A quantitative microbial risk assessment framework for cholera infection from post-flood ponds

Area of Science:

• Environmental Health
• Epidemiology
• Hydrology

Background:

• Floods are common global disasters with significant health and socioeconomic impacts.
• Floodwaters can transmit infectious diseases like cholera, posing severe public health risks.
• Accra, Ghana, experiences frequent floods and cholera outbreaks, highlighting a critical health concern.

Purpose of the Study:

• To assess health risks from Vibrio cholerae pathogens following flood events in Accra.
• To evaluate the impact of post-flood cholera risk on the population, focusing on Alajo.
• To develop a model for simulating pathogen distribution and infection probability.

Main Methods:

• Developed a Spatio-temporal Pathogen after flood Events (SPATE) model.
• Integrated hydrological processes (evaporation, infiltration) and pathogen decay rates.
• Calculated infection probability using quantitative microbial and flood risk assessment.

Main Results:

• Elevated Vibrio cholerae infection risk identified in scattered ponds near drainage, Onyasia river, and northeastern Alajo.
• Peak infection risk occurs within 12 hours post-flooding, decreasing rapidly thereafter.
• Children engaging in water activities face higher infection risks than adults.

Conclusions:

• Findings aid flood risk management and health risk assessment in Accra.
• Prioritization of vulnerable areas and resource allocation can mitigate flood-related health impacts.
• The study emphasizes elevated risks in the immediate post-flooding period.