Seroprevalence and Associated Risk Factors of Rift Valley Fever in Livestock from Three Ecological Zones of Malawi
Abstract
:1. Introduction
2. Materials and Methods
2.1. Study Sites
2.2. Agro-Ecological Zones in Malawi
2.3. Study Design and Sampling
2.4. Sample Size Estimate
2.5. Sample Collection, Storage, and Transportation
2.6. Serum Sample Laboratory Analysis
2.6.1. IgG ELISA
2.6.2. IgM ELISA
2.7. Questionnaire Administration
2.8. Data Analysis
3. Results
3.1. Description of Study Population
3.2. RVFV Antibodies Results
3.3. Seroprevalence by Livestock Species at Individual Animal Level
3.4. Seroprevalence in Ecological Zones and Districts
3.5. Seroprevalence According to the Sex and Age
3.6. RVFV Seroprevalence at Livestock Herd Level
3.7. Analysis of Association between Potential Risk Factors and RVFV Seropositivity
3.8. Determining Potential Risk Factors
4. Discussion
5. Conclusions
Supplementary Materials
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
- King, A.M.Q.; Lefkowitz, E.J.; Mushegian, A.R.; Adams, M.J.; Dutilh, B.E.; Gorbalenya, A.E.; Harrach, B.; Harrison, R.L.; Junglen, S.; Knowles, N.J.; et al. Changes to taxonomy and the International Code of Virus Classification and Nomenclature ratified by the International Committee on Taxonomy of Viruses. Arch. Virol. 2018, 163, 2601–2631. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Gauliard, N.; Billecocq, A.; Flick, R.; Bouloy, M. Rift Valley Fever virus noncoding regions of L, M and S segments regulate RNA synthesis. Virology 2006, 351, 170–179. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Suzich, J.A.; Kakach, L.T.; Collett, M.S. Expression strategy of a Phlebovirus: Biogenesis of proteins from the Rift Valley Fever virus M segment. J. Virol. 1990, 64, 1549–1555. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Bird, B.H.; Khristova, M.L.; Rollin, P.E.; Ksiazek, T.G.; Nichol, S.T. Complete Genome Analysis of 33 Ecologically and Biologically Diverse Rift Valley Fever Virus Strains Reveals Widespread Virus Movement and Low Genetic Diversity due to Recent Common Ancestry. Virol. J. 2007, 81, 2805–2816. [Google Scholar] [CrossRef] [Green Version]
- Grobbelaar, A.A.; Weyer, J.; Leman, P.A.; Kemp, A.; Paweska, J.T.; Swanepoel, R. Molecular epidemiology of Rift Valley fever virus. Emerg. Infect. Dis. 2011, 12, 2270–2276. [Google Scholar] [CrossRef]
- Tshilenge, G.M.; Justin, M.; Victor, M.; Marie, K.J.; Mark, R.; Léopold, M.M.K. Seroprevalence and Virus Activity of Rift Valley Fever in Cattle in Eastern Region of Democratic Republic of the Congo. J. Vet. Med. 2018, 2018, 4956378. [Google Scholar] [CrossRef] [Green Version]
- Juma, J.; Fonseca, V.; Konongoi, S.L.; van Heusden, P.; Roesel, K.; Sang, R.; Bett, B.; Christoffels, A.; de Oliveira, T.; Oyola, S.O. Genomic surveillance of Rift Valley fever virus: From sequencing to lineage assignment. BMC Genom. 2022, 23, 520. [Google Scholar] [CrossRef]
- Cêtre-Sossah, C.; Zeller, H.; Grandadam, M.; Caro, V.; Pettinelli, F.; Bouloy, M.; Cardinale, E.; Albina, E. Genome analysis of Rift Valley fever virus, Mayotte. Emerg. Infect. Dis. 2012, 18, 969–971. [Google Scholar] [CrossRef] [Green Version]
- Daubney, R.; Hudson, J.R.; Garnham, P.C. Enzootic hepatitis or Rift Valley fever. An undescribed virus disease of sheep cattle and man from East Africa. Am. J. Pathol. 1931, 34, 545–579. [Google Scholar] [CrossRef]
- Bird, B.H.; Ksiazek, T.G.; Nichol, S.T.; MacLachlan, N.J. Rift Valley fever virus. J. Am. Vet. Med. Assoc. 2009, 234, 883–893. [Google Scholar] [CrossRef]
- Jeanmaire, E.M.; Rabenarivahiny, R.; Biarmann, M.; Rabibisoa, L.; Ravaomanana, F.; Randriamparany, T.; Fy Andriamandimby, S.; Diaw, C.S.; Fenozara, P.; de La Rocque, S.; et al. Prevalence of Rift Valley fever infection in ruminants in Madagascar after the 2008 outbreak. Vector-Borne Zoonotic Dis. 2011, 11, 395–402. [Google Scholar] [CrossRef]
- Cêtre-Sossah, C.; Pédarrieu, A.; Guis, H.; Defernez, C.; Bouloy, M.; Favre, J.; Girard, S.; Cardinale, E.; Albina, E. Prevalence of Rift Valley Fever among Ruminants, Mayotte. Emerg. Infect. Dis. 2012, 18, 972–975. [Google Scholar] [CrossRef]
- Roger, M.; Girard, S.; Faharoudine, A.; Halifa, M.; Bouloy, M.; Cetre-Sossah, C.; Cardinale, E. Rift valley fever in ruminants, Republic of Comoros, 2009. Emerg. Infect. Dis. 2011, 17, 1319–1320. [Google Scholar] [CrossRef]
- World Health Organization. WHO Rift Valley Fever—Kenya. 12 February 2021. Available online: www.who.int/emergencies/disease-outbreak-news/item/2021-DON311 (accessed on 24 February 2022).
