Date: Tue 6 Aug 2018
Source: New Times (Kigali, Rwanda) [summ., edited]
Livestock farmers have appealed to the government to ensure that cows get timely vaccination in order to effectively control deadly epidemics in cattle. The appeal comes after an outbreak of Rift Valley Fever [RVF] -- a deadly and infectious viral disease -- killed 154 cows countrywide since May , according to figures from Rwanda Agricultural Board (RAB). Gahiga Gashumba, the chairman of Rwanda National Dairy Farmers' Federation, told The New Times that in their performance contracts, districts set themselves targets to inoculate cows, which leaves a gap in achieving effective vaccination.
Efforts to contain the recent outbreak of RVF included vaccinating 257 902 cows countrywide of which 119 520 were from Ngoma, Kirehe, and Kayonza -- the hardest hit by the disease. "All cows should be vaccinated at least in areas prone to given diseases," Gashumba said adding, "We need a clear vaccination calendar detailing the cows that should be immunised in a given period of time. When there are heavy rains, we should be prepared of [immunising cows against] East Coast fever."
Also known as theileriosis, East Coast fever is a deadly tickborne disease in cattle. Ngoma district vice mayor for Finance and Economic Development, Jean Marie Vianney Rwiririza, said that this year , they want many cows to get vaccines against different diseases, including RVF and foot and mouth disease [FMD]. "With using funds from the district's budget alone, we cannot manage to give vaccines to all cows.
We request farmers' cooperatives and the farmers themselves to partake in the activity so that all the cows can be inoculated," he told The New Times. In Kirehe district, there are over 52 000 cows and over 30 000 of them were vaccinated against different diseases, including Rift Valley fever in the 2017/2018 financial year, according to Jean Damascane Nsengiyumva, Kirehe district vice mayor for Finance and Economic Development. "We have increased funding for the vaccination activity so that we inject all cows which we should vaccinate because we do not want the recurrence of such a problem," he said referring to RVF.
Rwanda Agriculture Board (RAB) said that they do not vaccinate all the cows because it can be wastage of resources or poor management when vaccination is done in areas where a disease has not been reported while it can be contained by vaccinating livestock in the risk zone. Instead of spending money on vaccinating all cows, currently estimated at over a million countrywide, appropriate strategies are devised to control the spread of outbreaks, said RAB director general Dr Patrick Karangwa. "We give more attention to diseases that spread faster than others. We do impact assessment based on spread pattern of a disease.
If a disease can be transmitted through air, measures taken to prevent its spreading should be different from the disease that cows or people catch through contact," Karangwa said. He cited FMD which often affects cattle on areas bordering Tanzania, such as Gatsibo, Kayonza, and Nyagatare, observing that when the disease has been checked in those areas, it dose spread elsewhere, pointing out that if all cows in the country are vaccinated, all the funds used [for the development of the livestock] sector might be consumed by such a single activity. Some vaccines are given free of charge, while others have to be paid for by farmers with government subsidy. [byline: Emmanuel Ntirenganya]
[RVF has become, according to local media, active in Rwanda in April 2018, as reported from the districts of Ngoma, Kirehe, and Kayonza, in the south west of the Eastern province. It was expressed mainly by cattle death and abortions. Later, Kamonyi, a southern province was added. The Rwandan Ministry of Agriculture and Animal Resources announced on [Mon 30 Jul 2018] the lifting of the ban imposed since mid-June  on the movement of cattle in several parts of Eastern province. According to the ministry, 99 of the 147 604 cows in the affected districts died, and 452 aborted. This differs from other statistics from various sources, including the 154 deaths in cattle, as mentioned in the above media report, quoting the Rwanda Agricultural Board.
Official statistics are expected to be included in Rwanda's RVF report to the OIE, which all member countries are obliged to submit. In the absence of data on the number of susceptible animals on the affected holdings, the mortality rate in cattle is not known. Based on accumulated field observations and experimental RVF infection trials, the mortality in adult cattle would, generally, not exceed 10 per cent. No human cases have been reported in Rwanda during the recent event. Vaccination of livestock against RVF can be applied either with a live attenuated (Smithburn) vaccine (relatively cheap, several years immunity rendered, but may cause foetal abnormalities or abortion in pregnant animals).
Alternatively, particularly in pregnant animals, an inactivated (formalin-killed) RVF vaccine can be selected (more costly, safer in all breeds/ages/reproductive stages of cattle, sheep, and goats, but requires a booster 3-6 months after the initial vaccination, then followed by yearly boosters). For the considerations related to vaccine policies, vaccines to be selected, and other tools for the prevention and control of RVF under various epidemiological situations, please refer to references 1-3.
1. Consultative Group for RVF Decision Support. Decision-support tool for prevention and control of Rift Valley fever epizootics in the Greater Horn of Africa. Am J Trop Med Hyg. 2010. 83(2 Suppl): 75-85. DOI: 10.4269/ajtmh.2010.83s2a03; <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2913494/
2. Anonymous. Risk-based decision-support framework for prevention and control of Rift Valley fever epidemics in eastern Africa. EU Collaborative Project, Seventh Framework Programme. 2015. (Grant Agreement no. 266327); <http://www.healthyfutures.eu/images/healthy/deliverables/d5.4%20risk-based%20decision-support%20framework.pdf
3. Mariner J. Rift Valley fever surveillance. FAO animal production and health manual no. 21. Rome: FAO. 80 pages; <http://www.fao.org/3/i8475en/I8475EN.pdf
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