The epidemiological triad is a classic model used to understand the factors involved in the occurrence and spread of infectious diseases. It consists of three components: 1) The Agent: The causative pathogen (e.g., Giardia lamblia cyst). 2) The Host: The human or animal that harbors the infection. Host factors influencing giardiasis include age (children are more susceptible), immune status, genetics, and behavior (e.g., poor hand hygiene, drinking untreated water). 3) The Environment: All external factors that affect the interaction between agent and host. For giardiasis, environmental factors are crucial: contaminated water supplies, poor sanitation, inadequate sewage disposal, climate (cysts survive better in cool, moist conditions), and socio-economic factors like overcrowding in daycare centers. The model posits that disease occurs when a susceptible host, a virulent agent, and a conducive environment intersect. Interventions aim to break one side of the triangle: e.g., treating water (affecting environment/agent), treating patients (host), or promoting hygiene (host behavior affecting environment).

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Zambia

• loveness Phiri – 801 pts

• Visual Pathway Lesions
• Positive and Negative Symptoms
• Hallucinations and Delusions
• Antipsychotic Medications
• Emergency: Environmental Emergencies