Infectious Disease Flashcards
Fever in Returning Traveller
Differential
Ddx: Malari, typhoid, Mening, Viral Hemorrhagic Fever
It is always important to ask where the patient went, their encounters, immunizations and prophylaxis.
Malaria:
P. Falciparum
P Vivax
Falciparum will usually present within the first two months of being home. and it is the most common
P. Vivax: Can remain dormant for years
Typhoid - Diagnosis
The most sensitive test is blood culture;
Vaccine is 50-70% effective
What is the initial work up for a new immigrant or adopted child?
Cbc and diff Liver Serologies: HBV, HCV, HIV, Syph TB and CXR Stool O and P U/A
What is a fever of unknown origin?
Classic: 2-3 weeks of fever and 3 or more outpatient visits OR 3 days in hospital with investigations
Nosocomial: Not present at admission; unsure with 3 days of investigations and 2 days of incubation
Neutropenia: 3 days of investigations, 2 days of incubation
HIV Associated: 4 weeks as outpatient or 3 days as inpatient with investigations and 2 days of cultures.
Congenital CMV
Characteristics: CNS, SKIN and EYES
Treatment: when and what
Microcephally, IUGR, calcifications and seizures; SNHL
Skin: Petichiae, purpura and jaundice
Eyes: Chorioretinitis, strabismus and optic atrophy
If confirmed CMV infection with chorioretinitis, Brain invovlement or SNHL then Gancyclovir IV x 6 weeks.
Need to ensure you are monitoring for Neutropenia.
Congenital Syphilis
Characteristics: Premature, IUGR, FTT HSM
Snuffles, Hands and soles have copper colour and desquamation.
Eyes: Salt and Pepper chorioretinitis
Bones- have bony changes
Late Changes: CNS manifestations, saddle nose, hutchinson teeth, mullberry molars and saber shins
Treatment and testing in suspected congenital Syphilis
Maternal Adequate treatment AND four fold drop: Test baby: If negative, follow up in 18 monts (RPR)
Inadequate treatment, unknown, not a four fold drop, infant rpr > mom: Full work up and treatment.
IV Crystalline Pen G 10-14 days
Congenital Toxoplasmosis
Triad: Hydrocephalus, calcifications and chorioretinitis
If the mom is infected in the first and second trimester the baby is going to be symptomatic; if in the third trimester, only likely to have chorioretinitis.
Treatment: Pyrimethamine + Sulfadiazine + leucovirin x 12 months
Steroids for eye disease
Intrauterine Varicella
Cicatrical Scars: There is new tissue forming that will develop into a scar. NO crossing midline for scars.
Findings: Scaring, hypoplasic limbs, microopthalmia, cataracts, chorioretinitis, seizures and microcephally.
Pregnancy Exposure to Varicella
Exposure =
- House hold exposure OR
- Face to Face x 5 minutes OR
- 15 minute indoor exposure
If mom Unsure or NO VZV History:
Stat IgG Serology.
Negative Result: VZIG in 96 hours
Acyclovir if Chickenpox develops
Parvo B19
If mom is exposed then you need to test IgM and IgG.
If negative, repeat in 2 weeks.
If IgM + and IgG negative - weekly ultrasounds x 12 weeks to monitor for the development of Non immune hydrops
Congenital Rubella Syndrome
IUGR, Blueberry Muffin Rash, HSM, Cataracts, Cardiac (PDA), SNHL and Bony Lesions
Presentations of the following:
Pertonsillar abscess
RPA
PTA: Trismus, muffled voice, uvula to the contralateral side
Lateral Pharyngeal Abscess: There is swelling under the mandible
RPA: infancy and early childhood. Insidious onset with torticollis
Secondary Infections with Varicella
Pneumonia
Nec Fasc - S. pyogenes and anaerobes
Chemoprophylaxis for GAS
If someone is exposed to SEVERE GAS infection then they require prophylaxis.
