Inhumed: Danger posed by anthrax bacteria in soil and bitter lessons for livestock farmers

The month of January, 2024, recorded above average rainfall. The previous year, the Kenya Meteorological Department had forecast El Nino beginning October the same year.

The showers came down in Kanguku village, Murang’a County, like a blessing from heaven. It watered a strip of Napier grass at Christopher Ngugi’s small scale farm turning them lush green; succulent food that boosts a dairy cow’s milk production. “Every now and then we feed them the grass,” Ngugi explained as he gave us a quick tour.

One evening, early in February, Ngugi noticed one of the animals lying on its side in the cowshed; its limbs stretched out and its eyes popping. ‘Something is amiss,’ he thought to himself.

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Losing the cow – a Friesian breed – would be too painful for a peasant farmer. The cow’s market value at the time, he says, was about Sh150,000. Slaughtering it and selling the meat would not have fetched the same amount but would have blunted the loss.

“This is the common wisdom among our farmers,” says Chiefman Njoroge, the area Member of County Assembly. “This is what we do; we slaughter the animal then have villagers buy the meat at throw-away price.”

Ngugi and Kaigai called a local vet (whose credentials are in question today) to assess the meat. “He opened the stomach. We found tufts of nylon rope. He concluded that the rope was the likely cause of the cow’s distress.

“He cut into other parts of the animal: the liver, the pancreas and the muscles. All of them appeared normal and healthy. He concluded that the animal was fit for consumption. We proceeded to sell the meat to villagers. The ‘vet’ himself took some home,” Ngugi says.

In the local butcheries meat retailed at Sh600. Ngugi was selling at Sh400. “Meat is not something villagers eat daily; it is too expensive to be part of the average family’s regular menu. Hence, when it is available cheaply it’s a treat,” MCA Njoroge says.

In all, as per Ngugi’s own estimation – at least 300 people partook in the feast. Four days later Ngugi and his family woke up to another dead cow. Coincidentally, it was a biological offspring of the one that had died.

“This time we called a veterinarian who works for the county government,” Ngugi says. “When he arrived (just after mid-day) and we described to him everything that had transpired he proceeded to slice its neck. To our surprise the blood had not clotted. It oozed out like it would in an animal that was still alive.”

‘This is anthrax!’ the veterinarian pronounced. Samples for laboratory testing subsequently confirmed the diagnosis.

No sooner had the vet made the call did villagers begin coming forward with sores that had developed on their fingers, arms, foreheads and other parts of skin.

Cutaneous anthrax manifests as itchy bumps or blisters that can turn into black, painless ulcers. ‘You are a victim too,’ Kaigai recalls the veterinarian telling him as he too had developed a wound on his hand.

Authorities quickly took over: Ngugi and his wife were questioned several times. The ‘vet’ who had pronounced the meat as fit for consumption went on the run. It was subsequently established that he did not have the academic background to be a veterinarian.

Anthrax is a zoonotic disease caused by the bacteria Bacillus anthracis. It is primarily a disease of domestic and wild grazers. “The bacteria survive naturally in soil as spores: a form that withstands heat and other extreme weather.

“Animals become infected through consumption of spores while grazing,” says Dr Khadija Chepkorir, a Veterinary epidemiologist at Zoonotic Disease Unit (ZDU).

Priority Disease

The agency says anthrax is endemic in Kenya. The disease tops ZDU’s Priority Disease list. Usually, more than 100 people are exposed to anthrax by one animal. One confirmed case of Anthrax is therefore treated as a full outbreak in the locality.

On average, in the recent years (since 2005) Kenya records approximately 50 anthrax outbreaks annually. Studies on climate change scenarios predict that the frequency will keep going up.

In January 2025 alone – last month – three outbreaks were reported: “In Meru, Kakamega, and Embu,” Dr Chepkorir told this publication. Even so, there is suspicion that not all anthrax outbreaks are reported to public health authorities.

Humans get infected during close contact with infected animal carcasses or contaminated animal products, says Dr Mathew Mutiiria, an infectious disease epidemiologist.

Human anthrax is classified into three: depending on the route of infection. Cutaneous anthrax is the most common globally. Gastrotrointestinal anthrax – following consumption of infected meat, milk or an edible animal product.

“The inhalation form is the least common. It comes about when one inhales anthrax spores or aerosolised bacteria. It is also the most dangerous form – killing nearly all of its victims,” Mutiiria says.

The disease is treatable with a raft of antibiotics. Overall, human anthrax case fatality rate in Kenya is 5.2 per cent. In other words, for every 100 Kenyans who become infected, 5 or 6 will die from related complications.

