Experts push for human vaccines against Rift Valley Fever
Kenya Veterinary Vaccines Production Institute (Kevevapi) CEO Jane Wachira whose institution is tasked with producing livestock vaccines for pasteurella, enterotoxaemia and Rift Valley Fever, three stubborn diseases.
What you need to know:
- Encroaching wildlife habitats, tropical climate, climate change and wildlife trade around the globe increase the risk of zoonotic disease transmission.
- The World Health Organization notes that there has been a 63 per cent increase in the number of zoonotic outbreaks in Africa from 2012-2022 compared to 2001-2011.
Experts are pushing for the development of human vaccines against Rift Valley Fever (RVF) following a recently confirmed case in Marsabit County. In a circular to county health directors on January 24, the confirmed case was from an individual from Turbi, North Horr in Marsabit.
Prof Omu Anzala, a virologist and immunologist, noted that although there are three vaccines for livestock against RVF, there are no human vaccines for the disease.
“We don’t have any licensed vaccine for humans against RVF though we have two or three licensed vaccines for livestock and the question is; what are we doing about it? We have to interrogate the recent outbreak. Could we have known about it and what could we have done? Posed the expert during a virtual webinar titled ‘Combating Rift Valley Outbreak: A One Health Approach’ that brought together experts from various institutions. The event was organised by Capacitating One Health in Eastern and Southern Africa.
Prof Anzala noted that there is need for all professionals from animal or public health, environment and those in nutrition to collaborate through the One Health approach to combat any outbreak linked to deadly viruses. “We reviewed data between October and November last year and noticed that in our continent, we are having 68 crises of emergencies, most of which are a result of infectious pathogens, and some of which we have countermeasures like vaccines yet we are witnessing continuous problems,” said Prof Anzala.
Dr Evans Mwangi, an ecologist from the University of Nairobi, noted that the Aedes mosquito species transmits RVF. The other species of the same family are Culex and Mansoni, which also spread the disease. Human-to-human transmission of RVF has not been documented.
“Although domestic animals are the most significant disease transmitters, studies indicate that wild animals like buffalo can serve as important reservoir or hosts for the RVF.”
While urging counties to step up surveillance on January 24, Director General for Health Patrick Amoth said the RVF outbreak was closely associated with the conclusion of the El Nino rains, leading to a surge in mosquito population and an increased transmission of vector borne diseases.
“All counties are advised to remain on high alert for the potential spread of RVF. The Ministry of Health is working closely with the Directorate of Veterinary Services to monitor the situation and will update you accordingly,” said Dr Amoth.
Encroaching wildlife habitats leading to increased interactions, tropical climate, climate change and wildlife trade around the globe increase the risk of zoonotic disease transmission.
The World Health Organization notes that there has been a 63 per cent increase in the number of zoonotic outbreaks in Africa from 2012-2022 compared to 2001-2011.
Prof Salome Bukachi from the Institute of Anthropology at University of Nairobi said the one health approach is critical in combating epidemics including the RVF, noting there exists knowledge among local communities on preventing these disease outbreaks. Dr Bernard Bett from One Health center Africa said there is need for authorities to step up surveillance and vaccination of livestock ahead of the long rains, considering that cases of the disease go up due to flooding.
In 2021, WHO confirmed cases of the Rift Valley fever in humans in Isiolo and Mandera counties and in animals in Isiolo, Mandera, Murang’a and Garissa.
As of February 4, 2021, there were a total of 32 human cases – with 14 confirmed positive and 11 deaths.
Rift Valley Fever outbreaks are recurrent in Kenya and there have been several reported cases in the past (1998, 2006-2007, 2014, 2018). The RVF outbreak is associated with rivers and flooding.
In a past interview, Dr Mathew Muturi, the co-leader at zoonotic diseases unit at the Ministry of Health, disclosed that in 2018, the government listed some of the priority zoonotic diseases in the country such as Rift Valley Fever, rabies, anthrax and brucellosis due to prevalence and economic burden.
