Browsing by Author "Mead, Paul S."

Now showing 1 - 7 of 7
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    Assessing Human Risk of Exposure to Plague Bacteria in Northwestern Uganda Based on Remotely Sensed Predictors
    (The American journal of tropical medicine and hygiene, 2010) Eisen, Rebecca J.; Apangu, Titus; Owor, Nicholas; Acayo, Sara; Acidri, Rogers; Mead, Paul S.
    Plague, a life-threatening flea-borne zoonosis caused by Yersinia pestis, has most commonly been reported from eastern Africa and Madagascar in recent decades. In these regions and elsewhere, prevention and control efforts are typically targeted at fine spatial scales, yet risk maps for the disease are often presented at coarse spatial resolutions that are of limited value in allocating scarce prevention and control resources. In our study, we sought to identify sub-village level remotely sensed correlates of elevated risk of human exposure to plague bacteria and to project the model across the plague-endemic West Nile region of Uganda and into neighboring regions of the Democratic Republic of Congo. Our model yielded an overall accuracy of 81%, with sensitivities and specificities of 89% and 71%, respectively. Risk was higher above 1,300 meters than below, and the remotely sensed covariates that were included in the model implied that localities that are wetter, with less vegetative growth and more bare soil during the dry month of January (when agricultural plots are typically fallow) pose an increased risk of plague case occurrence. Our results suggest that environmental and landscape features play a large part in classifying an area as ecologically conducive to plague activity. However, it is clear that future studies aimed at identifying behavioral and fine-scale ecological risk factors in the West Nile region are required to fully assess the risk of human exposure to Y. pestis.
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    Epidemiology, Ecology and Prevention of Plague in the West Nile Region of Uganda: The Value of Long-Term Field Studies
    (The American Journal of Tropical Medicine and Hygiene., 2021) Eisen, Rebecca J.; Atiku, Linda A.; Enscore, Russell E.; Mpanga, Joseph T.; Acayo, Sarah; Mead, Paul S.; Apangu, Titus; Yockey, Brook M.; Borchert, Jeff N.; Beard, Charles B.; Gage, Kenneth L.
    Plague, a fleaborne rodent-associated zoonosis, is a neglected disease with most recent cases reported from east and central Africa and Madagascar. Because of its low incidence and sporadic occurrence, most of our knowledge of plague ecology, prevention, and control derives from investigations conducted in response to human cases. Long-term studies (which are uncommon) are required to generate data to support plague surveillance, prevention, and control recommendations. Here we describe a 15-year, multidisciplinary commitment to plague in the West Nile region of Uganda that led to significant advances in our understanding of where and when persons are at risk for plague infection and how to reduce morbidity and mortality. These findings provide data-driven support for several existing recommendations on plague surveillance and prevention and may be generalizable to other plague foci
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    An Evaluation of the Flea Index as a Predictor of Plague Epizootics in the West Nile Region of Uganda
    (Journal of medical entomology, 2020) Eisen, Rebecca J.; Atiku, Linda A.; Mpanga, Joseph T.; Enscore, Russell E.; Acayo, Sarah; Kaggwa, John; Yockey, Brook M.; Apangu, Titus; Kugeler, Kiersten J.; Mead, Paul S.
    Plague is a low incidence flea-borne zoonosis that is often fatal if treatment is delayed or inadequate. Outbreaks occur sporadically and human cases are often preceded by epizootics among rodents. Early recognition of epizootics coupled with appropriate prevention measures should reduce plague morbidity and mortality. For nearly a century, the flea index (a measure of fleas per host) has been used as a measure of risk for epizootic spread and human plague case occurrence, yet the practicality and effectiveness of its use in surveillance programs has not been evaluated rigorously. We sought to determine whether long-term monitoring of the Xenopsylla flea index on hut-dwelling rats in sentinel villages in the plague-endemic West Nile region of Uganda accurately predicted plague occurrence in the surrounding parish. Based on observations spanning ~6 yr, we showed that on average, the Xenopsylla flea index increased prior to the start of the annual plague season and tended to be higher in years when plague activity was reported in humans or rodents compared with years when it was not. However, this labor-intensive effort had limited spatial coverage and was a poor predictor of plague activity within sentinel parishes.
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    Intervention To Stop Transmission of Imported Pneumonic Plague — Uganda, 2019
    (Morbidity and Mortality Weekly Report, 2019) Apangu, Titus; Acayo, Sarah; Atiku, Linda A.; Apio, Harriet,; Candini, Gordian; Okoth, Felix; Kaggwa Basabose, John; Ojosia, Lawrence; Ajoga, Sam; Mongiba, Grace; Makoba Wetaka, Milton; Kayiwa, Joshua; Balinandi, Stephen; Schwartz, Amy; Yockey, Brook; Sexton, Christopher; Dietrich, Elizabeth A.; Pappert, Ryan; Petersen, Jeannine M.; Mead, Paul S.; Lutwama, Julius J.; Kugeler, Kiersten J.
