the common cold…progresses to paroxysms of coughing with inspiratory whooping and possibly posttussive emesis
In the catarrhal stage of pertussis is the patient febrile?
Typically the patient is afebrile
WBC count of 20-40K with increased lymphocytes, and a cough described in a preschooler…?
Pertussis
*Usually imply lack of immunization (parents who are against immunization, recent immigrants, ect.)
Describe the presentation of pertussis in infants
Can be atypical, very short catarrhal stage
-Infant who is gasping, gagging, or experiencing apnea
Who is at the greatest risk for complications from pertussis?
Infants younger than 6 months of age
What is the typical duration of pertussis?
Last up to 10 weeks
In the olden days it was known as the 100 day cough
Why is a pertussis vaccine booster now recommended for all pregnant women, all teenagers, and all adult household contacts of newborn infants?
Immunity to pertussis wanes over time… many adults with protracted “colds” with cough might have pertussis and pass it to an unimmunized neonate (watch for this in history)
How is pertussis transmitted?
Via close contact or via aerosolized droplets
How is pertussis diagnosed?
Culture is gold standard for confirming diagnosis, but often not practical (many factors can affect growth of organism)
PCR is now method of choice for diagnosis
Direct immunofluorescent assay (DFA) is no longer in common use and will be the incorrect choice
Do you immunize children who have had documented pertussis?
Yes…duration of immunity following clinical disease is unknown so kids should go through the full series
What is treatment for pertussis?
Erythromycin, clarithromycin, or azithromycin
Bactrim is an alternative
What does treatment with antibiotics actually do for pertussis?
Only shortens the catarrhal stage (first 1-2 weeks when URI, not cough, is major symptom)
What is the result if antibiotic treatment is given during the paroxysmal stage (actual whoop and cough stage)?
Decreases the period of communicability, but doesn’t shorten the coughing stage
Who gets post-exposure prophylaxis for pertussis?
Anyone exposed to someone with pertussis, regardless of immunization status (to prevent spread)
Includes all household contacts and close contacts in child care
What is given for post-exposure prophylaxis for pertussis?
Erythromycin, azithromycin, or clarithromycin
Who carries salmonella?
Chickens and humans
What can you get salmonella from?
Foods (poultry or eggs), contaminated unwashed veggies, contaminated medical instruments, pets (turtles, snakes, hedgehogs)
Group on a picnic in the summer, 1-2 days later several attendees present with watery loose stools with vomiting, abdominal cramps, and fever…
Salmonella
How is salmonella diagnosed?
Stool culture
Otherwise healthy patient, history classic for Salmonella diarrhea (picnic, undercooked chicken salad with mayo in sun for 8 hours)…what is correct treatment?
Supportive care (don’t be tempted by antibiotics)
What is treatment for uncomplicated (non-invasive) Salmonella gastroenteritis?
Not necessary…it may lead to the carrier state
Which people would you treat for salmonella?
Treatment indicated in infants younger than 3 months of age and anyone else at risk for invasive disease (malignancies, severe colitis, immunocompromized)
What drugs are used to treat salmonella (if you need to treat it)?
Cefotaxime or ceftriaxone are appropriate initial treatment choices pending culture and sensitivity confirmation
General systemic signs (malaise, fever, poor appetite), hepatosplenomegaly, red/rose spots…
Salmonella typhi
What GI issue can be an early presenting sign of salmonella typhi?
Constipation (versus diarrhea seen in many forms of salmonella)
What is the treatment for salmonella typhi?
Cefotaxime and ceftriaxone
When does the onset of illness occur after ingestion of Shigella?
Several days
What is the initial presentation of Shigella?
Watery diarrhea and fever
When does the bloody diarrhea appear in Shigella?
After the fever subsides
What is seen on the CBC with Shigella?
Increased number of bands, regardless of actual WBC
Kid with bloody diarrhea who is also having a seizure?
Shigella
*Might describe seizure without mentioning diarrhea, but will give hint that it’s Shigella (like WBCs or RBCs in stool with left shift on CBC)
Memory aid for Shigella?
Shake-ella…shake is the tonic clonic seizure
What is the primary treatment for shigella?
Oral rehydration
Who is treatment recommended for in Shigella?
Severe disease, dysentery, or those who are immunosuppressed… most infections are self-limited
What is the drug of choice for Shigella?
Trimethoprim-sulfamethoxazole
*Ampicillin might be a correct answer if culture shows susceptibility…but some areas show high (80%) resistance
What bug can present similarly to Shigella?
Campylobacter
What can cause osteomyelitis/osteochondritis as a result of puncture wounds?
Pseudomonas
Nail goes through a shoe…bug causing problems?
Pseudomonas
What causes otitis externa (swimmer’s ear)?
Pseudomonas
What causes infection from mechanical ventilators?
Pseudomonas
What bug should you think of with water as a common denominator?
Pseudomonas
What type of pseudomonas is a major cause of sepsis and pneumonia and has a very high mortality rate?
Pseudomonas aeruginosa
What type of pseudomonas is a major cause of pneumonia and death in kids with CF?
Pseudomonas cepacia
What is the most likely bug for skin infection at all times?
Staph and Strep
If a lesion involves soil and water, what bug should you consider?
Pseudomonas
what bug are cancer patients (especially those experiencing neutropenia) at risk for?
Pseudomonas
What antibiotics are effective against pseudomonas (2)?
Piperacillin/tazobactam and gentamicin
What drugs can be used for pulmonary infections caused by pseudomonas?
Carbapenems (imipenem and meropenem) and ceftazidime
What are the only quinolones effective against pseudomonas?
Ciprofloxacin and levofloxacin
Which cephalosporin can be used for pseudomonas?
Ceftaz
Ceftaz is the Tazmanian Devil of cephalosporins
Which 2 patients are at risk for pseudomonas infection?
- CF
2. Malignancy
What bug is transmitted via unpasteurized milk and dairy products like cheese?
Brucellosis
Nonspecific findings like fever and malaise, exposure to cattle, sheep, or goats within the preceding 2 months?
Brucellosis
What type of disease is Brucellosis?
Zoonotic…humans are accidental hosts
Picture a COW going BRUUU v. MOOOO
How is Brucellosis treated?
Tetracycline (doxycycline) or Trimethoprim/sulfamethoxazole (depending on age)
What vague finding should you consider Brucellosis in?
Fever of unknown origin (FUO)
What is a memory aid for bucellosis treatment?
Cow being milked…milk delivered through cow’s teat…
T=Teat-> Treatment -> Tetracycline (doxycycline) -> Trimethoprim/sulfamethoxazole
What most commonly presents as pseudomembranous colitis?
C. Diff
What is pseudomembranous colitis?
Severe form of diarrhea that develops after a course of clindamycin or any antibiotic including penicillins or cephalosporins
Bloody mucous diarrhea and a recent antibiotic course
C. Diff pseudomembranous colitis
Is the diarrhea in C. Diff colitis grossly bloody?
Not necessarily…may just be heme positive or guaiac positive
How is C. Diff diagnosed?
Must find C. Diff toxin using enzyme immunoassay
Isolation of C. Diff from Stool isn’t useful because colonization doesn’t indicate causation
What is the correct treatment of a patient with classic pseudomembranous colitis?
Metronidazole
Not vancomycin (this was previously correct treatment)
What are 3 infection control measures for C. Diff colitis?
- Meticulous hand washing (especially with diaper changes)
- Disinfecting fomites
- Limiting use of antimicrobials in general
What is the best way to cleanse hands for C. Diff?
Soap and water
Alcohol doesn’t kill C. Diff spores from contaminated hands so alcohol-base hand sanitizers aren’t as good
When can kids with C. Diff go back to child care?
When diarrhea is resolved
How is C. Diff colitis treated?
Oral metronidazole (Flagyl)
Vancomycin PO is alternative drug in patients who don’t respond to metronidazole
Why is vancomycin no longer the initial treatment of C. Diff?
Concerns of promoting vancomycin-resistant organisms
How is strep pneumonia spread?
Person to person via large droplets (strep pneumonia are part of normal upper respiratory flora)
What 2 classes of antibiotics that are generally effective against Strep pneumoniae?
Penicillins and cephalosporins
How is meningitis caused by strep pneumonia treated?
Combination of vancomycin and cefotaxime/ceftriaxone
Rifampin is an appropriate alternative in case of cephalosporin allergy
What condition requires susceptibility testing to tailor antibiotic treatment appropriately?
Meningitis from streptococcus pneumoniae
How is group A strep transmitted?
Close contact via inhalation of organisms in large droplets or by direct contact with respiratory secretions
How does strep pharyngitis present?
Sore throat, fever, headache, abdominal pain
Erythema and edema of the posterior pharynx, palatal petechiae, strawberry tongue
Strep pharyngitis
Associated rash that blanches easily and spares the face, palms, and soles. Pastia lines (red lines in the skin folds of neck, axilla, groin, elbows, and knees). Sunburn-like sandpapery rash and perioral pallor.
Scarlet fever
What is the leading bacterial cause of respiratory tract infections and most important cause of otitis media?
Strep pneumoniae
(Was leading cause of bacteremia and meningitis until the introduction of the vaccine… still shows up on boards in kids who are underimmunized or from developing countries)
What 3 things does the risk of colonization with antibiotic resistant strains of strep pneumonia correlate with?
- Younger than 2
- Child care attendance
- Recent antibiotic administration
What is a clue for colonization with antibiotic resistant strains of strep pneumoniae?
Unresolving otitis media
In strep pharyngitis, is a cough usually present?
No
What is the testing for strep pharyngitis?
A positive standard rapid strep test is reliable, but a culture is required for a negative rapid test to rule out false negatives
What is useful to confirm a recent strep pharyngitis infection, but not a current infection?
Antibodies to streptolysin O (ASO antibodies)
What is preferred treatment for strep throat?
Penicillin or amoxicillin
PCN allergy should be treated with erythromycin, azithromycin, clindamycin, or a first generation cehpalosporin
When do you treat contacts of someone with strep pharyngitis?
