Tribal Community Visit to Malaria-Endemic Areas Can Pose Risk to Car Nicobar Island: Deterrent for Malaria Elimination

In the past 10 years, a declining trend was seen in the annual parasite incidence (API) of malaria in the Car Nicobar Island. For the past few years, the API in the island has been below one. Car Nicobar Island is struggling with malaria cases reported to have been brought from other, malaria-endemic islands. The movements of people were monitored by door-to-door visits during early morning hours, and the frequency of their movements to different islands (malarious and non-malarious areas) were monitored. A larger number of villagers visited non-malarious areas (OS-O) than malarious areas (OS-N). The maximum number of people was found out of station during the month of June. Thirty-seven percent of people were out of the station to non-malarious areas, while only 6% were out of the station to islands endemic for malaria. In the latter category, the majority of those who left the village were in the age groups of 16-30 years and 31–45 years. Even though fewer villagers visited malaria-endemic areas, their visits can pose a threat of malaria transmission, in view of the prevalence of local anopheline vectors. Understanding people’s movement patterns to and from high malaria-transmission areas is important to designing strategic evidence-based control plans. In Car Nicobar, the main transport facilities within the inter-islands are ship and helicopter services. Hence, post-arrival medical examinations should be made mandatory to prevent the introduction of malaria parasites into the island.