Infectious diseases and antibiotics
Cholera (bacterium Vibrio cholerae): contaminated water; toxin causes severe diarrhoea; controlled by clean water, sanitation, oral rehydration. Malaria (Plasmodium, a protoctist): spread by female Anopheles mosquitoes; controlled by nets, insecticides, drugs, draining water. Tuberculosis (Mycobacterium tuberculosis): airborne droplets; BCG vaccine, long antibiotic courses, contact tracing. Measles (virus): droplets; MMR vaccine. HIV/AIDS (retrovirus): body fluids; destroys T-helper cells; antiretroviral drugs, condoms, screening. Antibiotics target features of bacteria absent in human cells; penicillin inhibits enzymes building peptidoglycan cross-links, so cells burst by osmosis. Antibiotics don't affect viruses. Resistance arises by random mutation and spreads by natural selection and plasmid transfer, worsened by overuse and unfinished courses.
≈ 45 min