Asymptomatic contacts don’t have to be treated, unless they become symptomatic by developing fever, pharyngitis, abdominal pain, or pain with swalloing
What complication does treatment for strep throat prevent?
Rheumatic fever
What complication does treatment for strep throat not prevent?
Post streptococcal glomerulonephritis
Rapidly growing inflammation with red skin, fever, chills
Red streaks associated with lymphangitis?
Strep cellulitis
What is another name for strep cellulitis?
Erysipelas
Start of infection with a relatively minor trauma, which rapidly evolves to erythema, marked inflammation, and bullous formation. Marked pain that seems out of proportion to the appearance of the lesion.
Necrotizing fasciitis
Starts as fever, nausea, vomiting, diarrhea. Then evolves to shock and organ failure.
Toxic Shock Syndrome
What bugs can cause TSS?
Strep Pyogenes
Strains of Staph, EB virus, Coxsackievirus, Adenovirus
Catalase-negative, weakly acid-fast, facultative, hemolytic, anaerobic, gram-positive, slender, sometimes club shaped bacillus…
Arcanobacterium haemolyticum
Previously called Corynebacterium haemolyticum
What does Arcanobacterium haemolyticum cause?
Acute pharyngitis that mimics Group A Strep with fever, pharyngeal exudate, lymphadenopathy, rash, and pruritus.
No palatal petechiae or strawberry tongue
What mimics diptheria with membranous pharyngitis, sinusitis, and pneumonia?
Respiratory tract infections
What bug can possibly cause invasive infections…including septicemia, peritonsillar abscess, brain abscess, orbital cellulitis, meningitis, endocarditis, pyogenic arthritis, osteomyelitis, UTI, pneumonia, SBP, pyothorax?
Arcanobacterium haemolyticum
No nonsuppuratve sequelae have been reported
What is arcanobacterium haemolyticum susceptible to?
Erythromycin, azithromycin, and clindamycin
NOT PENICILLINS
Who does GBS (Strep Agalactiae, Group B Beta-Hemoolytic Strep) usually affect?
Newborns
What is methicillin sensitive Staph Aureus (MSSA) treated with?
Beta lactamase-resistant agents such as oxacillin/nafcillin (may be more effective than cephalosporins or vancomycin especially for certain infection sites)
What drug can be used in addition to beta lactamase-resistant agents for more invasive infections (endocarditis, bacteremia, or meningitis) caused by MSSA?
Gentamicin or rifampin
What % of hospital acquired Staph Aureus infections are hospital acquired MRSA infections?
Over 50%
What is the primary source for S. Aureus and therefore is the highest risk factor for developing hospital acquired MRSA infection?
Nasal and skin carriage
Nasal carrier state can persist for years
What should you use for hospital acquired MRSA infection and why?
Vancomycin…usually multi-drug resistant, so assume that it is only susceptible to vancomycin
What typically occurs as a result of indwelling IVs and central venous catheters?
Coagulase-negative infections with S. Epidermidis
How can you discern whether a positive culture for coagulase-negative staphlococci represents specimen contamination or infection?
In general, if patient doesn’t have a foreign body, culture will represent contamination
What 3 toxin-mediated syndromes does S. Aureus cause?
- TSS
- Scalded skin syndrome
- Food poisoning
What is associated with acute onset of fever, generalized erythroderma, rapid-onset hypotension, and signs of multisystem organ involvement?
TSS
What 3 things is TSS usually related to?
- Menstruation
- Childbirth
- Abortion
What does community acquired MRSA infection usually involve?
Skin and soft tissue
More invasive disease such as pneumonia can also occur
What is community acquired infection with MRSA often susceptible to?
Several antibiotics including trimethoprim-sulfamethoxazole and clindamycin
Although community acquired MRSA is resistant to all beta-lactam antimicrobials, its resistance isn’t as widespread
Under what size do MRSA abscesses require only I&D, not antibiotics?
Smaller than 5cm
What are the 3 types of botulism?
- Food-Borne: Injection of improperly packaged or incorrectly stored food
- Wound: Systemic spread of organism from an infected wound
- Infantile: Intestinal colonization in infants (intestinal flora is too underdeveloped to prevent infection)
How would an infant younger than 6 months of age present with botulism?
Poor sucking or feeding, progressive descending generalized weakness and hypotonia, loss of facial expressions, ocular palsies, loss of head control, ptosis, weak cry, poor gag reflex, constipation
Infants with botulism usually have what symptom for several days before the other symptoms present?
Constipation
What are the 6 D’s of botulism (in a bottle)?
- Diplopia
- Dysphagia
- Dysarthria
- Dying to pee (urinary retention)
- Dysphonia
- Descending symmetrical paralysis
*Can also picture 6 D’s as if they were 6 bees buzzing around in a bottle of honey
Why don’t you give honey to infants younger than 12 months?
Botulism
*But don’t look for a history of honey intake because it won’t be there, but botulism will still be the correct answer
What is the MOA for the adult form of botulism (from poorly canned goods)?
Preformed botulism toxin is ingested (don’t eat from a can that is expanded)
What is the MOA for the infantile form of botulism?
Spores are ingested and they germinate after ingestion…toxin is produced and absorbed in the GI tract
Picture a baby eating a jar of honey, which then expands in the GI tract
How is infant and wound botulism diagnosed?
By demonstrating C. Botulinum toxin or organism in feces, wound exudate, or tissue specimens
Can PCR be used to diagnose infantile botulism?
NO
What is the pathophysiology of the botulism toxin?
The toxin blocks the release of acetylcholine into the synapse
Picture a GIANT bottle of honey sitting in the way of “a little Colleen”
What non-patient related thing has to be done for suspected cases of botulism?
Any case of suspected botulism is a nationally notifiable disease and is required by law to be reported immediately to local and state health departments. Immediate reporting of suspect cases is particularly important because of possible use of botulinum toxin as a bioterrorism weapon.
Infant with infantile botulism…most appropriate treatment?
Supportive care, unless antitoxin (either BabyBig for infants and standard antitoxin for the rest) is a choice. If then, antitoxin is probably correct answer.
No antibiotics!
What antibiotic class can potentiate the paralytic effects of the toxin in botulism?
Aminoglycosides
Antimicrobial therapy isn’t indicated in infant botulism
What do most cases of infant botulism progress to?
Complete respiratory failure…sometimes requiring 2-3 weeks of ventilation
How do you tell Myasthenia gravis from infant botulism?
They can present similarly…with myasthenia gravis, the Tensilon test will be positive and the onset is more gradual. In botulism the Tensilon won’t be positive.
With wound botulism, what is given after antitoxin has been administered?
Penicillin or metronidazole
Infection with treponema pallidum (syphilis) in childhood or adulthood can be divided into how many stages?
3
Describe the primary stage of syphilis.
Appears as one or more painless indurated ulcers (chancres) of the skin or mucous membranes at the site of inoculation approximately 3 weeks after exposure and heal spontaneously in a few weeks.
When does the secondary stage of syphilis begin?
1-2 months after primary stage
Describe the secondary stage of syphilis?
Rash, mucocutaneous lesions, and lymphadenopathy
Describe the rash of secondary syphilis.
Polymorphic maculopapular rash, generalized, includes palms and soles
What can be seen in the moist areas around the vulva or anus in secondary syphilis?
Condylomata lata
How is secondary syphilis managed?
This stage resolves spontaneously without treatment in 3-12 weeks (leaves infected person completely asymptomatic)
What happens after secondary syphilis resolves?
A variable latent period follows
When does the tertiary stage of syphilis occur?
15-30 years after initial infection
What are features of tertiary syphilis?
Gumma formation, cardiovascular involvement, neurosyphilis
How is acquired syphilis almost always contracted?
Direct sexual contact with lesions of the primary or secondary stages
Presumptive diagnosis of syphilis is made using what?
Serologic tests
Why can’t the nontreponemal tests (RPR and VDRL) be used for actual diagnosis of syphilis?
They may be positive with other viruses like EBV, varicella, and hepatitis
They serve as good screens, but may not be used for actual diagnosis
What needs to be done after any reactive nontreponemal test result?
Must be confirmed by one of the specific treponemal tests to exclude a false-positive test result
When is treatment started for syphilis?
After reactive nontreponemal test result…treatment for syphilis shouldn’t be delayed while awaiting the results of the treponemal test results if the patient is symptomatic or at high risk of infection
What is the main treponemal test used?
FTA-ABS
When does the treponemal test result turn to negative after successful therapy of syphilis?
Never…people who have reactive treponemal test results usually remain reactive for life, even after successful therapy
FTA-ABS is Forever
When are treponemal test antibody titers used for syphilis?
Never, the treponemal test antibody titers correlate poorly with disease activity and shouldn’t be used to assess response to therapy
Are treponemal tests 100% specific for syphilis?
NO…Positive reactions occur variably in patients with other spirochetal diseases (Lyme disease)
What test can differentiate Lyme disease from syphilis?
Nontreponemal tests (VDRL test is nonreactive in Lyme disease and positive in syphilis)
When can manifestations of neurosyphilis occur?
At any stage of infection…
Manifestation of neurosyphilis can occur especially in which 2 groups of patients?
- People infected with HIV
2. Neonates with congenital syphilis
All patients who have syphilis should be tested for what?
HIV
How is definitive diagnosis of syphilis made?
When spirochetes are identified by microscopic darkfield examination or direct fluorescent antibody tests of lesion exudate, nasal discharge, or tissue (placenta, umbilical cord, or autopsy specimens)
What is the preferred drug for treatment of syphillis at any stage?
Parenteral penicillin G
Which patients should always be treated with penicillin for syphilis (even if desensitization for penicillin allergy is necessary)?
Neurosyphillis, congenital syphilis, syphilis during pregnancy, HIV-infected patients
Parenteral PCN G is the only documented effective therapy for first 3, recommended for 4th
How is congenital syphilis contracted from an infected mother?
Via transplacental transmission of T. Pallidum at any time during pregnancy or possibly at birth from contact with maternal lesions
How should pregnant women be screened for syphilis?
