Miriam Nakanwagi1, Alex Riolexus Ario1, Leocadia Kwagonza1, Freda Loy Aceng1, James Mwesigye2, Lilian Bulage1, Joshua Buule3, Juliet Nsimire Sendagala4, Robert Downing5, Bao-Ping Zhu6,7. 1. Uganda Public Health Fellowship Program-Field Epidemiology Track, Kampala, Uganda. 2. Department of Microbiology, Mbarara Regional Referral Hospital, Mbarara, Uganda. 3. UVRI-Abbott Research Laboratory, Uganda Virus Research Institute, Entebbe, Uganda. 4. MRC/LSHTM/UVRI, Uganda Virus Research Institute, Entebbe, Uganda. 5. Global Health Security Agenda, Uganda Virus Research Institute, Entebbe, Uganda. 6. US Centers for Disease Control and Prevention, Kampala, Uganda. 7. Division of Global Health Protection, Center for Global Health, US Centers for Disease Control and Prevention, Atlanta, United States of America.
Abstract
INTRODUCTION: Gastrointestinal anthrax is a rare but serious disease. In August 2017, Isingiro District, Uganda reported a cluster of >40 persons with acute-onset gastroenteritis. Symptoms included bloody diarrhoea. We investigated to identify the etiology and exposures, and to inform control measures. METHODS: We defined a suspected case as acute-onset of diarrhoea or vomiting during 15-31 August 2017 in a resident (aged≥2 years) of Kabingo sub-county, Isingiro District; a confirmed case was a suspected case with a clinical sample positive for Bacillus anthracis by culture or PCR. We conducted descriptive epidemiology to generate hypotheses. In a case-control study, we compared exposures between case-patients and neighbourhood-matched controls. We used conditional logistic regression to compute matched odds ratios (MOR) for associations of illness with exposures. RESULTS: We identified 61 cases (58 suspected and 3 confirmed; no deaths). In the case-control study, 82% of 50 case-patients and 12% of 100 controls ate beef purchased exclusively from butchery X during the week before illness onset (MOR = 46, 95%CI = 4.7-446); 8.0% of case-patients and 3.0% of controls ate beef purchased from butchery X and elsewhere (MOR = 19, 95%CI = 1.0-328), compared with 6.0% of case-patients and 30% of controls who did not eat beef. B. anthracis was identified in two vomitus and one stool sample. Butchery X slaughtered a sick cow and sold the beef during case-patients' incubation period. CONCLUSION: This gastrointestinal anthrax outbreak occurred due to eating beef from butchery X. We recommended health education, safe disposal of the carcasses of livestock or game animals, and anthrax vaccination for livestock.
INTRODUCTION: Gastrointestinal anthrax is a rare but serious disease. In August 2017, Isingiro District, Uganda reported a cluster of >40 persons with acute-onset gastroenteritis. Symptoms included bloody diarrhoea. We investigated to identify the etiology and exposures, and to inform control measures. METHODS: We defined a suspected case as acute-onset of diarrhoea or vomiting during 15-31 August 2017 in a resident (aged≥2 years) of Kabingo sub-county, Isingiro District; a confirmed case was a suspected case with a clinical sample positive for Bacillus anthracis by culture or PCR. We conducted descriptive epidemiology to generate hypotheses. In a case-control study, we compared exposures between case-patients and neighbourhood-matched controls. We used conditional logistic regression to compute matched odds ratios (MOR) for associations of illness with exposures. RESULTS: We identified 61 cases (58 suspected and 3 confirmed; no deaths). In the case-control study, 82% of 50 case-patients and 12% of 100 controls ate beef purchased exclusively from butchery X during the week before illness onset (MOR = 46, 95%CI = 4.7-446); 8.0% of case-patients and 3.0% of controls ate beef purchased from butchery X and elsewhere (MOR = 19, 95%CI = 1.0-328), compared with 6.0% of case-patients and 30% of controls who did not eat beef. B. anthracis was identified in two vomitus and one stool sample. Butchery X slaughtered a sick cow and sold the beef during case-patients' incubation period. CONCLUSION: This gastrointestinal anthrax outbreak occurred due to eating beef from butchery X. We recommended health education, safe disposal of the carcasses of livestock or game animals, and anthrax vaccination for livestock.
Authors: Angella Musewa; Bernadette Basuta Mirembe; Fred Monje; Doreen Birungi; Carol Nanziri; Freda Loy Aceng; Steven N Kabwama; Benon Kwesiga; Deo Birungi Ndumu; Luke Nyakarahuka; Joshua Buule; Caitlin M Cossaboom; David Lowe; Cari B Kolton; Chung K Marston; Robyn A Stoddard; Alex R Hoffmaster; Alex Riolexus Ario; Bao-Ping Zhu Journal: Trop Med Health Date: 2022-08-06