Communicable diseases monitored by disease surveillance in Kottayam district, Kerala state, India

A disease surveillance model developed in the North Arcot district, Tamil Nadu, was found to be practical, efficient, inexpensive and useful for public health action to monitor the success of ongoing interventions and to detect and intercept outbreaks. It was centred in the private (voluntary) sector with full co-operation and participation by the government sector. As Kerala state wanted to replicate this model in all districts, one district was chosen to pilot test it centred within the existing district public health system, soliciting participation from the private sector. A two-year (1999-2001) performance of this model is presented.

After elaborate preparations including the selection of 14 diseases to be reported and training of doctors in the private sector health care institutions and doctors and paramedical staff in all government health centres and hospitals, printed post cards were widely distributed. The business reply system was used so as to avoid handling postage stamps. Cards were received by the nodal officer in the district public health office and checked on a daily basis to detect disease prevalence and evidence of clustering in time and space. Swift action was taken on detecting case clustering. A monthly bulletin containing disease summaries and other useful information was freely distributed to all reporting centres.

On an average, just over 100 disease reports were received every month. The most frequently reported diseases were, in the descending order, leptospirosis, acute dysentery, typhoid fever and acute hepatitis. Among vaccine-preventable childhood diseases, only measles was reported, but no diphtheria, tetanus or whooping cough. Several outbreaks were detected early and interventions applied to intercept them. The most striking example was that of cholera, the occurrence of which was detected swiftly for instituting highly successful control measures.

The district level disease surveillance system centred in the government public health system has been highly successful. Disease surveillance was responsible for the government to obtain information on the prevalence of leptospirosis in the district. The reports enabled the public health officers to detect disease-clustering as the early signals of outbreaks and to take quick remedial measures.