Infectious Diseases Part I Flashcards
1
Q
CBC Laboratory Aids (4)
A
- Bacterial infections: Leukocytosis with a differential left shift
* Shift to polys or bands - Viral infections: Leukopenia.
3 . Specific exceptions
- Pertussis causes an elevated white blood cell count with lymphocytosis).
- Overwhelming sepsis, immunosuppressive drugs, and corticosteroids alters CBC and confuses the picture
- Monocytosis reflects recovery phase of viral illness
* Common finding as someone is getting better
* Can persist for a couple of weeks
2
Q
Acute Phase Reactants (5)
A
- Sed rate (ESR)
- C-reactive Protein
- Procalcitonin
* Used a lot with sepsis - Serum ferritin
- Platelets
3
Q
Cultures (3)
A
- Bacteria, viruses, fungi and parasites require different media.
- Gram stains:
* Helps in antibiotics choice before the culture sensitivity tests are available
* Want them to look at urine and do gram stain to see what the microorganism looks like - Blood cultures are sometimes done with a very sick child
* Less concern to do it nowadays with high fever because of PCV13 and Hib vaccines
4
Q
Serological Tests (4)
A
- Specific antisera can cause an agglutination reaction.
- Measured by dilutional factors.
- Fourfold rise is considered positive
- 4x over the normal value is considered a positive serology
* Ex: with syphilis tests
5
Q
Antibody Detection techniques (3)
A
- Complement fixation
- Hemagglutination inhibition
- ELISA (enzyme-linked immunosorbent assay) testing.
* Trumped by PCR testing; PCR is usually what we use to test for STDs
6
Q
Antimicrobial Sensitivity Testing (2)
A
- Standard zone diameters indicate sensitivity or resistance of a microbe to a specific antibiotic.
- Plate the microorganism of test and look for zone of inhibition; you want to pick the one that is the most sensitive when picking for antibiotics
7
Q
Chest Radiographs (2)
A
- PA and Lateral
- There is no indication for a chest X-ray in a well appearing child with a clinical pneumonia and a normal oxygen
* If you aren’t going to admit child, if it isn’t recurrent, and if it is improving with antibiotics then do not do chest X-ray!
8
Q
Sinus Series
A
Not recommended because the respiratory tract starts at the beginning of the nose, a sinus series would be positive and so would CT of sinuses but that’s simply because of a cold
*Don’t image unless it’s a recurrent problem
9
Q
Radioactive scans
A
Detection of osteomyelitis or abscesses.
*Ultrasound of abscesses
10
Q
CT and MRI (3)
A
- Abscesses or other purulent material collections
- Not first choice to do CT because it exposes a child to radiation
- MRI is good especially for osteomyelitis
11
Q
Coxsackie Etiology (7)
A
- Enterovirus family
- Related to both polio and echo viruses.
- RNA viruses
- A and B
- Coxsackie enteroviruses and polio enteroviruses
- Occur in MAY-OCTOBER; strong summertime predilection
- Can stay on surfaces for over 2 weeks
12
Q
Coxsackie Epidemiology (5)
A
Enteroviruses (entero = intestinal)
- Fecal-oral contamination, especially in diapered children
- Transmitted during parturition.
- Worldwide distribution
- Increased prevalence: May to October.
- Most commonly 1 to 4 years of age.
13
Q
Coxsackie Incubation Period (4)
A
- 3 to 6 days.
- Shed for several weeks
- Child can go back to school as long as not febrile because it is ubiquitous
- Viable on environmental surfaces for at least two weeks.
14
Q
Coxsackie Virus Type A - Hand, Food and Mouth Disease (6)
A
- Fever, vesicular eruption of the buccal mucosa of the mouth, and a maculopapular rash involving the hands and feet.
- Acrodermatitis distribution
- Evolves to vesicles, especially on the dorsa of the hands and the soles of the feet
- 1 to 2 weeks duration
- The hallmark disease of coxsackie virus type A
- No fever, no diarrhea, no vomiting → can go back to school
15
Q
Coxsackie Virus Type A - Aseptic Meningitis (5)
A
- Fever, stiff neck, and headache.
- Altered sensorium and seizures are common.
