AS and A Level Biology 2 Views 1 Answers
Explain how cholera, malaria, TB and HIV are transmitted
Explain how cholera, malaria, TB and HIV are transmitted
Answer
Here’s an overview of how cholera, malaria, tuberculosis (TB), and HIV are transmitted:
Cholera
- Pathogen: Vibrio cholerae (bacteria)
- Transmission:
- Waterborne: Cholera is primarily transmitted through contaminated water sources. Ingestion of water contaminated with the bacteria—often due to poor sanitation and hygiene—leads to infection.
- Foodborne: Eating food washed with contaminated water or food that has been prepared in unsanitary conditions can also transmit the disease.
Malaria
- Pathogen: Plasmodium species (protozoan parasites)
- Transmission:
- Vector-Borne: Malaria is transmitted through the bite of infected female Anopheles mosquitoes. When the mosquito bites a person, it injects the malaria parasites into the bloodstream, leading to infection.
- Other Routes: Less commonly, malaria can be transmitted through blood transfusions, sharing of needles, or from mother to child during childbirth.
Tuberculosis (TB)
- Pathogen: Mycobacterium tuberculosis (bacteria)
- Transmission:
- Airborne: TB is primarily transmitted through the air when a person with active TB disease coughs, sneezes, or talks, releasing tiny droplets containing the bacteria.
- Close Contact: Prolonged exposure to someone with active TB, especially in enclosed spaces, increases the risk of transmission. It is important to note that TB is not spread through casual contact, such as shaking hands.
Human Immunodeficiency Virus (HIV)
- Pathogen: Human Immunodeficiency Virus (virus)
- Transmission:
- Bloodborne: HIV is transmitted through direct contact with infected blood, such as through sharing needles, transfusions with contaminated blood, or accidental needle sticks.
- Sexual Transmission: Unprotected sexual intercourse with an infected person can lead to transmission through bodily fluids (semen, vaginal fluids).
- Mother-to-Child Transmission: HIV can be transmitted from an infected mother to her child during childbirth or breastfeeding.
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