- Youssouf, H.; Subiros, M.; Dennetiere, G.; Collet, L.; Dommergues, L.; Pauvert, A.; Rabarison, P.; Vauloup-Fellous, C.; Le Godais, G.; Jaffar-Bandjee, M.C.; et al. Rift Valley Fever Outbreak, Mayotte, France, 2018-2019. Emerg. Infect Dis. 2020, 26, 769–772. [Google Scholar] [CrossRef]
- Pepin, M.; Bouloy, M.; Bird, B.H.; Kemp, A.; Paweska, J. Rift Valley fever virus (Bunyaviridae: Phlebovirus): An update on pathogenesis, molecular epidemiology, vectors, diagnostics and prevention. Vet. Res. 2010, 41, 61–101. [Google Scholar] [CrossRef] [Green Version]
- Thonnon, J.; Picquet, M.; Thiongane, Y.; Lo, M.; Sylla, R.; Vercruysse, J. Rift valley fever surveillance in the lower Senegal River Basin: Update 10 years after the epidemic. Trop Med. Int. Health 1999, 4, 580–585. [Google Scholar] [CrossRef] [Green Version]
- Ahmed, A.; Makame, J.; Robert, F.; Julius, K.; Mecky, M. Seroprevalence and spatial distribution of Rift Valley fever infection among agro-pastoral and pastoral communities during Interepidemic period in the Serengeti ecosystem, northern Tanzania. BMC Infect. Dis. 2018, 18, 276. [Google Scholar] [CrossRef] [Green Version]
- Saasa, N.; Kajihara, M.; Dautu, G.; Mori-Kajihara, A.; Fukushi, S.; Sinkala, Y.; Morikawa, S.; Mweene, A.; Takada, A.; Yoshimatsu, K.; et al. Expression of a Recombinant Nucleocapsid Protein of Rift Valley Fever Virus in Vero Cells as an Immunofluorescence Antigen and Its Use for Serosurveillance in Traditional Cattle Herds in Zambia. Vector Borne Zoonotic Dis. 2018, 18, 273–277. [Google Scholar] [CrossRef]
- Ngoshe, Y.B.; Avenant, A.; Rostal, M.K.; Karesh, W.B.; Paweska, J.T.; Bagge, W.; Jansen van Vuren, P.; Kemp, A.; Cordel, C.; Msimang, V.; et al. Patterns of Rift Valley fever virus seropositivity in domestic ruminants in central South Africa four years after a large outbreak. Sci Rep. 2020, 26, 5489. [Google Scholar] [CrossRef] [Green Version]
- Tshilenge, G.M.; Mulumba, M.L.; Misinzo, G.; Noad, R.; Dundon, W.G. Rift Valley fever virus in small ruminants in the Democratic Republic of the Congo. Onderstepoort J. Vet. Res. 2019, 86, e1–e5. [Google Scholar] [CrossRef]
- Blomström, A.L.; Scharin, I.; Stenberg, H.; Figueiredo, J.; Nhambirre, O.; Abilio, A.; Berg, M.; Fafetine, J. Seroprevalence of Rift Valley fever virus in sheep and goats in Zambézia, Mozambique. Infect. Ecol. Epidemiol. 2016, 4, 31343. [Google Scholar] [CrossRef] [Green Version]
- Linthicum, K.J.; Davies, F.G.; Kairo, A.; Bailey, C.L. Rift Valley fever virus (family Bunyaviridae, genus Phlebovirus). Isolations from Diptera collected during an inter-epizootic period in Kenya. J. Hyg. 1985, 95, 197–209. [Google Scholar] [CrossRef] [PubMed]
- Gear, J.; Botha de Meillon, C.B.; Le Roux, A.F.; Kofsky, R. Rift Valley fever in South Africa: A study of the 1953 outbreak in the Orange Free State, with special reference to the vectors and possible reservoir hosts. S. Afr. Med. J. 1955, 29, 514–518. [Google Scholar] [PubMed]
- Turell, M.J.; Linthicum, K.J.; Patrican, L.A.; Davies, F.G.; Kairo, A.; Bailey, C.L. Vector competence of selected African mosquito (Diptera: Culicidae) species for Rift Valley fever virus. J. Med. Entomol. 2008, 45, 102–108. [Google Scholar] [CrossRef] [PubMed]
- Linthicum, K.J.; Britch, S.C.; Anyamba, A. Rift Valley Fever: An Emerging Mosquito-Borne Disease. Annu. Rev. Entomol. 2016, 61, 395–415. [Google Scholar] [CrossRef]
- Cornel, A.J.; Lee, Y.; Almeida, A.P.G.; Johnson, T.; Mouatcho, J.; Venter, M.; de Jager, C.; Braack, L. Mosquito community composition in South Africa and some neighboring countries. Parasit. Vectors 2018, 11, 331. [Google Scholar] [CrossRef] [Green Version]
- Chambaro, H.M.; Hirose, K.; Sasaki, M.; Libanda, B.; Sinkala, Y.; Fandamu, P.; Muleya, W.; Banda, F.; Chizimu, F.; Squarre, D. An unusually long Rift valley fever inter-epizootic period in Zambia: Evidence for enzootic virus circulation and risk for disease outbreak. PLoS Negl. Trop. Dis. 2022, 16, e0010420. [Google Scholar] [CrossRef]
- World Health Organization. Rift Valley Fever–Kenya. Available online: https://www.who.int/csr/don/18-june-2018-rift-valley-fever-kenya/en/ (accessed on 3 November 2022).
