Cholera, Tuberculosis, and HIV: Causes, Symptoms, and Treatment

Cholera

Pathogen: Vibrio cholerae

Methods of Transmission:

• Foodborne
• Waterborne

Note: 3/4 of infected people may be asymptomatic carriers and pass large numbers of bacteria in their feces.

Global Distribution: Asia, Africa

Incubation Period: 1-5 days

Site of Action: Wall of the small intestine; secretes a toxin called choleragen

Clinical Features:

• Severe diarrhea
• Loss of water and salts
• Weakness

Note: Can be fatal if not treated within 24 hours.

Method of Diagnosis: Microscopic analysis of feces

Annual Incidence Worldwide: 5.5 million

Annual Mortality Worldwide: 120,000

Treatment: Antibiotics

Tuberculosis

Pathogen: Mycobacterium tuberculosis

Transmission:

• Airborne droplets
• Infected meat

Global Distribution: Worldwide

Incubation Period: A few weeks or months

Site of Action:

• Primary infection in lungs
• Secondary infection in lymph nodes, bones

Clinical Features:

• Racking cough
• Coughing blood
• Chest pain
• Sweating

Method of Diagnosis:

• Microscopic examination of sputum for bacteria
• Chest X-ray

Note: 30% of the world population is infected with Tuberculosis without showing any symptoms of the infection. This inactive bacteria does not spread.

Treatment: Antibiotics; long treatment of about 1 year.

Vaccination:

• BCG vaccine
• Mantoux reaction: The antigen is placed in the dermis, and if the body reacts with inflammation, it indicates the presence of defenses against the bacteria.

HIV

HIV destroys T helper lymphocytes. When the number is low, the body is unable to defend itself, leading to infections from opportunistic agents.

Note: AIDS is not a disease but a collection of opportunistic infections associated with HIV.

Transmission: Intimate human contact, such as sexual intercourse and blood donation.

Note: HIV is a slow virus, and after infection, there may not be any symptoms until years later.

Opportunistic Agents: Candida albicans

Treatment: Drug therapy can slow down the onset of AIDS.

Vaccine: Very difficult to develop because the virus changes its surface proteins.

Control by Education: Condoms, femidoms.

Diagnosis: HIV test: Identifies HIV antibodies, which only appear several weeks after infection.