Infectious Disease

Question 1

Treatment for opportunistic HIV infection with a CD4 count of 750-1,500

Answer 1

normal disease

Question 2

Treatment for opportunistic HIV infection with a CD4 count of >500

Answer 2

lymphadenopathy

Question 3

Treatment for opportunistic HIV infection with a CD4 count of 500 to 200

Answer 3

tuberculosis, Kaposi sarcoma, thrush, lymphoma, zoster
primary prophylaxis: INH
secondary prophylaxis: Rifampin

Question 4

Treatment for opportunistic HIV infection with a CD4 count of <200

Answer 4

PJP, Histoplasmosis
primary prophylaxis: TMP/SMC, Itraconazole
secondary prophylaxis: Dapsone, Amphotericin B

Question 5

Treatment for opportunistic HIV infection with a CD4 count of < 100

Answer 5

Toxoplasmosis, cryptococcus
primary prophylaxis: TMP/SMX, fluconazole
secondary prophylaxis: primethamine + sulfadiazine + folinic acid, Amphotericin B

Question 6

Treatment for opportunistic HIV infection with a CD4 count of < 50

Answer 6

MAC, CMV retinitis
primary prophylaxis: valganciclovir
secondary prophylaxis: ganciclovir + foscarnet

Question 7

What is the post exposure prophylaxis for HIV?

Answer 7

• PEP should be started within 72 hours of exposure
• the chances of contracting HIV from a needlestick injury involving a patient with known HIV is <0.3%
• testing should be done on the worker and the patient - resting at 6 week, 3 and 6 months
• can take antiretrovirals - combo therapy with drugs from different classes should be continued for at least 4 weeks, full course PEP reduces the chance of HIV transmission by up to 70%

Question 8

What is the presentation of influenza?

Answer 8

fevers, chills, coryza, myalgia

-rapid antigen test can be performed in the clinic

Question 9

What is the tx of influenza?

Answer 9

• supportive therapy
• Zanamivir and Oseltamivir (Tamiflu) both treat influenza A and B must be given within 48 hours
• amantadine and rimantadine treat only influenza A
• annual vaccine for everyone 6 months and older unless contrainidicated

Question 10

What is lyme disease?

Answer 10

caused by Borrelia burgdorferi (gram-negative spirochete) that is spread by lodes (deer) tick

Question 11

What are the characteristics of lyme disease?

Answer 11

early localized: usually 7-10 days after bite - erythema migrans rash “bullseye”

• early disseminated: 1-12 weeks after bite - musculoskeletal, flu-like syndrome, consisting of malaise, fatigue, chills, fever, headahce, stiff neck, myalgias, and arthralgias that may last for weeks, cardiac (AV block)
• late disease: persistent synovitis and arthritis
• ELISA testing will be positive by 3rd week

Question 12

What is the tx of Lyme disease?

Answer 12

treat with doxycycline or amoxicillin (10-21 days) is started immediately after diagnosis
-prophylaxis: docycycline 200 mg x 1 dose within 72 hours if lxodes tick

Question 13

What is the presentation of meningitis?

Answer 13

fever, headache, stiff neck, petechiae (especially N. meningitidis)

• unlike encephalitis no mental status change
• N.meningitidis (most likely if pt. has a rash)

Question 14

What is the physical exam for meningitis?

Answer 14

• Kernig sign - knee extension cuases pain in neck

- Brudzinski sign - leg raise when bend neck

Question 15

What is the etiolology of Bacterial meningitis?

Answer 15

• Neonate: E.coli (gram-negative rods) and S. agalactiae (group B streptococcus)
• Most people: S. pneumoniae (gram-postive diplococci), N. meningitidis (gram-negative diplococci)
• Immunocompromised: cryptococcus neoformans (diagnosis: India ink stain)

Question 16

What does the spinal tap of meningitis show?

Answer 16

increased opening pressure, decreased glucose, increase WBC (neutrophils), increased protein

Question 17

What is the CSF finding on lumbar puncture for meningitis?

Answer 17

• bacterial: increase protein, decrease glucose (baceria love to eat glucose)
• viral: no specific characteristics but may have lymphocytes
• make sure the patient does not have increased intrcranial pressure prior to LP check fo papilledmea, get a CT scan if you are unsure if there is swelling in the brain (risks include age > 60, immunocompromised, AMS, focal neuro finding, or papilledema)

Question 18

What is the tx for for meningitis?

Answer 18

Dexamethasone + Empiric IV antibiotics (cephalosporin, vancomycin, penicillins)

Question 19

What are the characterisitcs of aseptic meningits?

Answer 19

• etiology: enterovirus, HSV, TB, fungus
• spinal tap - normal pressure, increase WBC (lymphocytes)
• treatment: symptomatic or IV acyclovir for HSV

Question 20

What is mononucleosis?

Answer 20

Epstein Barr mononucleosis is a viral illness characterized by a classic triad of fever + lymphadenopathy + pharyngitis

Question 21

What are the characteristics of mononucleosis?

Answer 21

• diagnosed with postive heterophile antibody screen (monospot) - may not appear early in the illness (positive within 4 weeks)
• atypical lymphocytes with enlarged nuclei and prominent nucleoli
• a maculopapular rash develops in 80% of patients treated with ampicillin
• left upper quadrant pain secondary to splenomegaly and are at risk for splenic rupture - athletes should avoid vigorous sports for at least the first three to four weeks of the illness

Question 22

What is the tx of mononucleosis?

Answer 22

supportive

Question 23

What is salmonellosis?

Answer 23

diarrhea from poultry or pork: Salmonella
-although there are many types of Salmonella, they can be divided intwo two broad categories: those that cause typhoid and enteric fever and those that primarily induce gastroenteritis

Question 24

What are the characteristics of Enteric fever?

Answer 24

• salmonella typhi
• a flu-like bacterial infectoin characterized by fever, GI symptoms, and headache
• transmitted via consumption of fecally contaminatied food or water
• GI symptoms may be marked constipation or “pea soup diarrhea”
• rose spots may be present (2-3 mm papule on trunk usually)
• more common in the developing world (usually immigration cases)

Question 25

What are the characteristics of gastroenteritis?

Answer 25

salmonella typhimurium, enteritidis, and newport

• results from improperly handled food that has been contaminated by animal or human fecal material
• it is estimated that 1 in 10,000 egg yolks is infected with salmonella enteritidis

Question 26

What is the tx of salmonellosis?

Answer 26

ceftriaxone or other medications based on the sensitivity

Question 27

What is shigellosis?

Answer 27

gram-negative bacteria shigella that results in watery diarrhea or dysentery (the frequent and often painful passage of small amounts of stool that contains blood, pus, and mucus)

Question 28

What are the characteristics of shigellosis?

Answer 28

• the illness starts abruptly with diarrhea, lower abdominal cramps, and tenesmus accompanied by fever, chills, anorexia, headache and malaise
• in the US, shigellosis predominantly affects children and is often spread in areas with crowded conditions (like daycare centers)
• transmission is via direct person-to-person contact and contaminated food and water
• stools are loose and mixed with blood and mucus, the abdomen is tender; dehydration is common
• the stool is positive for leukocytes and red blood cells; culture yields Shigella pp

Question 29

What is the tx of Shigellosis?

Answer 29

treat with TMP-SMX or ciprofloxacin