The Epidemiology and Socio-economic Impact of Rift Valley Fever in Tanzania a Review

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• Published: fourteen June 2018

Sero-prevalence and spatial distribution of Rift Valley fever infection among agro-pastoral and pastoral communities during Interepidemic catamenia in the Serengeti ecosystem, northern Tanzania

BMC Infectious Diseases volume xviii, Commodity number:276 (2018) Cite this article

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Abstract

Background

In the past ii decades, Rift Valley Fever (RVF) outbreaks have been reported twice in Tanzania, with the most recent outbreak occurring in 2006/07. Given the ecology and climatic factors that back up musquito vectors in the Serengeti ecosystem, we hypothesized a continued transmission of RVF virus (RVFV) during interepidemic periods. This written report was carried out to decide sero-prevalence, spatial distribution and factors associated with RVF in at-adventure agro-pastoral and pastoral communities in the Serengeti Ecosystem in northern Tanzania.

Methods

A cross exclusive study was carried out to establish the general exposure to RVFV past detecting anti–RVFV IgG and anti–RVFV IgM using ELISA techniques. The health facilities where homo subjects were claret sampled concurrent with interviews included Bunda District Designated Hospital, Wasso DDH, Endulen hospital, Arash, Malambo, Olbabal, and Piyaya dispenaries (Ngorongoro commune) and Nyerere DDH (Serengeti district) respectively. In addition, human subjects from Lamadi ward (Busega district) were recruited while receiving medical service at Bunda DDH. We conducted logistic regression to assess independent hazard factor and mapped the hotspot areas for exposure to RVFV.

Results

A total of 751 subjects (males = 41.5%; females = 58.5%) with a median age of 35.5 years were enrolled at out-patient clinics. Of them, 34 (4.five, 95%CI 3.3–vi.iii%) tested positive for anti–RVFV IgG. Of the 34 that tested positive for anti–RVFV IgG, six (17.vi%) tested positive for anti–RVFV IgM. Odds of exposure were higher among pastoral communities (aOR two.9, 95% C.I: 1.21–6.89, p < 0.01), and agro-pastoral communities residing in Ngorongoro District (aOR 1.8, 95% C.I ane.fourteen–three.39, p = 0.03). Hotspot areas for exposure to RVFV were Malambo, Olbalbal and Piyaya wards in Ngorongoro district, and Lamadi ward in Busega district.

Conclusions

The study found both previous and contempo exposure of RVFV in humans residing in the Serengeti ecosystem equally antibodies against both IgG and IgM were detected. Detection of anti-RVF IgM suggests an ongoing manual of RVFV in humans during inter-epidemic periods. Residents of Ngorongoro commune were most exposed to RVFV compared to Bunda and Serengeti districts. Therefore, the hazard of exposure to RVFV was higher among pastoral communities compared to farming communities.

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Background

Rift Valley Fever (RVF) is a viral zoonotic fever acquired by RVF virus (RVFV), a member of the genus Phlebovirus in the family Bunyaviridae [1,2,3]. It is an illness characterized by deaths and abortion storms primarily in goats, sheep, and cattle [4]. The illness likewise affects humans, dogs, camels and wildlife [v]. Wild animals such as African buffalo (Syncerus caffer), black rhino (Diceros bicornis), lesser kudu (Tragelaphus imberbis), impala (Aepyceros melampus), kongoni (Alcelaphus buselaphus), monkeys (Cercopithecus spp.), waterbuck (Kobus ellipsiprymnus) and African elephants (Loxodonta africana) have shown to be exposed to the virus [6, 7].

Tanzania has experienced 10 epidemic episodes of RVF since 1930s. During the final RVF epidemic a example fatality of 46% was reported among humans [six,7,8]. Death of animals due to the illness was estimated to toll around 6 1000000 Us dollars, with external market flow dropping by 54% [8] Shortage of meat and milk probably acquired acute malnutrition [ix]. Well-nigh of the markets were closed and toll of alternative source of poly peptide such as fish and craven was very high [nine, 10]. In humans, RVFV usually causes balmy fever that is ofttimes associated with spontaneous recovery [half-dozen, 9]. However, infections characterized by flu-similar illness, headache, muscles and joint pain, diarrhoea, vomiting [11] anorexia and loftier respiratory rate [12] practice occur. RVFV may cause serious hepatitis and liver necrosis [6, 7] besides as other complications including loss of eyesight, meningo-encephalitis and haemorrhagic fever [6, thirteen]. Economically, autonomously from high livestock loss, the epidemic may affect the tourism industry that contributes over 17% of Gross domestic product in Tanzania [14] considering of fear among tourists of contacting the disease from afflicted wildlife and loss of animal species that are sought for game viewing.