Close contact includes:
Household (>4 hours per day >20 hours per week); share bed, mucosal contact or sexual relations
Severe Disease: TSS, necrosis, meningitis, pneumonia or other life threatening conditions.
Lyme Disease
Caused by: Borrelia Burgdefori
There are three stages:
1. Early localized disease: erythema migrans and sysetmic (fever, myalgia and neck stiffness)
2. Early Disseminated: multiple EM, facial palsy and carditis
3. Late Disease: pauciarticular arthritis and polyneuropathy
Treatment: IV if menigitis or carditis
Amoxicillin or cefuroxime or doxy (>8 years)
Prevention of Ticks
Clothing
Deet: <12 years 10%; >12 years 30%
Icaridan: 6 months - 12 years
Tuberculosis
What are the three different types of TB
TB Exposure: Asymptomatic, TST - and CXR -
Infection (latent): Asymptomatic, Normal CXR and + TST
Disease: Disease manifestations or abnormal cxr
TB Testing:
Positive Test
False+
False -
Positive Test:
0-4 mm: <5 years of age, high risk
4-9 mm: all others
>10 mm: Malnutrition, DM, Heme malignancy or TST conversion
False Positive: Active Disease, atypical mycobacterium, BCG vaccine
False negative: Improper technique, Severe disease, immunodeficiency, steroids
How do you diagnosis TB
TST
Interferon Gamma release assay (improved specificity but same sensitivity)
Chest Xray
Gastric Aspirate - x 3 (first thing in the morning)
Micro - acid fast, DNA
Bronchialveolar lavage
TB Treatment
Latent TB: INH x 9 months
TB Disease: Start with 4 (RIPE) if sensitive then can decrease to 3; need 2 months of 3-4 then finish with Rifampin and INH
Side Effects of TB Treatment
Rifampin: Liver, skin, memory and drug interactions. Orange urine
Isoniazid: Hepatotoxicity and neuropathy
Pyrazinamide: Increased urate
Ethobutamol: optic neuropathy
In pregnancy and malnuourished patients give B6
vitamin D in children
HIV - in pregnancy
Timing of Transmission occurs mainly during labor and deliver
Prevention: Triple therapy in 2nd trimester
IV AZT during labor then AZT x 6 weeks in newborn.
If viral load >1000 - C/S
The Vaccine Types: Live Attenuated Inactivated Recombinant Conjugage Polysaccharide Toxoid
Live: LAIV, Varicella, MMR, Yellow Fever, Rota, BCG and Japanese Encephalitis
Note: MMR doesn’t cause problems in pregnancy.
Inactivated: IPV, Flu, Hep A, Rabies Typhoid
Recombinant: HPV, Hep B
Conjugate: Men, Pneumo and HiB
Polysacchardie: Pneumo 23 and Men B
Toxoid: Tetanus and diptheria
Chemoprophylaxis for Meningits
Rifampin (go to) Cipro Ceftriaxone (pregnancy) If non immunized, then need to be. Give regardless of immunization status.
Risk Factors for invasive pneumococcal disease
Asplenia Functional Asplenia Cochlear implants CSF Leak Immunosuppression
At what age do children need 2 flu vaccines?
Who can not get live attenuated
<9 years of age
b. <2 years of age; severe asthma (steroids in the last 7 days or on high dose ICS), pregnancy, chronic ASA or immunocompromised
Hepatitis A post exposure
Less than 1 year of age Hep A Ig; > 1 year of age Vaccine
Who gets VZIG (5)
Immunocompromised and no vaccine history
Susceptible pregnant women
newborn infant of mom who had 5 days before or 2 days after
Hospitalized >28weeks and mom did not have vaccine/infection
Hospitalized <28 weeks or <1000g regardless
Contraindications to vaccines
Anaphylaxis to any of the components Immunodeficiency- live Chemo in last year - live IVIG - 11 months live Pregnancy - live Active TB: no mmr or varicella
