Occurrence of rift valley fever in cattle in Ijara district, Kenya

Owange, Nelson O.; Ogara, W. O.; Affognon, Hippolyte; Peter, Gathura B.; Kasiiti, J.; Okuthe, Sam; Onyango-Ouma, Washington; Landmann, Tobias; Sang, Rosemary; Mbabu, Murithi

doi:10.1016/j.prevetmed.2014.08.008

Cited by 29 publications

(33 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, the river marks the northern border of Tanzania, which is a national park. Contact with wildlife has http://www.jsava.co.za Open Access been identified as an important RVF transmission pathway risk factor (Owange et al 2014). …”

Section: Discussionmentioning

confidence: 99%

Seroprevalence of Rift Valley fever in cattle along the Akagera-Nyabarongo rivers, Rwanda

Umuhoza

Berkvens

Gafarasi

et al. 2017

J. S. Afr. Vet. Assoc.

View full text Add to dashboard Cite

Rift Valley fever (RVF) virus is caused by a zoonotic arbovirus that is endemic to eastern and southern Africa. It has also been reported in West and North Africa, Madagascar and the Arabian Peninsula. The virus is transmitted by mosquitoes, but people can also become infected while handling blood or other body fluids of animals and humans with RVF. In 2007, there was a large outbreak of RVF in Kenya, Tanzania, Sudan and Somalia. Outbreaks were also reported in South Africa in 2008–2011. The epidemiology of RVF and factors for disease occurrence in Rwanda are neither clear nor documented. Therefore, we conducted a crosssectional study from December 2012 to March 2013 to generate baseline information on RVF in cattle. Purposive sampling of cattle (n = 595) was done in six districts, and serum samples were screened with competitive enzyme-linked immunosorbent assay (ELISA). We performed a statistical analysis on the generated data, and risk factors associated with RVF seroprevalence were determined by a simple logistic regression. Overall, RVF seroprevalence was 16.8% (95% confidence interval [CI] [13.8% – 20.0%]). The highest seroprevalence was recorded in Kirehe district (36.9%) followed by Ngoma (22.3%), and the least was recorded in Nyagatare (7.9%). RVF was more likely to occur in adult cattle (19.9% [odds ratio {OR} = 1.88, 95% CI {0.98–3.61}]) compared to young cattle (10.5% [OR = 0.47, 95% CI {0.26–0.83}]). Pure exotic or cross-breeds were significantly exposed to RVF virus (seroprevalence 22.9% [OR = 4.26, 95% CI {1.82–9.99}]) in comparison to 14.1% (OR = 0.55, 95% CI [0.35–0.86]) in local breeds. Sex differences were not statistically significant. These findings indicated that cattle have been exposed to RVF virus in six districts in Rwanda with a significant risk in adult, exotic or cross-breeds in Kirehe district.

show abstract

Section: Discussionmentioning

confidence: 99%

Seroprevalence of Rift Valley fever in cattle along the Akagera-Nyabarongo rivers, Rwanda

Umuhoza

Berkvens

Gafarasi

et al. 2017

J. S. Afr. Vet. Assoc.

View full text Add to dashboard Cite

show abstract

“…This is in spite of low level circulation of the RVFV noted through monitoring of livestock migrating through these regions [28]. Previous efforts to isolate RVFV from vectors in the inter-epidemic period have not been successful [29] and we suggested that outside of outbreaks, RVFV circulates in vectors at levels that are below detection in terms of minimum infection rates (infection rates per 1000 mosquitoes tested). During the 2006/2007 outbreak [9], minimum infection rates in mosquito species sampled ranged between 0.8 and 2.5, during which time RVFV was detected in 51 out of 1,038 mosquito pools of diverse species in Garissa county, thus during inter-epidemic period, RVFV isolation becomes very unlikely, requiring analysis of huge numbers of mosquitoes to be able to detect a single infected mosquito.…”

