Research Article: Rat Fall Surveillance Coupled with Vector Control and Community Education as a Plague Prevention Strategy in the West Nile Region, Uganda

Date Published: January 23, 2018

Publisher: The American Society of Tropical Medicine and Hygiene

Author(s): Karen A. Boegler, Linda A. Atiku, Russell E. Enscore, Titus Apangu, Joseph Tendo Mpanga, Sarah Acayo, John Kaggwa, Paul S. Mead, Brook M. Yockey, Kiersten J. Kugeler, Martin E. Schriefer, Kalanthe Horiuchi, Kenneth L. Gage, Rebecca J. Eisen.


Plague, primarily a disease of rodents, is most frequently transmitted by fleas and causes potentially fatal infections in humans. In Uganda, plague is endemic to the West Nile region. Primary prevention for plague includes control of rodent hosts or flea vectors, but targeting these efforts is difficult given the sporadic nature of plague epizootics in the region and limited resource availability. Here, we present a community-based strategy to detect and report rodent deaths (rat fall), an early sign of epizootics. Laboratory testing of rodent carcasses is used to trigger primary and secondary prevention measures: indoor residual spraying (IRS) and community-based plague education, respectively. During the first 3 years of the program, individuals from 142 villages reported 580 small mammal deaths; 24 of these tested presumptive positive for Yersinia pestis by fluorescence microscopy. In response, for each of the 17 affected communities, village-wide IRS was conducted to control rodent-associated fleas within homes, and community sensitization was conducted to raise awareness of plague signs and prevention strategies. No additional presumptive Y. pestis-positive carcasses were detected in these villages within the 2-month expected duration of residual activity for the insecticide used in IRS. Despite comparatively high historic case counts, no human plague cases were reported from villages participating in the surveillance program; five cases were reported from elsewhere in the districts. We evaluate community participation and timeliness of response, report the frequency of human plague cases in participating and surrounding villages, and evaluate whether a program such as this could provide a sustainable model for plague prevention in endemic areas.

Partial Text

The RFS program described here is based on the premise that early recognition of plague epizootics coupled with IRS should reduce human plague case occurrence. During the first 3 years of this surveillance and response program in the plague-endemic West Nile region of Uganda, nearly 600 small mammal carcasses were submitted for testing. Carcass testing by DFA identified Y. pestis in 24 small mammals and led to IRS treatment and community sensitization of 17 villages in the region. No human plague cases were reported from participating villages during the evaluation period. Continued carcass submissions over 3 years by participating villages, as well as spontaneous submissions from neighboring or “out of network” villages demonstrated community engagement and support for the program. However, local, long-term sustainability of the program will require further evaluation of methods to reduce cost while maintaining the ability to recognize plague activity before the onset of human plague cases and provide adequate prevention resources.




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