- Davies, F.G.; Linthicum, K.J.; James, A.D. Rainfall and epizootic Rift Valley fever. Bull. World Health Org. 1985, 63, 941–943. [Google Scholar]
- Gudo, E.S.; Pinto, G.; Weyer, J.; le Roux, C.; Mandlaze, A.; José, A.F.; Paweska, J.T. Serological evidence of rift valley fever virus among acute febrile patients in Southern Mozambique during and after the 2013 heavy rainfall and flooding: Implication for the management of febrile illness. Virol J. 2016, 13, 96. [Google Scholar] [CrossRef] [Green Version]
- El Mamy, A.B.; Baba, M.O.; Barry, Y.; Isselmou, K.; Dia, M.L.; El Kory, M.O.; Diop, M.; Lo, M.M.; Thiongane, Y.; Bengoumi, M.; et al. Unexpected Rift Valley fever outbreak, northern Mauritania. Emerg. Infect. Dis. 2011, 17, 1894–1896. [Google Scholar] [CrossRef]
- Fafetine, J.M.; Coetzee, P.; Mubemba, B.; Nhambirre, O.; Neves, L.; Coetzer, J.; Venter, E.H. Rift Valley Fever Outbreak in Livestock, Mozambique, 2014. Emerg. Infect. Dis. 2016, 22, 2165–2167. [Google Scholar] [CrossRef]
- Sindato, C.; Karimuribo, E.; Mboera, L.E.G. The epidemiology and socio-economic impact of rift valley fever epidemics in Tanzania: A review. Tanzan. J. Health Res. 2011, 13, 305–318. [Google Scholar] [CrossRef] [Green Version]
- Sindato, C.; Karimuribo, E.; Mboera, E.G. The epidemiology and socio-economic impact of Rift Valley fever epidemics in Tanzania: A review. Onderstepoort J. Vet. Res. 2012, 79, 410–412. [Google Scholar] [CrossRef]
- Chengula, A.A.; Mdegela, R.H.; Kasanga, C.J. Socio-economic impact of Rift Valley fever to pastoralists and agro pastoralists in Arusha, Manyara and Morogoro regions in Tanzania. Springerplus 2013, 18, 549. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Millstone, E.; Odame, H.; Okumu, O. Rift Valley Fever in Kenya: Policies to Prepare and Respond, STEPS Working Paper 82, Brighton: STEPS Centre. 2015. Available online: https://steps-centre.org/publication/rift-valley-fever-in-kenya-policies-to-prepare-and-respond-briefing/ (accessed on 26 March 2021).
- Nanyingi, M.O.; Muchemi, G.M.; Thumbi, S.M.; Ade, F.; Onyango, C.O.; Kiama, S.G.; Bett, B. Seroepidemiological Survey of Rift Valley Fever Virus in Ruminants in Garissa, Kenya. Vector Borne Zoonotic Dis. 2017, 17, 141–146. [Google Scholar] [CrossRef] [PubMed]
- Fafetine, J.; Neves, L.; Thompson, P.N.; Paweska, J.T.; Rutten, V.P.M.G.; Coetzer, J.A.W. Serological Evidence of Rift Valley Fever Virus Circulation in Sheep and Goats in Zambézia Province, Mozambique. PLoS Negl. Trop. Dis. 2013, 7, e2065. [Google Scholar] [CrossRef] [Green Version]
- Msimang, V.; Thompson, P.N.; Jansen van Vuren, P.; Tempia, S.; Cordel, C.; Kgaladi, J.; Khosa, J.; Burt, F.J.; Liang, J.; Rostal, M.K.; et al. Rift Valley Fever Virus Exposure amongst Farmers, Farm Workers, and Veterinary Professionals in Central South Africa. Viruses 2019, 11, 140. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Archer, B.N.; Thomas, J.; Weyer, J.; Cengimbo, A.; Landoh, D.E.; Jacobs, C.; Ntuli, S.; Modise, M.; Mathonsi, M.; Mashishi, M.S.; et al. Epidemiologic Investigations into Outbreaks of Rift Valley Fever in Humans, South Africa, 2008–2011. Emerg. Infect. Dis. 2013, 19, 1918–1925. [Google Scholar] [CrossRef]
- Métras, R.; Jewell, C.; Porphyre, T.; Thompson, P.N.; Pfeiffer, D.U.; Collins, L.M. Risk factors associated with Rift Valley fever epidemics in South Africa in 2008–11. Sci. Rep. 2015, 5, 9492. [Google Scholar] [CrossRef]
- Kainga, H.; Mponela, J.; Basikolo, L.; Phonera, M.C.; Mpundu, P.; Munyeme, M.; Simulundu, E.; Saasa, N. Assessment of Knowledge, Attitudes, and Practices towards Rift Valley Fever among Livestock Farmers in Selected Districts of Malawi. Trop. Med. Infect. Dis. 2022, 7, 167. [Google Scholar] [CrossRef]
- Bryony, J. A sero-epidemiological study of Rift Valley fever in the Zomba Area of Malawi. Master’s Thesis, University of Edinburgh, Centre for Tropical Veterinary Medicine, Royal (Dick) School of Veterinary Studies, Scotland, UK, 1992. [Google Scholar]
- Edelsten, M. Rift Valley fever in Malawi. In Proceedings of the Annual Malawi Veterinary Association Conference, Blantyre, Malawi, 4 December 1990. [Google Scholar]
- Tebug, S.F.; Kasulo, V.; Chikagwa-Malunga, S.; Wiedemann, S.; Roberts, D.J.; Chagunda, M.G.G. Smallholder dairy production in Northern Malawi: Production practices and constraints. Trans. R. Soc. Trop. Med. Hyg. 2012, 44, 55–62. [Google Scholar] [CrossRef] [PubMed]
- Chintsanya, N.C.; Chinombo, D.O.; Gondwe, T.N.; Wanda, G.; Mwenda, A.R.E.; Banda, M.C.; Hami, J.C. Management of Farm Animal Genetic Resources in the SADC Region Malawi, SADC/UNDP/FAO PROJECT RAF/97/032. A Final Report on the State of the World’s Animal Genetic Resources. Available online: http://ndr.mw:8080/xmlui/bitstream/handle/123456789/662/MANAGEMENT%20OF%20FARM%20ANIMAL%20GENETIC%20RESOURCES%20in%20the%20SADC%20region.pdf?sequence=1 (accessed on 18 May 2021).
