Skip to main content Skip to main navigation menu Skip to site footer
Published: 2023-03-27

Seroprevalence of leptospirosis among hospitalized febrile patients in Unguja Island

Department of Veterinary Medicine and Public Health, Sokoine University of Agriculture, P. O. Box 3015, Chuo Kikuu, Morogoro, Tanzania
Department of Veterinary Medicine and Public Health, Sokoine University of Agriculture, P. O. Box 3015, Chuo Kikuu, Morogoro, Tanzania
ST Francis University College of Health and Allied Sciences, P.O. Box 175, Ifakara-Morogoro, Tanzania
African Centre of Excellence for Innovative Rodent Pest Management and Biosensor Technology Development (ACE II IRPM and BTD) of the Sokoine University of Agriculture, Morogoro, Tanzania; Institute of Pest Management, Sokoine University of Agriculture, P.O. Box 3110, Chuo Kikuu, Morogoro, Tanzania


Background: Leptospirosis is one of the neglected causes of febrile illness and death in developing countries, including Tanzania. The study aims to determine the seroprevalence of leptospirosis among hospitalized febrile patients in Unguja Island. 

Methods: A cross-sectional study was carried out in the three selected hospitals in Unguja Island between January and March 2022. A total of 402 participants with febrile illness were enrolled in the study, and blood samples were collected for sera preparation. Microscopic agglutination test (MAT) was used to detect antibodies against five Leptospira serovars, including Sokoine, Lora, Pomona, Grippotyphosa, and Hebdomadis. All sera samples reacted with MAT titers≥1:160 were counted as positive, MAT titers ranging from 1:20 to 1:80 were counted as exposed to Leptospira bacteria while the absence of agglutination was regarded as negative. The data was analyzed using SPSS version 26, 2019. Descriptive and logistic regression was performed, and p≤0.05 was considered statistically significant.

Results: The mean age of study participants was 29.62 ±16.34, with a range of 0 days to 80 years. Most of them were females (64.2%) and unemployed (67.9%). The overall seroprevalence of leptospirosis was 7.7% (95% CI: 5.3-10.8). Females were 1.016 times higher likelihood to have leptospirosis (AOR = 1.016, 95% CI: 0.47-2.185, p = 0.968). Participants aged 18-35 were 2.093 times more likely to be infected with leptospirosis (AOR= 2.093, 95% CI: 0.835-5.250, p = 0.115). Participants who were unemployed (AOR = 1.169, 95% CI: 0.522-2.615, p = 0.704) revealed a significantly higher likelihood of being infected with leptospirosis. The predominant Leptospira serovars circulating among febrile patients were Sokoine 44 (10.9%), Lora 25 (6.2%), Grippotyphosa 20 (5.0%), Pomona 10 (2.5%), and Hebdomadis 9 (2.2%).

Conclusion: Leptospirosis is a public health threat among febrile patients in Unguja Island; therefore, it’s important to be considered in the differential diagnosis of non-malaria febrile patients for early prevention and control strategies.


Download data is not yet available.


