At least 42 people have been killed by one of the world’s deadliest diseases, Rift Valley Fever (RVF), in west Africa.
Officials are desperately trying to contain the killer virus, which began spreading in Senegal and Mauritania in late September.
As of October 30, 404 cases have already been detected, with the World Health Organization (WHO) labelling it an ‘unusually severe outbreak’.
Experts have now been dispatched to the affected areas to strengthen disease surveillance, treatment and infection prevention and control in health facilities.
The UN agency said it was first alerted after human cases emerged on September 20 in Senegal.
Since then, the vast majority of cases have been reported in the country’s northern livestock-producing region.
RVF is a viral disease most commonly seen in livestock and domesticated animals in sub-Saharan Africa, including cattle, buffalo, sheep, goats, and camels.
But can also spread to humans and has been responsible for several deadly outbreaks in recent decades.
Officials are desperately trying to contain the killer virus, which began spreading in Senegal and Mauritania in late September
In a statement, the WHO said the risk of further spread ‘remains high’, especially with the warm, humid weather conditions and periods of heavy rain that favour mosquitos.
Moving livestock, particularly towards Mali and Gambia for grazing and trade may also increase the likelihood of the virus surging they added.
Humans typically become infected either through mosquito bites, or contact with the blood or organs of infected animals, putting herders, farmers, slaughterhouse workers and vets at particular risk.
There are no recorded cases of human-to-human transmission.
Most who contract RVF either experience no symptoms or a mild cold-like illness with fever, weakness, back pain and dizziness.
But rarer severe cases can cause eye damage, brain swelling or haemorrhagic fever, which can be fatal.
‘A high proportion of severe human cases have been reported’, the WHO said, suggesting cases may have slipped under the radar with the virus only detected at a later stage when it is far harder to treat.
Just over one in ten cases in Senegal have suffered hemorrhagic symptoms, resulting in 20 deaths, officials said.
In 2018, the WHO identified nine priority diseases (listed) that pose the biggest risk to public health. They were deemed to be most risky due to a lack of treatments or their ability to cause a pandemic
Humans typically become infected with RVF either through mosquito bites, or contact with the blood or organs of infected animals, putting herders, farmers, slaughterhouse workers and vets at particular risk
Every three in every ten cases in Mauritania have proved fatal.
For this reason, the WHO has raised the public health risk to ‘high’ at a national level but ‘low’ still on a global level.
The UN agency has previously also labelled RVF as a disease with potential to spark a future pandemic.
Outbreaks have previously occurred in other African countries, including in Kenya and Somalia in 1998 when it killed over 470 people.
In 2000, the virus spread to Saudi Arabia and Yemen – its first cases outside Africa – killing over 200 people and raising concerns of wider spread to Asia and Europe.
Senegal’s last major outbreak occurred in the late 1980s, when it killed more than 200 people in the country and neighbouring Mauritania.
There have been no known cases of RVF ever recorded in the UK.