- Sikasunge, C.S.; Phiri, I.K.; Phiri, A.M.; Siziya, S.; Dorny, P.; Willingham, A.L. Prevalence of Taenia solium porcine cysticercosis in the Eastern, Southern and Western provinces of Zambia. Vet. J. 2008, 176, 240–244. [Google Scholar] [CrossRef]
- Sumaye, R.D.; Geubbels, E.; Mbeyela, E.; Berkvens, D. Inter-epidemic transmission of Rift Valley fever in livestock in the Kilombero River Valley, Tanzania: A cross-sectional survey. PLoS Negl. Trop. Dis. 2013, 7, e2356. [Google Scholar] [CrossRef] [PubMed]
- Thrusfield, M. Veterinary Epidemiology, 2nd ed.; Blackwell Science: Oxford, UK, 2005; pp. 117–198. [Google Scholar]
- Phonera, M.C.; Simuunza, M.C.; Kainga, H.; Ndebe, J.; Chembensofu, M.; Chatanga, E.; Kanyanda, S.; Changula, K.; Muleya, W.; Mubemba, B. Seroprevalence and Risk Factors of Crimean-Congo Hemorrhagic Fever in Cattle of Smallholder Farmers in Central Malawi. Pathogens 2021, 10, 1613. [Google Scholar] [CrossRef]
- Cochran, W.G. Sampling Techniques, 3rd ed.; Wiley: New York, NY, USA, 1977; p. 9780471162407. [Google Scholar]
- Baur, I.; Chiumia, D.; Gazzarin, C.; Lips, M. Perceived challenges in business development of smallholder dairy farmers in three Malawian Regions. Afr. J. Food Agric. Nutr. Dev. 2017, 17, 12791–12806. [Google Scholar] [CrossRef]
- WOAH. Collection and Shipment of Diagnostic Specimens. 2018. Available online: https://www.oie.int/fileadmin/Home/eng/Animal_Health_in_the_World/docs/pdf/1.1.01_collection.pdf (accessed on 22 January 2020).
- Comtet, L.; Pourquier, P.; Marié, J.; Davoust, B.; Cêtre-sossah, C. Preliminary validation of the ID Screen® Rift Valley fever competition multi-species ELISA. In Proceedings of the EAVLD Meeting, Lelystad, The Netherlands, 15–17 September 2010. [Google Scholar]
- Kortekaas, J.; Kant, J.; Vloet, R.; Cêtre-Sossah, C.; Marianneau, P.; Lacote, S.; Banyard, A.C.; Jeffries, C.; Eiden, M.; Groschup, M.; et al. European ring trial to evaluate ELISAs for the diagnosis of infection with Rift Valley fever virus. J. Virol. Methods 2013, 187, 177–181. [Google Scholar] [CrossRef]
- Cêtre-Sossah, C.; Billecocq, A.; Lancelot, R.; Defernez, C.; Favre, J.; Bouloy, M.; Martinez, D.; Albina, E. Evaluation of a commercial competitive ELISA for the detection of antibodies to Rift Valley fever virus in sera of domestic ruminants in France. Prev. Vet. Med. 2009, 90, 146–149. [Google Scholar] [CrossRef]
- Otte, J.; Chilonda, P. Classification of Cattle and Small Ruminant Production Systems in Sub-Saharan Africa. Outlook Agric. 2003, 32, 183–190. [Google Scholar] [CrossRef]
- Abdi, I.H.; Affognon, H.D.; Wanjoya, A.K.; Onyango-Ouma, W.; Sang, R. “Knowledge, Attitudes and Practices (KAP) on Rift Valley Fever among Pastoralist Communities of Ijara District, North Eastern Kenya. PLoS Negl. Trop. Dis. 2015, 9, e0004239. [Google Scholar] [CrossRef] [Green Version]
- Lichoti, J.K.; Kihara, A.; Oriko, A.A.; Okutoyi, L.A.; Wauna, J.O.; Tchouassi, D.P.; Tigoi, C.C.; Kemp, S.; Sang, R.; Mbabu, R.M. Detection of Rift Valley Fever Virus Interepidemic Activity in Some Hotspot Areas of Kenya by Sentinel Animal Surveillance, 2009–2012. Vet. Med. Int. 2014, 2014, 379010. [Google Scholar] [CrossRef] [Green Version]
- Sindato, C.; Pfeiffer, D.U.; Karimuribo, E.D.; Mboera, L.E.; Rweyemamu, M.M.; Paweska, J.T. A Spatial Analysis of Rift Valley Fever Virus Seropositivity in Domestic Ruminants in Tanzania. PLoS ONE 2015, 10, e0131873. [Google Scholar] [CrossRef] [PubMed]
- Ringot, D.; Durad, J.P.; Tolou, H.; Boutin, J.P.; Davoust, B. Rift Valley fever in Chad. Emerg. Infect. Dis. 2004, 10, 945–947. [Google Scholar] [CrossRef] [Green Version]
- Ngoshe, Y.B.; Avenant, L.; Rostal, M.K.; William, K.B.; Paweska, J.T.; van Vuren, J.; Cordel, C.; Msimang, V.; Thompson, P.N. Seroprevalence and factors associated with seropositivity to Rift Valley fever virus in livestock. Online J. Public Health Inform. 2019, 11, e408. [Google Scholar] [CrossRef]
- DAHLD. Policy Document on Livestock in Malawi 2004. Policy Document on Livestock in Malawi 2004—CEPA (rmportal.net). Available online: https://cepa.rmportal.net/Library/government-publications (accessed on 26 September 2022).
