Identification of Risk Factors for Plague in the West Nile Region of Uganda

Abstract

Abstract. Plague is an often fatal, primarily flea-borne rodent-associated zoonosis caused by Yersinia pestis. We sought to identify risk factors for plague by comparing villages with and without a history of human plague cases within a model-defined plague focus in the West Nile Region of Uganda. Although rat (Rattus rattus) abundance was similar inside huts within case and control villages, contact rates between rats and humans (as measured by reported rat bites) and host-seeking flea loads were higher in case villages. In addition, compared with persons in control villages, persons in case villages more often reported sleeping on reed or straw mats, storing food in huts where persons sleep, owning dogs and allowing them into huts where persons sleep, storing garbage inside or near huts, and cooking in huts where persons sleep. Compared with persons in case villages, persons in control villages more commonly reported replacing thatch roofing, and growing coffee, tomatoes, onions, and melons in agricultural plots adjacent to their homesteads. Rodent and flea control practices, knowledge of plague, distance to clinics, and most care-seeking practices were similar between persons in case villages and persons in control villages. Our findings reinforce existing plague prevention recommendations and point to potentially advantageous local interventions.

Use of Insecticide Delivery Tubes for Controlling Rodent-Associated Fleas in a Plague Endemic Region of West Nile, Uganda

“…As in previous studies from the West Nile region (Amatre et al 2009, Borchert et al 2012, Eisen et al 2014), R. rattus was the most commonly encountered rodent in the domestic setting. Almost exclusively, it harbored Xenopsylla spp.…”

“…Though Mastomys was once the predominant commensal rodent within the region, it has largely been displaced by R. rattus (Hopkins 1949). Currently, both A. niloticus and Mastomys are most commonly trapped in sylvatic and peridomestic environments away from the huts (Amatre et al 2009, Eisen et al 2014) and tend to nest in burrows and underbrush at ground level (Delany 1975, Nowak 1999). Given these differences in habitat preference and behavior, non-Rattus individuals are probably less likely to encounter IDTs placed on the wall plate, and therefore less likely to receive treatment.…”

“…Most residents of this region live on incomes which fall below the poverty line and rely on subsistence agriculture to make a living (Lakwo et al 2008). Poor housing construction allows easy access to stored foods and hinders efforts to eliminate rodents from the home environment (Eisen et al 2013, 2014). As a result, recent plague control efforts have focused largely on reducing fleas (both on- and off-host) within huts.…”

“…This species is highly susceptible to Y. pestis infection, often exhibits high mortality during epizootics, and harbors fleas that readily bite humans and are competent vectors of Y. pestis (Pollitzer 1954, Gratz 1999, Amatre et al 2009). In the West Nile region, R. rattus are the most common species of rodent infesting rural homes, and represent >90% of in-hut live captures (Amatre et al 2009, Borchert et al 2012, Eisen et al 2014). Here, as in other regions worldwide, R. rattus is highly commensal, and exists in a permanent association with humans and their habitations (Kingdon 1974, Nowak 1999).…”

Physical integrity of three Long-Lasting Insecticidal Net products 30 months after a mass-distribution campaign in Benin

“…The frequency of LLIN use (often or every night), the type of sleeping material (mat or bed), the appearance of the LLIN (clean or dirty), the location of the kitchen (indoor or outdoor) and the frequency washing were correlated with loss of tissue integrity. These different practices in the use and maintenance of LLINs vary from one community to another and probably affect the status of different types of LLINs [24,25,26,27,28,29]. It is therefore important to strengthen the awareness of the best practices for the maintenance of LLINs.…”