infectious disease Flashcards
What is the proper treatment in a septic newborn born to a mother with flu like symptoms and white nodules on placenta?
Amp and gent for listeria
What is the infectious etiology associated with rose spots in the skin?
Salmonella typhosa
What is the infectious etiology associated with ecthyma gangrenosum (large pustules on indurated inflamed base)?
Pseudomonas
What is the infectious etiology of non blanching rash and petechiae?
Neisseria
What is the common benign side effect of rifampin?
Orange secretions
What is the prophylactic drug of choice for meningococcemia?
Rifampin
What are the indications for meningococcemia prophylaxis?
Persons with contact to oral secretions
Household contacts or close contacts outside the house
What should you consider in a patient with elevated d dimer, low platelets and low fibrinogen?
DIC
What etiology should you consider in septic shock and how should you empirically treat?
Vancomycin and ceftriaxone to cover meningococcemia
What are the likely causes of meningitis in the neonate?
GBS
Listeria
E. coli
Enterovirus
What are the common causes of meningitis in young children?
Strep pneumo Neisseria meningitidis Enterovirus Borrelia burgdorferi Rickettsia
What complications of meningitis should be monitored for?
Focal deficits and SIADH
When does primary peritonitis occur?
Without an obvious intraabdominal source in patients with nephrotic syndrome or cirrhosis
What is the treatment for pneumococcal peritonitis ?
Third generation cephalosporin PLUS aminoglycoside
What type of abdominal infection is the likely source in a child with nephrotic syndrome? Why?
Encapsulated organism such as pneumococcus due to loss of IgG
What is the likely source of infection in a child with secondary peritonitis?
Gram negative organisms and anaerobes
What should you consider as a diagnosis in a dialysis patient with fever and abdominal pain ? What infectious etiology would you consider ?
Secondary peritonitis due to perforated bowel - due to staph epidermidis
What is the most common cause of vp shunt infection?
Staph epidermidis
What organisms does latex agglutination test for?
GBS
H. Flu
Neisseria meningitidis
Strep pneumo
When is latex agglutination helpful?
When partially treated infections are unreliably detected by culture
When can latex agglutination give false positives?
After HIb vaccine or with cross reactivity of E. coli
What is the treatment of choice in an immunocompromised child with fever or neutropenia ?
Zosyn + aminoglycoside OR
Ceftazidime (gram negative coverage)
What is used for prophylaxis against PcP?
Bactrim
What diagnosis should you consider in a patient with ground glass appearance on X-ray?
Pcp and HIV
What is the treatment for cryptosporidium ?
Nitazoxanide
What are the symptoms of cryptosporidium ?
Diarrhea that is severe, non bloody, watery lasting up to 10 days
What bacteria should you consider in a patient with intracytoplasmic inclusion bodies on scraping ?
Chlamydia pneumonia
What diagnosis should you consider in a patient with afebrile staccato cough, tachypnea and eye discharge?
Chlamydia pneumonia
How is chlamydia definitively diagnosed?
Chlamydia trachomatis - PCR
Chlamydia pneumoniae - microimmunofluotescent antibody test
How would you treat a chlamydia conjunctivitis ?
Oral erythromycin or Sulfonamides (do not treatment with topical)
How would you treat chlamydia pneumonia?
Azithromycin x 5 days
Erythromycin x 14 days
How would you treat an uncomplicated chlamydia genital infection ?
Doxycycline x 7 days
Azithromycin 1 gram x 2
A teenager presents with cough and low grade fever, chest x-ray shows scattered perihilar infiltrates. You want to choose mycoplasma on the exam but that option is not available, what is the diagnosis?
Chlamydia pneumonia
What disease should you consider if fever, myalgia, headache and petechiae rash that starts on hands and feet then spreads centrally? What “bug” is the culprit?
Rocky Mountain spotted fever - rickettsia rickettsii
What are the peak times for Rocky Mountain spotted fever?
May and June
What do you do when a patient presents with suspicion for Rocky Mountain spotted fever?
Treat with doxycycline x 7 days (even if child is under 8) – then order direct immunoflourescence. TREAT FIRST
What is the difference between Rocky Mountain spotted fever and ehrlichiosis?
