A Look at the Change in the Seasonality of Influenza between Three Distinct Regions of Uganda: Central, Northwest, and Western

Autor: McClellan, Sarah K, Rothenberg, Richard, MD MPH, Chowell, Gerardo, PhD
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Zdroj: Public Health Theses.
Druh dokumentu: Text
Popis: Influenza is suspected to be endemic in tropical climates, with peaks during and/or following cold or rainy seasons. To date, only one study has been conducted examining the epidemiology and seasonality of influenza in Uganda. The focus of this analysis is to determine whether a change in the seasonality of influenza can been seen between three distinct regions of Uganda: Central, Northwest, and Western. Secondary data analysis was conducted on surveillance data collected by the Uganda Virus Research Institute (UVRI) between April 2007 to September 2010 from 10 surveillance sites. Surveillance sites were grouped for this analysis into three regions: Central, Northwest, and Western. A total of 3,944 samples were collected and tested for any strain of influenza. The prevalence of influenza over the 4 years of surveillance was 10.1%. The majority of cases came from the Central region (81.7%) and the highest prevalence of influenza-positive samples were collected in the Central region (88.7 cases/1,000 persons). A clear difference in influenza activity was observed during the 2009 H1N1 pandemic. Uganda reported its first case of H1N1 in July 2009 (Relief Web). The Central region experienced its initial flux of influenza activity in July and August 2009 (Figure 1). However, the Northwest region did not experience a flux in activity until October 2009 (Figure 2). Influenza activity in the Central and Northwest regions appear to coincide with colder temperatures and both rainy seasons. The Northwest region was the only region to experience a peak corresponding with warmer weather. Results showed a slight change in the seasonality of influenza between the Central and Northwest regions of Uganda from surveillance data collected between April 2007 and September 2010.
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