Despite the severity of the RVF, footling is known regarding prevalence and exposure status of humans in different ecosystems in Tanzania. Previous studies conducted in Kilombero valley in eastern Tanzania showed high manual of the disease in livestock, with sero-prevalence of 5.5% among animals born after last epidemic of 2007 [ix]. Correspondingly, current study in the Serengeti ecosystem, which is the sister study to this, has found contempo exposure amongst domestic animals and wild fauna. Cattle and sheep recorded IgM prevalence of five.seven% while buffaloes recorded 3.1% of IgM prevalence (Nyarobi unpublished). RVFV-RNA was extracted from 2.seven% of mosquitoes pools studied in the ecosystem (Nyarobi unpublished). This has raised need to understand the current disease burden in humans and predict the possibility of future outbreak. Therefore, this study was done to determine the exposure status of RVFV, its spatial distribution and factors associated with exposure to RVFV among pastoral and agro-pastoral communities of the Serengeti ecosystem.

Methods

Study surface area and population

The study was conducted in the Serengeti ecosystem in northern regions of Tanzania. The area included 3 districts of Bunda, Ngorongoro and Serengeti in the Serengeti ecosystem, (Fig. i). However, some human subjects were enrolled from Lamadi ward in Busega district. The expanse is located forth the border with Kenya, close to the equator, betwixt 2o to 4o S. minimum temperature ranges between fifteen-21oC, while maximum ranges between 24-27oC. The rainfall is highly seasonal with peaks in March to May and November to December. Mean annual rainfall in the Serengeti varies from 1050 mm in the northwest to 550 mm in the southeast. The surface area is covered with rich volcanic soil that supports the growth of vegetation. Meshwork of streams of h2o bodies are found throughout the area. The ecosystem extends to the shores of Lake Victoria in the w, (where Bunda and Busega districts are located), Lake Eyasi in the south and the Dandy Rift Valley to the east, covering Ngorongoro Conservation Area (NCA) and Loliondo Game Controlled Area (LGCA) in Ngorongoro district. The study also extended to the western side in Serengeti and Bunda districts (Fig. 1). Soil type, grassy apparently, temperature and rainfall of the ecosystem favor the endemicity of the disease in the area. The communities surrounding the surface area are mainly of pastoral and agro-pastoral communities. Pastoral communities are those deriving their income solely past keeping animals similar cattle, sheep, goats, donkey and dogs. Agro-pastoral communities are those depending on crop tillage supplemented with animal keeping mostly in small scale.

Fig. 1

Map of Serengeti ecosystem showing districts where anti RVF IgG seropositive humans were identified (see attached document)

Full size image

Study design and setting

A cantankerous-sectional, health facility based written report was conducted on humans in the Serengeti ecosystem during the dry flavor of August–October, 2014. The health facilities where the study were conducted included Wasso District Designated Hospital (DDH), Endulen hospital, Malambo, Piyaya, Arash and Olbabal dispensaries in Ngorongoro District; Bunda DDH in Bunda district and Nyerere DDH in Serengeti commune respectively. As a hospital-based study, participants from Lamadi ward (Busega district) bordering Bunda commune were also enrolled as they were frequently seeking medical services at Bunda DDH. We enrolled patients anile 5 years and in a higher place attending outpatient department (OPD) regardless of their clinical presentation. Patients who could not give assent or consent and those who were critically ill to give data were excluded from the study. A total of 751 human subjects were included in the report. Probability proportion to population size was used to classify the calculated sample size to the 3 districts' health facilities. The three districts of Ngorongoro, Serengeti and Bunda districts were allocated 210, 241 and 300 study respondents respectively. Based on geographical nature and sparse population distribution of Ngorongoro commune, apart from commune hospital, more health facilities were included in the study to allow wider coverage of all parts of the district as much as possible. The additional health facilities were Endulen hospital, as well as Malambo, Piyaya, Arash, and Olbalbal dispensaries. These are the main health facilities in the area that provide services to all population in the report area. Elementary random sampling technique was used to select participants amid out-patients who visited the respective health facility for medical services or individuals who escorted relatives for medical services in the eight health facilities in the three commune i.due east. six health facilities in Ngorongoro district, i in Bunda and one in Serengeti districts respectively. The coordinates of the study sites were recorded using a Global Positioning Organisation (GPS) device for subsequent apply in marker the sampling sites and indicate locations with sero-positive human subjects in the study expanse. In Tanzania, the mean straight-line altitude to a health facility is most 4.2 km (SD 3.ix km) [15].