All women should be screened serologically for syphilis early in pregnancy with a nontreponemal test (RPR or VDRL) and preferably again at delivery
What is the treatment for a pregnant woman with syphilis?
Penicillin…remember that treating Mom with PCN automatically treats the infant because PCN crosses the placenta (paper-thin P for PCN passing through placenta)
What 3 situations do you treat newborn for syphilis even if Mom was treated during pregnancy?
- If she was treated within last month of pregnancy
- If she was treated with erythromycin (doesn’t cross placenta)
- If baby’s titers are higher than Mom’s titers
What circumstance do you not have to treat infant for syphilis when Mom was treated during pregnancy?
If Mom was treated with PCN more than a month before delivery
Infant of a Mom who tested positive for syphilis and was treated with erythromycin 2 months prior to delivery… treatment for infant?
Start infant on PCN…even though Mom was treated more than one month prior to the delivery, erythromycin won’t cross the placenta so baby still needs PCN
True or False: Congenital syphilis is often picked up at birth?
False
What are some signs/symptoms of congenital syphilis?
Non-specific signs, snuffles (copious nasal secretions), bullous lesions, osteochondritis, pseudoparalysis of joints, poor feeding, lymphadenopathy, mucocutaneous lesions, pneumonia, edema, thrombocytopenia, hepatosplenomegaly, hemolytic anemia, jaundice, and a maculopapular rash (at birth or within first 4-8 weeks of age)
Infants with untreated syphilis can present at what age with what symptoms?
After 2 years of age
Symptoms involve CNS, bones and joints, teeth, eyes, skin
What is the Hutchinson triad?
- Interstitial keratitis
- 8th cranial nerve deafness
- Hutchinson teeth (peg-shaped, notched central incisors)
* This is seen in untreated congenital syphilis around age 2 or later
Irregularly staining, gram-positive, nonspore-forming, nonmotile, pleomorphic bacillus?
Corynebacterium diphtheria
What is the sole reservoir for Corynebacterium diphtheria?
Humans
How is corynebacterium diphtheria spread?
By respiratory tract droplets and by contact with discharges from skin, nose, throat, and eye lesions
What does corynebacterium diphtheria do in the respiratory tract?
Causes membranous nasopharyngitis that is associated with a blood nasal discharge and a low-grade fever
What does cutaneous diphtheria lead to?
Extensive neck swelling with cervical lymphadenitis (bull neck)
What are 3 life-threatening complications of respiratory diphtheria?
- Upper airway obstruction caused by extensive membrane formation
- Myocarditis, which is often associated with heart block
- Cranial and peripheral neuropathies
How do you treat corynebacterium diphtheria?
A single dose of equine antitoxin obtained through the CDC
Describe enterococci
Gram positive cocci in chains that are ubiquitous in the normal GI flora, and are generally of low virulence
What 2 main types of infections can enterococci cause?
- Neonatal and catheter-associated bacteremia
2. Infections in patients with anatomic abnormalities such as recent surgery and indwelling urinary catheters
When are enterococcal infections more common?
After recent antibiotic use
What can be used to treat enterococcal infections?
Typically respond to ampicillin and vancomycin (but resistance to vancomycin is increasing)
Enterococci are resistant to ALL cephalosporins
Describe Kingella
Fastidious, gram-negative coccobacilli (previously classified as Moraxella)
What is the usualy habitat for Kingella?
Human oropharynx
Who does Kingella frequently colonize?
Young children…can be transmitted among children in child care centers, generally without causing disease
What is infection with Kingella associated with?
Preceding or concomitant stomatitis or upper respiratory tract illness
What are the 3 most common infections associated with Kingella kingae?
- Suppurative arthritis
- Osteomyelitis
- Bacteremia
Almost all skeletal infections from Kingella kingae occur in what age group?
Children younger than 5
What symptoms will kids with Kingella kingae bacteremia frequently have?
Fever, respiratory, or GI symptoms
What is the drug of choice for Kingella kingae?
PCN
Facultative anaerobic, nonspore-forming, motile, gram-positive bacillus that multiplies intracellularly
Listeria monocytogenes
What is the predominant form of listeriosis transmission?
Foodborne
Who does listeriosis occur most frequently in?
- Pregnant woman and their fetuses or newborn infants
- People of advanced age
- Immunocompromised patients
Describe listeriosis in pregnant women
Infection can be asymptomatic or associated with an influenza-like illness with fever, malaise, headache, GI tract symptoms, and back pain
Describe listeriosis in neonates
Have early-onset and late-onset syndromes similar to those of group B streptococcal infections
What is sufficient to treat mild listeriosis in immunocompetent individuals?
Ampicillin
What is traditional initial therapy for listeriosis?
IV ampicillin and an aminoglycoside (gentamicin)
What do you give to treat someone with a PCN allergy who has listeriosis?
Desensitization and then ampicillin/gentamicin
*CEPHALOSPORINS ARE NOT ACTIVE AGAINST L MONOCYTOGENES
What is an important etiology to keep in mind for septic shock?
Meningococcemia
How does Neisseria meningitidis present?
With mild non-specific symptoms…Runny nose, headache, lethargy, myalgias and/or joint pain. Evolves to a petechial/purpuric rash. Can have signs of meningeal irritation.
Invasive infection with Neisseria meningitidis usually results in what?
Meningococcemia, meningitis, or both
What can invasive infection with neisseria meningitidis progress to?
Limb ischemia, coagulopathy, pulmonary edema, shock, coma, death in a few hours despite appropriate therapy
Which serogroups cause most cases of neisseria meningitidis among adolescents and young adults?
Serogroups C, Y, or W-135…these are all covered in the meningococcal vaccines
Which serogroup causes over half of all cases of neisseria meningitidis in infants?
Serogroup B…this isn’t covered in the available meningococcal vaccines
What is initial therapy for a critically ill child in septic shock (you are suspecting neisseria meningitidis)?
Vancomycin and ceftriaxone
*Once the microbiolgic diagnosis is established, definitive treatment with PCN G, ampicillin, or a cephalosporin (cefotaxime or ceftriaxone)
Who gets meningococcal prophylaxis?
Regardless of immunization status, close contacts of all people with invasive meningococcal disease are at high risk and should receive chemoprophylaxis. Currently licensed vaccines aren’t 100% effective, and some cases will be caused by serogroup B
6 specific groups meningococcal chemoprophylaxis is recommended for?
- Household contacts (especially kids under 2)
- Child care or preschool contacts at any time during 7 days before onset of illness
- Direct exposure to index patient’s secretions through kissing or through sharing toothbrushes or eating utensils, at any time during 7 days before illness onset
- Mouth to mouth resuscitation and unprotected contact during ET intubation at any time 7 days before illness onset
- Anyone who frequently slept in same dwelling as index patient during 7 days before onset of illness
- Passengers seated directly next to the index case during airline flights lasting more than 8 hours
What is the drug of choice for meningococcal prophylaxis for most kids?
Rifampin
What is the most common cause of bacterial gastroenteritis in the developed world?
Campylobacter
The highest rates of infection occur in children in what age group?
Under 4
What harbors campylobacter?
Farm animals and pets (dogs, cats, hamsters, and birds)
How is campylobacter transmitted?
Ingestion of contaminated food or by direct contact with fecal material from infected animals or people
What are the 3 main vehicles of transmission for campylobacter?
- Improperly cooked poultry
- Untreated water
- Unpasteurized milk
Who can get prolonged, relapsing, or extraintestinal infections with campylobacter?
Immunocompromised hosts
How does infection with campylobacter present?
Fever, abdominal pain, and/or bloody diarrhea
What 2 things can abdominal pain by campylobacter mimic?
- Appendicitis
2. Intussusception
What is the mainstay of treatment for all children with diarrhea (especially with campylobacter)?
Maintaining hydration status
What 2 drugs can shorten the duration of illness and excretion of organisms in campylobacter?
Azithromycin and erythromycin
What causes the bubonic plague?
Yersinia pestis
What the most commonly seen Yersinia infection (although it is rarely seen in the US)?
Yersinia enterocolitica
What is the principal reservoir for Yersinia?
Swine
What can enterocolitis due to Yersinia be mistaken for?
Acute appendicitis
What are buboes?
Swollen, painful lymph nodes (usually inguinal). Can involve cervical and axillary nodes. History will likely include exposure to or handling of dead animals.
What bug causes buboes?
Yersinia pestis (plague)
History of ingestion of unpasteurized milk or raw meat, including chitterlings (pork intestines), typically in a kid younger than 5?
Yersinia
How does Yersinia present?
Bloody diarrhea, typical signs seen with appendicitis (RLQ pain and elevated WBC)
What is the treatment for Yersinia?
None (in otherwise uncomplicated cases)
Who does bacteremia from Yersinia occur in?
- Kids younger than 1
- Older kids with predisposing conditions like excessive iron storage (sickle cell disease, beta-thalassemia) and immunosuppressive states
If you are going to treat Yersinia, what do you give?
Trimethoprim-sulfa, cefotaxmine, aminoglycosides, fluoroquinolones (older than 18)
*First generation cephalosporins and penicillin wouldn’t be recommended, due to resistance
Which 2 GI bugs can mimic appendicitis?
- Yersinia
- Campy
*Y is key..appY, Yersinia, campY
What are the most important manifestations of E. Coli?
Neonatal septicemia/meningitis, UTI, diarrhea
What bug is cat-scratch disease?
Bartonella (specifically bartonella henselae)
How does cat-scratch disease present?
After a scratch or bite from a cat (or a dog), the regional draining lymph node gets swollen and tender. Self-limiting, can cause anorexia and malaise.
Which groups can cat-scratch disease be serious in?
AIDS and other immunocompromised patients
How can diagnosis of bartonella (cat scratch disease) be made?
Serologic testing with enzyme immunoassay (EIA) or the immunofluorescent antibody (IFA) test
What is the treatment of choice for bartonella?
Supportive
Kid with a draining lymph node that was preceded by a bite from a cat… no other underlying disorders. Most effective treatment?