  1. Bharti AR, Nally JE, Ricaldi JN, Matthias MA, Diaz MM, Lovett MA. Peru United States Leptospirosis Consortium. Leptospirosis: A zoonotic disease of global importance. Lancet Infect Dis. 2003 Dec; 3(12): 757 – 71. doi: 10.1016/s1473-3099(03)00830-2.
  2. Soo ZMP, Khan NA, Siddiqui R. Leptospirosis: Increasing importance in developing countries. Acta Trop. 2020 Jan; 201:105183. doi: 10.1016/j.actatropica.2019.105183.
  3. Samrot AV, Sean TC, Bhavya KS, Sahithya CS, Chan-Drasekaran S, Palanisamy R, et al. Leptospiral infection, pathogenesis and its diagnosis–A review. Pathogens. 2021 Feb 1;10(2): 145. doi 10.3390/pathogens10020145.
  4. Costa F, Hagan JE, Calcagno J, Kane M, Torgerson P, Martinez-Silveira MS, et al. Global morbidity and mortality of leptospirosis: a systematic review. PLoS Negl Trop Dis. 2015 Sep 17;9(9): 1 – 19. Doi: 10.1371/journal.pntd.0003898.
  5. Mwachui MA, Crump L, Hartskeerl R, Zinsstag J, Hattendorf J. Environmental and behavioural determinants of leptospirosis transmission: a systematic review. PLoS Negl Trop Dis. 2015 Sep 17;9(9): 1 – 15. Doi: 10.1371/journal.pntd.0003843.
  6. Rahman MHAA, Hairon SM, Hamat RA, Jamaluddin TZMT, Shafei MN, Idris N, et al. Seroprevalence and distribution of leptospirosis serovars among wet market workers in northeastern, Malaysia: a cross sectional study. BMC Infect Dis. 2018 Nov 14;18(1): 1 – 5. doi 10.1186/s12879-018-3470-5.
  7. Allan KJ, Halliday JE, Moseley M, Carter RW, Ahmed A, Goris MG, et al. Assessment of animal hosts of pathogenic Leptospira in northern Tanzania. PLoS Negl Trop Dis. 2018 Jun 7;12(6): 1 – 19. Doi: 10.1371/journal.pntd.0006444.
  8. Mgode GF, Mhamphi GG, Massawe AW, Machang’u RS. Leptospira Seropositivity in Humans, Livestock and Wild Animals in a Semi-Arid Area of Tanzania. Pathogens. 2021 Jun 3;10(6): 1 – 12. doi: 10.3390/pathogens10060696.
  9. WHO. Human Leptospirosis: Guidance for Diagnosis, Surveillance and Control. World Health Organization, Geneva; 2003.
  10. Guernier V, Goarant C, Benschop J, Lau CL. A systematic review of human and animal leptospirosis in the Pacific Islands reveals pathogen and reservoir diversity. PLoS Negl Trop Dis. 2018 May 14;12(5): 1 – 32. Doi: 10.1371/journal.pntd.0006503.
  11. Galan DI, Roess AA, Pereira SVC, Schneider MC. Epidemiology of human leptospirosis in urban and rural areas of Brazil, 2000–2015. PloS One. 2021 Mar 4; 16(3): 1 – 20. doi 10.1371/journal.pone.0247763.
  12. Mgode GF, Mhamphi GG, Katakweba AS, Mboera LE, Machang RS. Leptospirosis In Tanzania: A Neglected Cause of Febrile Illness That Needs Attention of the Health System. National Institute for Medical Research, Dar es Salaam, Tanzania. 2017. 8pp.
  13. Maze MJ, Cash-Goldwasser S, Rubach MP, Biggs HM, Galloway RL, Sharples K J, et al. Risk factors for human acute leptospirosis in northern Tanzania. PLoS Negl Trop Dis. 2018 Jun 7; 12(6): 1 – 22. Doi: 10.1371/journal.pntd.0006372.
  14. Mgode GF, Japhary MM, Mhamphi GG, Kiwelu I, Athaide I, Machang’u RS. Leptospirosis in sugarcane plantation and fishing communities in Kagera northwestern Tanzania. PLoS Negl Trop Dis. 2019 May 31;13(5): 1 – 12. Doi: 10.1371/journal.pntd.0007225.