Laboratory investigation

Approximately, 4 mls of whole man blood was fatigued aseptically from each patient recruited in the study. Approximately i–2 mls of sera was obtained from each blood sample through centrifugation, and transferred into screw capped cryovials and stored at -twenty °C freezer awaiting serological analysis. Sera from patients were tested for the presence of anti-RVFV IgG antibody using competitive Enzyme linked Immuno-sorbent Assay (ID.Vet Innovative Diagnostics, Grabels, France). The examination has excellent sensitivity and specificity of 100%. Detection of anti-RVFV IgM was washed using capture ELISA kit, to all anti-RVFV IgG positive samples as described by the manufacturer (Biological Diagnostics Supply Limited -BDSL, UK). The sensitivity test was 100% and specificity ranged from 97.4 to 99.4% [16]. Validation of the results was done by repeating all positive and 10% of the negative samples and found 100% cyclopedia between the first exam and observed validation exam.

Data management and statistical assay

Information on social demographic characteristics including age, sex, level of education, occupation and area of residence was collected. Median, range, and proportion of seropositive samples amid those tested for anti-RVFV IgG (general exposure status) and anti-RVFV IgM (contempo exposure condition) were calculated. A number of socio-demographic factors associated with RVFV sero-positivity were assessed using prevalence Odds Ratio (OR) as a mensurate of association at 95% conviction interval. Socio-demographic factors with p-value ≤0.05 were considered as statistically significant in bivariate analysis. All variables with p ≤ 0.2 at bivariate level were entered into multivariate logistic regression model. Variables with p-value ≤0.05 at multivariate level were considered independently associated with RVF seropositivity.

Results

A total of 751 participants were enrolled in this report. Their median historic period was 35.v years (range = 5–90 years). Of them, 439 (58.5%) were females, 294 (45.nine%) were pocket-sized scale farmers, 420 (63.eight%) had primary education and 300 (twoscore%) were from Bunda district (Table ane).

Table 1 Socio-demographic distribution of study respondents in the Serengeti ecosystem, 2014

Full size table

Out of 751 participants tested for anti-RVFV IgG, 34 tested positive making the overall sero-prevalence of 4.five% (95% C.I 3.2–half dozen.3%) (Tabular array 2). Of the 34 positive anti-RVFV IgG subjects, vi (17.6%) tested positive for anti-RVFV IgM. Ngorongoro district recorded loftier seroprevalence of anti-RVFV antibodies of 8.1%, (17 of 210) compared to 2.i% recorded in Serengeti district (5 of 241) (P = 0.003) (Table 2). The seroprevalence of RVFV was significantly higher among pastoralists (8.nine%, twenty of 227) compared to agro-pastoralists (3.4%, 10 of 294) (p = 0.008) (Tabular array 2).

Table 2 Seroprevalence of anti-RVFV IgG by demographic factors in the Serengeti ecosystem, 2014

Total size table

The odds of testing positive were almost 3 times college among the pastoralists as compared to other occupational groups, which are pocket-sized scale farmers, businessmen and employees. (aOR 2.9, 95% C.I: i.21–vi.89, p < 0.01) (Table three). Those respondents who came from Ngorongoro (pastoral communities) were ii times more likely to test positive for anti-RVFV IgG every bit compared to respondents from other districts (aOR one.8, 95% C.I 1.14–3.39, p = 0.03) (Table 3). Age, sex and level of educational activity were statistically not associated with exposure to RVFV (Tabular array iii).

Table three Socio-demographic factors associated with RVFV sero-positivity in the Serengeti ecosystem, 2014

Full size table

The number of anti-RVFV IgG seroposivity was highest in Malambo, followed by Olbalbal, Nyerere (Serengeti) and Bunda health facilities. The seropositivity of IgM was adamant from IgG seropositive samples only, and was sparsely distributed in Endulen, Piyaya, and Malambo in Ngorongoro district, as well as Bunda and Serengeti districts. Despite the higher anti-RVFV IgG seroprevalence in Olbalbal, no anti-RVFV IgM was detected (Fig. ane).