- Epidemics or as unique cases
- Recover completely.
- Will not look sick, but if they do then they probably need admission
16
Q
Coxsackie Virus Type A Paralytic Disease - Guillain–Barré-type syndrome (3)
A
- Acute ascending polyneuropathy
- Weakess starts in lower extremities and goes up
* Difficulty walking = first sign
* A-reflexia
* Difficulty breathing
* Anorexia
* Goes on to respiratory failure
* Can even go on to chronic inflammatory polyneuropathy to be treated long-term with IVIG - IVIG treats Guillain-Barre by coxsackie 2mg/kg
17
Q
Coxsackie Virus Type A - Childhood insulin-dependent disease (2)
A
- Link between this disorder and Type A coxsackie infection has been proposed but not proven
- Varicella: yes
18
Q
Coxsackie Infection Type B - congenital or neonatal infection (13)
A
- Symptoms occur within two weeks of birth.
- Transplacental infection occurs
- Serious disseminated disease affects the fetal liver, heart, meninges, and adrenal cortex.
- Sudden onset of vomiting
- Coughing
- Fits
- Cyanosis, dyspnea
- Mistaken for pneumonia.
- Pallor and tachycardia leads to myocarditis and congestive heart failure.
- May not have a murmur.
- Cardiac collapse and death can occur
- If the neonates survives, the recovery can be quite rapid.
- Very serious; can cause myocarditis, neonatal overwhelming septic infection
19
Q
Coxsackie Virus Type B - Pleurodynia (11)
A
(Bornholm’s Disease or devil’s grip)
- Generally epidemic but isolated cases happen
- Can occur with A, but less likely
- Sudden severe chest pain, pleuritic in nature and aggravated by deep breathing, coughing, or sudden movements.
- Waves of spasms of 15-30 minutes duration
- Being stabbed with a knife
- Prodrome 1 to 10 days before the onset of chest pain
- Headache, malaise, anorexia, and myalgia.
- Fifty percent of patients have crampy abdominal pain.
- Low to high fever occurs, and a pleural friction rub often is heard.
- Lasts from 1 to 10 days (mean 3.5 d).
20
Q
Pleurodynia differential
A
Coronary artery disease, pneumonia or pleural inflammation.
*Because it mimics pain of cardiac problems
21
Q
Pleurodynia Pathology
A
- Causes inflammation of the pleura (lining of lungs) causing them to have severe remarkable pain
- Patients will complain of spasms
- Can last from 1-10 days
- Cough due to pleuritis
- May have vague symptoms
- The symptoms come from interferon and interleukin release
22
Q
Coxsackie Virus Type B - Myocarditis or Pericarditis (5)
A
- Mild to severe acute and chronic heart disease.
- Symptoms are apparent within two weeks after exposure.
- Chronic heart disability occurs in approximately 20% of cases
- More common in adult menu
- Vague complaints but keep index of suspicion up!
23
Q
Diagnostic Tests for Coxsackie (3 with descriptions)
A
- Viral cultures
- Throat, stool, and rectum.
- Laboratory frozen at 4°C (39°F).
- Usually available in < 1 week,
- Routinely, viral cultures are not done unless the child is very sick - Polymerase chain reaction (PCR)
- Sensitive for CSF
- Good for viral meningitis - Serologic specific titers
- 2 to 4 weeks apart
- In case of EBV, need to wait one week before ordering
- Must wait at least 1 week after presentatiosn before you can send titers, even for early antigen
24
Q
Cytomegalovirus (6)
A
TYPE OF HERPES VIRUS
- Affects about 1% of newborn
- Most common infection - Most infections are asymptomatic at birth
- Can develop hearing loss in toddler preschool years
- 99% are asymptomatic - May have neurosensory hearing loss around 4-5 years old
- If symptomatic, sometimes may get blueberry-muffin rash or hearing problem
- When symptomatic is seen, treat with gangciclovir
- Adolescents are the most common group that will give birth and have a CMV+ baby
25
Q
Herpes Simplex Type I and II (4)
A
- Common, contagious, and often recurrent infection of skin and mucous membranes
* One variety is herpes labialis (cold sore) - CAUSES VESICLES IN GROUPS
- Usually ulcerations after vesicles clear up
- Whole process is usually about 10 days
26
Q
Herpes Simplex I and II Clinical Manifestations (5)
A
- Following a brief prodrome of burning, vesicles filled with yellow fluid erupt on the lip
- Discrete red, swollen mucosal ulcerations
- Numerous yellow ulcerations with thin red halos
- Thick walled vesicles on an erythematous base
- GROUPED = hallmark
27
Q
Neonatal Herpes Simplex (4)
A
- Occurs in infants born to mothers with genital Herpes Simplex
- Usually mother is asymptomatic and infant appears normal at birth
- Can present (day 10-11 most common) with
- 1. Skin, eye, mucous membrane (SEM disease)
- 2. Systemic
- 3. CNS disease - Infant progresses to develop sudden onset of fever, lethargy, poor feeding with vesicular lesions, hepatosplenomegaly
28
Q
Neonatal Herpes Simplex Treatment
A
Put on acyclovir!
