‘Low risk’ as Africa hantavirus cases spur surveillance

[HARARE, SciDev.Net] Health officials say the hantavirus remains a low risk to public health in Africa despite several confirmed cases on the continent following an outbreak onboard an international cruise ship.

Three Zimbabweans evacuated from Ascension Island are under quarantine in Harare after potential exposure to the virus, placing Southern Africa’s surveillance systems on alert for a disease rarely recorded outside South America.

The three, who are “currently healthy”, will be monitored for 45 days in a designated isolation facility, Zimbabwe’s Ministry of Health said on social media.

“Hantavirus is not transmitted through casual person-to-person contact in most cases, and all precautionary measures are being implemented in line with international public health protocols,” the ministry said in a statement.

The outbreak is linked to the Dutch-flagged cruise ship MV Hondius, which sailed from Argentina to Cape Verde before some of its 147 passengers transited via South Africa.

In an update on Wednesday (13 May) the World Health Organization (WHO) said 11 cases, including three deaths, had been reported, eight of which have been confirmed as hantavirus. Two other cases are probable, and one case remains inconclusive pending further testing, the WHO said.

South Africa’s National Institute for Communicable Diseases said a 70-year-old man died on arrival at St Helena island, in the South Atlantic. His 69-year-old wife collapsed at OR Tambo International Airport in Johannesburg while heading home to the Netherlands. She was taken to a nearby health facility but later died, with laboratory tests confirming hantavirus.

A British man who tested positive after falling ill on the ship was isolated at a private medical facility in South Africa where he is in a critical condition, the institute said.

Health authorities say they are working to trace and monitor people who may have been in contact with infected individuals to prevent spread of the virus.

The overall probability of infection remains low, according to the WHO, which says transmission occurs through close, prolonged contact, and can be limited through early detection, isolation of cases, and contact tracing.

Canaan Tinashe Hodobo, antimicrobial resistance surveillance coordinator at Zimbabwe’s Central Veterinary Laboratory, told SciDev.Net: “At present, there is no evidence to suggest that hantavirus is a public health problem in Zimbabwe or countries within our region.”

“Hantavirus is also considered to have limited pandemic potential because the virus is generally not efficient at spreading between people.”

The WHO says the outbreak involves the Andes strain of hantavirus, a variant found mainly in South America and the only one with documented person-to-person transmission. The strain can cause hantavirus cardiopulmonary syndrome, a severe respiratory illness that can be fatal.

Preliminary investigations suggest exposure may have occurred during visits to rodent-infested areas in Argentina, Chile and Uruguay before passengers boarded the vessel.

Hantavirus is primarily spread through contact with infected rodent urine, droppings or saliva. Infection commonly occurs when contaminated dust particles become airborne and are inhaled while cleaning enclosed spaces or areas with heavy rodent activity.

Officials urged the public to reduce exposure to rodents by sealing holes in homes and grain storage facilities, storing food securely and using protective equipment when cleaning potentially contaminated spaces.

Strengthening surveillance

The incident has triggered heightened surveillance across Africa and elsewhere, plus renewed debate over the continent’s preparedness for emerging infectious diseases.

One Health experts say the Zimbabwe cases illustrate how disease alerts can rapidly spread cross borders through international travel networks, even when outbreaks originate outside the continent.

Public health experts say such events are increasingly testing Africa’s disease surveillance systems, especially in countries with limited diagnostic capacity and uneven outbreak preparedness infrastructure.

Hodobo says the outbreak demonstrates why countries must continue investing in preparedness systems before crises emerge. He says Zimbabwe has established coordination structures and laboratory networks that can support outbreak investigations.

Zimbabwe launched its One Health Strategic Plan in December 2025, bringing together the human health, animal health, wildlife and environmental sectors to improve preparedness for zoonotic diseases such as anthrax, rabies and other emerging threats.

According to Hodobo, the country is also strengthening frontline surveillance with support from the Pandemic Fund, a global financing mechanism established to improve preparedness for future outbreaks. The funding is supporting training programmes for frontline health and veterinary personnel, laboratory strengthening and expansion of disease surveillance systems.

“Our laboratories continue to test for priority zoonotic diseases, and capacity is being strengthened through procurement of equipment that supports automation and advanced testing methods such as genomics,” Hodobo said.

Rodent-borne diseases are particularly difficult to monitor because rodents are widespread and often live near to human populations, allowing infections to circulate undetected before severe cases emerge.

Spillover

At an Africa Centres for Disease Control and Prevention (Africa CDC) briefing, deputy incident manager Yap Boum warned that Africa remains vulnerable to zoonotic diseases because of increasing interaction between humans and animal environments.

“A significant proportion of diseases, about 60 to 70 per cent, are zoonotic and spillover from animals to humans,” Boum said.

He added that rodents are associated with several infectious diseases, including Lassa fever, reinforcing the need for stronger public awareness and prevention measures.

“The key message is how we educate communities on hygiene and sanitation and reduce risky interactions with rodents,” Boum said.

Tolbert Nyenswah, Africa CDC’s director for pandemic prevention, preparedness and response, said strengthening genomic sequencing capacity remains central to improving outbreak preparedness across the continent.

“Genomic sequencing helps identify the pathogen, track mutations and strengthen surveillance systems,” he said.

This piece was produced by SciDev.Net’s Sub-Saharan Africa English desk.