Word

This written report has shown past and contempo exposure to RVFV in the Serengeti ecosystem, as both anti-RVFV IgG and IgM were detected. Anti-RVFV IgG antibodies are believed to last decades after infection and so provide a reliable index of prior RVF exposure. In contrast, anti-RVFV IgM has been reported to persist for but 6 to 8 weeks later on initial infection [15]. Thus, finding anti-RVFV IgM antibodies does suggest recent exposure to the RVF infection amongst humans residing in the Serengeti ecosystem during interepidemic period. Living in Ngorongoro and being a pastoralist were the two common risk factors associated with exposure to RVF infection in our written report.

The overall seroprevalence (4.5%) of RVF in the Serengeti ecosystem was slightly higher than (4%) previously reported in Tanga before the 2006/7 outbreak [17]. The slight increase of prevalence in this study might be because of cumulative exposure to RVFV infection in humans. Detection of anti-RVFV IgM among IgG seropositive humans was testify that there is ongoing transmission of infection among humans during the interepidemic menstruum. Lack of clinical RVF cases among anti-RVFV IgM positive humans might be due to the fact that the infections were sub-clinical or they were being missed or misdiagnosed for other disease atmospheric condition at health facilities, and this needs more than studies. The ongoing transmission may be facilitated by the presence of several species of mosquitoes capable of spreading the illness [18, xix]. Some of these mosquitoes have been shown to be infected with RVFV in sister study to this (Nyarobi unpublished). In addition, eating raw animal products, including meat, claret and unpasteurised milk is a mutual practice among customs members living in the written report expanse [17, 20]. The detection might also be due to exposure to infected animals and wildlife in the area. The recorded anti-RVFV IgM seropositivity among anti-RVFV IgG reactive samples which were (17.6%) in this study, was depression compared to that of (23%) recorded in study done shortly after 2006 outbreak [17]. However, there are several studies that didn't discover any anti-RVFV IgM seropositive individuals in spite of presence of anti-RVFV IgG seropositive in both human being [18, 21] and other vertebrate samples [5]. A large sample size may exist useful to notice presence of IgM confronting the disease during interepidemic menses particularly in humans.

The evidence of spatial distribution of cases in this study shows that Ngorongoro district had higher seroprevalence, especially in Malambo, Olbabal and Piyaya wards, all of which are typical pastoral communities. In Bunda and Serengeti, well-nigh of the seropositive individuals were plant from people residing by and large where pastoral and agro-pastoral activities accept identify, while in Ngorongoro, cases were from typical pastoral communities. The findings is in line with previous studies, where number of clusters of RVF cases was constitute in several parts of Ngorongoro but neither in Bunda nor in Serengeti [8]. However, further enquiry is needed to observe out the reason backside this. It might be considering of uncontrolled motion of live animals and brute products from Ngorongoro, although data on livestock motion is very scarce [viii]. Some of the seropositive individuals in Bunda DDH were coming from the Lamadi ward in Busega district, which is bordering Bunda district, and nearly to where RVF virus nucleic acids was recently detected in competent vector mosquitoes past Nyarobi, (unpublished).

Geographically, Ngorongoro district had the highest seroprevalence of anti-RVFV IgG compared to Bunda and Serengeti districts. The big area of Ngorongoro district is sparsely populated and livestock keeping is the main activity of the residents, equally no cultivation is allowed in the surface area. The higher exposure rate in Ngorongoro commune could be attributed by the 2006/07 RVF outbreak [half dozen]. Loftier rainfall, high temperature and soil texture supportive of flooding in Malambo ward in Ngorongoro, and high animal density in the ecosystem may account for high illness prevalence in Ngorongoro district [viii]. It is known that Rift Valley fever virus once introduced in the area, continues to exist for decades equally it is maintained by Aedes mosquitoes through vertical transmission [22]. Thus effective surveillance should be enhanced in order to detect cases as early as possible also equally prediction of future outbreaks using satellite mapping. Also, community members should be informed on the current illness status, so that residents tin be motivated to adhere with preventive measures in lodge to keep themselves rubber from contracting the disease.