Despite presence of malaise and anorexia, cat scratch disease is usually self-limited and only needs supportive treatment
*Don’t get swayed by thinking staph and picking Bactrim or something… in otherwise healthy kid, go this way
Which 3 situations is treatment indicated for cat-scratch disease?
- Hepatosplenomegaly
- Large painful adenopathy
- Immunocompromised patient
What antibiotics are appropriate when clinically indicated for Bartonella?
- Azithromycin
- Erythromycin
- Ciprofloxacin (only in kids over 18)
- Trimethoprim-sulfamethoxazole
- Rifampin
What are 3 drug choices that are ineffective in antibiotic treatment for cat scratch disease?
- Penicillin
- Amoxicillin
- Nafcillin
When do you do an I&D for a painful suppurative lymph node from Bartonella?
Can do needle aspiration for relief of symptoms… but I&D can lead to fistula formation and other complications… if presented with patient with painful lymph nodes, choose looking for appropriate antibiotic treatment
What is important to remember about Bartonella (specifically with the lymph nodes)?
I&D and surgical excision are to be avoided
Kid who got a cat bite the day before… presents with tenderness and swelling of his right index finger…patient is PCN allergic and you are asked to pick appropriate treatment.
Patient who develops cellulitis at site of animal bite within 24 hours…likely Pasteurella multocida. Have to cover for Staph and Pasteurella. No PCN allergy, then use Augmentin. PCN allergy…cefuroxime, cefpodoxime, doxycycline, azithromycin, or Bactrim. If old enough (18+), can use fluoroquinolones.
*Don’t get fooled into thinking it’s cat scratch disease and pick supportive care only or surgical excision
How does initial TB in a kid present?
Most kids are initially asymptomatic and primary pulmonary focus (Ghon complex) isn’t always visible on CXR
What is the best way to watch for Ghon complex in a kid?
PPD, Quantiferon (QFN), and T-spot
Since Ghon complex is hard to see on CXR in kids and they are usually asymptomatic
What is done if a PPD, QFN, or T-spot is positive?
CXR
If you have a positive PPD, QFN, or T-spot and the CXR is negative, what is the diagnosis?
Latent TB infection (LTBI)
If you have a positive PPD, QFN, or T-spot and the CXR is abnormal (usually perihilar adenopathy or cavitary lesions), what is the diagnosis?
Active pulmonary disease is likely
What is the treatment of latent TB?
Isoniazid monotherapy for 9 months
What is given for latent TB if it is an INH-resistant strain or if INH isn’t tolerated?
Rifampin for 6-9 months
What are symptoms of active pulmonary disease of TB?
Classic symptoms are rare in kids, but might be present in their infectious contacts (low-grade fever and cough for a month or even longer)
What must be done for active pulmonary disease of TB?
Referral to ID is indicated to check for resistant strains in the community
What is the treatment for active TB?
2 months of RIP (rifampin, INH, and pyrazinamide) then 4 months of INH and Rifampin
or
9 months of INH and rifampin
What are 4 manifestations of extrapulmonary TB?
- Meningitis
- Adenitis
- Pleuritis
- Disseminated (Miliary TB)
While pulmonary TB often doesn’t have signs or symptoms, extrapulmonary is usually diagnosed after signs or symptoms have presented themselves
How can primary TB present on a CXR?
A localized pleural effusion… if they describe this in a preschool child, it is a clinically significant finding on its own. They will describe symptoms similar to bacterial pneumonia, but it will be in context of TB exposure or other clues.
How is extrapulmonary TB treated?
Same as pulmonary disease…more tailored to the clinical response since there are more signs to follow
How is meningitis due to TB managed?
You use rifampin, INH, and pyrazinamide for 2 months AND STREPTOMYCIN
After this, rifampin and INH is good for 10 months…you can stop streptomycin after you have isolated the strain and confirmed sensitivity to INH
What non-antibiotic treatment is used for TB meningitis?
Steroids
What does PCP (pneumocystis jiroveci (carinii) pneumonia) go hand in hand with?
HIV
When does PCP pneumonia occur and what is the prognosis?
This occurs early and is often fatal…they won’t mention a history of HIV
What is used prophylactically as soon as PCP diagnosis is made?
Trimethoprim/sulfamethoxazole TMP-SMX (Bactrim and Septra)
When do you start Bactrim prophylaxis for PCP in an infant born to an HIV positive mother?
4 weeks
What is mode of transmission of PCP?
Unknown
Ground-glass appearance on CXR, general perihilar infiltrates that can evolve to interstitial infiltrates?
PCP
What specific patients is PCP pneumonia common in?
Cancer/bone marrow transplant patients
How is PCP prophylaxis handled for cancer/bone marrow transplant patients?
They get TMP-SMX prophylaxis for 3 consecutive days each week
Who does cryptosporidium primarily occur in?
Immunocompromised patients (although this isn’t exclusively the case)
How long does cryptosporidium usually last in healthy children?
It can occur as a self-limiting illness typically lasting around 10 days
If you have an immunocompromised kid with fever and/or neutropenia, what do you start with?
Broad-spectrum antibiotics (especially for gram-negative organisms)
Zosyn (piperacillin-tazobactam) plus an aminoglycoside or ceftazidime monotherapy are good choices
What drugs are never the answer in treating an immunocompromised child with fever and neutropenia?
1st or 2nd generation cephalosporin
What can extensive crypto outbreaks result from?
Contamination of municipal water and swimming pools
What can cause transmission of crypto to humans?
Farm livestock, especially petting zoos
How can person to person transmission of crypto happen?
It’s common in child care centers due to poor hygiene after diaper changes
How does cryptosporidium diarrhea present?
Severe, non-bloody, watery diarrhea similar to viral gastroenteritis, except it lasts a lot longer
What diagnosis should you consider if they mention chronic diarrhea in an immunocompromised patient?
Cryptosporidium
Buzz Words: Swimming pools, municipal water
Cryptosporidium
Buzz Words: Farm livestock, petting zoos
Cryptosporidium, E. Coli
Buss Word: Immunocompromised
Cryptosporidium
Buzz Words: Apple juice/cider, undercooked ground beef
E. Coli
Buzz Words: Chitterlings, pork
Yersinia
Buzz Words: Recent Antibiotics
C. Difficile
Buzz Words: Improperly cooked poultry, untreated water, dairy farms
Campylobacter
Buzz Words: Unpasteurized milk
Campylobacter and E. Coli
What is unique about the effectiveness of aminoglycosides?
The effectiveness is dependent on high peak levels
What is a big toxicity you worry about with aminoglycosides?
Ototoxicity
Toxicity from aminoglycosides is associated with what?
High trough levels
When are peak levels of aminoglycoside measured?
30 minutes after the dose is given
When are trough levels of aminoglycoside measured?
30 minutes before the next dose
How do penicillins work?
By interfering with cell wall synthesis
What do beta lactamase producing bacteria do?
Produce penicillinases (which cleave penicillin)… you need penicillinase-resistant antibiotics for these organisms (includes Staph organisms)
What is indicated for penicillin-resistant pneumococcal ear or sinus infections?
High dose amoxicillin
Besides penicillin-resistant pneumococcal ear or sinus infections, what is high dose amoxicillin indicated for?
Routine OM, sinusitis, pneumonia, and initial treatment of UTIs (not indicated for “highly resistant” strains
What dose of amoxicillin/ampicillin is indicated for intermediate resistant strains?
80-90 mg/kg/day
What specifically constitutes an intermediate resistant strain of bacteria for which you would use 80-90 mg/kg/day dose of amoxicillin?
Kid younger than 2 attending daycare who got antibiotics in the preceding 3 months
What is the treatment of choice for Listeria monocytogenes infection?
Ampicillin with or without gentamicin
Why are MRSA infections resistant to methicillin?
Because of interference with penicillin binding proteins (these are required to attach to the organism)… not due to a penicillinase
What are first generation cephalosporins effective against?
Gram positive cocci (includes MSSA, but not MRSA)
What are 3 specific cases where first generation cephalosporins shouldn’t be used?
- Meningitis (don’t penetrate CSF well)
- Listeria
- Enterococcus
What are second generation cephalosporins good against?
Beta lactamase producing gram negative bacteria (Enterobacteriaceae, H. Influenza, and Moraxella catarrhalis)…Generally not as good as 3rd generation
Some effectiveness against gram positives, but not as good as first generation
Which cephalosporins are good for meningitis?
Third generation… they have excellent CSF penetration and cover a broad spectrum
What are cefpodoxime and cefdinir (3rd gen) effective oral medications for?
Otitis media, sinusitis, group A beta hemolytic strep
What are 2 3rd generation cephalosporins that are effective against UTI or respiratory infections?
- Ceftibuten
2. Cefixime
What has extensive use of cephalosporins lead to?
Resistant strains of Klebsiella, E. Coli, Proteus mirabilis, and Pseudomonas aeruginosa
What is the main example of a 4th generation cephalosporin?
Cefepime
What is cefepime good for?
Broad-spectrum… can be used for gram negatives like pseudomonas and good activity against gram positives like S. Aureus
Is clindamycin bacteriostatic or bactericidal?
Bacteriostatic (usually used with something else)
What 5 classes is clindamycin effective against?
- Aerobic gram positive cocci
- Anaerobic gram positive cocci
- Anaerobic gram negative cocci
- Chlamydia
- Protozoa
What are some aerobic gram positive cocci that clindamycin is effective against?
Streptococcus, staphylococcus, and Corynebacterium diptheriae
What are some anaerobic gram positive cocci that clindamycin is effective against?
Peptostreptococcus, gram-positive non spore-forming bacilli (actinomyces, propionibacterium), clostridia (minus C. Diff), and a significant % of some non perfringens clostridial species
What are some anaerobic gram negative cocci that clindamycin can be used for?
Bacteroides, prevotella, fusobacterium species
Which form of chlamydia can clindamycin be used for?
Chlamydia trachomatis
What protozoa can clindamycin be used for?
