Master Comparison Table
| Disease | Pathogen | Category | Vector/Transmission | Key Symptoms | Diagnostic Test |
|---|---|---|---|---|---|
| Typhoid | Salmonella typhi | Bacterium | Contaminated food/water | Sustained fever, intestinal perforation | Widal test |
| Pneumonia | Streptococcus pneumoniae + H. influenzae | Bacterium | Respiratory droplets | Fluid-filled alveoli, chest pain, breathlessness | Chest X-ray, sputum culture |
| Common cold | Rhinovirus | Virus | Droplets, direct contact | Nasal congestion, sore throat, mild fever | Clinical symptoms |
| AIDS | HIV (retrovirus) | Virus | Sexual contact, blood, needles, mother-to-child | CD4+ T-cell destruction, immunodeficiency, opportunistic infections | ELISA (screen) → Western blot (confirm) |
| Malaria | Plasmodium vivax/falciparum | Protozoan | Female Anopheles mosquito | Cyclic fever (48h), chills, haemozoin in RBCs | Blood smear, RDT |
| Amoebiasis | Entamoeba histolytica | Protozoan | Contaminated food/water | Abdominal cramps, bloody mucoid diarrhoea | Stool microscopy |
| Ascariasis | Ascaris lumbricoides | Helminth (nematode) | Contaminated soil/food | Intestinal blockage, muscular pain, Loeffler's syndrome | Stool examination |
| Filariasis | Wuchereria bancrofti/malayi | Helminth (nematode) | Culex mosquito | Lymphatic swelling, elephantiasis | Night blood smear (microfilariae) |
Immunity Comparison
| Feature | Active Natural | Active Artificial | Passive Natural | Passive Artificial |
|---|---|---|---|---|
| How acquired | Natural infection | Vaccination | Mother → child | Antiserum injection |
| Antibody source | Self-produced | Self-produced | Maternal (preformed) | External (preformed) |
| Onset | Slow (days-weeks) | Slow (days-weeks) | Immediate (present at birth) | Immediate |
| Duration | Long-lasting (years) | Long-lasting (years) | Short-lived (3-6 months) | Short-lived (weeks) |
| Memory cells | YES | YES | NO | NO |
| Example | Recovery from measles | MMR vaccine | IgG via placenta; IgA via colostrum | Anti-tetanus serum |
Drug Categories Comparison
| Drug | Category | Source Plant | CNS Effect | Primary Organ Affected |
|---|---|---|---|---|
| Heroin | Opioid | Papaver somniferum | CNS depressant | Brain, respiratory system |
| Cocaine | Coca alkaloid | Erythroxylum coca | CNS stimulant | Brain (dopamine pathway), nasal septum |
| Marijuana/Hashish | Cannabinoid | Cannabis sativa | Mixed/psychoactive | Cardiovascular system, brain |
| Nicotine | Tobacco alkaloid | Nicotiana tabacum | Stimulant (partially) | Lungs (cancer, emphysema), heart |
| Alcohol | Depressant | Fermentation | CNS depressant | Liver (cirrhosis), brain |