In this study, pastoralists were more than exposed to RVFV with anti-RVFV IgG seroprevalence of viii.9% compared to other occupations three.0%, which is in line with findings of other studies [23, 24]. This findings may be due to occupationally related risk of exposure exacerbated by high contact to infected animals and consumption of raw beast products such as blood, meat and milk [nine]. Increased exposure might exist enhanced because of poor community noesis; attitude and practices related to RVFV infection and transmission pathways. For example, Maasai are used to keep their animals indoors during night to prevent them from wild carnivores' attacks [20]. This practise increases the frequency of contact to animals and hence potential for animal-human manual during outbreak.

The study was washed in the Serengeti ecosystem, where several outbreaks of Rift Valley Fever have been reported previously [6, 7]. Thus the findings cannot exist extrapolated to the entire state and may accept limitation in generalization to other area of Tanzania. Likewise, as the study was cross-exclusive in nature, it tin can but determine human relationship at indicate in time and hence cannot determine temporal human relationship. The study was designed as infirmary-based written report because of time limitation and fiscal constraints. The findings from this study can be used as an estimate of anti-RVF IgG and IgM seroprevalence in the Serengeti ecosystem, however, hospital-based written report might take some bias and therefore information technology could be improved if it were supported past customs survey.

Another potential limitation is not performing confirmatory virus neutralization test. Withal, comparison of IgG-sandwich and IgM-capture ELISA with virus neutralization exam on field-collected sera from Africa (north = 2400) constitute the sensitivity of the IgG-sandwich ELISA was 100% and specificity 99.95%, while for the IgM-capture ELISA the values were 96.47 and 99.44%, respectively [19].

Following detection of anti-RVFV IgM, there is however, the demand to conduct a study to decide the virulence of the viral strains circulating in the ecosystem. There might exist some strains, which are less virulent compared to the previous ones, or its virulence might have been altered by mutation due to lack of clinical cases during the study.

Conclusion

The study found both previous and contempo exposure of RVFV in humans residing in the Serengeti ecosystem as antibodies against both IgG and IgM were detected. Detection of anti-RVFV IgM suggests an ongoing transmission of RVFV in humans during interepidemic periods. Since recent exposure to the disease was found in this study, wellness intendance workers should consider RVF during their differential diagnosis of fever, especially for patients coming from pastoral communities, or those highly exposed to animals and raw fauna products. Enhanced, well organized and constructive surveillance organisation should be in place to discover cases as early as possible.

Abbreviations

aOR:

Adjust odds ratio

DDH:

District designated hospital

Gross domestic product:

Gross domestic product

GPS:

Global positioning organisation

LGCA:

Loliondo game controlled area

MUHAS:

Muhimbili University of Health and Allied Sciences

NCA:

Ngorongoro conservation area

OPD:

Outpatient Department

OR:

Odds ratio

RVF:

Rift valley fever

TFELTP:

Tanzanian field epidemiology and laboratory direction training programme

References

1. Caroline AL, Powell DS, Bethel LM, Oury TD, Reed DS, Hartman AL. Broad spectrum antiviral activity of favipiravir (T-705): protection from highly lethal inhalational Rift Valley fever. PLoS Negl Trop Dis. 2014 April;8(4):e2790.

   Article  PubMed  PubMed Central  CAS  Google Scholar

2. Caminade C, Ndione JA, Diallo M, Macleod DA, Faye O. Rift Valley fever outbreaks in Mauritania and related environmental conditions. Int J Environ Res Public Health. 2014;11(10):903–18.

   Commodity  PubMed  PubMed Central  Google Scholar

3. Kahlon SS, Peter CJ, LeDuc J, Muchiri EM, Muiruri Southward, Njenga MK, et al. Case report: severe rift valley fever may present with a characteristic clinical syndrome. Am J Trop Med Hyg. 2010;82(3):371–5.

   Article  PubMed  PubMed Cardinal  Google Scholar

4. Gerdes GH. Rift Valley fever The importance of Rift Valley fever for fauna and public. Africa (Lond) [Internet] 2004;23(2):613–623. Bachelor from: https://pdfs.semanticscholar.org/abe9/8850bbd310910b95830d6ceaa64ec42fdb23.pdf.

5. Joshua Grand, Sallu R. Epidemiological study of Rift Valley fever virus in. Onderstepoort J Vet Res. 2014;8(2):2–half dozen.