- Heinrich, N.; Saathoff, E.; Weller, N.; Clowes, P.; Kroidl, I.; Ntinginya, E.; Hoelscher, M. High seroprevalence of Rift Valley fever and evidence for endemic circulation in Mbeya region, Tanzania, in a cross-sectional study. PLoS Negl. Trop. Dis. 2012, 6, e1557. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Morvan, J.; Saluzzo, J.F.; Fontenille, D.; Rollin, P.; Coulanges, P. Rift Valley fever on the east coast of Madagascar. Res Virol. 1991, 142, 475–482. [Google Scholar] [CrossRef]
- Nyakarahuka, L.; de St Maurice, A.; Purpura, L.; Ervin, E.; Balinandi, S.; Tumusiime, A.; Kyondo, J.; Mulei, S.; Tusiime, P.; Lutwama, J.; et al. Prevalence and risk factors of Rift Valley fever in humans and animals from Kabale district in Southwestern Uganda, 2016. PLoS Negl. Trop. Dis. 2018, 12, e0006412. [Google Scholar] [CrossRef] [PubMed]
- Alhaji, N.B.; Aminu, J.; Lawan, M.K.; Babalobi, O.O.; Ghali-Mohammed, I.; Odetokun, I.A. Seropositivity and associated intrinsic and extrinsic factors for Rift Valley fever virus occurrence in pastoral herds of Nigeria: A cross sectional survey. BMC Vet. Res. 2020, 16, 243. [Google Scholar] [CrossRef]
- Owange, N.O.; Ogara, W.O.; Kasiiti, J.; Gathura, P.B.; Okuthe, S.; Sang, R.; Affognon, H.; Onyango-Ouma, W.; Landmann, T.T.; Mbabu, M. Perceived risk factors and risk pathways of Rift Valley fever in cattle in Ijara district, Kenya. Onderstepoort J. Vet. Res. 2014, 81, 1–7. [Google Scholar] [CrossRef] [Green Version]
- Glancey, M.M.; Anyamba, A.; Linthicum, K.J. Epidemiologic and Environmental Risk Factors of Rift Valley Fever in Southern Africa from 2008 to 2011. Vector Borne Zoonotic Dis. 2015, 15, 502–511. [Google Scholar] [CrossRef]
Species | Antibody Test | n | Reactors | Seroprevalence (%) | 95% CI |
---|---|---|---|---|---|
Cattle | IgG | 857 | 160 | 18.67 | 16.20–21.41 |
IgM | 857 | 23 | 2.68 | 1.79–3.99 | |
Overall | 857 | 183 | 21.35 | 18.68–24.28 | |
Goat | IgG | 518 | 32 | 6.18 | 4.41–8.59 |
IgM | 518 | 8 | 1.54 | 0.78–3.01 | |
Overall | 518 | 40 | 7.72 | 5.64–10.45 | |
Sheep | IgG | 148 | 24 | 16.22 | 11.14–22.99 |
IgM | 148 | 14 | 9.46 | 5.71–15.25 | |
Overall | 148 | 38 | 25.68 | 19.02–33.62 |
Ecological Zones | Districts | n | Seroprevalence | 95% CI |
---|---|---|---|---|
EZ 1 | Chikwawa | 228 | 10.96 | 7.54–15.68 |
Nsanje | 179 | 21.79 | 16.37–28.39 | |
Salima | 202 | 23.76 | 18.42–30.09 | |
Mangochi | 222 | 25.68 | 20.38–31.81 | |
Overall | 831 | 20.34 | 17.68–23.27 | |
EZ 2 | Chiradzulu | 151 | 11.26 | 7.15–17.29 |
Thyolo | 163 | 12.27 | 8.09–18.19 | |
Overall | 314 | 11.78 | 8.53–15.99 | |
EZ 3 | Chitipa | 185 | 23.24 | 17.74–29.84 |
Karonga | 193 | 6.22 | 3.59–10.55 | |
Overall | 378 | 14.55 | 11.23–18.61 |
Species | Sex Category | Antibody | Reactors | n | Seroprevalence (%) | 95% CI |
---|---|---|---|---|---|---|
Male | Overall | 22 | 77 | 28.57 | 19.13–40.17 | |
Female | Overall | 161 | 780 | 20.64 | 17.88–23.69 | |
Male | IgG | 19 | 77 | 24.67 | 15.86–36.05 | |
Cattle | Female | IgG | 141 | 780 | 18.08 | 15.47–20.99 |
Male | IgM | 3 | 77 | 3.89 | 1.01–11.73 | |
Female | IgM | 20 | 780 | 2.56 | 1.61–4.01 | |
Male | Overall | 4 | 47 | 8.51 | 2.76–21.27 | |
Female | Overall | 36 | 471 | 7.64 | 5.48–10.52 | |
Male | IgG | 4 | 47 | 8.51 | 2.76–21.27 | |
Goat | Female | IgG | 28 | 471 | 5.94 | 4.05–8.58 |
Male | IgM | 0 | 47 | 0.00 | 0.00–9.41 | |
Female | IgM | 8 | 471 | 1.69 | 0.79–3.45 | |