Plasmodium, pneumocystis (jiroveci) carinii, toxoplasma gondii, and babesia
What is indicated for mycoplasma, Moraxella catarrhalis, H. flu, S. pyogenes, Strep viridans, Chlamydia, pertussis, Legionella pneumophilia, and nontuberbulosis mycobacteria?
Macrolides
Which are the first line macrolides used and why?
Azithromycin and clarithromycin…these are as effective as erythromycin and have fewer GI side effects (erythromycin is rarely a first line medication)
What is appropriate prophylaxis for meningocoocal or Hib exposure?
Rifampin
What is indicated for invasive/resistant Staph infection (osteomyelitis and endocarditis), latent TB, active TB
Rifampin
Can a pregnant patient get rifampin?
NO…it has potential for teratogenicity
What age group is tetracyclines contraindicated in?
Kids younger than 8
What is the one exception to kids under 8 getting a tetracycline?
Rocky Mountain Spotted Fever…kids get doxycycline regardless of age
What can Bactrim (trimethoprim with sulfamethoxazole) can be used to treat?
Acute UTI, IBD, burns, umbilical cord care, and Chlamydia urethritis, minor MRSA infections, GI infection due to Salmonella or Shigella in immunocompromised patients or those with severe disease
What are side effects of trimethoprim with sulfamethoxazole?
Stevens Johnson Syndrome, rash, neutropenia, anemia, thrombocytopenia
What 4 big things is vancomycin indicated for?
- MRSA infection in patients who can’t tolerate other meds
- Endocarditis
- Resistant corynebacteria
- Resistant pneumococcus
What is an important side effect of vancomycin?
Red Man Syndrome
How does Red Man Syndrome present? Is it a true drug allergy?
Reddening and itching of the head and neck. Not a true drug allergy…rate-dependent infusion reaction caused by histamine release
How is Red Man Syndrome treated?
Slowing infusion rate and giving diphenhydramine
What causes amebiasis?
Entamoeba Histolytica
Who are 3 groups at increased risk for amebiasis?
- Immigrants from or long-term visitors to areas with endemic infection
- Institutionalized people
- Men who have sex with men
How is E. Histolytica transmitted?
Fecal-oral route via contaminated food or water
How does amebic dysentery (acute amebic colitis) start?
1-2 weeks of belly pain, diarrhea, and tenesmus (painful but ineffectual urge to defecate). Stools are liquid, consisting mainly of water, blood and mucus.
What is the clinical course of amebic dysentery?
Can range from asymptomatic to severe GI effects, liver and brain abscesses, or lung disease
What % of E. Histolytica infections cause invasive disease?
10%…the rest are asymptomatic
What is seen in stool for amebic dysentery from E. Histolytica?
Stool cultures are usually positive…stool exam will identify hematophagous trophozoites
Memory aid for amebic dysentery?
Picture a hysterical, crazy amoeba playing tennis (tenesmus) in your bowels causing bloody mucous diarrhea
Entamoeba Histolytica
What can amebiasis do to the liver and how do you check for this?
Liver abscess…abdominal US is a minimally invasive and cost-effective diagnostic tool
What is done for symptomatic patients with Entamoeba histolytica infections?
Treat with metronidazole or tinidazole
Follow with a therapeutic course of iodoquinol or paromomycin
What is done for asymptomatic patients with positive screening for Entamoeba histolytica?
Treat with oidoquinol, paromomycin, or diloxanide
Are follow up stool studies and screening of household members recommended for Entamoeba histolytica?
Yes
What 2 things given to patients with amebiasis can worsen the symptoms and disease process?
- Corticosteroids
2. Antimotility drugs
What are the classic symptoms of malaria?
High fever with chills, rigor, sweats, and headache
How often does the fever in malaria occur (without treatment)?
Every 2-3 days
Where is malaria endemic and how is it acquired?
Endemic throughout the tropical areas of the world.
Acquired from the bite of the female nocturnal-feeding anopheles genus of mosquito
What is used to treat malaria (plasmodium falciparum)?
Quinidine
What presents with acute watery diarrhea with abdominal pain, foul-smelling stools associated with flatulence, abdominal distension, anorexia, weight loss, failure to thrive, and anemia?
Giardia intestinalis…Giardiasis
Formerly Giardia lamblia and Giardia duodenalis
What is the most common intestinal parasitic infection?
Giardiasis
Who is the principal reservoir of infection with giardia?
Humans
How do people become infected with giardia?
Directly from an infected person or through ingestion of fecally contaminated water or food
How is giardia diagnosed?
By use of enzyme immunoassay (EIA) and direct fluorescence antibody (DFA) assays in stool
What is treatment for Giardia?
Some infections are self-limited and treatment isn’t required. If treatment is needed, tinidazole, metronidazole, and nitazoxanide are drugs of choice
What is true of toxoplasmosis (toxoplasma gondii) early in pregnancy?
Lower chance of fetal infection, but when infection happens, more severe consequences
What is true of toxoplasmosis (toxoplasma gondii) late in pregnancy?
Greater chance of fetal infection, but the sequelae are less severe
What signs and symptoms of toxoplasmosis in affected pregnant women?
Most affected pregnant women show no clinical signs, but when they do, lymphadenopathy may be sole symptom
What are symptoms of newborn infants with congenital toxoplasmosis?
Most are asymptomatic in neonatal period… if they do have symptoms, common findings are microcephaly, hydrocepahy, chorioretinitis, cerebral calcifications, jaundice, and hepatosplenomegaly
Where are the cerebral calcifications in CMV versus Toxo?
CMV: Periventricular
Toxo: Diffuse cerebral calcifications
*cmV to remind you periVentricular…in CMV the calcifications circumvent, or circle around, the ventricles
What is the memory aid for associations with congenital toxoplasmosis?
GONDII Greatly reduced head On the brain/water (hydrocephalus) Nothing (asymptomatic) Diffuse calcifications I (Eyes/chorioretinitis) Icteric and hepatosplenomegaly
What are later signs of toxoplasmosis when the neonate was asymptomatic at birth?
Deafness, impaired vision, seizures, mental retardation, learning disabilities, cognitive deficits
What is the memory aid for the later signs of toxoplasmosis?
TOXO Tremors (seizures) O (zero hearing) X (optic chiasm, blindness) O (zero or impaired intelligence)
Who else does toxoplasmosis cause severe disease in besides affected neonates?
Immunocompromised hosts (HIV or chemo)
What is treatment for symptomatic congenital infection with toxoplasmosis?
Pyrimethamine, sulfadiazine, folinic acid
Why do we tell pregnant women to not change kitty litter box when pregnant?
This is a mode for transmission for toxoplasmosis
How toxoplasmosis be acquired?
- Changing the kitty litter
- Consumption of contaminated water and food (unwashed garden vegetables)
- Inadequately cooked meat
- Unpasteurized goat milk
What is recommended to treat acquired toxoplamosis?
No specific drug therapy, most acquired cases are self-limiting…acquired toxo would require treatment in symptomatic, especially immunocompromised infants
What are 4 ways CMV (human herpesvirus 5) transmission occurs?
- Horizontally (direct person-person contact with virus-containing secretions including sexual transmission)
- Vertically (mother to infant before, during, or after birth)
- Transfusions
- Transplantations
How does congenital CMV infection usually present?
Clinically silent
Some infants with silent congenital infection are later found to have what 2 things?
- Hearing loss
2. Learning disability
What is important to remember about patients who are seropositive for CMV (as a chronic carrier)?
They can shed the virus in urine, saliva, or genital secretions
*Young kids are little disease vectors that transmit CMV to their parents, including Mom’s who could be pregnant, and other caregivers including child care staff
Who can CMV cause serious disease in?
Immunocompromised patients
What is the definitive diagnostic study for diagnosing CMV?
Urine culture or PCR for CMV in the urine or saliva within the first 3 weeks of life
*Shell-vial assay is adaptation of tissue culture, which is more rapid than standard cultures
What are the 5 C’s of CMV?
- Chorioretinitis
2/3. Cerebral Calcifications - Diagnosis confirmed with urine Culture
- Potential for Censorineural hearing loss (sensorineural hearing loss)
Babies with thrombocytopenia with subsequent petechiae and purpura (blueberry muffin baby)?
Congenital CMV
Besides the blueberry muffin rash, what are additional findings of congenital CMV?
Hepatosplenomegaly, jaundice, SGA, microcephaly, seizures, hypotonia, weak suck
How does acquired CMV present?
Clinical picture much like mono with prolonged fever and mild hepatitis (if mono is described and EBV isn’t an option, CMV is the answer)
How can a presumptive diagnosis of CMV infection beyond the neonatal period be made?
On basis of a fourfold antibody titer increase in paired serum specimens or by demonstration of virus excretion
What is the treatment for CMV?
Ganciclovir and valganciclovir available for treatment only for those with severe symptomatic disease
What is the main side effect of ganciclovir and valganciclovir?
Marrow suppression
*Picture a gang of cyclists whose whipping chains destroy bone marrow
If you have any transfusion-related infection (especially pneumonia), what virus should you think?
CMV (remember, you order CMV negative blood for oncology patients because CMV is a common infection transmitted by transfusion)
What is the leading nongenetic cause of sensorineural hearing loss in kids in the US?
Congenital CMV
If a kid has a normal newborn hearing screen, do you have to worry about congenital CMV infection causing sensorineural hearing loss?
Yes…the hearing loss can appear years after birth, so a normal newborn hearing screen isn’t enough. These kids need close audiologic follow up until at least age 6.
Who is the only known reservoir of EBV?
Humans
Approximately what % of US adults have been infected with EBV (human herpesvirus 4)?
90%
What is usually required for transmission of EBV?
Close personal contact
How does infectious mono present?
High fever, tonsillitis, enlarged lymph nodes, hepatosplenomegaly, atypical lymphocytosis
What confirms the diagnosis of EBV?
Presence of heterophile antibody
If you suspect EBV and the heterophile antibody is negative, what is a secondary test to confirm the diagnosis?
Serum IgM (this is especially important to note if patient is younger than 4)
What can EBV evolve to in immunocompromised hosts?
Lymphoma
EBV associated lymphoproliferative disorders can result in a number of complex syndromes in which patients?