Herbivores are generally susceptible to contracting anthrax: goats and sheep included. Even so, majority – more than 90 per cent – of human anthrax cases are associated with cattle; and people who live in close proximity to cattle are usually the ones affected.

Not many farmers have a full understanding as to how the disease afflicts livestock; as well as standard operating procedure of handling such an animal.

Ngugi and Kaigai narrated to The Standard the much they knew about the disease prior to the February 2024. “Our fathers talked about it,” Kaigai said, Ngugi interjecting in support.

‘How would you tell if the cow is infected with anthrax?’ we asked.

“Our forefathers told us that meat from a cow with anthrax does not ‘stay’ (sic) in the pan when it’s being cooked. It does not cook calmly: the meat sputters relentlessly; jumping off the pan eventually.”

Obviously, none of that happened with meat from the cow that Ngugi and Kaigai had slaughtered. “The meet was prepared in many forms: cooked, fried, roasted and boiled,” Ngugi recalls. “Nothing about it was suspicious.”

To which Dr Chepkorir says: “The only way to prove if an animal has anthrax is by taking its blood and putting it through laboratory processes.”

Moreover, animals with anthrax, Chepkorir adds, “die suddenly; with little to no symptoms.”

She offers this analogy: “A farmer could milk the animal at 6am, take the milk to point of sale, come back, and two hours later find the animal dead.”

Anthrax outbreaks in Kenya, research shows, follow this script: an animal that is dying is butchered and the meat sold cheaply – or shared communally, ‘a common practice among poor, rural communities in sub-Saharan Africa,’ one study notes.

Dr Chepkorir’s advice to farmers is to call a registered veterinarian when they have a dying animal at hand, and to avoid close contact with it.

Anthrax-suitable zones

A team of researchers conducted an analytical study, to model the potential geographic distribution of anthrax in Kenya, using livestock surveillance records collected by the Directorate of Veterinary Services (DVS) between 2011 and 2017.

The map of anthrax-suitable zones reveals that the disease is prominent in agriculturally productive regions; with fertile soils that provide optimum conditions for the survival of bacterial spores, and where intensified livestock husbandry is practiced.

“Currently, these places are: Murang’a, Nakuru, Bomet, Kakamega, Meru, Embu, Tharaka-Nithi, Kiambu and Kericho counties,” Dr Chepkorir says.

The researchers also conclude that soil properties (its clay content, pH, and organic carbon content), climate and weather (rainfall and temperature patterns), cattle density, and availability of pasture – in that order – are the determining factors on potential distribution of anthrax.

Published in March 2021, the findings were similar to others done in South Africa and Kazakhstan: which found that long dry seasons and excessively wet months appear to trigger outbreaks, a point Dr Mutiiria espoused during our interview.

“These weather conditions are suspected to dig up anthrax spores. Run-off water collect and bring to the surface buried spores.”

Ngugi still remembers the wet weather just before the incident occurred. An analysis of rainfall for January (2024) shows that most stations over the Highlands, east of the Rift Valley – where Murang’a is located – recorded above average rainfall.

The Ndakaini rainfall station in Murang’a recorded 145.6mm of rainfall in the month. In neighbouring Kiambu County, Kamae Forest Rainfall Station recorded the highest – in the country – monthly rainfall of 411.4mm.

As for the dry seasons, Mutiira said: “Due to scarcity in vegetation animals feed on short grass close to the soil; increasing chances of eating or inhaling the spores.”

Anthrax remains an important disease not only because of the associated socio-economic losses but also due to higher public health burden, and decimation of wildlife.

Yes, wildlife! In fact, as per available data, more wildlife deaths from anthrax have been recorded compared to livestock or even humans.

Over 65 per cent of all wildlife conservation areas fall in the high burden areas.

As such, outbreaks hamper tourism resulting in reduced gross domestic product (GDP) and unexpected decline in abundance of endangered animals. Globally outbreaks remain constantly monitored as the bacteria – because of the ease of manipulating its spores in laboratory settings – became a choice tool for perpetrators of bioterrorism and bio-warfare.

Anthrax is highly fatal upon inhalation of spores. The bacteria produce toxins in the blood stream which destroy cells lining blood vessels; resulting in internal bleeding and oozing of non-clotting blood from natural orifices (ears, nostril, mouth, anus, and vagina) – when the animal/human is about to die or is already dead.

Today, Bacillus anthracis is classified as a class A highly infectious agent by the United States Centers for Disease Control and Prevention (CDC).

The whereabouts of the vet who certified Ngugi’s first cow as fit for consumption is not known to date.

This story was produced with support from Internews’ Earth Journalism Network.