   Google Scholar

6. Labeaud AD, Cross PC, Getz WM, Glinka A, King CH. Rift Valley Fever Virus Infection in African Buffalo (Syncerus caffer) Herds in Rural South Africa : Evidence of Interepidemic Transmission. Am J Trop Med Hyg. 2011;84(4):641–6.

   Commodity  PubMed  PubMed Fundamental  Google Scholar

7. Chiyo PI, Ng E. Spatio-temporal variation in prevalence of Rift Valley fever: a post- epidemic serum survey in cattle and wildlife in Kenya. Infect Ecol Epidemiol. 2015;1(2):1–8.

   Google Scholar

8. Mohamed M, Mosha F, Mghamba J, Zaki SR, Shieh WJ, Paweska J, et al. Epidemiologic and clinical aspects of a Rift Valley fever outbreak in humans in Tanzania, 2007. Am J Trop Med Hyg. 2010;83(ii SUPPL):22–7.

   Commodity  PubMed  PubMed Primal  Google Scholar

9. Fyumagwa RD, Ezekiel MJ, Nyaki A, Mdaki ML, Katale ZB. Response to Rift Valley fever in Tanzania: challenges and opportunities. Tanzan J Wellness Res. 2011;13(Dec):1–9.

   Google Scholar

10. Sindato C, Karimuribo ED, Pfeiffer DU, Mboera LEG, Kivaria F, Dautu M, et al. Spatial and temporal pattern of Rift Valley fever outbreaks in Tanzania; 1930 to 2007. Tanzania J Health Res. 2014;9(2):888–97.

    Google Scholar

11. Chengula AA, Mdegela RH, Kasanga CJ. Socio-economic impact of Rift Valley fever to pastoralists and agro pastoralists in Arusha, Manyara and Morogoro regions in Tanzania. Springerplus. 2013 Jan;2(1):549.

    Commodity  PubMed  PubMed Fundamental  Google Scholar

12. Sindato C, Karimuribo ED, Mboera LEG. The epidemiology and socio-economic impact of Rift Valley fever epidemics in Tanzania: a review. Tanzan J Wellness Res. 2007;ane(ii):20–2.

    Google Scholar

13. Chipwaza B, Mugasa JP, Mayumana I, Amuri M, Makungu C, Gwakisa PS. Community knowledge and attitudes and health workers' practices regarding not-malaria delirious illnesses in eastern Tanzania. PLoS Negl Trop Dis. 2014 May;8(5):28–96.

    Article  Google Scholar

14. Fafetine J, Neves L, Thompson PN, Paweska JT, Rutten VPMG, Coetzer JAW. Serological evidence of Rift Valley fever virus circulation in sheep and goats in Zambézia Province, Mozambique. PLoS Negl Trop Dis. 2013;vii(2):ane–8.

    Article  Google Scholar

15. Shieh W-J, Paddock CD, Lederman East, Rao CY, Gould LH, Mohamed M, et al. Pathologic studies on doubtable animal and human cases of Rift Valley fever from an outbreak in eastern Africa, 2006-2007. Am J Trop Med Hyg. 2010 Aug;83(two Suppl):38–42.

    Article  PubMed  PubMed Central  Google Scholar

16. Paweska JT, Burt FJ, Anthony F, Smith SJ, Grobbelaar AA, Croft JE, et al. IgG-sandwich and IgM-capture enzyme-linked immunosorbent assay for the detection of antibody to Rift Valley fever virus in domestic ruminants. J Virol Methods. 2003 Nov;113(2):103–12.

    Commodity  PubMed  CAS  Google Scholar

17. Mwakatobe A, Nyahongo JW, Røskaft E. Livestock depredation by carnivores in the Serengeti ecosystem, Tanzania. Environ Nat Resour Res. 2013;3(4):46–57.

    Google Scholar

18. Sumaye RD, Geubbels East, Mbeyela Due east, Berkvens D. Inter-epidemic manual of Rift Valley fever in livestock in the Kilombero River valley, Tanzania : a cross-survey. PLoS Negl Trop Dis. 2013;seven(8):e2356.

    Article  PubMed  PubMed Central  Google Scholar

19. Paweska JT, Felicity J, Burt RS. Validation of IgG-sandwich and IgM-capture ELISA for the detection of antibody to Rift Valley fever virus in humans. J Virol Methods. 124(1–2):173–81.