Immunocompromised…like transplant recipients or people infected with HIV
What can be indicated for pending airway compromise or thrombocytopenia associated with EBV?
Steroids
What can happen if you give a patient with infectious mono ampicillin?
Rash… not necessarily allergic reaction, especially if they specifically state the patient was diagnosed with mono
Who are EBV serologic tests especially useful for?
Heterophile-negative patients
What is the most commonly performed EBV serologic test?
Test for antibody against the viral capsid antigen (VCA)
Why would serum specimens for anti-VCA (when testing for mono) not be useful for establishing the presence of active infection?
Because IgG antibodies against VCA occur in high titers early in infection and persist for life… so testing for acute and convalescent serum specimens for anti-VCA might not be useful
Which 2 things are useful for identifying active and recent EBV infections?
- IgM anti-VCA antibodies
2. Absence of antibodies to Epstein-Barr nuclear antigen (EBNA)
Why does a positive anti-EBNA antibody test exclude an active primary infection?
Because serum antibody against EBNA isn’t present until several weeks to months after onset of infection
What is human herpesvirus 6 (HHV-6) also known as?
Roseola, Roseola Infantum, and Exanthem Subitum
3-5 days of high fever…after the fever passes, “mac-pap rash” will appear?
Roseola
*Think of the rash as a dozen roses being presented AFTER the fever to say goodbye…Roses=Roseola
What neurological issue can happen after an infection with roseola?
Febrile seizure…can get a classic clinical scenario of roseola followed by a seizure…most likely cause would be human herpesvirus type 6
What is HHV4?
EBV
What is HHV5?
CMV
What is HHV6?
Roseola
What is HHV7?
Similar to roseola
What is HHV8?
Kaposi Sarcoma
What is another name for Rubella?
German Measles
When do you worry about Rubella?
Rubella is only a mild viral illness… becomes important when an expectant mother is infected (congenital rubella syndrome)
What % of infants infected during their first trimester are affected by Rubella?
50%
What does congenital rubella syndrome cause?
Cataracts and PDA most commonly
Memory aid for Rubella?
Rubella is German Measles: Picture a “bell” ringing in Germany during Oktoberfest. The bell has a white eye on it (cataract)
Do you vaccinate pregnant women for Rubella?
NO…pregnant women shouldn’t be vaccinated
Recently adopted boy (unknown immunization status) who presents with a low grade fever, generalized maculopapular rash, and enlarged occipital and preauricular lymph nodes. Doesn’t appear toxic. Most likely diagnosis?
*Uncertain immunization status
This is rubella: Maculopapular rash, low grade fever, subacute clinical picture
-Rubeola (measles): Maculopapular rash, cough, coryza, conjunctivitis
-EBV: Higher fever, more toxic clinical presentation
Confluent macular popular rash, Koplik spot (pathognomonic), and conjunctivitis in a miserable kid who is coughing?
Rubeola (measles)
How is measles transmitted?
By airborn droplets with an incubation period of 8-12 days
Who are the only natural hosts of rubeola?
Humans
Name symptoms of rubeola?
Fever, cough, coryza, mac pap rash, conjunctivitis, fever, photophobia
When are kids with rubeola most contagious?
4 days before to 4 days after rash appears
Exposure before the rash appears it still a problem
How long is the inculation period for Rubeola?
8-12 days
When does the prodrome of rubeola occur?
First 2 days
When do Koplik spots appear in rubeola?
Shortly after the prodrome (first 2 days)
When does the rash come in rubeola?
Around day 5
When does the rash get the worst and when does it resolve for rubeola?
Worst after about 1 week…resolves around day 10
What types of precautions are needed for rubeola?
Standard precautions as well as airborne transmission precautions are indicated for 4 days after the onset of rash in otherwise healthy kids and for duration of illness in immunocompromised kids
An immunocompromised kid with rubeola requires what else besides isolation to protect them?
Immunization and immunoglobulin
Preschool age kid from a developing country with fever, cough, coryza…what do you think?
Rubeola
Preschool because hand-washing practices lack in this group
Do you think Rubeola only if the kid arrived from another country?
NO…Immunization rates are less than 100%, so there are measles outbreaks in US…so arriving from another country isn’t a prerequisite for a kid with measles
Patient with cough, coryza, vomiting, diarrhea?
Influenza (don’t get tricked into thinking measles)
If patient has been exposed to rubeola within 6 days, what should be given?
Immune globulin
Who especially needs immune globulin within 6 days of rubeola exposure?
- Infants under 12 months
- Pregnant women
- Immunocompromised individuals
What do you do for people who are exposed to measles who aren’t completely immunized (including infants 6-12 months of age)?
Measles vaccine
MMR given within how may days of exposure can help prevent the onset of disease?
3 days
*M has 3 down strokes…remember 3 days for MMR
What is required for an infant who got the MMR vaccine before age 1?
Need to revaccinated after their 1st birthday
If IM immunoglobulin is given, when does revaccination have to occur?
5 months after (as long as child is at least 12 months of age)
What is the one live vaccine you give to HIV patients?
MMR…patients with mild or asymptomatic HIV should be given the MMR vaccine even though it is live…morbidity and risk associated with measles if worse than risk associated with vaccine
What type of virus is Mumps?
Paramyxovirus
What are the general symptoms of mumps?
Fever, headache, malaise, and muscle aches
What symptoms are give away for mumps?
Swelling of parotid gland and/or testicles
Unilateral facial swelling anterior to the ear, with difficulty opening the mouth. No abnormalities in oral cavity.
Mumps
What are complications of mumps?
Parotitis, meningitis/encephalitis, orchitis, or pancreatitis (watch out for belly pain in description)
Memory aid to remember the complications of MUMPS?
MUMPS Meningitis Underwear (orchitis)- Common complication... infertility isn't a common result Muscle aches Pancreatitis (belly pain) Swelling of the parotid gland
Mumps outbreak at school…what do you do with kids who are fully immunized?
Can remain in school
Mumps outbreak at school…what do you with kids who haven’t gotten their 2nd booster dose?
Need to get their booster before they return
Mumps outbreak at school…what do you do with kids to never got the mumps vaccine?
They need to get the vaccine before returning
Mumps outbreak at school…what do you do with kids whose parents refuse to immunize based on religion or other reasons?
Must wait 26 days after the last person in the class developed parotitis
Mumps outbreak at school…what do you do with the kid who has mumps?
Can return to school 9 days after the onset of parotitis
Kid with high fever who is toxic appearing and is fully immunized…has unilateral preauricular submandibular swelling…diagnosis?
Bacterial parotitis (because of high fever and toxic appearance)
Mumps is associated with low grade fever and non-toxic appearance. Also, if patient fully immunized, it’s not mumps.
What causes intermittent swelling in the face/parotid area?
Stone in the salivary gland
What 3 things can cause parotid tenderness and parotid swelling?
- Parotid infection
- Mumps
- Salivary gland stone
Parotid tenderness, parotid swelling, low grade fever, non-toxic appearing?
Mumps
Parotid tenderness, parotid swelling, high fever, toxic appearance?
Parotid infection
Parotid tenderness, parotid swelling, intermittent swelling?
Salivary gland stone
Teenage boy with typical clinical presentation of mumps, including parotitis (might even just say he has mumps)…what is most likely additional manifestation?
Orchitis (but infertility is rare)
- Subclinical pancreatitis is rare
- Pleocytosis can be seen in 1/2 patients
- Encephalitis is rare
What is the treatment of mumps?
Supportive
What is fifth disease also known as?
Erythema Infectiosum or Parvovirus B19
What do you pick for any question of what causes hydrops fetalis or aplastic crisis in sickle cell disease?
Parvovirus B19
How is Parvovirus B19 spread?
By respiratory droplets
What is the prodrome for parvovirus B19?
Non-specific…fevers, sore throat, runny nose, headache, and malaise
Describe the rash in parvovirus B19
Prodrome is followed by classic “slapped-cheek” rash. Over next few days, a “lacey” rash on extremities can develop
What other symptom can develop from Parvovirus B19 besides prodrome and rash?
Polyarthropathy
What can happen if a pregnant Mom gets parvovirus B19?
Fetal hydrops
Any seizure in the newborn period should make you consider what?
Herpes infection
What location of seizure should make you think of Herpes infection?
Temporal lobe seizure
What is usually described of Mom in a kid with systemic HSV?
Mother will be described as asymptomatic because there is usually no history of herpes documented when an infant presents with systemic HSV, despite our best efforts at eliciting one
Most invasive neonatal herpes infections are caused by what?
Type 2 HSV
What is the typical presentation of herpes simplex infection in a neonate (first 28 days)?
Signs of sepsis, meningitis, and seizures
What might they tell you about the CSF for a suspected neonatal herpes simplex infection?
Gram stain on CSF is negative
Rapid diagnosis of HSV meningitis can be made by what?
PCR (especially in CSF)
Why is CSF culture not the method of choice for diagnosing HSV meningitis?
Because of false negatives
What is a reliable method to identify HSV in vesicle scrapings?
Direct fluorescent antibody staining
In general, when are viral cultures obtained?
- Serious illness
- Fever of unknown origin
- When biopsies are obtained
- When bacterial cultures are negative
If you are presented with a prepubertal patient with a genital herpes simplex type 2 infection, what should be suspected?
Sexual abuse
Why does delivery via C-section not rule out transmission of perinatal infection with HSV?
Because herpes can also be transmitted as an ascending infection through the infected birth canal
How can neonatal infection of HSV be transmitted postnatally?
From an adult with a cutaneous or oral lesion
What is used for primary genital and mucocutaneous HSV infections for prophylaxis and treatment in immunocompetent patients?
Acyclovir
What is indicated for immunocompromised patients with varicella or disseminated zoster, and to treat HSV encephalitis in any patient?
IV acyclovir
What does HSV typically cause in older kids?
Localized infection or viral meningitis
What are neonates with skin or mucous membrane manifestations of herpes initially treated with?
IV acyclovir, followed by extended PO treatment
Which virus is a lentivirus in the retrovirus family?
