Dataset Information

Human leptospirosis in Tanzania: sequencing and phylogenetic analysis confirm that pathogenic Leptospira species circulate among agro-pastoralists living in Katavi-Rukwa ecosystem.

ABSTRACT: Leptospirosis is a neglected zoonotic disease of worldwide public health importance. The disease affects humans, domestic animals and wildlife. However, leptospirosis is challenging in its diagnosis in humans. Culture technique, which is time consuming, is not recommended for clinical diagnosis. For these reasons, serological and molecular techniques remain the test of choice. The major objective of this study was to explore the genetic characteristic of Leptospira species which are prevalent among agro-pastoralists living in Katavi-Rukwa Ecosystem, Tanzania.A cross-sectional epidemiological study was carried out in the Katavi-Region South-west, Tanzania between August, 2013 and November, 2014. A total of 267 participants were randomly recruited for the study. Microscopic agglutination test (MAT) was used to detect antibody against six Leptospira antigens including local serogroups Icterohaemorrhagiae, Ballum, Grippotyphosa, Sejroe and reference serogroups Hebdomadis, and Australis. Samples with MAT titers???1:160 were scored as positive, samples with MAT titers ranging from 1:20 to 1:80 were scored as exposed to Leptospira, and absence of agglutination titers was scored as negative. All MAT positive samples, including the low titre samples were subjected to PCR using the respective 16S rRNA primers for the pathogenic and non-pathogenic species.Out of 267 samples tested, 80 (29.9 %) were positive with MAT. The major circulating leptospiral serogroups were Sejroe (15.7 %,), Icterohaemorrhagiae (8.9 %), Grippotyphosa (4.8 %), Hebdomadis (3.37 %), Australis (1.49 %) and Ballum (1.19 %). By using PCR, 33 (15.7 %) out of 210 samples were pathogenic Leptospira while no saprophytic Leptospira spp. was detected. Partial 16S rRNA gene sequences of Leptospira species which were obtained from this study were submitted to GenBank and acquired accession numbers KP313246 and KP313247. Phylogenetic analysis of the nucleotide sequences revealed that species obtained from Katavi-Rukwa ecosystem clustered in the same group with several published pathogenic Leptospira specifically Leptospira interrogans and Leptospira kirschneri. To the best of the authors' knowledge(,) this is the first study from Tanzania to confirm pathogenic Leptospira in human subjects using genomic typing technique.These findings provide ultimate evidence of pathogenic Leptospira species circulating among agro-pastoralists living in Katavi-Rukwa Ecosystem suggesting that active disease surveillance should be undertaken in order to achieve greater protection of the agro-pastoral communities in Tanzania.

SUBMITTER: Muller SK

PROVIDER: S-EPMC4902944 | biostudies-literature | 2016 Jun

REPOSITORIES: biostudies-literature

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Human leptospirosis in Tanzania: sequencing and phylogenetic analysis confirm that pathogenic Leptospira species circulate among agro-pastoralists living in Katavi-Rukwa ecosystem.

Muller Shabani K SK Assenga Justine A JA Matemba Lucas E LE Misinzo Gerald G Kazwala Rudovick R RR

BMC infectious diseases 20160610

<h4>Background</h4>Leptospirosis is a neglected zoonotic disease of worldwide public health importance. The disease affects humans, domestic animals and wildlife. However, leptospirosis is challenging in its diagnosis in humans. Culture technique, which is time consuming, is not recommended for clinical diagnosis. For these reasons, serological and molecular techniques remain the test of choice. The major objective of this study was to explore the genetic characteristic of Leptospira species whi ...[more]

