Arare hantavirus outbreak on the MV Hondius, a cruise ship travelling from Argentina to Cape Verde, emerged as a global concern in May. The affected ship, carrying 88 passengers and 61 crew members, had 23 nationalities on board. 

The ship, which had previously stopped by at South Georgia, Tristan da Cunha and St Helena, was barred from disembarking at Cape Verde following a report of an infectious outbreak.

The World Health Organisation on April 4 said suspected passengers in the cruise ship reported symptoms such as “fever, gastrointestinal issues, pneumonia and acute respiratory distress syndrome”. Barely four days later, the WHO said it had recorded “a total of eight cases (six confirmed and two probable cases), including three deaths (two confirmed and one probable)”.

“Four patients are currently hospitalised, one in intensive care in Johannesburg, South Africa, two in different hospitals in the Netherlands and the other in Zurich, Switzerland,” the WHO stated.

A travel vlogger and passenger aboard the cruise ship, James Rosmarin, shared an emotional TikTok video in which he said the outbreak left passengers feeling uncertain and longing for safety.

“We are not just a story, we are not just headlines, we are people, people with families, with lives, with people waiting for us at home,” Mr Rosmarin said. “There is a lot of uncertainty, and that is the hardest part. All we want right now is to feel safe, to have clarity and to get home.”

A global concern trickling down

African countries, particularly Nigeria, have been closely monitoring the outbreak, likely due to the continent’s ongoing struggle to eradicate a similar virus, Lassa fever.

The Nigeria Centre for Disease Control and Prevention, in its situation report for Epidemiological week 11, spanning March 9 to 15, disclosed that Nigeria recorded no fewer than 146 Lassa fever deaths between January and mid-March, prompting a prompt response to the global hantavirus threat, particularly to douse public fear.

The Africa Centres for Disease Control and Prevention, on the penultimate Tuesday, in a statement, announced that there was “no evidence of (the virus) transmission within Africa”, adding that infection “risk to the general public remained low”.

“The clustering of cases among travellers in a confined environment warrants heightened vigilance and further investigation to determine the source and mode of exposure,” the statement said.

“At this time, the outbreak appears confined to the cruise ship, with no evidence of transmission within African countries. The risk to the general public remains low,” Africa CDC stated.

Similarly, its Nigerian counterpart, the NCDC, in a public advisory on Saturday, affirmed that Nigeria had no record of hantavirus cases. The NCDC director-general, Jide Idris, noted that the country had intensified disease surveillance efforts while assuring Nigerians there was no cause for alarm.

“The event involves a limited number of confirmed and suspected cases associated with the cruise ship, with investigations and contact tracing ongoing. Current reports indicate that the risk to the general public remains low,” Mr Idris said.

Experts’ overview and recommendations

Health experts in separate chats with the Peoples Gazette warned the public against practices that could increase the risk of contracting the virus and its variants.

Ezekiel Adebowale, a lecturer at the Faculty of Veterinary Medicine, University of Ibadan, urged Nigerians to prioritise staying informed rather than expressing anxiety in the wake of the outbreak.

The lecturer described hantavirus as “a group of viruses carried by rodents such as rats and mice”, mainly contracted through “inhaling tiny particles from rodents’ urine, droppings, or saliva, especially when cleaning dirty areas or disturbing rodent nests”.

He stated that effective rodent control can help protect Nigerians from contracting hantavirus, Lassa fever and other rodent-borne diseases.

“The current risk to the average Nigerian is very low. The ship outbreak is being managed internationally and has not reached Nigeria. However, rodents are common in our environment, so strong rodent control protects us from Lassa, hantavirus, and other diseases,” Mr Adebowale said.

He advised that homes and surroundings be kept clean and rodent-proof, including cleaning rodent droppings with disinfectant first, washing hands regularly after possible contact with rodent areas, seeking early hospital care for flu-like symptoms and breathing problems, especially after rodent exposure, and following NCDC updates.

Tayo Fasuan, founder of MicroBiotics, noted that Nigeria is well prepared to contain the hantavirus outbreak. He cited efforts such as restricting Lassa fever and the one-health approach currently undertaken by the federal government.

“I believe Nigeria is well-equipped and prepared. For instance, we have been able to restrict the spread of Lassa beyond its endemic locations for a long time,” Mr Fasuan said. “The public health system of the country has been actively adopting the one-health approaches in recent years, merging human health with animal and environmental health successfully.”

According to him, with such an approach fully operational and all professionals across the separate health systems fully involved and cooperating well, the government should be able to quickly detect and respond to hantavirus outbreaks or cases nationwide.

The public health expert also noted that waste management plays a key role in hantavirus transmission.

“While rats like Norway rats, Black rats and Bandicoot rats are usually living closer to human homes, rats like deer rats, cotton rats and rat rice are more of wild rats, interacting only with humans occasionally. Hence, the risk factors are slightly different,” Mr Fasuan said. “In urban areas, the odds of people living close to waste disposal sites getting infected with hantavirus-carrying peridomestic rats are high. In rural areas, the odds are different. The proximity to forests makes the wild rats more likely to spread the virus more.”

Mr Fasuan called on individuals and communities to avoid contact with rat or rodent droppings, noting that those living in close proximity to where rodents can actively interact with them are particularly susceptible to infection. Proximity to bushes or forests is also a risk factor. Humans living around both scenarios should do their best to limit exposure to the rats or their droppings and urine, the public health expert said.

“Hantavirus is primarily an airborne threat and is being transmitted via the inhalation of aerosolised rodent excreta. So steps should be taken to prevent what I will call the aerosolisation of the potentially infectious materials,” he explained.

Lateef Adebisi, a research officer at the Global Emerging Pathogens Treatment Consortium, further noted that although hantavirus is uncommon in Nigeria and Africa, it could be introduced and potentially spread to other regions.

“The world is now a global village, and an infected individual from regions such as Europe or South America could travel to Africa, including Nigeria. This could potentially trigger an outbreak or even an epidemic under the right conditions,” Mr Adebisi stated.

The researcher similarly expressed concern over the close proximity between rodents and humans in Nigeria, as well as the unregulated hunting and consumption of wild game.

“When individuals are exposed to any of the bodily fluids of an infected rodent, they can become infected. Rodents often live in close proximity to humans, especially in homes and markets where environmental hygiene is not adequately maintained,” Mr Adebisi explained.

Previous research conducted in Nigeria showed that some rodent species, such as the multimammate rat and African wood mouse, may have been previously exposed to the virus, as evidenced by the presence of antibodies (which are produced by the body in response to infection) in rodents used in earlier studies, according to Mr Adebisi.

He explained that Lassa fever and hantavirus share several similarities as zoonotic viruses, but can be addressed through strategies such as “strengthening molecular diagnostic laboratory capacity, improving existing laboratory systems, enhancing community awareness and strengthening infection prevention and control measures”.

The researcher warned Nigerians against practices that may attract rats into homes and markets, noting that improper storage of foodstuffs can expose them to rats.

Mr Adebisi called on the federal government and all other concerned authorities to work towards creating and strengthening a one-health team or agency that would lead cross-sector collaboration for continuous surveillance in the human, animal, and environmental health sectors.

“This will allow all these sectors to work together and share data to support informed public health decision-making, prevent the spill over of zoonotic diseases from animals to humans, build an early warning system, and ensure epidemic and pandemic preparedness to prevent outbreaks in humans,” he said. Peoples Gazette