Global Health and Epidemiology Flashcards
4 important things about ELISA
- Excellent sensitivity, but limited specificity
- In LOW incidence settings, most positives are FALSE positive
- Technically simpler, automatable, obective readout
- Needs a “reader” that can be simple
Western blot assays important considerations
- Limited sensitivity, but good specificity
- Can improve sensitivity with radio label
- Interpreation adds subjective element
- Requires MULTIPLE bands to be positive
*Complex and needs power sources etc
What are the considerations of antigen detection assays
- decent sensitivity when antigen abundant , good specificity
- Amenabe to POC Formats
- Robust with no machinery needed
- Small element of subjectivity in reading hte result
PCR assays considerations
- has good sensitivity and specificity
- assay can be over sensitive
- Subject to sampling error
- Needs sophisticated equipment
What is ELISA
Enzyme linked immunosorbent assay: A plate based assay technique for detecting and quantifying soluble substances such as peptides, proteins, antibodies, hormones; (i.e. coat the plate with Ag, Wash, Add test antibody, Wash, add conjugate, wash, add substrate, and develop the plate)
What is western blot?
Lab technique used to detect specific protein in a blood or tissue sample; gel electrophoresis to separate the samples proteins
Pt with ELISA + Schisto and IgG4 negative suggests
No acute infection likely (adult worms are likely gone)
What does a LIVE schisto embryo look like?
Flame cells
34yoM immigrant with RUQ pain,Stool + E histolytica cyst. Positive amoebiasis serology. Had an ameobic abscess at 20 years old.
Does NOT have active disease-just because the antigen is positive, can be positive for a long time
48yoM presents with low grade fever and fatigue, Has had malaria 3 times, has been in endemic malaria areas. Malaria smear and antigen detection is NEGATIVE. PCR was positive.
Treat-tropical splenomegaly, follow up PCR overtime
Patient with eye swelling after eating goose, duck, seal, walrus, caribou and bear.
Trichinella -treat CLINICALLY. Do not rely on serology!
in the absence of thermoregulation, how quickly will you die
4 hours doing nothing, 20-30 minutes if you are working out
heat stroke Tc definition
40-47, usually CNS dysfunction
tx for heat stroke
rehydration, cooling (bring skin to 30degrees), spray tepid water, benzos, ice water immersion
5 Ds of antibiotic prescribing
Right diagnosis, right drug, right dose, right duration, de-escalate
What is one vaccine you should give to all adult immigrants without immunization records
MMR(at least 1 dose)
Tdap (3 doses)
Which immigrants need varicella vaccine?
Vaccinate all immigrant children <13 of age with varicella vaccine without prior serological testing.
Screen all immigrants and refugees from Tropical Countries >13 years of age for serum varicella Abs
Who do you vaccinate:
-HBcAb HBsAB detected?
-HBcAb not detected, HBsAb Detected?
or
-HBsAb not detected, HBcAb not detected ?
HBcAb + HBsAb + –>they have had a previous infection, no further action required
HBcAb not detected, but the HBsAb is detected–>They are immune
HBsAb and HBcAb not detected? *They need immunization
What should we screen immigrants from Africa?
Strongy, Malaria, HIV, Schisto, Hep B, LTBI
What should we screen for in immigrants from Asia
HIV/AIDs, Strongy, Hepatitic C, Hepatitis B, LTBI
What are we screening for in immigrants from latin america
hepatitis B, HIV/AIDs, Neurocysticercosis, Strongy, Chagas, LTBI
Highest risks of VFRs with fever?
Malaria, Typhoid, Hepatitis A
Macronutrients for malnourished patients
carbohydrates, fat, protein
Minimum ration of energy requirements in famine/refuge aid
2100kcal/person/day
If someone is in a hypothermic region, what to consider iwth nutrition:
add 100kcal for every 5 degrees under 20 degrees C
What is the GLIM Diagnostic Scheme
Risk screening (are they at risk for malnutrition?) –>Diagnostic assessment (Phenotypic or etiologic) ->Diagnosis (meets criteria for malnutrition with 1 phenotypic and 1 etiological) –>determine severity of the malnutrition
This is a 32yo Zambian man who presents with 2 weeks diarrhea. Height 1.65m (65 in), current weight 51.4 kg (previously 65kg), BMI 18. Use GLIM Criteria
Phenytoypic:
Weight loss >5% in 6 months or weight loss >10% in >6 months (YES)
Low BMI <20 if <70 years old (YES)
Etiological:
<50% of energy requiremetns for 1 week or reduced intake in general for >2 weeks or GI impacts ?
Inflammation: is there acute or chronic?
Meets phenotypical and etiological criteria here (lost 21% of body weight, low body weight, diarrhea): Meets severe deficit
Patient with nutritional deficiency, has wasting and perpheral nerve damage, loss of tendon reflexes, loss of muscle function
Dry Beri Beri-thiamine deficiency
30 year old zambian woman with skin rash in sun exposed areas, eats nshima, vegetables. Recently treated for LTBI Has Some dementia like symptoms and diarrhea. What nutritional deficiency?
Niacin-Pellagra, Diarrhea, dermatitis, dementia, death (Likely 2/2 isoniazid which interferes with niacin metabolism)
32year old zambian woman with shortness of breath, lower extr edema, has TB and being treated, irritable. What nutritional deficiency?
Thiamine-wet beriberi , likely 2/2 her diet
10 year old girl, gradual weight loss, brought in because everything hurt. Has spots in her eyes, mouth ulcers. Eats Nshima, meat sometimes, ground nuts.
Vitamin A
Side effects of Vitamin A Deficiency
kidney stones, anemia, cessation of bone growth, painful joints, night blindness, keratinization; Xeropthalmia (dry cornea, spots on the eyes);
*Barriers to absorption: low at diet, CKD