Ehrlichiosis may cause leukopenia and elevated LFTs
What are the symptoms of human ehrlichiosis ? And what disease presents with the same symptoms?
Fever, headache, myalgia
Thrombocytopenia and hyponatremia
Same as Rocky Mountain spotted fever
What is the treatment of Q fever?
Doxycycline
What are symptoms of Q fever?
Flu like symptoms followed by respiratory symptoms and pneumonia (no rash)
How is Q fever transmitted?
Inhalation of infected particles
What is the appropriate treatment for cat scratch disease with draining lymph node?
Nothing! Unless immunocompromised, hepatomegaly or large painful adenopathy
What is the bacteria that causes cat scratch disease ? How is it diagnosed ?
Bartonella henselae Serologic testing (enzyme immunoassay or immunofluorescent antibody test)
Which antibiotics would be appropriate for cat scratch disease?
Azithromycin
Cipro (if >18)
Bactrim
Rifampin
What should NoT be done for treatment of cat scratch disease?
Penicillins
I&D
What should you use to treat cellulitis after a cat bite? What if penicillin allergic patient?
Augmentin --> if allergic, use: Doxycycline Azithromycin Bactrim Cefuroxime (if not severe PCN allergy)
What bacteria should you consider if described as a pleomorphic gram negative organism?
Haemophilus influenza
What disease should you consider in a patient from another country with peri orbital cellulitis or Pyogenic arthritis?
Haemophilus influenza
What bacteria should be considered in a non-immunized patient with bacterial meningitis?
Heamophilus influenza
What is the appropriate treatment if invasive haemophilus influenza infection is suspected?
Ceftriaxone or cefotaxime (if allergic, use chloramphenicol or merrem)
What 3 encapsulated organisms should be considered in patients without functioning spleen?
Strep pneumo
Neisseria meningitidis
H. Flu (non typable)
When is prophylaxis for H Flu contacts indicated?
If any household members who are immunocompromised or unvaccinated then all household members need rifampin prophylaxis
What is the appropriate prophylaxis for non typable h flu infection in household member?
None!! Prophylaxis Only in typable h flu
When do all nursery children need to be treated prophylactically for H. Flu?
Only if 2 or more cases within 60 days!
What are the three phases of pertussis?
Catarrhal
Paroxysmal
Recovery
How is diagnosis of pertussis confirmed?
PCR (DFA not used)
What is the treatment for pertussis? How does it help?
Erythromycin, azithromycin or clarithromycin
Bactrim can also be used
Decreases period of communicability but does not shorten the paroxysmal stage!
When should prophylaxis against pertussis be given?
Anyone exposed to someone with pertussis regardless of immunization status needs azithromycin
What should you consider in a preschool age child wth cough and elevated wbcs with high lymphocytes?
Pertussis
What is the appropriate diagnosis and treatment in a patient who ate chicken salad at a picnic and then developed vomiting and diarrhea?
Salmonella - supportive therapy
When should treatment for salmonella be given? What treatment is appropriate in those cases?
If under age 3 months, immunocompromised or with hx of colitis - give ceftriaxone
What is the treatment for invasive typhoid fever?
Broad spectrum cephalosporins
What should you consider as a diagnosis in a patient with diarrhea, malaise, fever and “rose spots”?
Typhoid serotype of salmonella
What infection should you consider when a nail goes through a shoe?
Pseudomonas osteomyelitis
In what population does pseudomonas cepacia cause pneumonia and death?
Cystic fibrosis
What should you consider in a child on a dairy farm who presents with fevers and myalgias?
Brucellosis
How do you treat brucellosis?
Prolonged treatment with tetracycline or bactrim and rifampin
How would you choose to treat pseudomonas?
Piperacillin/tazobactam and gentamicin
Ceftazidime for pulmonary infections
What are the most common antibiotics that cause clostridium difficile?
Clindamycin
Cephalosporins
What is the most appropriate first line treatment for pseudomembranous colitis?
Metronidazole
Vancomycin PO is only used if flagyl does not work
What is the appropriate treatment for strep pneumo meningitis?