Male | Overall | 7 | 18 | 38.89 | 18.26–63.86 | |
Female | Overall | 31 | 130 | 23.85 | 17.00–32.27 | |
Male | IgG | 6 | 18 | 33.33 | 14.35–58.84 | |
Sheep | Female | IgG | 18 | 130 | 13.84 | 8.63–21.26 |
Male | IgM | 1 | 18 | 5.55 | 0.29–29.37 | |
Female | IgM | 13 | 130 | 10 | 5.65–16.81 |
Species | Age Groups (Years) | Antibody | Reactors | n | Seroprevalence (%) | 95% CI |
---|---|---|---|---|---|---|
<2 | Overall | 11 | 213 | 5.16 | 2.74–9.30 | |
2–4 | Overall | 97 | 256 | 37.89 | 31.98–44.17 | |
5–8 | Overall | 64 | 348 | 18.39 | 14.54–22.95 | |
≥9 | Overall | 11 | 40 | 27.50 | 15.14–44.13 | |
<2 | IgG | 8 | 213 | 3.85 | 1.75–7.53 | |
Cattle | 2–4 | IgG | 89 | 256 | 34.76 | 29.01–40.98 |
5–8 | IgG | 54 | 348 | 15.52 | 11.96–19.85 | |
≥9 | IgG | 9 | 40 | 22.50 | 11.40–38.85 | |
<2 | IgM | 3 | 213 | 1.41 | 0.36–4.39 | |
2–4 | IgM | 8 | 256 | 3.12 | 1.46–6.29 | |
5–8 | IgM | 10 | 348 | 2.87 | 1.47–5.39 | |
≥9 | IgM | 2 | 40 | 5.00 | 0.87–18.21 | |
<2 | Overall | 6 | 158 | 3.79 | 1.55–8.45 | |
2–3 | Overall | 23 | 210 | 10.95 | 7.21–16.17 | |
4–5 | Overall | 10 | 136 | 7.35 | 3.78–13.45 | |
≥6 | Overall | 1 | 14 | 7.14 | 0.37–35.83 | |
<2 | IgG | 4 | 158 | 2.53 | 0.81–6.76 | |
Goat | 2–3 | IgG | 18 | 210 | 8.57 | 5.30–13.41 |
4–5 | IgG | 9 | 136 | 6.62 | 3.26–12.55 | |
≥6 | IgG | 1 | 14 | 7.14 | 0.37–35.83 | |
<2 | IgM | 2 | 158 | 1.26 | 0.22–4.97 | |
2–3 | IgM | 5 | 210 | 2.38 | 0.87–5.77 | |
4–5 | IgM | 1 | 136 | 0.74 | 0.04–4.64 | |
≥6 | IgM | 0 | 14 | 0.00 | 0.00–26.76 | |
<2 | Overall | 3 | 46 | 6.52 | 1.69–18.92 | |
2–3 | Overall | 24 | 68 | 35.29 | 24.36–47.90 | |
4–5 | Overall | 10 | 32 | 31.25 | 16.74–50.14 | |
≥6 | Overall | 1 | 2 | 50.00 | 9.45–90.55 | |
<2 | IgG | 2 | 46 | 4.34 | 0.75–16.03 | |
2–3 | IgG | 11 | 68 | 16.17 | 8.75–27.52 | |
Sheep | 4–5 | IgG | 9 | 32 | 28.13 | 14.39–46.97 |
≥6 | IgG | 1 | 2 | 50.00 | 9.45–90.55 | |
<2 | IgM | 1 | 46 | 2.17 | 0.11–12.96 | |
2–3 | IgM | 13 | 68 | 19.11 | 10.95–30.82 | |
4–5 | IgM | 1 | 32 | 3.12 | 0.16–17.99 | |
≥6 | IgM | 0 | 2 | 0.00 | 0.00–80.21 |
Factor | District | n | Seroprevalence (%) | 95% CI |
---|---|---|---|---|
Salima | 29 | 44.83 | 26.95–64.02 | |
Mangochi | 19 | 84.24 | 59.51–95.83 | |
Chikwawa | 20 | 55.00 | 32.04–76.17 | |
Districts | Nsanje | 17 | 76.50 | 49.80–92.18 |
Chiradzulu | 80 | 16.13 | 9.36–26.55 | |
Thyolo | 63 | 23.78 | 14.35–36.49 | |
Chitipa | 70 | 42.89 | 31.28–55.22 | |
Karonga | 63 | 14.33 | 7.14–25.97 | |
Total | 361 | 33.24 | 28.18–38.11 | |
Salima | 10 | 7.01 | 35.37–91.91 | |
Mangochi | 12 | 83.32 | 50.88–97.06 | |
Chikwawa | 10 | 30.00 | 8.09–64.63 | |
Nsanje | 8 | 87.51 | 46.68–99.34 | |
Chiradzulu | 39 | 28.24 | 15.55–45.10 | |
Cattle | Thyolo | 32 | 31.34 | 16.75–50.14 |
Karonga | 53 | 11.30 | 4.69–23.72 | |
Chitipa | 60 | 45.00 | 32.33–58.31 | |
Salima | 16 | 18.76 | 4.97–46.31 | |
Mangochi | 5 | 80.00 | 29.88–98.95 | |
Chikwawa | 5 | 60.00 | 17.04–92.74 | |
Nsanje | 6 | 50.00 | 18.76–81.23 | |
Chiradzulu | 41 | 4.92 | 0.81–17.05 | |
Goat | Thyolo | 31 | 16.12 | 6.09–34.47 |
Chitipa | 10 | 30.00 | 8.09–64.63 | |
Karonga | 9 | 22.22 | 3.95–59.81 | |
Salima | 3 | 100 | 19.79–1.00 | |
Sheep | Mangochi | 2 | 100 | 19.79–1.00 |
Chikwawa | 5 | 100 | 56.55–1.00 | |
Nsanje | 3 | 100 | 39.58–1.00 | |
Karonga | 1 | 100 | 5.46–1.00 |
Factor | Level | Frequency | Percent (n = 1523) |
---|---|---|---|