HIV
What type of cells does HIV affect?
CD4 T-Lymphocytes
In the pediatric age group, what are the 2 major forms of transmission of HIV?
- Mother to child
2. Behavioral
What should chronic non-specific symptoms (weight loss, fevers, night sweats, recurrent or persistent thrush) in a child or neonate make you consider?
HIV infection
What is the main laboratory finding in HIV?
Decreased C4 count
What is the most common mode of transmission of HIV in kids?
Vertical transmission of HIV during delivery
Can you transmit HIV via breastfeeding?
Yes
Why is routine prenatal HIV screening recommended for all women?
Because mother-to-child transmission is almost always preventable with a combination of maternal antiretroviral therapy, intrapartum maternal zidovudine, neonatal zidovudine, and not breastfeeding
C/S reduces the risk of HIV transmission by what % in mothers with active viremia?
50%
If someone is going to seroconvert with HIV, when does it occur?
During first 6 months of exposure
When should testing and tracking be done for HIV exposure?
At time of exposure, 6 weeks, 12 weeks, and 6 months
This applies to any form of exposure, including child abuse
The use of antiretroviral agents is limited to what for HIV exposure?
Needle sticks where there is a strong likelihood of HIV transmission… ARV agents aren’t administered routinely for all needle sticks (especially where there is low risk of disease transmission)
Why is serologic testing for HIV in infants under 18 months unreliable?
Because maternal antibody to HIV is an IgG (can cross placenta)
What is the gold standard for HIV testing in the neonatal period in the US?
HIV DNA PCR
If the patient is 18 months or older, what is the initial test for serum HIV antibody?
Enzyme immunoassay (EIAs)
What is a positive EIA for HIV confirmed by?
Western blot analysis
Do rapid tests for HIV antibodies require confirmatory testing?
Yes
What do kids with HIV need to receive for prophylaxis against opportunistic infections while their counts are decreased?
Trimethoprim-sulfamethoxazole
Clinical description consistent with Pneumocystis jiroveci (PCP) with no history of AIDS or HIV exposure?
HIV manifestation
What is the buzzword for PCP on CXR?
Ground glass appearance
Name some manifestations of pediatric HIV infection.
Unexplained fevers, generalized lymphadenopathy, hepatomegaly, splenomegaly, failure to thrive, persistent or recurrent oral and diaper candidiasis, recurrent diarrhea, parotitis, hepatitis, CNS disease (hyperreflexia, hypertonia, floppiness, developmental delay), lymphoid interstitial pneumonia, recurrent invasive bacterial infections, and other opportunistic infections (viral and fungal)
What causes the recurrent bacterial infections in the first year of life in kids with HIV?
Increased production of nonfunctional antibodies
What causes developmental delay in kids with HIV?
Encephalitis
What do you do about vaccines in kids with HIV?
HIV positive kids get all routine vaccines, with exception of measles and varicella (contraindicated in kids who are severely immunocompromised with CD4+ counts less than 15% of normal for age). They also get inactivated rather than live influenza vaccine.
What is the only source of varicella zoster?
Human (this is a highly contagious virus)
When does infection result from varicella?
When the virus comes in contact with the mucosa of the upper respiratory tract or the conjunctiva
How does person-to-person transmission of varicella occur?
By the aerosolized route or by direct contact with the lesions or respiratory secretions
What precautions are required for varicella?
Standard, airborne, and contact precautions for a minimum of 5 days after onset of rash and until all lesions are crusted (in immunocompromised patients it can be a week or longer)
What precautions are recommended for neonates born to mothers with varicella?
Airborne and conact
If a neonate born to a Mom with varicella is still hospitalized, how long should airborne and contact precautions be continued?
21-28 days of age if they received Varicella-Zoster Immune Globulin or IVIG
When are kids with varicella considered contagious?
From several days before they have their rash until all the lesions are crusted over
Who is considered “exposed” to varicella?
Anyone around a child with varicella from several days before they have their rash until all the lesions are crusted over
What should be given to an immunocompromised child exposed to varicella to help prevent infection?
Varicella zoster immune globulin
Who does varicella tent to be more severe in?
Infants, adolescents, and adults (versus young kids… most kids with chicken pox do fine)
What is the most common complication of Varicella?
Superinfection with Staph aureus involing skin
In more severe cases of Varicella, what can invasive infections lead to?
Pneumonia and osteomyelitis
Because immunocompromised kids (chemo, AIDS) are much more susceptible to disseminated varicella, what can develop?
Viremia, pneumonia, encephalitis, or other complications
What is the secondary infection of varicella, caused by the reactivation of VZV from latency?
Zoster (shingles)
When can a kid with zoster return to school?
If the lesions can be covered or once they are crusted
What is the treatment of choice for a newborn exposed to chickenpox?
VZIG
What is considered exposure of a neonate to chickenpox?
If Mom gets chickenpox between 5 days before delivering through 2 days after delivering (then infant is at risk)
5=V and 2 L in VariceLLA (5 before, 2 after)…So normal infants older than 2 days who were exposed to varicella don’t need VZIG
What time frame does VZIG need to be given to an infant exposed to chickenpox?
Needs to be given within 96 hours of exposure…VZIG is considered to be a preventive measure rather than treatment
What should be done for exposed immunocompromised kids (including certain newborns) and pregnant women with no history of Varicella who have been exposed to chicken pox?
Receive Varicella-Zoster Immune Globulin or IVIG ASAP
True or False: Oral acyclovir or valacyclovir are recommended for routine use in kids with varicella?
FALSE
Who is oral acyclovir or valacyclovir considered for in varicella?
Otherwise healthy people at increased risk of moderate to severe varicella…unvaccinated people over 12, chronic cutaneous or pulmonary disorders, long-term salicylate therapy, kids on short, intermittent, or aerosolized courses of corticosteroids
Who is IV acyclovir recommended for to treat varicella?
Immunocompromised patients, including patients being treated with chronic corticosteroids
What virus can cause encephalitis in the late spring and early summer months?
Arboviruses
What transmits arbovirus?
Ticks and mosquitos
What is the best prevention for arbovirus?
Tick and mosquito control
Name 7 arboviruses
- St. Louis encephalitis
- La Crosse encephalitis
- Western and Eastern equine encephalitis
- California encephalitis
- West Nile encephalitis
- Colorado tick fever
- Dengue fever
What is the typical presentation of arbovirus?
Fever, irritability, change in mental status, and headache
What are the 2 enteroviruses?
- Echovirus
2. Coxsackie virus
What are symptoms of enteroviruses?
High fever, rash, and signs of viral meningitis in summer
Patient younger than 5, presents with vague symptoms (malaise, fever, vomiting), pharyngitis, conjunctivitis
Enterovirus
What can happen to a neonate exposed to enterovirus?
Can develop severe disseminated infection if exposed at birth…may be indistinguishable from sepsis due to bacteria
How can you identify an enterovirus?
Via PCR in 24 hours
What virus can result in myocarditis?
Coxsackie B (myo coxsarditis)
Conjunctivitis, pharyngitis, and otitis media, it is summer…Treatment?
Supportive measures only…combo of conjunctivitis and pharyngitis is often how adenovirus is presented on exam (especially if it’s summer)…don’t pick antibiotics
What 4 things can adenovirus cause?
- Conjunctivitis
- Pharyngitis
- Adenopathy
- Intussusception
What season should make you think adenovirus?
Summer… it is seen more frequently in the late winter, spring, and early summer
What does enteric adenovirus and norovirus cause?
Diarrhea
Kid with diarrhea who recently went on a cruise ship?
Norovirus
How is norovirus often transmitted?
Infected food handlers
What is the most common manifestation of RSV?
Bronchiolitis
Infant with expiatory wheeze, crackles, nasal flaring, retractions, tachypnea, fever, URI symptoms…
RSV Bronchiolitis
What is seen on CXR in RSV?
Diffuse infilatrates and hyperinflation
What diagnosis of RSV best confirmed with?
Rapid diagnostic assay via antigen testing
What is the only source of RSV infection?
Humans
How is RSV transmitted?
By direct or close contact with contaminated secretions, which may occur from exposure to large-particle droplets at short distances or fomites
How long can RSV linger on environmental surfaces or hands?
Environmental surfaces for several hours and for half-hour or more on hands
Is confirmation of RSV necessary for management?
No
How is RSV diagnosed?
Immunofluorescence is how it is confirmed (picture a Really Shiny Virus because it lights up)
How can healthcare providers best prevent the spread of RSV?
Good hand washing
Does pure RSV bronchiolitis respond to albuterol or corticosteroid therapy?
NO..management is largely supportive, don’t pick these on boards
Does response to beta agonist therapy rule out RSV bronchiolitis?
Not necessarily, because there is often a reactive component
What reduces the risk of RSV lower respiratory tract disease?
Palivizumab (Synagis)
Who is Synagis (palivizumab) recommended for?
Infants with chronic lung disease, preterm birth, and congenital heart disease
What is Palivizumab used for?
Available for primary prevention of RSV in certain infants, but isn’t effective in treatment of RSV disease and isn’t approved or recommended for this indication.
What typically begins with sudden onset of fever, often accompanied by chills or rigors, headache, malaise, diffuse myalgia, and nonproductive cough? Upper respiratory symptoms like sore throat, nasal congestion, rhinitis, and productive cough follow.
Influenza
Who are complications and rates of hospitalization due to influenza higher in?
Newborns and children with high-risk conditions (hemoglobinopathies, bronchopulmonary dysplasia, asthma, CF, malignancy, DM, chronic renal disease, and congenital heart disease)
What is the quickest and most useful method to ID influenza?
Rapid antigen screen
What is indicated for most uncomplicated cases?
Supportive therapy
When are antiviral medications indicated for influenza?
Severe disease or those patients at risk for complications or who have close family contacts at risk
What are the 2 classes of antiviral medications available for treatment or prophylaxis of influenza infections?
- Neuraminidase inhibitors (oseltamivir and zanamivir)
2. Adamantanes (amantadine and rimantadine)
What is the class of antiviral medications recommended for influenza?
