A July 2019 Facebook post first flagged to us in July 2019 but still doing the rounds on social media warns people in Nigeria not to eat beef because "800,000 cows from the North" have been "poisoned" with the cowpox virus.
It shows photos of severe-looking lesions or sores on human skin.
The text reads: "Poison 80,000 COW from the NORTH with the VIRUS of COW POX, Pls call all your family, tell them not to buy or eat Cow meat from tomorrow by Nigeria Govt... Send it to people you know, you might save life's."
Has there been an outbreak of cowpox in Nigeria in 2019? Can you be "poisoned" by the virus if you eat infected beef? And is it life-threatening? Africa Check investigated.
Cowpox virus not predominantly transmitted by cows
The cowpox virus is a milder version of smallpox. It is considered a skin disease.
The first comprehensive description of human cowpox was by Englishman Edward Jenner in 1798, in the publication An Inquiry Into the Causes and Effects of the Variolae Vaccinae.
Jenner observed the disease in women who milked cows. He saw that they became infected with the virus by touching infected cow udders and as a result developed pustules on their hands. It was later discovered that rodents and cats were mostly responsible for transmitting the virus to humans, and not cattle.
He told Africa Check that the Facebook claim was "nonsensical, given what is known about the epidemiology of cowpox, and should be ignored".
The cowpox virus "is not maintained in cattle", Frean said.
"Cases of human infection acquired from pet rats have been described. The more common way that humans acquire infection is via cats, which are themselves probably infected from rodents or directly from other cats."
Rarely fatal, no risk from eating beef
Africa Check asked Dr Andreas Nitsche if the cowpox virus was life-threatening.
Nitsche said that only a "few fatal cases have been observed" in patients whose immune systems were compromised. He said that even with a suppressed immune system "not all ... patients become severely sick".
"Cowpox infection is usually self-limiting, with localised lesions commonly on the skin of hands or face. Occasionally the eye may be involved," Frean said. He emphasised that patients with a weak immune system "can sometimes develop a serious, even fatal, systemic disease".
Dr Tom Wolfs is an assistant professor at the University Medical Center Utrecht in the Netherlands. He is part of the infection and immunity research programme and works in infectious diseases patient care.
Wolfs was "not aware of the possibility that cowpox can be transmitted through the eating of contaminated meat". He said that direct skin contact with infected animals could cause transmission.
"Transmission by ingestion of contaminated food has not been described so far. The regular way is virus contact by scratches of diseased animals, usually cats, rodents and rarely exotic zoo animals," Nitsche said.
Frean agreed that "transmission is usually from skin contact with infected animals. Therefore, eating beef is not typically a risk factor for transmission".
No current outbreak of cowpox in Nigeria
Conclusion: Cowpox not deadly, not transmitted through beef, no Nigerian outbreak in 2019
A Facebook post claimed that 80,000 cows in the north of Nigeria had been "poisoned" with cowpox. It warned people not to eat beef.
But there have been no recent reports of cowpox in Nigeria. A person can get cowpox, a skin disease, from direct contact with an infected animal, but the cowpox virus is rare and is not known to be transmitted by eating beef.