  15. Motto SK, Shirima GM, de Clare Bronsvoort BM, Cook EAJ. Epidemiology of leptospirosis in Tanzania: A review of the current status, serogroup diversity and reservoirs. PLoS Negl Trop Dis. 2021 Nov 16;15(11): 1 – 17. 10.1371/journal.pntd.0009918.
  16. Crump JA, Morrissey AB, Nicholson WL, Massung RF, Stoddard RA, Galloway, RL, et al. Etiology of severe non-malaria febrile illness in Northern Tanzania: A prospective cohort study. PLoS Negl Trop Dis. 2013 Jul 18;7(7): 1 – 8. doi: 10.1371/journal.pntd.0002324.
  17. Masunga DS, Rai A, Abbass M, Uwishema O, Wellington J, Uweis L, et al. Leptospirosis outbreak in Tanzania: An alarming situation. Ann Med Surg (Lond). 2022 Aug 6;80(104347): 1 – 5. doi: 10.1016/j.amsu.2022.104347.
  18. Ali MA, James OC, Mohamed AA, Mubi M, Omodior O. Etiologic agents of fever of unknown origin among patients attending Mnazi Mmoja hospital, Zanzibar. J Community Health. 2020 Oct; 45(5): 1073 – 1080. doi 10.1007/s10900-020-00832-w.
  19. Monroe A, Msaky D, Kiware S, Tarimo BB, Moore S, Haji K., et al. Patterns of human exposure to malaria vectors in Zanzibar and implications for malaria elimination efforts. Malar J. 2020 Jun 22;19(1): 1 – 14. Doi: 10.1186/s12936-020-03266-w.
  20. SMZ. Zanzibar Health Sector Strategic Plan III 2013/14-2018/19. Ministry of Health Zanzibar, Zanzibar; 2013.
  21. URT. National Population and House Census of Tanzania. National Bureau of Statistics, Dar es Salaam, Tanzania; 2022.
  22. Tejada JJ, Punzalan JRB. On the misuse of Slovin’s formula. The Philippine Statistician. 2012; 61(1): 129 – 136.
  23. Goris MG, Leeflang MM, Loden M, Wagenaar JF, Klatser PR, Hartskeerl RA, et al. Prospective evaluation of three rapid diagnostic tests for diagnosis of human leptospirosis. PLoS Negl Trop Dis. 2013 Jul 11;7(7): 1 – 11. Doi: 10.1371/journal.pntd.0002290.
  24. Assenga JA, Matemba LE, Muller SK, Mhamphi GG, Kazwala RR. Predominant Leptospiral serogroups circulating among humans, livestock and wildlife in Katavi-Rukwa ecosystem, Tanzania. PLoS Negl Trop Dis. 2015 Mar 25;9(3): 1 – 14. Doi: 10.1371/journal.pntd.0003607.
  25. Muller SK, Assenga JA, Matemba LE, Misinzo G, Kazwala RR. Human leptospirosis in Tanzania: sequencing and phylogenetic analysis confirm that pathogenic Leptospira species circulate among agro-pastoralists living in the Katavi-Rukwa ecosystem. BMC Infect Dis. 2016 Jun 10;16(1): 1 – 9. doi: 10.1186/s12879-016-1588-x.
  26. Biggs HM, Bui DM, Galloway RL, Stoddard RA, Shadomy SV, Morrissey AB, et al. Leptospirosis among hospitalized febrile patients in northern Tanzania. Am J Trop Med and Hyg. 2011 Aug; 85(2): 275 – 81. doi: 10.4269/ajtmh.2011.11-0176.
  27. Rafizah AN, Aziah BD, Azwany YN, Imran MK, Rusli AM, Nazri SM, et al. A hospital-based study on sero-prevalence of leptospirosis among febrile cases in northeastern Malaysia. Int J Infect Dis. 2013 Jun;17(6): 394 – 397. doi: 10.1016/j.ijid.2012.12.012.
  28. Nepal HP, Acharya A, Gautam R, Shrestha S, Ansari S, Paudel R, et al. Serological study of leptospirosis in central Nepal. International Journal of Biomedical and Advance Research. 2013; 4(7): 455 – 459.
  29. Ribeiro P, Bhatt N, Ali S, Monteiro V, da Silva E, Balassiano IT, et al. Seroepidemiology of leptospirosis among febrile patients in a rapidly growing suburban slum and a flood-vulnerable rural district in Mozambique 2012–2014: Implications for the management of fever. Int J Infect Dis. 2017 Nov; 64:50 – 57. doi: 10.1016/j.ijid.2017.08.018.
