Anthrax Outbreak in Sierra Leone

Given its presence in animals that are edible by humans, especially livestock, the health risks are particularly concerning.  

— Implications for Liberia

The Government of Liberia has reported an outbreak of the deadly anthrax pathogen in northern Sierra Leone, with a death toll of well over 200 livestock and only a few humans infected.

Because there have been no recorded human casualties in that country, it appears that the threat level might be very low and under control. But is it?  It has been exactly two weeks since 16 May 2022, when the Sierra Leone Ministry of Health reported the death of 223 livestock: (91 cattle, 53 goats, and 79 sheep) as a result of the anthrax outbreak. Samples were collected for investigation and the tests were positive for anthrax.

The deaths were in Port Loko District, Northwestern region of Sierra Leone which is 12 hours (730.9 km) away from the national capital Monrovia but 269 km from Grand Cape Mount County.  

This is the first outbreak of anthrax among animals to be reported in Sierra Leone in nearly 30 years. With the Mano River Union reeling from one biological scourge after another since Ebola, the sudden discovery of anthrax in the subregion cannot be passed off as an animal-only pandemic.

Easily found in nature, Anthrax spores can be produced in a lab, and can last for a long time in the environment. It makes a good weapon because it can be released quietly and without anyone knowing. The microscopic spores could be put into powders, sprays, food, and water. Because they are so small, they may not be visible to natural eyesight, smell, or taste. 

Given its presence in animals that are edible by humans, especially livestock, the health risks are particularly concerning. Which is why the Liberian Ministry of Health has banned the importation of all livestock from Sierra Leone for now. 

Sierra Leone authorities have also reported a total of three cases in humans which are currently being treated. According to the Global Alliance for Vaccines and Immunization (GAVI), the standard treatment for anthrax is an antibiotic such as ciprofloxacin or doxycycline. There is also a preventive vaccine against anthrax. 

More importantly — and there is no evidence to prove that this is the case in Sierra Leone — it is noteworthy that Anthrax has been used as a weapon in the past. According to the U.S. Centers for Disease Control (CDC), anthrax is one of the most likely pathogens to be used in bioterrorism. 

The CDC also notes that Anthrax is part of a subset of select agents and toxins that have been designated as Tier 1, because these biological agents and toxins present the greatest risk of deliberate misuse with significant potential for mass casualties or devastating effect to the economy, critical infrastructure, or public confidence, and pose a severe threat to public health and safety.

“The Government of Liberia, through the One Health Technical Committee, has instituted preparedness measures in response to the ongoing Anthrax outbreak in neighboring Sierra Leone,” says a release from the National Public Health Institute of Liberia (NPHIL).

 “As part of the measures, the Ministry of Agriculture and the National Public Health Institute of Liberia has heightened disease surveillance activities within Grand Cape Mount, Gbarpolu and Lofa Counties, which are the main corridors of entry from Sierra Leone. Also, the Ministry of Agriculture has temporarily banned the importation of livestock from Sierra Leone; this ban is subject to update as more information becomes available.” 

Anthrax is a zoonotic disease that commonly affects farm, domestic, and wild animals. Humans can also contract anthrax if they come in contact with infected animals or contaminated animal products (particularly through the consumption of contaminated meat), although human to human transmission is very rare. 

Studies show that the bacteria that causes anthrax produces spores when it comes into contact with oxygen. These spores are extremely resistant and remain viable for years in the soil, wool, or hair of an infected animal. They can germinate and cause disease by entering the body of an animal through ingestion, inhalation or skin wounds. Anthrax is treatable but mortality can be very high, especially in livestock. 

Symptoms in animals include tremors and breathing difficulties; bloody discharge through external orifices (nasal, anus, vagina, ear); edema of genitals; belly (equines) and throat (cattle). Human symptoms include painless blisters, fever, vomiting, diarrhea, sore throat, anorexia (not eating), abdominal pain, cough, breathing difficulty, and chest pain. 

“For the first time in Liberia, in September 2020,” the NPHIL recalls, “the Ministry of Agriculture (MOA) through the Central Veterinary Laboratory confirmed anthrax in a dead cow in Buchanan, Grand Bassa County. No human transmission has been reported in Liberia. 

“Although there is no case of anthrax reported in Liberia at this time, a One Health team from the national level comprising staff from the Ministry of Health, National Public Health Institute of Liberia, Ministry of Agriculture, and Environmental Protection Agency has been dispatched to bordering counties to support ongoing enhanced surveillance and raise awareness in the communities.” 

NPHIL  added that the country’s One Health concept is an integrated, unifying approach that aims to sustainably balance and optimize the health of people, animals, and ecosystems.

“While the One Health authorities continue to take aggressive actions to keep the population of Liberia safe, the public is also advised to take the following public health measures: Properly cook meat before eating; Report all cases of animal sickness and death to the animal health worker(s) in your area; Avoid direct contact with dead animals; Do not eat animals that died by themselves. 

“Under the One Health framework, MOA, Ministry of Health (MOH), NPHIL, the Environmental Protection Agency (EPA), and partners will continue to improve the rapid response teams at the county, district, and community levels, and to provide technical, financial and logistical support to the country's preparedness efforts,” NPHIL noted.