Vancomycin + ceftriaxone (or cefotaxime)
What are red lines in the skin folds and what infection are they associated with?
Pastia lines - scarlet fever and strep pharyngitis
What does treatment of strep throat prevent? What does it not prevent?
Prevents rheumatic fever
Does not prevent glomerulonephritis
What is the appropriate treatment for strep throat?
PCN or amoxicillin
If allergic, azithromycin, clindamycin or first generation cephalosporin
What is the name of strep cellulitis causing red streaks and lymphangitis?
Erysipelas
What diagnosis should you consider in a patient with rapidly evolving erythema and inflammation after minor trauma?
Necrotizing fasciitis
What infections can cause toxic shock syndrome?
Staph
Epstein Barr virus
Coxsackie
Adenovirus
How does late gbs infection occur?
Focal infection at 1-3 months
The CDC recommends prophylaxis for GBS under what conditions?
Previous infant with GBS.
GBS bacteriuria during current pregnancy
Positive GBS screen (35-37 wk)
Unknown GBS with preterm labor, ROM>18 hr or fever >38
How does the infantile form of botulism develop in infants?
Spores are ingested and they germinate in the underdeveloped GI tract
What condition should you consider in an infant with poor sucking/feeding, hypotonia with descending paralysis and ptosis?
Botulism
What condition should you consider in a 6 month old infant with constipation, urinary retention, weak cry and absent gag reflex?
Botulism
How is botulism caused in adults?
Ingestion of botulism toxin from poorly canned goods
How do you diagnose botulism?
Presence of toxin in stool or serum, PCR is not used.
How does the botulism toxin cause symptoms?
Toxin blocks release of acetylcholine into the synapse
What is the appropriate treatment for botulism and why?
Supportive care only!
Antibiotics cause lysis or spores and release of neurotoxins
What is the difference between botulism and myasthenia gravis?
With MG, tensilon is positive and onset is gradual
With botulism, tensilon is negative and onset is rapid
What is the worst choice of antibiotics for botulism?
Aminoglycoside potentiate the toxin
Under what conditions do you need to treat an infant for syphillis?
If mother treated within the last month of pregnancy or if she was treated with erythromycin; if baby’s titers are higher than mothers
What disease should you consider in a newborn with maculopapular rash, hepatosplenomegaly and peeling skin?
Syphilis
Which syphilis screens are nonspecific nontreponemal antibody tests?
VDRL
RPR
What conditions may cause false positive VDRL and RPR?
Epstein Barr
Hepatitis
Varicella
What test for syphillis remains positive for life and what type of test is it?
FTA ABS - treponemal test used to verify positive screen
What is the appropriate treatment for congenital syphillis ?
Penicillin
What should you consider in an infant with poor feeding, sniffles, bullous lesions and osteochondritis of joints?
Syphillis
What hepatic defects are associated with congenital syphilis?
Hydrops fetalis
Hepatosplenomegaly
Hemolytic anemia
What type of skin findings are associated with congenital syphillis ?
Maculopapular rash
Bullous lesions
What should you consider in a patient with diarrhea, low platelets and anemia?
HUS
What is the treatment for campylobacter fetus ?
Broad spectrum cephalosporins or gentamicin
What is the treatment for campylobacter jejuni?
Azithromycin
Tularemia is caused by what type of bacteria? What is the appropriate antibiotic for tularemia ?
Gram negative francisella tularensis.
Gentamicin (second line: tetracycline, ciprofloxacin, streptomycin)
How does a child become infected with tularemia?
Consumption of rabbit meat - fever, hepatosplenomegaly, rash and lymphadenopathy
What disease is caused by yersinia pestis?
Bubonic plague
What is the best choice of treatment for bubonic plague?
Streptomycin and gentamicin
May also use doxycycline, chloramphenicol and tetracycline
What should you consider in a young child with bloody diarrhea and elevated WBC with hx of ingesting unpasteurized milk or raw meat?
Yersinia enterocolitica
What is the appropriate treatment for yersinia enterocolitica?
