title: Comparison of the Estimated Incidence of Acute Leptospirosis in the Kilimanjaro Region of Tanzania between 2007-08 and 2012-14.
abstract: The sole report of annual leptospirosis incidence in continental Africa of 75-102 cases per 100,000 population is from a study performed in August 2007 through September 2008 in the Kilimanjaro Region of Tanzania. To evaluate the stability of this estimate over time, we estimated the incidence of acute leptospirosis in Kilimanjaro Region, northern Tanzania for the time period 2012-2014.
  
  
  
  Leptospirosis cases were identified among febrile patients at two sentinel hospitals in the Kilimanjaro Region. Leptospirosis was diagnosed by serum microscopic agglutination testing using a panel of 20 Leptospira serovars belonging to 17 separate serogroups. Serum was taken at enrolment and patients were asked to return 4-6 weeks later to provide convalescent serum. Confirmed cases required a 4-fold rise in titre and probable cases required a single titre of ≥800. Findings from a healthcare utilisation survey were used to estimate multipliers to adjust for cases not seen at sentinel hospitals. We identified 19 (1.7%) confirmed or probable cases among 1,115 patients who presented with a febrile illness. Of cases, the predominant reactive serogroups were Australis 8 (42.1%), Sejroe 3 (15.8%), Grippotyphosa 2 (10.5%), Icterohaemorrhagiae 2 (10.5%), Pyrogenes 2 (10.5%), Djasiman 1 (5.3%), Tarassovi 1 (5.3%). We estimated that the annual incidence of leptospirosis was 11-18 cases per 100,000 population. This was a significantly lower incidence than 2007-08 (p<0.001).
  
  
  
  We estimated a much lower incidence of acute leptospirosis than previously, with a notable absence of cases due to the previously predominant serogroup Mini. Our findings indicate a dynamic epidemiology of leptospirosis in this area and highlight the value of multi-year surveillance to understand leptospirosis epidemiology.
authors.affiliation: Centre for International Health, University of Otago, Dunedin, New Zealand.|Kilimanjaro Christian Medical Centre, Moshi, Tanzania.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Maze
authors.affiliation: Division of Infectious Diseases, Duke University Medical Center, Durham, North Carolina, United States of America.
authors.forename: Holly M
authors.initials: HM
authors.lastname: Biggs
authors.affiliation: Kilimanjaro Christian Medical Centre, Moshi, Tanzania.|Division of Infectious Diseases, Duke University Medical Center, Durham, North Carolina, United States of America.|Duke Global Health Institute, Duke University, Durham, North Carolina, United States of America.
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Rubach
authors.affiliation: Centers for Disease Control and Prevention, Bacterial Special Pathogens Branch, Atlanta, Georgia, United States of America.
authors.forename: Renee L
authors.initials: RL
authors.lastname: Galloway
authors.affiliation: Kilimanjaro Christian Medical Centre, Moshi, Tanzania.|Duke Global Health Institute, Duke University, Durham, North Carolina, United States of America.
authors.forename: Shama
authors.initials: S
authors.lastname: Cash-Goldwasser
authors.affiliation: Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Kathryn J
authors.initials: KJ
authors.lastname: Allan
authors.affiliation: Boyd Orr Centre for Population and Ecosystem Health, Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Jo E B
authors.initials: JE
authors.lastname: Halliday
authors.affiliation: Duke Global Health Institute, Duke University, Durham, North Carolina, United States of America.
authors.forename: Julian T
authors.initials: JT
authors.lastname: Hertz
authors.affiliation: Mawenzi Regional Referral Hospital, Moshi, Tanzania.
authors.forename: Wilbrod
authors.initials: W
authors.lastname: Saganda
authors.affiliation: Mawenzi Regional Referral Hospital, Moshi, Tanzania.
authors.forename: Bingileki F
authors.initials: BF
authors.lastname: Lwezaula
authors.affiliation: Mawenzi Regional Referral Hospital, Moshi, Tanzania.
authors.forename: Sarah
authors.initials: S
authors.lastname: Cleaveland
authors.affiliation: Kilimanjaro Christian Medical Centre, Moshi, Tanzania.|Duke Global Health Institute, Duke University, Durham, North Carolina, United States of America.|Kilimanjaro Christian Medical University College, Moshi, Tanzania.
authors.forename: Blandina T
authors.initials: BT
authors.lastname: Mmbaga
authors.affiliation: Kilimanjaro Christian Medical Centre, Moshi, Tanzania.|Kilimanjaro Christian Medical University College, Moshi, Tanzania.
authors.forename: Venance P
authors.initials: VP
authors.lastname: Maro
authors.affiliation: Centre for International Health, University of Otago, Dunedin, New Zealand.|Division of Infectious Diseases, Duke University Medical Center, Durham, North Carolina, United States of America.|Duke Global Health Institute, Duke University, Durham, North Carolina, United States of America.|Kilimanjaro Christian Medical University College, Moshi, Tanzania.
authors.forename: John A
authors.initials: JA
authors.lastname: Crump
mesh_terms: D000208:Acute Disease / Q000453:epidemiology; D000293:Adolescent; D000372:Agglutination Tests; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005334:Fever / Q000175:diagnosis / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007919:Leptospira; D007922:Leptospirosis / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology* / Q000276:immunology; D008297:Male; D013636:Tanzania / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000907:Antibodies, Bacterial