  30. Wambi R, Worodria W, Muleme J, Aggrey S, Mugisha L. Prevalence of leptospirosis among patients attending renal and general outpatient clinics in Mulago Hospital, Kampala, Uganda. Sci Rep. 2022 May 19;12(1): 1 – 7. doi: 10.1038/s41598-022-12544-3.
  31. Chipwaza B, Mhamphi GG, Ngatunga SD, Selemani M, Amuri M, Mugasa JP. Prevalence of bacterial febrile illnesses in children in Kilosa District, Tanzania. PLoS Negl Trop Dis. 2015 May 8;9(5):1 – 18. Doi: 10.1371/journal.pntd.0003750.
  32. Barragan V, Chiriboga J, Miller E, Olivas S, Birdsell D, Hepp C, et al. High Leptospira diversity in animals and humans complicates the search for common reservoirs of human disease in rural Ecuador. PLoS Negl Trop Dis. 2016 Sep 13;10(9): 1 – 14. Doi: 10.1371/journal.pntd.0004990.
  33. Regmi L, Pandey K, Malla M, Khanal S, Pandey BD. Sero-epidemiology study of leptospirosis in febrile patients from Terai region of Nepal. BMC Infect Dis. 2017 Sep 18;17(1): 1 – 6. doi: 10.1186/s12879-017-2733-x.
  34. Del Valle-Mendoza J, Palomares-Reyes C, Carrillo-Ng H, Tarazona-Castro Y, Kym S, Aguilar-Luis MA, et al. Leptospirosis in febrile patients with suspected diagnosis of dengue fever. BMC Res Notes. 2021 May 29;14(1): 1 – 6. doi: 10.1186/s13104-021-05627-3.
  35. Kakita T, Okano S, Kyan H, Miyahira M, Taira K, Kitashoji E. Laboratory diagnostic, epidemiological, and clinical characteristics of human leptospirosis in Okinawa Prefecture, Japan, 2003–2020. PLoS Negl Trop Dis. 2021 Dec 14;15(12): 1 – 15. Doi: 10.1371/journal.pntd.0009993.
  36. Ricardo T, Bergero LC, Bulgarella EP, Previtali MA. Knowledge, attitudes and practices (KAP) regarding leptospirosis among residents of riverside settlements of Santa Fe, Argentina. PLoS Negl Trop Dis. 2018 May 7;12(5): 1 – 19. Doi: 10.1371/journal.pntd.0006470.
  37. Hagan JE, Moraga P, Costa F, Capian N, Ribeiro GS, Wunder JEA, et al. Spatiotemporal determinants of urban leptospirosis transmission: four-year prospective cohort study of slum residents in Brazil. PLoS Negl Trop Dis. 2016 Jan 15;10(1): 1 – 16. Doi: 10.1371/journal.pntd.0004275.
  38. Narkkul U, Thaipadungpanit J, Srisawat N, Rudge JW, Thongdee M, Pawarana R, et al. Human, animal, water source interactions and leptospirosis in Thailand. Sci Rep. 2021 Feb 5;11(1): 1 – 13. Doi: 10.1038/s41598-021-82290-5.
  39. Mgode GF, Machang’u RS, Mhamphi GG, Katakweba A, Mulungu LS, Durnez L, et al. Leptospira serovars for diagnosis of leptospirosis in humans and animals in Africa: common Leptospira isolates and reservoir hosts. PLoS Negl Trop Dis. 2015 Dec 1; 9(12): 1 – 19. Doi: 10.1371/journal.pntd.0004251.
  40. Mirambo MM, Silago V, Msemwa B, Nyawale H, Mgomi MG, Madeu JM, et al. Seropositivity of Leptospira spp. Antibodies among Febrile Patients Attending Outpatient Clinics in Mwanza, Tanzania: Should It Be Included in Routine diagnosis? Trop Med Infect Dis. 2022 Aug 9;7(8): 1 - 8. doi: 10.3390/tropicalmed7080173.

How to Cite

Ally AA, Lupindu AM, Machang’u R, Katakweba AS. Seroprevalence of leptospirosis among hospitalized febrile patients in Unguja Island. jidhealth [Internet]. 2023 Mar. 27 [cited 2024 Jun. 20];6(1):820-7. Available from: