Global Health and Epidemiology

Question 1

4 important things about ELISA

Answer 1

1. Excellent sensitivity, but limited specificity
2. In LOW incidence settings, most positives are FALSE positive
3. Technically simpler, automatable, obective readout
4. Needs a “reader” that can be simple

Question 2

Western blot assays important considerations

Answer 2

1. Limited sensitivity, but good specificity
2. Can improve sensitivity with radio label
3. Interpreation adds subjective element
4. Requires MULTIPLE bands to be positive
   *Complex and needs power sources etc

Question 3

What are the considerations of antigen detection assays

Answer 3

1. decent sensitivity when antigen abundant , good specificity
2. Amenabe to POC Formats
3. Robust with no machinery needed
4. Small element of subjectivity in reading hte result

Question 4

PCR assays considerations

Answer 4

1. has good sensitivity and specificity
2. assay can be over sensitive
3. Subject to sampling error
4. Needs sophisticated equipment

Question 5

What is ELISA

Answer 5

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)

Question 6

What is western blot?

Answer 6

Lab technique used to detect specific protein in a blood or tissue sample; gel electrophoresis to separate the samples proteins

Question 7

Pt with ELISA + Schisto and IgG4 negative suggests

Answer 7

No acute infection likely (adult worms are likely gone)

Question 8

What does a LIVE schisto embryo look like?

Answer 8

Flame cells

Question 9

34yoM immigrant with RUQ pain,Stool + E histolytica cyst. Positive amoebiasis serology. Had an ameobic abscess at 20 years old.

Answer 9

Does NOT have active disease-just because the antigen is positive, can be positive for a long time

Question 10

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.

Answer 10

Treat-tropical splenomegaly, follow up PCR overtime

Question 11

Patient with eye swelling after eating goose, duck, seal, walrus, caribou and bear.

Answer 11

Trichinella -treat CLINICALLY. Do not rely on serology!

Question 12

in the absence of thermoregulation, how quickly will you die

Answer 12

4 hours doing nothing, 20-30 minutes if you are working out

Question 13

heat stroke Tc definition

Answer 13

40-47, usually CNS dysfunction

Question 14

tx for heat stroke

Answer 14

rehydration, cooling (bring skin to 30degrees), spray tepid water, benzos, ice water immersion

Question 15

5 Ds of antibiotic prescribing

Answer 15

Right diagnosis, right drug, right dose, right duration, de-escalate

Question 16

What is one vaccine you should give to all adult immigrants without immunization records

Answer 16

MMR(at least 1 dose)
Tdap (3 doses)

Question 17

Which immigrants need varicella vaccine?

Answer 17

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

Question 18

Who do you vaccinate:
-HBcAb HBsAB detected?
-HBcAb not detected, HBsAb Detected?
or
-HBsAb not detected, HBcAb not detected ?

Answer 18

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

Question 19

What should we screen immigrants from Africa?

Answer 19

Strongy, Malaria, HIV, Schisto, Hep B, LTBI

Question 20

What should we screen for in immigrants from Asia

Answer 20

HIV/AIDs, Strongy, Hepatitic C, Hepatitis B, LTBI

Question 21

What are we screening for in immigrants from latin america

Answer 21

hepatitis B, HIV/AIDs, Neurocysticercosis, Strongy, Chagas, LTBI

Question 22

Highest risks of VFRs with fever?

Answer 22

Malaria, Typhoid, Hepatitis A

Question 23

Macronutrients for malnourished patients

Answer 23

carbohydrates, fat, protein

Question 24

Minimum ration of energy requirements in famine/refuge aid

Answer 24

2100kcal/person/day

Question 25

If someone is in a hypothermic region, what to consider iwth nutrition:

Answer 25

add 100kcal for every 5 degrees under 20 degrees C

Question 26

What is the GLIM Diagnostic Scheme

Answer 26

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

Question 27

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

Answer 27

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

Question 28

Patient with nutritional deficiency, has wasting and perpheral nerve damage, loss of tendon reflexes, loss of muscle function

Answer 28

Dry Beri Beri-thiamine deficiency

Question 29

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?

Answer 29

Niacin-Pellagra, Diarrhea, dermatitis, dementia, death (Likely 2/2 isoniazid which interferes with niacin metabolism)

Question 30

32year old zambian woman with shortness of breath, lower extr edema, has TB and being treated, irritable. What nutritional deficiency?

Answer 30

Thiamine-wet beriberi , likely 2/2 her diet

Question 31

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.

Answer 31

Vitamin A

Question 32

Side effects of Vitamin A Deficiency

Answer 32

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