Dengue outbreak; descriptive epidemiological analysis and vector surveillance in District Faisalabad during 2011

ABSTRACT

This longitudinal study was conducted during August to December 2011 in District Faisalabad to analyze epidemiological pattern of dengue outbreak in the district. Weekly trends of all cases [893] reported through Disease Surveillance System from week No. 33 to 52 were monitored. On the basis of this continuous flow of information, different ongoing vector control measures were adopted simultaneously in different areas of the district and larval indices were calculated. The Surveillance data was used to monitor the trends of the outbreak in terms of time, person and place. Teams of 3102 trained workers were formed to conduct various surveillance activities like vector surveillance, fogging, larviciding, and indoor residual sprays. During indoor and outdoor vector surveillance, teams also calculated the larval indices for vector control. The rural to urban ratio of cases was 13. Maximum cases [215] were reported from Jinnah Town in urban area and [102] cases were reported from Tehsil Sadar among the rural areas. Most cases of dengue fever were observed during the 37-46 weeks of the year 2011. Mean age was 29 +/- 14.7 years for rural and 35 +/- 16.5 years for urban. Male to Female ratio was 1.21 in urban and 1.81 in rural areas. Majority of the cases belonged to the age group 21 -30. The case fatality rate was 6/1000 cases. The house Index was 1.03%, the indoor container index was 0.26% and the breateu index was found 1.21%. Maximum cases occurred during 40th to 44th weeks. Male were affected more as compared to females. Jinnah Town in urban areas and Tehsil Sadar among the rural areas reported maximum number of cases. The different calculated larval indices like house index, indoor/outdoor container index and breateu index showed moderate larval growth and hence, the outbreak was within control