20. Swai ES, Choonman L. Prevalence of Rift Valley fever immunoglobulin G antibiotic in diverse occupational groups earlier the 2007 outbreak in Tanzania. Vector-Borne Zoonotic Dis. 2009;9:579-82.

21. Mhina AD, Kasanga CJ, Sindato C, Karimuribo Due east, Mboera LEG. Rift Valley fever potential musquito vectors and their infection status in Ngorongoro district in Northern Tanzania. Tanzan J Health Res. 2015;17(4):1-9.

22. Mweya CN, Kimera SI, Mellau LS, Mboera LE. Inter-epidemic abundance and distribution of potential mosquito vectors for Rift Valley fever virus in Ngorongoro district, Tanzania. Glob Health Action. 2015;viii:25929.

23. Muiruri S, Sutherland LJ, Dahir S, Gildengorin One thousand, Muchiri EM, Peters CJ, et al. Postepidemic assay of Rift Valley fever virus transmission in northeastern Kenya: a village cohort study. Trop Med Int Heal. 2011;five(viii):1420–9.

24. Nicholas DE, Jacobsen KH, Waters NM. Risk factors associated with man Rift Valley fever infection: systematic review and meta-analysis. Trop Med Int Health. 2014;19(12):1420–nine.

    Article  PubMed  Google Scholar

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Acknowledgements

We acknowledge the Nelson Mandela African Institute of Science and Engineering and National Health Laboratory Quality Assurance and Training Centre for permission to use their laboratory facilities for sample analysis. We would like to thank Dr. Moshiro Candida and Alfred Musekiwa for statistical support, and fellow residents and TFELP staff, Dorothy L Southern and Leonard Mboera for useful comments in this paper. Mr. Machoke is thanked for drawing a map for the study area. Mr. Mdaki is thanked for his participation in data collection and laboratory sample analysis.

Funding

This work was supported past funds from the Tanzanian Field Epidemiology and Laboratory Management Training Programme (TFELTP). The funding agency did not any mode influence the design of the study. Further funder did have access to the information and its direction.

Availability of data and materials

The data sets used in the analysis of this current study is readily bachelor from the corresponding author and can be accessed upon reasonable request.

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Affiliations

1. Tanzania Field Epidemiology and Laboratory Training Plan, Ministry of Wellness, Customs Development, Gender, Elderly and Children, P.O Box 71286, Ocean Road, Dar es Salaam, Tanzania

   Abade Ahmed & Jabir Makame

2. Department of Microbiology and Immunology, Muhimbili Academy of Health and Allied Science, Dar es Salaam, Tanzania

   Jabir Makame & Matee Mecky

3. Tanzania Wild fauna Research Establish, Arusha, Tanzania

   Fyumagwa Robert & Keyyu Julius

Contributions

AA, JM, FR, KJ, MM conceived and designed the study; JM contributed to sample collection; JM performed laboratory work; JM, AA, FR, KJ, MM analysed and interpreted the data; AA, JM, FR, KJ and MM drafted the manuscript While AA supervised the overall work; All authors read and approved the final manuscript.

Respective author

Correspondence to Abade Ahmed.

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Ethics approval and consent to participate

We obtained written informed consent from all written report participants. For the instance of children, Consent was obtained from the parents/guardians of children who participated in the written report and assent was sought for those aged 7–17 years. The written report was reviewed and canonical by the Upstanding Committee of Muhimbili University of Health and Centrolineal Sciences (MUHAS). Potency to conduct the study was obtained from Tanzania Wild animals Research Institute, Commission for Science and Technology, Ngorongoro Conservation Expanse Authority, the respective Commune Councils for Bunda, Ngorongoro, Serengeti and the Management of the respective wellness facilities.

Competing interests

The authors declare that they take no competing interests.

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Ahmed, A., Makame, J., Robert, F. et al. Sero-prevalence and spatial distribution of Rift Valley fever infection amid agro-pastoral and pastoral communities during Interepidemic period in the Serengeti ecosystem, northern Tanzania. BMC Infect Dis 18, 276 (2018). https://doi.org/ten.1186/s12879-018-3183-9

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• Received: 17 March 2017

• Accepted: 03 June 2018

• Published: 14 June 2018

• DOI : https://doi.org/10.1186/s12879-018-3183-9

Keywords

• Rift valley
• Serengeti ecosystem
• Inter-epidemic homo
• Tanzania

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