PMID: 27287703

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Project description:BackgroundLeptospirosis is a worldwide zoonotic disease and a serious, under-reported public health problem, particularly in rural areas of Tanzania. In the Katavi-Rukwa ecosystem, humans, livestock and wildlife live in close proximity, which exposes them to the risk of a number of zoonotic infectious diseases, including leptospirosis.Methodology/principal findingsA cross-sectional epidemiological study was carried out in the Katavi region, South-west Tanzania, to determine the seroprevalence of Leptospira spp in humans, domestic ruminants and wildlife. Blood samples were collected from humans (n = 267), cattle (n = 1,103), goats (n = 248), buffaloes (n = 38), zebra (n = 2), lions (n = 2), rodents (n = 207) and shrews (n = 11). Decanted sera were tested using the Microscopic Agglutination Test (MAT) for antibodies against six live serogroups belonging to the Leptospira spp, with a cutoff point of ? 1:160. The prevalence of leptospiral antibodies was 29.96% in humans, 30.37% in cattle, 8.47% in goats, 28.95% in buffaloes, 20.29% in rodents and 9.09% in shrews. Additionally, one of the two samples in lions was seropositive. A significant difference in the prevalence P<0.05 was observed between cattle and goats. No significant difference in prevalence was observed with respect to age and sex in humans or any of the sampled animal species. The most prevalent serogroups with antibodies of Leptospira spp were Sejroe, Hebdomadis, Grippotyphosa, Icterohaemorrhagie and Australis, which were detected in humans, cattle, goats and buffaloes; Sejroe and Grippotyphosa, which were detected in a lion; Australis, Icterohaemorrhagie and Grippotyphosa, which were detected in rodents; and Australis, which was detected in shrews. Antibodies to serogroup Ballum were detected only in humans.ConclusionsThe results of this study demonstrate that leptospiral antibodies are widely prevalent in humans, livestock and wildlife from the Katavi-Rukwa ecosystem. The disease poses a serious economic and public health threat in the study area. This epidemiological study provides information on circulating serogroups, which will be essential in designing intervention measures to reduce the risk of disease transmission.

Project description:BackgroundBrucellosis is an infectious zoonotic disease that poses serious health threats around the world including Uganda. Brucellosis is caused by Brucella spp., the bacteria being transmitted via contact through skin breaks, via inhalation, or orally through the consumption of raw milk and other dairy products. The aim of this study was to investigate self-reported prevalence, knowledge, and perceptions towards brucellosis transmission, within agro-pastoralist communities in the Nakasongola district, central Uganda.MethodsThis study employed a cross-sectional survey design. A semi-structured questionnaire was developed and administered to 398 participants selected through convenience sampling method. The survey gathered information on socio-demographic characteristics, knowledge of brucellosis transmission, symptoms, preventive measures, and self-reported prevalence of brucellosis. Qualitative data involved the use of six focus group discussions, identifying factors for transmission based on their perceived level of risk or impact using ranking by proportional piling.ResultsA majority (99.2%, n = 398) had heard about brucellosis and 71.2% were aware of the zoonotic nature of the disease. There were varied responses regarding transmission routes, symptoms, and preventive measures. Self-reported prevalence was relatively high (55.5%). Following adjusted analysis, factors such as subcounty, source of income, knowledge about symptoms of brucellosis, whether brucellosis is treatable, perception, and living close to animals were statistically significant. Participants from Wabinyonyi had 2.7 higher odds of reporting brucellosis than those from Nabiswera, aOR = 2.7, 95%CI 1.4-5.5. Crop farming and livestock had much higher odds of reporting brucellosis than those earning from casual sources, aOR = 8.5, 95%C 1.8-40.1 and aOR = 14.4, 95%CI 3.1-67.6, respectively. Those who had knowledge about symptoms had 6.9 higher odds of reporting brucellosis than who mentioned fever, aOR = 4.5, 95%CI 2.3-18.3. Likewise, living close with animals and handling aborted fetuses (aOR = 0.4, 95%CI: 0.17-0.86), (aOR = 0.2,95% CI: 0.07-0.0.42,) had significantly lower odds for self-reported prevalence compared to those who believed did not cause brucellosis. Risk factors identified included, handling of aborted fetuses and living in close proximity with animals. Overall, there was a moderate statistical agreement in the ranking across the focus groups discussion (Wc = 0.48, p < 0.01; n = 6).ConclusionWhile awareness of brucellosis is high in the community, understanding of the transmission routes, clinical symptoms, and preventive measures varied. Investigating the understanding and assessing knowledge, perceptions and self-reported prevalence in this region indicated a necessity for risk communication strategies and community-based interventions to better control brucellosis transmission.

Dataset Information

Human leptospirosis in Tanzania: sequencing and phylogenetic analysis confirm that pathogenic Leptospira species circulate among agro-pastoralists living in Katavi-Rukwa ecosystem.

Publications

Human leptospirosis in Tanzania: sequencing and phylogenetic analysis confirm that pathogenic Leptospira species circulate among agro-pastoralists living in Katavi-Rukwa ecosystem.

Similar Datasets

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