Distribution of dengue cases in the state of Oaxaca, Mexico, during the period 2004-2006

Abstract

Background: Dengue virus infection is an emergent viral disease and the most important transmitted by a vector worldwide. In Mexico it has been an important public health problem since 1995 and Oaxaca is one of the most affected states in the country. Objective: To determine the geographic distribution of confirmed dengue cases in the state of Oaxaca, Mexico, the serotypes circulating, and the main gender and age groups affected. Study design: Information about confirmed dengue cases obtained by LESPO during the period 2004–2006 was classified, sorted, and analysed. A RT-PCR technique was used to determine the serotype of the virus in serum samples. Results: A substantial increment in thenumber of dengue caseswas noticed during the period of this study. The most affected sanitary jurisdictionwas located on the coast where the climatic conditionswere ideal for vector development and where there is significant migratory activity. The most affected group was the 11–15-year-old group. Dengue haemorrhagic feverwas more frequent in men than inwomen over 16 years old, with a significant difference evaluated by X2-test (p < 0.001). Four serotypes of the virus were detected in the state and two co-infections with DEN2–3 and DEN3–4 were identified. Conclusions: The increment in the number of dengue cases in the state of Oaxaca could be explained by several factors such as the presence of the four serotypes of the virus, the migratory phenomenon, the climatic conditions and the socioeconomic level of the population.