Water-borne and Food-borne: Pathogens like are egested in faeces and contaminate water supplies. Transmission occurs when uninfected individuals ingest this contaminated water or food, often due to inadequate sewage treatment.
Vector-borne: Some pathogens require an intermediate organism, known as a vector, to move between hosts. For example, the parasite is transmitted via the bite of an infected female Anopheles mosquito, which acts as a biological vehicle.
Airborne Droplets: Respiratory pathogens, such as , are expelled in tiny liquid droplets when an infected person coughs or sneezes. These droplets remain suspended in the air and are inhaled by others, making overcrowded conditions a high-risk factor.
Direct Fluid Exchange: Certain viruses, like HIV, are fragile and cannot survive outside the body. They require the direct exchange of body fluids (blood, semen, or breast milk) through activities like sexual contact, needle sharing, or childbirth.
| Feature | Infectious Disease | Non-Infectious Disease |
|---|---|---|
| Cause | Pathogenic organisms (bacteria, viruses, etc.) | Genetics, lifestyle, or environmental factors |
| Transmission | Can be spread between individuals | Cannot be passed from person to person |
| Examples | Cholera, Malaria, TB, HIV/AIDS | Lung cancer, Sickle cell anemia, Diabetes |
Bacterial vs. Viral Pathogens: Bacteria are single-celled prokaryotic organisms that can often be treated with antibiotics, whereas viruses are non-living genetic entities that require host cells to replicate and are unaffected by antibiotics.
Direct vs. Indirect Transmission: Direct transmission involves physical contact or fluid exchange, while indirect transmission involves an intermediary such as contaminated water, air, or an animal vector.
Identify the Pathogen Type: Always double-check if a disease is caused by a bacterium, virus, or protist. For instance, students often mistake Malaria for a viral disease, but it is caused by the protoctist .
Link Transmission to Prevention: When asked for control methods, look at the transmission route. If it is water-borne, suggest sanitation; if it is airborne, suggest reducing overcrowding or improving ventilation.
Social and Economic Context: Be prepared to explain why certain diseases are more prevalent in developing countries. Focus on the lack of infrastructure, high costs of treatment, and the impact of natural disasters on sanitation systems.
Precision in Terminology: Use terms like 'vector' for malaria and 'droplet infection' for TB. Avoid vague terms like 'germs' and instead specify the pathogen name where possible.