Gender of farmer | Male | 1226 | 80.50 |
Female | 297 | 19.50 | |
Species | Cattle | 857 | 56.27 |
Goat | 518 | 30.01 | |
Sheep | 148 | 9.72 | |
Sex of livestock | Male | 143 | 9.39 |
Female | 1380 | 90.61 | |
Ecological zones | EZ1 | 831 | 54.56 |
EZ2 | 314 | 20.62 | |
EZ3 | 378 | 24.82 | |
Districts | SA | 202 | 13.26 |
MH | 222 | 14.58 | |
CK | 228 | 14.97 | |
NE | 179 | 11.75 | |
TO | 163 | 10.70 | |
CZ | 151 | 9.91 | |
KA | 185 | 12.15 | |
CP | 193 | 12.67 | |
None | 19 | 1.25 | |
Night shelter | Communal | 862 | 56.60 |
Private | 642 | 42.15 | |
Herd composition | Single species | 109 | 7.16 |
Mixed species | 1414 | 92.84 | |
Grazing site | Communal | 1214 | 79.71 |
Stall feeding | 309 | 20.29 | |
Permanent water | Swamps | 634 | 41.53 |
Swamps and rivers | 889 | 58.47 | |
Vegetative cover | Trees | 632 | 41.50 |
Trees and green grass | 513 | 33.68 | |
Forest | 378 | 24.82 | |
Education level | None | 69 | 4.53 |
Primary | 1010 | 66.32 | |
Secondary | 412 | 27.05 | |
Tertiary | 32 | 2.10 | |
Routine management | No | 385 | 25.28 |
Yes | 1138 | 74.72 | |
Average rainfall | <1000 mm | 393 | 25.80 |
1001–1500 mm | 660 | 43.34 | |
>1600 mm | 470 | 30.86 | |
Herd size | <25 | 864 | 56.72 |
26–50 | 196 | 12.87 | |
≥ 51 | 463 | 30.40 | |
RVF awareness | Yes | 54 | 3.55 |
No | 1469 | 96.45 |
Factor | Level | Frequency | Percent (n = 361) |
---|---|---|---|
Gender of farmer | Male | 210 | 58.17 |
Female | 151 | 41.83 | |
Goat | 123 | 34.07 | |
Species | Cattle | 224 | 62.05 |
Sheep | 14 | 3.88 | |
District | SA | 29 | 8.03 |
MH | 19 | 5.26 | |
CK | 20 | 5.54 | |
NE | 17 | 4.71 | |
TO | 63 | 17.45 | |
CZ | 80 | 22.16 | |
KA | 70 | 19.39 | |
CP | 63 | 17.45 | |
Ecological zone | EZ1 | 85 | 23.55 |
EZ2 | 143 | 39.61 | |
EZ3 | 133 | 36.84 | |
Night shelter | None | 7 | 1.94 |
Communal | 179 | 49.58 | |
Private | 175 | 48.48 | |
Herd composition | Single species | 69 | 19.11 |
Mixed species | 292 | 80.89 | |
Grazing site | Communal | 219 | 60.66 |
Stall feeding | 142 | 39.34 | |
Permanent water | Swamps | 56 | 15.51 |
Swamps and rivers | 305 | 84.49 | |
Vegetative cover | Trees | 199 | 55.12 |
Trees and green grass | 29 | 8.03 | |
Forest | 133 | 36.84 | |
None | 15 | 4.16 | |
Education level | Primary | 248 | 68.70 |
Secondary | 81 | 22.44 | |
Tertiary | 17 | 4.71 | |
Routine management | No | 90 | 24.93 |
Yes | 271 | 75.07 | |
Average rainfall | <1000 mm | 28 | 7.76 |
1001–1500 mm | 258 | 71.47 | |
>1600 mm | 75 | 20.78 | |
Herd size | less 25 | 305 | 84.49 |
26–50 | 18 | 4.99 | |
more than 51 | 38 | 10.53 | |
1–4 | 236 | 65.37 | |
Years in farming | 5–8 | 114 | 31.58 |
≥ 9 | 11 | 3.05 | |
RVF awareness | No | 349 | 96.68 |
Yes | 12 | 3.32 |
Potential Risk Factors | Number Tested (n = 1523) | Reactors (n = 261) | Seropositivity (%) | OR | 95% CI | p-Value |
---|---|---|---|---|---|---|
Species (n = 1523) | ||||||
Cattle | 857 | 183 | 21.35 | Ref | ||
Goat | 518 | 40 | 7.72 | 0.30 | 0.21–0.44 | 0.001 *** |
Sheep | 148 | 38 | 25.68 | 1.27 | 0.85–1.90 | 0.242 * |
Sex (n = 1523) | ||||||
Male | 142 | 33 | 23.24 | Ref | ||
Female | 1381 | 228 | 16.51 | 0.65 | 0.43–0.98 | 0.044 *** |
Education level (n = 1523) | ||||||
None | 69 | 69 | 100.00 | Ref | ||
Primary | 1010 | 111 | 10.99 | 4.55 | 1.41–14.64 | 0.011 *** |
Secondary | 412 | 72 | 17.47 | 4.96 | 1.51–16.20 | 0.008 *** |
Tertiary | 32 | 9 | 28.12 | 8.60 | 2.14–34.56 | 0.002 *** |
Rainfall (n = 1523) | ||||||