None unless immunocompromised, then give bactrim, Aminoglycosides or cefotaxime
What disease should you be concerned about in a patient with swollen painful lymph nodes and hx of exposure to a dead animal?
Bubonic plague
What is the appropriate first line treatment for MSSA?
Beta lactamase resistant agents such as oxacillin or nafcillin
What is considered a coagulate negative staph infection and when does it occur?
Staph epidermitis - with IV lines or catheter
What is the appropriate treatment for a carbuncle/furuncle?
Incision and drainage (if >5cm, treat for MRSA)
What is the treatment for hospital acquired MRSA ?
Vancomycin
What antibiotics are community acquired MRSA infections sometimes susceptible to?
Bactrim
Gentamicin
Doxycycline
When are peak and trough levels measured with Aminoglycosides?
Peak - 30 minutes after dose
Trough - 30 minutes before next dose
Why is it important to prevent high peak levels of Aminoglycosides ?
Ototoxicity
How do penicillins work?
Interfere with cell wall synthesis
What is “special” about beta lactamase bacteria?
They produce penicllinase which cleaves PCN - therefore penicillinase resistant antibiotics are required
How are MRSA infections resistant to methicillin?
They interfere with PCN binding proteins therefore the antibiotic can’t bind to the organism
What is the dose of amoxicillin for otitis media, pneumonia or sinusitus?
80-90 mg/kg/day
What limitations are associated with use of first generation cephalosporins?
Do not penetrate the CSF
Not effective against listeria or enterococcus
What are first generation cephalosporins good for? What are the available oral Medications available in this class?
Gram positive cocci (including MSSA).
Cephalexin, cefadroxil
What is the fourth generation cephalosporin and what is it used for?
Cefepime - gram negatives (pseudomonas) and gram positives (staph)
What classes of infection are covered by clindamycin ?
Aerobic and anaerobic gram positives, anaerobic gram negatives cocci, chlamydia and Protozoa
What are the oral third generation cephalosporins?
Cefpodozime and cefdinir
What types of infections have good coverage with third generation cephalosporins?
Meningitis
Sinusitis / respiratory infections
Uti
What types of infections are covered by macrolides?
Mycoplasma Moraxella / H. Flu Strep pyogenes Chlamydia Pertussis legionella Nontuberculous mycobacterium
What types of infections can be treated with rifampin?
Staph osteomyelitis or endocarditis
TB
When would quinolones be indicated in children ?
Multiresistance
Pseudomonas
Anthrax
What interferes with quinolone absorption?
Antacids with aluminum, mag or calcium
When are tetracyclines contraindicated?
In children <8 unless Rocky Mountain spotted fever
What antibiotic increases risk for cardiac arrhythmia?
Quinolones
What should be used to treat enterococcus infection?
Ampicillin plus vancomycin (unless VRE)
What is the appropriate treatment for neisseria gonrrhea?
Ceftriaxone IM x 1
What 4 types of infections are treated with metronidazole?
Trichomonas
Syphilis
Gardnerella
H. Pylori
What test can be used to screen and to verify diagnosis of mono?
Heterophile antibody
If negative, confirm with serum IgM
There is high false positive rate of screening test in children <4
What is the diagnostic study for cmv?
Urine culture within first 3-4 weeks of life
What disease should you consider in an infant with chorioretinitis, periventricular cerebral calcifications and sensorineural hearing loss?
CMV
What TORCH infection causes petechiae and outputs secondary to thrombocytopenia (blueberry muffin baby)?
CMV
How is CMV infection spread?
Virus is shed in urine, saliva or genital secretions
A patient presents with mono type infection but mono testing is negative…what should you consider?
CMV
What is the treatment for CMV and what is the major side effect?
Ganciclovir - marrow suppression
What type of infections are caused by arboviruses and when do they typically occur?
Encephalitis - late spring and early summer
What are the csf findings in arbovirus encephalitis?
Mild pleocytosis and elevated protein
How is west Nile encephalitis diagnosis confirmed ?
IgM in serum or CSF or Fourfold elevation of serum IgG during acute infection
What diagnosis should you consider when a patient presents with high fever, rash and viral meningitis during summer?
