Background & objectives: In the tsunami (December 2004) affected coastal villages located on southern parts of Coramandel Coast of India, seawater intrusion has created serious problems for the people. In order to assess the risk of outbreak of fly-borne diseases, a longitudinal study for one year was carried out to investigate muscoid fly abundance and their distribution in relation to various phases of relief measures in disaster-hit villages. Method: Muscoid fly density was monitored in devastated human settlements, temporary shelters, garbage dumping yards and open defaecation yards in seawater intrusion and indoors and outdoors of seawater non intrusion areas using scudder grill and sweep net at monthly intervals from February 2005 to January 2006. Results: Muscoid fly density recorded in the seawater incursion area was significantly higher, compared to that observed in the seawater non incursion area with scudder grill sampling (F= 57.896, df = 1, P<0.01) or sweep net sampling (F= 63.6, df = 1, P<0.01). Fly density in seawater non incursion area was higher during hotter months (June-July 2005) and lower during cooler months. On the contrary, the fly density in the seawater incursion areas was higher during the cooler months than in hotter months, indicating that the normal trend was upset by the tsunami. Interpretation & conclusion: Seawater incursion, crowding of tsunami victims at relief camps, accumulation of solid waste at centralized relief kitchen and temporary shelters were responsible for the sudden increase in the number of flies. However, the post-disaster relief efforts kept the situation tinder control, without outbreak of any vector-borne diseases.