< 1000 mm | 393 | 75 | 19.08 | Ref | ||
1001–1500 mm | 660 | 78 | 11.82 | 0.587 | 0.41–0.83 | 0.003 *** |
>1600 mm | 470 | 110 | 23.40 | 1.33 | 2.96–9.81 | 0.044 *** |
RVF awareness (n = 1523) | ||||||
No | 1469 | 245 | 16.68 | Ref | ||
Yes | 54 | 16 | 29.63 | 2.10 | 1.15–3.83 | 0.015 *** |
Herd composition (n = 1523) | ||||||
Single spp. | 109 | 29 | 26.61 | Ref | ||
Mixed spp. | 1414 | 232 | 16.41 | 0.513 | 0.037–0.70 | 0.001 *** |
Ecological zones (n = 1523) | ||||||
EZ3 | 378 | 55 | 14.86 | Ref | ||
EZ1 | 831 | 169 | 20.34 | 1.499 | 1.07–2.09 | 0.017 *** |
EZ2 | 314 | 37 | 11.78 | 0.784 | 0.50–1.22 | 0.287 |
Potential Risk Factors | Number Tested (n = 361) | Reactors (n = 120) | Seropositivity (%) | OR | 95% CI | p-Value |
---|---|---|---|---|---|---|
Species (n = 361) | ||||||
Cattle | 224 | 81 | 36.16 | Ref | ||
Goat | 123 | 25 | 20.32 | 2.22 | 1.32–3.72 | 0.002 *** |
Sheep | 14 | 14 | 100.00 | 0.001 | 0.00–0.00 | 0.998 |
Education level (n = 361) | ||||||
None | 15 | 3 | 20.00 | Ref | ||
Primary | 248 | 82 | 33.06 | 0.232 | 0.06–0.79 | 0.019 *** |
Secondary | 81 | 34 | 42.0 | 0.163 | 0.04–0.58 | 0.005 *** |
Tertiary | 17 | 1 | 5.88 | 0.23 | 0.01–0.37 | 0.014 *** |
Rainfall (n = 361) | ||||||
< 1000 mm | 28 | 8 | 28.57 | Ref | ||
1001–1500 mm | 238 | 73 | 30.37 | 4.925 | 1.44–23.35 | 0.024 *** |
>1600 mm | 75 | 39 | 52.00 | 9.023 | 1.37–17.97 | 0.037 *** |
RVF awareness (n = 361) | ||||||
No | 349 | 118 | 33.81 | Ref | ||
Yes | 12 | 2 | 16.67 | 2.587 | 0.55–11.99 | 0.225 * |
Herd composition (n = 361) | ||||||
Mixed spp. | 292 | 99 | 33.90 | Ref | ||
Single spp. | 69 | 21 | 30.43 | 0.353 | 0.02–0.80 | 0.022 *** |
Ecological zones (n = 361) | ||||||
EZ3 | 133 | 39 | 29.32 | Ref | ||
EZ1 | 85 | 53 | 62.35 | 6.802 | 3.72–12.42 | 0.001 *** |
EZ2 | 143 | 28 | 19.58 | 1.704 | 0.97–2.97 | 0.061 * |
Variable | Level | OR | 95% CI | p-Value |
---|---|---|---|---|
Sex (n = 1523) | Male | Ref | ||
Female | 1.740 | 1.08–12.82 | 0.016 *** |
Variable | Level | OR | 95% CI | p-Value |
---|---|---|---|---|
Rainfall (n = 361) | <1000 mm | Ref | ||
1001–1500 mm | 2.475 | 1.14–5.37 | 0.022 *** | |
>1600 mm | 2.239 | 1.07–8.83 | 0.023 *** | |
Herd composition (n = 361) | Single spp. | Ref | ||
Mixed spp. | 10.410 | 3.04–35.59 | 0.001 *** |
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Kainga, H.; Phonera, M.C.; Chatanga, E.; Kallu, S.A.; Mpundu, P.; Samutela, M.; Chambaro, H.M.; Kajihara, M.; Shempela, D.M.; Sikalima, J.; et al. Seroprevalence and Associated Risk Factors of Rift Valley Fever in Livestock from Three Ecological Zones of Malawi. Pathogens 2022, 11, 1349. https://doi.org/10.3390/pathogens11111349
Kainga H, Phonera MC, Chatanga E, Kallu SA, Mpundu P, Samutela M, Chambaro HM, Kajihara M, Shempela DM, Sikalima J, et al. Seroprevalence and Associated Risk Factors of Rift Valley Fever in Livestock from Three Ecological Zones of Malawi. Pathogens. 2022; 11(11):1349. https://doi.org/10.3390/pathogens11111349
Chicago/Turabian StyleKainga, Henson, Marvin Collen Phonera, Elisha Chatanga, Simegnew Adugna Kallu, Prudence Mpundu, Mulemba Samutela, Herman Moses Chambaro, Masahiro Kajihara, Doreen Mainza Shempela, Jay Sikalima, and et al. 2022. "Seroprevalence and Associated Risk Factors of Rift Valley Fever in Livestock from Three Ecological Zones of Malawi" Pathogens 11, no. 11: 1349. https://doi.org/10.3390/pathogens11111349