- If you’re given acyclovir even without having herpes, it gets phosphorylated into the active form and it would be passed out of your body unchanged
- Mis-diagnosis is OK
- Herpes cell has thimadine-kinase which causes phosphorylation of the herpes virus
29
Q
Roseola (7)
A
- Type of Human Herpes Virus 6 and 7
- For HHV 6: incubation of 9-10 days
- Can have gastrointestinal symptoms, respiratory tract signs, post occipital adenopathy
* May have some loose stool
* Clear nasal discharge - Fever without rash
* If given amoxicillin with the fever, can break out into rash and be misdiagnosed for amoxicillin allergy
* #1 reason for misdiagnosed penicillin allergy - Ask what kind of rash it is
* If it is fine, pink truncal rash then it is roseola - # 1 reason for febrile convulsions
- Well-appearing child
- Hemiplegia, aseptic meningitis - RARE
30
Q
Differential Dx for Herpes Viruses (5)
A
- Rubella
- Enterovirus disease
- Lupus
- Atypical measles
- Drug rashes.
31
Q
Mononucelosis Causative Organisms (3)
A
- EBV
- CMV
* CMV mono can look like EBV mono
* EBV titers negative → consider CMV mono
* In inner-cities like Newarks, CMV Mono is very common in daycare center - Adenovirus
32
Q
Mono Epidemiology (3)
A
- Worldwide in distribution
2, By 5 years of age, 70 to 90% of children in poor urban settings or developing countries are seropositive for Epstein–Barr virus.
*Mild symptoms or is subclinical.
- In more affluent social economic groups, symptomatic cases of IM present during adolescence and in young adults
33
Q
Mono Mode of Transmission (4)
A
- Close personal contact (e.g., kissing/saliva).
- Pharyngeal secretions
- Main source of transmission; - 35% household transmission
- Fomite contamination
- Clothing, tables, all non-human type of pick up
- Can shed EBV long after having it
- Stays in B-cell - Shedding is greater when on steroids or immunocompromise
* Up to 50% of patients on immunosuppressive therapy, including those on steroids, shed virus.
34
Q
Mono Incubation Period (3)
A
Infectious mononucleosis virus
- Saliva and blood of clinically ill and asymptomatic infected persons for many months
- Period of communicability is difficult to assess
- Period of incubation is thought to be from 2 to 6 weeks (average 20-30 days).
35
Q
Mono Clinical Signs (9)
A
- Sore throat
- Fever
- Malaise
- Myalgia
- Arthralgia
- Photophobia
- Lymphadenopathy
- Maculopapular rash
- Symptoms are variable and can last up to 2-3 weeks.
36
Q
Mono and Lymph Nodes
A
- Disease of the primary lymphoid tissue and peripheral blood.
- Enlargement of lymphoid tissue: regional lymph nodes, tonsils, spleen, and liver.
- Atypical lymphocytes in peripheral blood
* Not monocytes - Classic sore throat + fever + monocytosis and no atypical lymphocytes → answer is NOT EBV if rapid strep was negative
- Almost all body organs are involved, including but not limited to the lungs, heart, kidneys, adrenals, central nervous system, and skin.
