Incidence estimates of acute Q fever and spotted fever group rickettsioses, Kilimanjaro, Tanzania, from 2007 to 2008 and from 2012 to 2014

Pisharody, S. et al. (2022) Incidence estimates of acute Q fever and spotted fever group rickettsioses, Kilimanjaro, Tanzania, from 2007 to 2008 and from 2012 to 2014. American Journal of Tropical Medicine and Hygiene, 106(2), pp. 494-503. (doi: 10.4269/ajtmh.20-1036) (PMID:34929672) (PMCID:PMC8832940)

Abstract

Q fever and spotted fever group rickettsioses (SFGR) are common causes of severe febrile illness in northern Tanzania. Incidence estimates are needed to characterize the disease burden. Using hybrid surveillance—coupling case-finding at two referral hospitals and healthcare utilization data—we estimated the incidences of acute Q fever and SFGR in Moshi, Kilimanjaro, Tanzania, from 2007 to 2008 and from 2012 to 2014. Cases were defined as fever and a four-fold or greater increase in antibody titers of acute and convalescent paired sera according to the indirect immunofluorescence assay of Coxiella burnetii phase II antigen for acute Q fever and Rickettsia conorii (2007–2008) or Rickettsia africae (2012–2014) antigens for SFGR. Healthcare utilization data were used to adjust for underascertainment of cases by sentinel surveillance. For 2007 to 2008, among 589 febrile participants, 16 (4.7%) of 344 and 27 (8.8%) of 307 participants with paired serology had Q fever and SFGR, respectively. Adjusted annual incidence estimates of Q fever and SFGR were 80 (uncertainty range, 20–454) and 147 (uncertainty range, 52–645) per 100,000 persons, respectively. For 2012 to 2014, among 1,114 febrile participants, 52 (8.1%) and 57 (8.9%) of 641 participants with paired serology had Q fever and SFGR, respectively. Adjusted annual incidence estimates of Q fever and SFGR were 56 (uncertainty range, 24–163) and 75 (uncertainty range, 34–176) per 100,000 persons, respectively. We found substantial incidences of acute Q fever and SFGR in northern Tanzania during both study periods. To our knowledge, these are the first incidence estimates of either disease in sub-Saharan Africa. Our findings suggest that control measures for these infections warrant consideration.

• Item Type: Articles
• Additional Information: Financial support: This research was supported by the joint US National Institutes of Health (NIH; www.nih.gov)-National Science Foundation (NSF; www.nsf.gov) Ecology of Infectious Disease program (R01TW009237) and the Research Councils UK, Department for International Development (UK) and UK Biotechnology and Biological Sciences Research Council (BBSRC; www.bbsrc.ac.uk) (grant numbers BB/J010367/1, BB/L018926, BB/L017679, BB/ L018845, BB/S013857/1), US National Institutes of Health International Studies on AIDS Associated Co-infections (ISAAC) award (grant number U01 AI062563), US National Institutes for Allergy and Infectious Diseases awards (grant number R01 AI121378), and the Bill & Melinda Gates Foundation-funded Typhoid Fever Surveillance in sub-Saharan Africa Program (TSAP) grant (OPPGH5231). MJM received support from the Frances G. Cotter Scholarship and the McGibbon Travel Fellowship from the University of Otago. HMB received support from the National Institutes of Health Interdisciplinary Research Training Program in AIDS (grant number NIAIDAI007392). KJA received support from the Wellcome Trust (096400/ Z/11/Z). MPR received support from National Institutes of Health Research Training Grants (R25 TW009337) funded by the Fogarty International Center and from US NIH K23 AI116869.
• Keywords: Virology, Infectious Diseases, Parasitology
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Allan, Dr Kathryn and Cleaveland, Professor Sarah and Halliday, Dr Jo
• Authors: Pisharody, S., Rubach, M. P., Carugati, M., Nicholson, W. L., Perniciaro, J. L., Biggs, H. M., Maze, M. J., Hertz, J. T., Halliday, J. E. B., Allan, K. J., Mmbaga, B. T., Saganda, W., Lwezaula, B. F., Kazwala, R. R., Cleaveland, S., Maro, V. P., and Crump, J. A.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: American Journal of Tropical Medicine and Hygiene
• Publisher: American Society of Tropical Medicine and Hygiene
• ISSN: 0002-9637
• ISSN (Online): 1476-1645
• Published Online: 20 December 2021
• Copyright Holders: Copyright © 2022 by The American Society of Tropical Medicine and Hygiene
• First Published: First published in American Journal of Tropical Medicine and Hygiene 106(2): 494-503
• Publisher Policy: Reproduced under a Creative Commons license