Epidemiology Week 35, 2015

Flooding and communicable diseases

Risk assessment

Floods can potentially increase the transmission of the following communicable diseases:

Water-borne diseases, such as Typhoid Fever, Cholera, Leptospirosis and Hepatitis A

Vector-borne diseases, such as Malaria, Dengue and Dengue Haemorrhagic Fever, Yellow Fever, and West Nile Fever


Water-borne diseases

Flooding is associated with an increased risk of infection, however this risk is low unless there is significant population displacement and/or water sources are compromised.

The only epidemic-prone infection which can be transmitted directly from contaminated water is Leptospirosis, a zoonotic bacterial disease.

Transmission occurs through contact of the skin and mucous membranes with water, damp soil or vegetation (such as sugarcane) or mud contaminated with rodent urine.


Vector-borne diseases

Floods may indirectly lead to an increase in vector-borne diseases through the expansion in the number and range of vector habitats.


Preventive measures

Communicable disease risks from flooding can be greatly reduced if the following recommendations are followed.

(Including)…Chlorination of water, vaccination against hepatitis A (for high risk groups-involved in the management of drinking water, waste water or sewage), (use of) insecticides, and health education.

Download Weekly Bulletin EW 35 complete PDF