Neuraminidase inhibitors (oseltamivir and zanamivir)
Due to resistance
What viruses are the major cause of laryngotracheobronchitis (croup) and what else do they commonly cause?
Parainfluenza viruses…upper respiratory tract infection, pneumonia, and/or bronchiolitis
1-2 day history of fever, several episodes of watery stools, intermittent vomiting, evidence of dehydration.
Rotavirus
How is rotavirus diagnosed?
Antigen testing of stool
How long is the incubation period for rotavirus?
1-3 days
What is the treatment for rotavirus?
No specific treatment, many small infants need to be hositalized because of dehydration
Animal bite by bat, raccoon, skunk, fox, coyote, or bobcat?
RABIES
True or False: Rabies in small rodents (squirrels, hamsters, guinea pigs, gerbils, chipmunks, rats, and mice) and lagomorphs (rabbits, pikas, and hares) is rare
True
Song to remember animals that can carry rabies?
"Frere Jacques" - Remember them in pairs Foxy Ferrets Cats and Dogs Wolves, Coyotes, and Bobcats Raccoons and Skunks Opossums and Bats
What should be done with a dog, cat, or ferret that appears healthy and has bitten a human?
Be confined and observed by a veterinarian for 10 days
When is human prophylaxis given for rabies?
If confined animal develops signs of rabies
What should be started for a bite from an animal suspected of being rabid?
Rabies prophylaxis (immunization and HRIG)
Important to consult with local health department to assess the risk of rabies in the area, especially if the animal is unknown or cannot be contained and observed
What can transmit rabies to humans even without known bites?
Bats
If you have a patient who woke up in a room with a bat, what is indicated?
Treatment for rabies (even in absence of a known bite taking place)
True or false: Once symptoms have developed, neither rabies vaccine nor Rabies Immune Globulin (RIG) improves the prognosis?
True
What is the most prevalent of all human intestinal nematodes (roundworms)?
A. Lumbricoides (more than 1 billion people infected worldwide)
Describe the life cycle of A. Lumbricoides?
Adult worms live in lumen of small intestine. Female worms produce about 200,000 eggs per day, which are excreted in stool and must incubate in soil for 2-3 weeks for an embryo to become infectious. Infection follows ingestion of embryonated eggs, usually from contaminated soil
How do infections with A. Lumbricoides present?
Usually asymptomatic, but moderate to heavy infections can lead to malnutrition and nonspecific GI tract symptoms
Someone who traveled, symptoms consistent with obstruction or abdominal pain?
A. Lumbricoides infection (especially if visiting or returning from a faraway place where ascaris is endemic)
Child with signs of acute abdominal obstruction (implication of appendicitis or other surgical cause), history of immigration from or travel to a tropical region…
Obstruction due to A. Lumbricoides infestation
They will focus more on obstruction than any parasitic concern
What is the memory aid for A. Lumbricoides?
A Scary Lumbar Coilee… Picture a scary coil tangled up in the lumbar spine causing abdominal pain and obstruction
What are appropriate treatment options for asymptomatic or symptomatic Ascaris Lumbricoides?
- Albendazole in a single dose
2. Ivermectin in a single dose
What is the presentation of Necator Americanus (hookworm)?
Often asymptomatic
Chronic infection is associated with hypochromic, microcytic anemia, physical growth delay, deficits in cognition, and developmental delay
What can be a presenting symptom with Necator Americanus (hookworm)?
Stinging or burning sensation followed by pruritus and a papulovesicular rash that can persist for 1-2 weeks… after contact with contaminated soil, initial skin penetration of larvae (often involving feet) causes this
How does taeniasis (tapeworm) present?
Often asymptomatic, but nausea, diarrhea, and pain can occur. You can sometimes see tapeworm segments migrating from the anus or in feces.
Which tapeworm is acquired by ingesting eggs of the pork tapeworm?
T. Solium… Cysticercosis
How is Cysticercosis contracted?
Through fecal-oral contact with a person harboring the adult tapeworm, or by autoinfection
Where are eggs of pork tapeworm found?
Only in human feces (humans are obligate definitive host)… T. Solium, Cysticercosis
True or False: Mebendazole is used to treat tapeworms
False…Mebendazole is no longer available in the US
What is toxocariasis due to?
Roundworm, Toxocara canis
How does toxocariasis present?
GI symptoms: Hepatomegaly and abdominal pain
Respiratory symptoms: Wheezing
Why does toxocariasis present with both GI and respiratory symptoms?
It migrates everywhere
What is a risk factor for toxocariasis?
Exposure to cats and dogs
What can be seen on CBC in toxocariasis?
Eosinophilia
Preschooler eating dirt
Toxocariasis
What are the 3 clinical manifestations of toxocariasis?
- Visceral larval migrans: Fever, hepatomegaly, wheezing
- Ocular larval migrans: Visual disturbances
- Covert Toxocariasis: GI symptoms, pruritus, rash
Abdominal pain, wheezing, exposure to cats/dogs, eosinophilia, hepatomegaly, eating dirt while playing
Visceral larva migrans…keys are hepatomegaly and dirt
Abdominal pain and wheezing = Pneumonia
Cats = Asthma and allergies
What is done to diagnose visceral larva migrans?
ELISA…but still do stool cultures to rule out other parasitic infections
How is visceral larva migrans treated?
Albendazole or thiabendazole
Memory aid for visceral larva migrans?
L’s: Longhaired cats and Licking dogs cause Larval disease in the Lungs and the Liver
How do kids with enterobius vermicularis (pinworms) present?
Perianal or perivulvar itching
How does egg transmission occur for pinworms?
Fecal-oral route…either directly or indirectly via contaminated hands or fomites (shared toys, bedding, clothing, toilet seats, baths)…. reinfection is very common
How is diagnosis of enterobius vermicularis made?
When adult worms are visualized in perianal region…best examined 2-3 hours after child is asleep
What is treatment for pinworm?
Pyrantel pamoate or albendazole
What is the most likely cause of a mild candidal infection?
Antibiotic use
What is the most likely cause of systemic candidiasis?
Immunosuppression (bone marrow/organ transplant, malignancy, or corticosteroids)
Memory aid for most likely causes of systemic candidiasis?
YEAST Y: Widespread immunosuppression Extensive burns Antibiotics Suppressed immunity TPN use
How is oral candidiasis in immunocompetent hosts treated?
Oral nystatin suspension
What can be used for oral candidiasis in immunocompromised patients?
Fluconazole or itraconazole
What is the treatment of choice for neonates with invasive disease due to candidiasis?
IV amphotericin
What is cryptococcus neoformans?
Encapsulated yeast
What does cryptococcus neoformans cause?
Pulmonary disease and meningitis/meningoencephalitis
What is cryptococcuss neoformans most commonly associated with?
AIDS
History of exposure to bird droppings (pigeons)?
Cryptococcus
Memory aid for cryptococcus?
Someone stuck with a pigeon in a giant CRYPT…no air and he is getting a headache so severe it feels like meningitis
What is indicated as initial therapy for meningitis and other serious cryptococcal infections?
Amphotericin B, in combination with oral flucytosine or fluconazole
Patient presenting with vague influenza-like symptoms…recent travel to California, Arizona, or Texas
Coccidioidomycosis
CAT (California, Arizona, Texas): CAT city-oidomycosis
When do symptoms develop for Coccidioidomycosis?
Within a month of exposure
How to patients with coccidioidomycosis present?
Vague complaints…including fevers, night sweats, headaches, chest pains, and muscle aches
How is coccidioidomycosis treated?
Amphotericin B, fluconazole, or ketoconazole
Asthmatic with worsening symptoms despite treatment, increased eosinophils, infiltrates noted on CXR…
Aspergillosis
Who does invasive aspergillosis occur in?
Immunocompromised patients
How is aspergillosis diagnosed?
Positive serum galactomannan… this is an antigen in the Aspergillus cell wall
What is the treatment of choice for invasive aspergillosis?
Voriconazole (except in neonates)
What do you give to neonates for aspergillosis?
Amphotericin B in high doses
Where is histoplasmosis found?
Throughout the Ohio, Missouri, and Mississippi river valleys
Who gets sick from histoplasmosis?
Most people who are infected remain asymptomatic… those who get sick are usually immunocompromised
How will histoplasmosis be described?
General influenza-like symptoms and hepatosplenomegaly (this is the key to choosing this)
How is histoplasmosis obtained?
Bird droppings
What is done to treat immunocompetent children with uncomplicated histoplasmosis?
Supportive care
What is recommended for disseminated histoplasmosis, especially in immunocompromised patients?
Amphotericin B
What is the most appropriate azole for histoplasmosis (disseminated)?
Fluconazole
What 2 illnesses are associated with bird droppings?
Histoplasmosis and cryptococcosis
How to distinguish histoplasmosis and cryptococcosis (since both are associated with bird droppings)?
Crypto: Headache
Histo: Hepatosplenomegaly
What defines droplet transmission?
Infections spread by droplet transmission (sneezing or coughing)… do not remain suspended for prolonged periods of time
What are precautions for droplet transmission?
Covering mouth when sneezing or coughing…do not require any special air ventilation systems to prevent spread
What are examples of organisms transmitted by droplet transmission?
Mumps, rubella, and pertussis
What defines airborne transmission?
Organisms that can remain airborne for prolonged periods of time…aka they can spread through the hospital ventilation system
What is needed to prevent spread of airborne transmission?
Special air handling units are needed to prevent
What are examples of airborne transmission?
Aspergillosis, tuberculosis, measles, varicella, and disseminated zoster
Memory aid for airborne transmission?
Picture an ATM as a hospital air conditioning system delivering V’s and Z’s as droplets to remember that the hospital ventilation system can spread varicella and zoster
What 3 bugs don’t spread through the hospital ventilation system and only require standard precautions?
- Legionella pneumophilia
- Candidia parapsilosis
- Pseudomonas aeruginosa
What is an example of an organism transmitted by direct contact?
RSV virus
What is the best method of preventing transmission of RSV?
Handwashing