Coxsackie (enterovirus)
How is an enterovirus infection confirmed ?
PCR
When can unimmunized children return to school if there is a measles outbreak in a local school?
Give the vaccine prior to return to school (or the booster if not completed) OR
Wait 26 days after the last person developed parotitis
When can a child with mumps return to school?
9 days after the onset of parotitis
What are the 4 complications of mumps infection?
Parotitis
Meningitis/encephalitis
Orchitis
Pancreatitis
What diagnosis should you consider In a patient with fever, headache, muscle aches and unilateral facial swelling anterior to the ear?
Mumps
What is the difference between mumps and viral parotitis?
Mumps is associated with low fever and non toxic appearance in unimmunized child
Viral parotitis is associated with high fever and toxic appearing child who is fully immunized
What should you consider in a patient with intermittent salivary gland swelling?
Salivary gland stone
What is the most likely manifestation in a patient with mumps and parotitis?
Orchitis (but not infertility)
What disease should you consider in a patient with high fever for 3 days followed by maculopapular rash?
HHV-6 aka roseola
What should you consider in an unvaccinated hold with maculopapular rash associated with mild viral symptoms ?
Rubella
What vaccine should NOT be given to pregnant women?
MMR
What occurs in 50% of infant infected with rubella in their first trimester?
Cataracts and PDA
What are the 7 main symptoms associated with measles ?
Cough Coryza conjunctivitis Koplik spots Confluent maculopapular rash Fever Photophobia
What is measles the most contagious?
5 days before to 5 days after the appearance of the rash
What is the method for measles diagnosis?
Serum IgM (elevated for one month)
How can immunocompromised patients be protected after measles contact ?
Immunization and immunoglobulin
What is the appropriate measles post-exposure management for incompletely immunized children ?
Immunoglobulin within 6 days
MMR vaccine within 3 days
When should children receive revaccination after post exposure treatment?
After age 12 months and at least 5 months after immunoglobulin was given
What is the diagnosis in a patient with slapped cheek rash that spreads to extremities?
Parvovirus b19 aka fifth disease
What virus can cause hydrops fetalis? What else can this virus cause?
Parvovirus B19 - also causes aplastic crisis in sickle cell disease
What is the best test for diagnosis of hsv?
Csf PCR
When is acyclovir used?
Hsv prophylaxis and treatment
Varicella only in immunocompromised
What is the appropriate test for HIV in children and why?
When should exposed infants be tested?
If <18 months, need PCR (antibodies can cross the placenta)
Birth, 2 months, 4 months and 6 months
What are 4 buzzwords that might point toward HIV infection in a child?
Recurrent bacterial infection
Hepatosplenomegaly
Failure to thrive
Developmental delay
When should testing for HIV be performed after any form of exposure to HIV?
At time of exposure
6 weeks, 12 weeks and 6 months
How can HIV vertical transmission be reduced?
Zidovudine and nevirapine during the perinatal period
Which vaccines are contraindicated in children with HIV?
Measles and varicella (only contraindicated if severely immunocompromised )
Why do children with HIV develop recurrent bacterial infections?
Increased production of nonfunctional antibodies
When can children with zoster return to school?
Once lesions can be covered or are crusted over
What are the only indications for use of Foscarnet?
CMV retinitis in immunocompromised
Severe mucocutaneous HSV resistant to acyclovir
Zoster
What should be the treatment for immunocompromised children exposed to active chicken pox infection?
When should it be given?
Varicella zoster immune globulin (also indicated for newborns)
Within 96 hours or exposure
How does adenovirus typically present in the summer?
Conjunctivitis, pharyngitis and otitis media
Intussusception or diarrhea
What test confirms RSV infection?
Immunofluorescence
How can you diagnose rotavirus infection?
rotazyme antigen test of the stool
What diagnosis should you consider in an infant with 1-2 days of fever, several episodes of watery stool and vomiting ?
Rotavirus
What should you do in a patient exposed to a bat but not bitten by it?
Treat for rabies - immunoglobulin plus rabies vaccine within 7 days
What are possible treatment options for ascaris lumbricoides infection?
