Prevention of infectious and parasitic diseases Dr. Wasantha Gunathunga Department of Community Medicine

Levels of prevention Primary Secondary Tertiary H- nutr, imm

Host Age Sex Poor nutrition Habits HIV Immunity - BCG

Host Age Sex Poor nutrition Habits HIV Immunity - BCG Age : Old age (eg. TB) Infancy(eg.diarrhoea) Reproductive age (HIV) Sex: Male female

Host Age Sex Poor nutrition Habits HIV Immunity - BCG Poor nutrition Proper infant and child feeding Nutrition during illness Nutrition in special groups Proper feeding of senior citizens

Host Age Sex Poor nutrition Habits HIV Immunity - BCG Habits Prevention of substance abuse Prevention of risk sexual behaviour Hygiene Other

Host Age Sex Poor nutrition Habits HIV Immunity - BCG Prevention of HIV will prevent many other infections Immunity –by vaccinations

Agent Prevent drug resistance -Tubercle bacillus Not giving opportunity Look for new forms – mutations, eg. SARS

Environment Manage overcrowding Recognize occupational exposure Improve domestic ventilation public transport Prevent antibiotic residues in food Treat open cases

secondary prevention Surveillance Screening Complete treatment Defaulter tracing

Surveillance Epidemiological surveillance is the continuous scrutiny of factors that determine the occurrence and distribution of diseases or other conditions of ill health. It includes systematic collection, analysis, interpretation and distribution of relevant data for action.

Approaches of prevention Population approach High risk approach

Control Elimination Eradication

Disease Control The disease ‘agent is allowed to persist in the environment The disease ceases to become a public health problem A state of equilibrium Disease control involves activities of primary prevention and secondary prevention

Elimination Interruption of disease transmission in the community e.g. Diphtheria

Eradication Total removal of the infective agent thereby terminating disease transmission and the possibility of disease transmission e.g. Small pox, ?polio

Controlling the reservoir of infection The aim is to reduce the quantity of the agent available for dissemination 1. Early Diagnosis 2. Notification 3. Epidemiological investigation 4. Isolation 5. Treatment 6. Quarantine