- EBV mono and strep like each other; 25% incidence of having both
* Always use PCN in these cases, not Amox
37
Q
Mono fever
A
<103 degrees lasting 1-3 days is very common
38
Q
Mono Sore Throat (6)
A
- Few days after the fever.
- Painful.
- Tonsils enlarge
- Grayish-colored exudates
- Ulceration, and pseudomembrane formation.
- Palatal Petechiae
39
Q
Mono Lymphadenopathy (4)
A
- Anterior, but especially the posterior cervical nodes
- Any lymphoid tissue can be affected.
- Firm but usually non-tender, and discrete in nature.
- Lymphadenopathy spares the jaw line but can be very severe
* If airway is compromised → admit
* Ex: marked tonsillar hypertrophy
40
Q
Mono Splenomegaly and Hepatomegaly
A
Splenomegaly: Occurs in 50 to 75% of cases. Rupture is rare, must use scratch test
Hepatomegaly
- Common.
- Abnormal liver function tests common
- 5 to 25%clinical hepatitis.
41
Q
Mono Skin Rash (2)
A
- 20% of cases. Can be maculopapular, urticarial, scarlatiniform, hemorrhagic, or nodular.
- Associated with taking amoxicillin and probably represents a form of arteritis or vasculitis.
42
Q
Other Mono Manifestations
A
- Periorbital edema
* Reported in 25% of cases - Myalgia, arthralgia, chest pain, ocular pain, photophobia, conjunctivitis, gingivitis, abdominal pain, diarrhea, cough, pneumonia, rhinitis, epistaxis, bradycardia, aseptic meningitis, Guillain-Barré syndrome, Bell palsy, Reye syndrome, and acute cerebellar ataxia. (less common)
43
Q
Mono Differential Dx (13)
A
- Gram positive alpha-beta hemolytic streptococcal pharyngitis
- Leukemia
- Lymphoreticular malignancies
- Adenoviruses
- Toxoplasmosis
- CMV
- Rubella
- HIV
- Hepatitis
- SLE
- Drug reactions
- Diphtheria
* Very uncommon - Burkitts lymphoma
* Especially if the child is from Africa
44
Q
Mono Diagnostic Testing (5)
A
- WAIT ONE WEEK!
- CBC
* More than 10% atypical lymphocytes and 50% lymphocytosis. - Serological tests.
* Monospot
* Serum heterophile test
- Positive in 80%-90% of infected patients over four years of age.
- Children older than 4 years of age usually must be ill for approximately 2 weeks before seroconverting. - Viral culture
- Epstein–Barr specific core and capsule antibody testing
45
Q
Epstein–Barr specific core and capsule antibody testing (5)
A
- Early antigen: will be the first antigen to be positive
- EBV-IGM: Second antigen that will be positive
* IGM is an acute serology for any antigen - EBV-IGg: As body starts to recover, IGg gets elevated (ex: with hepatitis vaccine)
- EBNA IGM and IGG: Elevated if mono is reactivated
- Test for CMV in patients with Negative EBV serology
* CMV is common in daycares (or from sibling)
46
Q
Mono Complications (5)
A
Rare!
- Splenic rupture, thrombocytopenia, agranulocytosis, hemolytic anemia, orchitis, myocarditis and chronic infectious mononucleosis.
- Can’t do contact sports due to risk of splenic rupture
- Fatal disseminated disease, or B-cell lymphoma, occurs in patients with congenital or acquired cellular immunity deficiencies.
- Burkitt B-cell lymphoma and nasopharyngeal carcinoma are also caused by Epstein–Barr virus; these conditions are more commonly found in Central Africa and Southeast Asia.
- Death from infective mono occurs in approximately 1 out of 3000 cases.
47
Q
Mono Management (5)
A
- Treatment is supportive with adequate fluids and calories.
- Corticosteroids and acyclovir are not recommended for routine disease.
- Acyclovir has little effect.
* Because the virus doesn’t have thiamadine kinase in it - Contact sports and strenuous exercise should be avoided if the patient has hepatosplenomegaly.
- Participation is acceptable after the splenomegaly has resolved.
48
Q
Mono Prevention
A
Persons with a recent history of infectious mononucleosis or an infectious mononucleosis–like disease should not donate blood.