Albendazole x 1
Mebendazole x 3
Ivermectin x 1
What diagnosis should you consider in a patient with recent travel from a tropical region who presents with signs of acute abdominal obstruction?
Ascaris lumbricoides
What is the antibiotic of choice for entamoeba histolytica?
Flagyl
What medications should Never be given to people with amebiasis?
Corticosteroids or anti motility agents
What infection should you consider in a patient with 1 week of abdominal pain, tenesmus and bloody diarrhea as well as liver or brain abscess?
Entamoeba
What is seen on stool culture in amebiasis?
Hematophagous trophozoites
What is the recommended treatment for intraluminal entamoeba infection?
Amebicide (iodoquinol, paramomycin, diloxanide)
What infection should you consider in a child with hepatomegaly, abdominal pain and wheezing?
Toxocara canis
Exposure to what animal may lead to toxocariasis?
Dogs and cats
What signs and symptoms are present in visceral larval migrans?
Fever, hepatomegaly and wheezing
What form of toxocariasis presents with visual problems ?
Ocular larval migrans
What symptoms are seen with covert toxocariasis?
GI symptoms plus pruritis and rash
How is toxocariasis diagnosed?
Elisa
Stool cultures should still be done to rule out other parasitic infections
What is the treatment for visceral larval migrans?
Mebendazole or thiabendazole
What is the treatment of giardia?
Flagyl, tinidazole and nitazoxanide
What is the treatment for tapeworm?
Praziquantel
What is the treatment for strongyloides?
Thiabendazole
What is the treatment for enterobius vermicularis?
Mebendazole, Albendazole or pyrantel (given once then repeated in 2 weeks)
What is permethrin 1% used for?
Lice ( the 5% must be used to treat scabies)
How should anti-malaria medication be taken when traveling to a chloroquine resistant region?
Chloroquine x 1, one week prior to travel, weekly during travel and for 4 weeks after travel
Which fungal infection is an encapsulated yeast?
Cryptococcus
What infection is associated with pigeon droppings ?
Cryptococcus
What is the treatment of cryptococcal infection?
Amphotericin b PLUS Fluconazole
What medication should be added to the recommended treatment for cryptococcosis when the infection is resistant?
Flucytosine
What infection should be considered in a patient with aids who develops severe pulmonary disease or meningoencephalitis?
Cryptococcus neoformans
What infection should you consider in a patient with flu like symptoms from California, Arizona or Texas?
Coccidioidomycosis
What is the treatment for coccidioidomycosis?
Amphotericin, Fluconazole or Ketoconazole
What infection should you consider in an asthmatic with worsening symptoms with eosinophils or infiltrates on CXR?
Aspergillosis
What is the treatment for invasive aspergillosis ?
Voriconazole or amphotericin B
What infection should you consider in a patient with flu like symptoms and hepatosplenomegaly ?
Histoplasmosis
What is the treatment for histoplasmosis ?
Amphotericin
What regions of the country is histoplasmosis found in?
Ohio, Missouri and Mississippi River valleys
What animal is associated with histoplasmosis ?
Pigeon droppings
What infection causes an ulcer on the skin with a chain of nodules parallel to the drainage lymphatic channel which may also cause joint involvement ?
Sporotrichosis
What are possible side effects of amphotericin ?
Fever
Hypokalemia
Nephrotoxicity
What medication should be given to an immunocompromised patient with low neutrophils who is not responding to antibiotics ?
Amphotericin
What is Fluconazole used for?
Candida albicans (used once daily for resistant oral thrush)
What type of contact precautions are needed for RSV?
Direct contact - hand washing for transmission prevention
What type of precautions are needed for mumps, rubella and pertussis?
Droplet precautions (no special ventilation system needed)
What type of precautions are needed for legionella, candida and pseudomonas?
Droplet precautions (no special ventilation system needed)
What type of precautions are needed for aspergillosis, measles and varicella?
Airborne transmission (special hospital ventilation system needed)
What is the etiology of septicemia in a child 1-12 months?
GBS E. coli Strep pneumo Staph aureus Salmonella
