Implications for Public Health

Knowledge of the portals of exit and entry and modes of transmission provides a basis for determining appropriate control measures. In general, control measures are usually directed against the segment in the infection chain that is most susceptible to intervention, unless practical issues dictate otherwise.

Interventions are directed at:

• Controlling or eliminating agent at source of transmission by diagnosing and treating infected individuals as early as possible

• Protecting portals of entry (preventing the transmission of infection) through isolation, quarantine, personal hygiene, disinfection, use of condoms or use of personal protective equipment like masks. This has achieved a high level of importance during the Covid-19 pandemic

• Increasing host’s defences and reducing the number of susceptible individuals through immunisation or chemoprophylaxis where possible

Health education also performs an important role in disease prevention and control.