    Plague, an acute zoonosis caused by Yersinia pestis, isendemic in the West Nile region of northwestern Uganda andneighboring northeastern Democratic Republic of the Congo(DRC) (1–4). The illness manifests in multiple clinical forms,including bubonic and pneumonic plague. Pneumonic plagueis rare, rapidly fatal, and transmissible from person to person via respiratory droplets. On March 4, 2019, a patient withsuspected pneumonic plague was hospitalized in West Nile,Uganda, 4 days after caring for her sister, who had come toUganda from DRC and died shortly thereafter, and 2 daysafter area officials received a message from a clinic in DRCwarning of possible plague. The West Nile-based Uganda Virus Research Institute (UVRI) plague program, together withlocal health officials, commenced a multipronged responseto suspected person-to-person transmission of pneumonicplague, including contact tracing, prophylaxis, and education.Plague was laboratoryconfirmed, and no additionaltransmission occurred in Uganda. This event transpired inthe context of heightened awareness of cross-border disease spread caused by ongoing Ebola virus disease transmission in DRC, approximately 400 km to the south. Building expertise in areas of plague endemicity can provide the rapid detection and effective response needed to mitigate epidemic spread and minimize mortality. Cross-border agreements can improve ability to respond effectively.
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    Intervention To Stop Transmission of Imported Pneumonic Plague — Uganda, 2019
    (, 69(9),, 2020) Apangu, Titus; Acayo, Sarah; Atiku, Linda A.; Apio, Harriet; Candini, Gordian; Okoth, Felix; Basabose, John Kaggwa; Ojosia, Lawrence; Ajoga, Sam; Mongiba, Grace; Wetaka, Milton Makoba; Kayiwa, Joshua; Balinand, Stephen; Schwartz, Amy; Yockey, Brook; Sexton, Christopher; Dietrich, Elizabeth A.; Pappert, Ryan; Petersen, Jeannine M.; Mead, Paul S.; Lutwama, Julius J.; Kugeler, Kiersten J.
    A plague is an acute zoonosis that occurs on several continents and can manifest in different clinical forms. Pneumonic plague is highly fatal and directly transmissible from person to person via infectious respiratory droplets. Importation of pneumonic plague from the Democratic Republic of the Congo into an area of Uganda with effective public health response capabilities resulted in prompt action to halt transmission. Despite multiple high-risk exposures, only a single transmission event occurred. Building expertise in areas of plague endemicity can provide the rapid detection and response needed to mitigate the epidemic spread and minimize mortality. Cross-border agreements can improve ability to respond effectively
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    Patterns of Human Plague in Uganda, 2008–2016
    (Emerging Infectious Diseases, 2017) Forrester, Joseph D.; Apangu, Titus; Griffith, Kevin; Acayo, Sarah; Yockey, Brook; Kaggwa, John; Kugeler, Kiersten J.; Schriefer, Martin; Sexton, Christopher; Beard, Ben C.; Candini, Gordian; Abaru, Janet; Candia, Bosco; Okoth, Jimmy Felix; Apio, Harriet; Nolex, Lawrence; Ezama, Geoffrey; Okello, Robert; Atiku, Linda; Mpanga, Joseph; Mead, Paul S.
    Plague is a highly virulent fleaborne zoonosis that occurs throughout many parts of the world; most suspected human cases are reported from resource-poor settings in sub-Saharan Africa. During 2008–2016, a combination of active surveillance and laboratory testing in the plague-endemic West Nile region of Uganda yielded 255 suspected human plague cases; approximately one third were laboratory confirmed by bacterial culture or serology. Although the mortality rate was 7% among suspected cases, it was 26% among persons with laboratory-confirmed plague. Reports of an unusual number of dead rats in a patient’s village around the time of illness onset was significantly associated with laboratory confirmation of plague. This descriptive summary of human plague in Uganda highlights the episodic nature of the disease, as well as the potential that, even in endemic areas, illnesses of other etiologies might be being mistaken for plague
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    Rat Fall Surveillance Coupled with Vector Control and Community Education as a Plague Prevention Strategy in the West Nile Region, Uganda
    (The American Society of Tropical Medicine and Hygiene, 2018) Boegler, Karen A.; Atiku, Linda A.; Enscore, Russell E.; Apangu, Titus; Tendo Mpanga, Joseph,; Acayo, Sarah; Kaggwa, John; Mead, Paul S.; Yockey, Brook M.; Kugeler, Kiersten J.; Schriefer, Martin E.; Horiuchi, Kalanthe; Gage, Kenneth L.; Eisen, Rebecca J.
    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. Weevaluate 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.