Infectious Diseases

Question 1

What is a Jarisch-Herxheimer reaction?

Answer 1

A Jarisch–Herxheimer reaction is a reaction to endotoxin-like products released by the death of harmful microorganisms within the body during antibiotic treatment.
Spirochete Infections: Syphillis, Lyme, Leptospirosis
It comprises part of what is known as sepsis and occurs after initiation of antibacterials when treating Gram negative bacterial infections such as E. Coli, louse-borne infections and in tick-borne infections. It usually manifests in 1–3 hours after the first dose of antibiotics as fever, chills, rigor, hypotension, headache, tachycardia, hyperventilation, vasodilation with flushing, myalgia (muscle pain), exacerbation of skin lesions and anxiety. The intensity of the reaction indicates the severity of inflammation. Reaction commonly occurs within two hours of drug administration, but is usually self-limiting. It is observed in 50% of patients with primary syphilis and about 90% of patients with secondary syphilis

Question 2

What is the treatment for Cerebral Toxoplasmosis?

Answer 2

Sulphadiazine & Pyrimethamine

Question 3

What is Epidemic typhus?

Answer 3

Epidemic typhus is a form of typhus so named because the disease often causes epidemics following wars and natural disasters. The causative organism is Rickettsia prowazekii, transmitted by the human body louse (Pediculus humanus corporis)

Symptoms include severe headache, a sustained high fever, cough, rash, severe muscle pain, chills, falling blood pressure, stupor, sensitivity to light, delirium and death. A rash begins on the chest about five days after the fever appears, and spreads to the trunk and extremities. A symptom common to all forms of typhus is a fever which may reach 39 °C (102 °F)
…sort of similar presentation to Meningitis?

Question 4

Which antiretroviral is associated with lipoatrophy

Answer 4

Stavudine (can manifest as muscle wasting and high blood lipids)

Question 5

Which one of these is a live attenuated vaccine:

1. Diphtheria
2. Hep A
3. Tetanus
4. Yellow fever
5. Inactivated Influenza

Answer 5

Yellow fever

Question 6

What is/are the organism(s) and transmission vector of Brucellosis

Answer 6

1. Brucella abortus - cattle
2. Brucella melitensis - goats/sheep
3. Brucella canis - dogs
4. Brucella suis - swine/rodents
   All G- coccobacilli, non-motile, non-spore forming, strict aerobe, facultate intracellular, urease, catalase positive.
   The bacteria can enter through skin lesions, mucus membranes, inhalation, or ingestion of contaminated animal products e.g. unpasteurised milk, cheese, undercooked meat.

Question 7

What are the symptoms of Brucellosis

Answer 7

The symptoms are like those associated with many other febrile diseases, but with emphasis on muscular pain and night sweats. The duration of the disease can vary from a few weeks to many months or even years.

In the first stage of the disease, bacteremia occurs and leads to the classic triad of undulant fevers, sweating (often with characteristic foul, moldy smell sometimes likened to wet hay), and migratory arthralgia and myalgia (joint and muscle pain).
Blood tests characteristically reveal a low number of white blood cells and red blood cells, show some elevation of liver enzymes such as aspartate aminotransferase and alanine aminotransferase, and demonstrate positive Bengal rose and Huddleston reactions. Gastrointestinal symptoms occur in 70% of cases and include nausea, vomiting, decreased appetite, unintentional weight loss, abdominal pain, constipation, diarrhea, an enlarged liver, liver inflammation, liver abscess, and an enlarged spleen.

On exam there may be:

• Hepatomegaly,
• Splenomegaly,
• Lymphadenopathy

Question 8

How is Brucellosis treated

Answer 8

Doxycycline + Rifampin for 6 weeks

Question 9

What organism causes Leshminasis and what is its transmission vector

Answer 9

Leshmania donovani

Sandfly

Question 10

What illnesses can Aedes mosquitos transmit?

Answer 10

Chikungunya virus
Zika virus
Dengue fever
Yellow fever

Question 11

What is the most common opportunistic eye disease (infection) in HIV patients?

Answer 11

CMV retinitis - presents with floaters, no pain

Question 12

Name infections related to acute pancreatitis

Answer 12

Coxsackie, mumps, CMV, HIV, toxoplasma (rubella isn’t)

Question 13

What is the Post-Exposure Prophylaxis (PEP) of high risk HIV exposures (e.g. needle stick)?

Answer 13

Truvada (Tenofovir + Emtricitabine) + Raltegravir

Question 14

What is the mechanism by which cholera leads to fluid loss?

Answer 14

GM1 agonism (on small intestine mucosa cells).

Question 15

What are the pathogens associated with Lyme disease?

Answer 15

1. Borellia Burgdorferi (U.S.)
2. Borellia gariini (Europe)
3. Borellia afzelii (Europe)
   Bonus: Borellia Mayonii
   All spirochetes

Question 16

What is Lyme disease? How is it treated?

Answer 16

Lyme disease, also known as Lyme borreliosis, is an infectious disease caused by the Borrelia bacterium which is spread by ticks.
The most common sign of infection is an expanding area of redness on the skin, known as erythema migrans, that appears at the site of the tick bite about a week after it occurred. The rash is typically neither itchy nor painful.[1] Approximately 70–80% of infected people develop a rash.
Other early symptoms may include fever, headache and tiredness. If untreated, symptoms may include loss of the ability to move one or both sides of the face, joint pains, severe headaches with neck stiffness, or heart palpitations, among others.
Months to years later, repeated episodes of joint pain and swelling may occur. Occasionally, people develop shooting pains or tingling in their arms and legs. Despite appropriate treatment, about 10 to 20% of people develop joint pains, memory problems, and tiredness for at least six months.

Treatment: Doxycycline