Section: Discussionmentioning

confidence: 85%

Distribution and abundance of key vectors of Rift Valley fever and other arboviruses in two ecologically distinct counties in Kenya

et al. 2017

Self Cite

View full text Add to dashboard Cite

BackgroundRift Valley fever (RVF) is a mosquito-borne viral zoonosis of ruminants and humans that causes outbreaks in Africa and the Arabian Peninsula with significant public health and economic consequences. Humans become infected through mosquito bites and contact with infected livestock. The virus is maintained between outbreaks through vertically infected eggs of the primary vectors of Aedes species which emerge following rains with extensive flooding. Infected female mosquitoes initiate transmission among nearby animals, which amplifies virus, thereby infecting more mosquitoes and moving the virus beyond the initial point of emergence. With each successive outbreak, RVF has been found to expand its geographic distribution to new areas, possibly driven by available vectors. The aim of the present study was to determine if RVF virus (RVFV) transmission risk in two different ecological zones in Kenya could be assessed by looking at the species composition, abundance and distribution of key primary and secondary vector species and the level of virus activity.MethodologyMosquitoes were trapped during short and long rainy seasons in 2014 and 2015 using CO2 baited CDC light traps in two counties which differ in RVF epidemic risk levels(high risk Tana-River and low risk Isiolo),cryo-preserved in liquid nitrogen, transported to the laboratory, and identified to species. Mosquito pools were analyzed for virus infection using cell culture screening and molecular analysis.FindingsOver 69,000 mosquitoes were sampled and identified as 40 different species belonging to 6 genera (Aedes, Anopheles, Mansonia, Culex, Aedeomyia, Coquillettidia). The presence and abundance of Aedes mcintoshi and Aedes ochraceus, the primary mosquito vectors associated with RVFV transmission in outbreaks, varied significantly between Tana-River and Isiolo. Ae. mcintoshi was abundant in Tana-River and Isiolo but notably, Aedes ochraceus found in relatively high numbers in Tana-River (n = 1,290), was totally absent in all Isiolo sites. Fourteen virus isolates including Sindbis, Bunyamwera, and West Nile fever viruses were isolated mostly from Ae. mcintoshi sampled in Tana-River. RVFV was not detected in any of the mosquitoes.ConclusionThis study presents the geographic distribution and abundance of arbovirus vectors in two Kenyan counties, which may assist with risk assessment for mosquito borne diseases.

show abstract

“…This study also shows close interaction between humans and animals which could also be of importance for other dimensions of study in human carnivore studies including a one health dimension. Diseases at the human-animal interface is an area of concern with specific attention to emerging and re-emerging diseases as demonstrated by Owange et al (2014).…”

Section: Discussionmentioning

confidence: 99%

Human carnivores conflict in Wamba District, Samburu County, Kenya

Ogara¹,

Gitahi²,

Mainga³

et al. 2017

Int. J. Biodivers. Conserv.

View full text Add to dashboard Cite

Human-livestock-carnivores conflict is a unifying theme on a complex problem of a shared environment. The study was conducted to determine the levels and nature of human wildlife conflict in Samburu County, Kenya. The data was collected from 2006 to 2009, in three community areas. A total of 266 homesteads were randomly selected for interviews and characterization. The survey was carried out using semi-structured questionnaires, direct field observations and physical measurements. Data obtained was analyzed using Genstat® Discovery (3 rd Edition University of Reading), and levels of association established using chi-square. Carnivores within the ecosystem were identified using motion sensor cameras which included lion (Panthera leo), leopard (Panthera pardus), hyena (Crocuta crocuta and Hyaena hyena), jackal (Canis mesomelas), and wild-dog (Lycaon pictus). Livestock predation occurred at different sites notably homestead, water-point and grazing field. A total of 435 cattle, 801 sheep, 1138 goats, 189 donkeys, and 92 camels were killed by carnivores during the study period. The magnitude of depredation was mainly influenced by animal husbandly practices, including poorly constructed animals' sheds and animals left in the field without headers or under the care of minors unable to scare the carnivores away. The dynamics of both wild and domestic ungulates at different seasons are considered to be possible influencing factors on carnivore diet composition, hence presenting as increased conflict during droughts.

show abstract

Occurrence of rift valley fever in cattle in Ijara district, Kenya

Cited by 29 publications

References 10 publications

Seroprevalence of Rift Valley fever in cattle along the Akagera-Nyabarongo rivers, Rwanda

Seroprevalence of Rift Valley fever in cattle along the Akagera-Nyabarongo rivers, Rwanda

Distribution and abundance of key vectors of Rift Valley fever and other arboviruses in two ecologically distinct counties in Kenya

Human carnivores conflict in Wamba District, Samburu County, Kenya

Contact Info

Product

Resources

About