Hong Kong health authorities are seeking more information from the World Health Organization (WHO) on an outbreak of a deadly hantavirus strain capable of limited human-to-human transmission reported on a cruise ship in the Atlantic, while ramping up efforts to prevent the rare disease from reaching the city’s shores.
The Department of Health’s Centre for Health Protection revealed on Thursday that it had contacted the WHO about the hantavirus cluster found on the MV Hondius after the vessel departed from Argentina on April 1.
As of Wednesday, the cluster comprised three confirmed cases and another five suspected patients.
The department noted that the first patient in the cluster only showed symptoms on April 6, with all three of the confirmed cases later dying.
“Further laboratory testing showed that the hantaviruses in two of the confirmed cases belonged to the Andes genotype, which is currently the only type of hantaviruses confirmed to have limited human-to-human transmission,” it said.
In Hong Kong, the centre had recorded an average of zero to two cases of hantavirus infections annually over the past five years.
The city has recorded no cases this year as of May 6.
Health officials also confirmed that there were no Hong Kong residents among the 147 passengers and crew on board the MV Hondius.
Dr Edwin Tsui Lok-kin, controller of the centre, said authorities were taking a “proactive and precautionary” approach to safeguard the city, despite the WHO currently assessing the global health risk as low.
“The CHP’s port health division has contacted the Airport Authority, as well as relevant organisations and operators in the travel industry to provide them with information on the epidemiological development of the hantaviruses, preventive measures, guidelines and relevant health information,” Tsui said.
The virus primarily spreads to humans through contact with infected rodents’ faeces, saliva or urine – either by breathing in particles, touching contaminated surfaces or through bites.
It can also be contracted by eating contaminated food, though it rarely spreads from person to person.
Early signs include flu-like symptoms such as fever, headaches and muscle pain. The hantavirus can cause serious lung or kidney problems after an incubation period of one to eight weeks, with its death rate reaching 40 per cent.
Tsui said that the centre had provided information on rodent control to the relevant parties and reminded them to implement control measures and strengthen environmental hygiene monitoring at all boundary control points.
He also emphasised that hantavirus was a statutory notifiable disease in Hong Kong, meaning doctors must report all suspected or confirmed cases to the centre for immediate epidemiological investigations and control measures.
“At the immigration level, the centre conducts medical assessments of arrivals who appear unwell or have a fever at all boundary control points. The centre also refers them to hospitals for medical examinations when necessary,” Tsui said.
The centre urged the public to maintain strict hand hygiene, avoid contact with rodents or their waste, eliminate infestations and report symptoms immediately if they were travelling on cruises or camping.
The MV Hondius, operated by Dutch firm Oceanwide Expeditions, is currently sailing towards Spain’s Canary Islands after departing Cabo Verde in Africa.
The cruise operator said on Thursday that it was working to trace everyone who had embarked or departed at various stops since late March.
The outbreak has also caused concerns for the remote island of Saint Helena, a British overseas territory with a population of 4,400, after 30 people from the cruise disembarked on April 24.
While the island has reported no cases so far, a small group of higher-risk contacts were ordered to isolate until June 9.
Meanwhile, a Dutch passenger who flew from the island to South Africa died of the virus in Johannesburg. A British passenger, who also tested positive, remained hospitalised in the city.
In Singapore, two residents aged 65 and 67 who had been on the vessel were being held in isolation at the city state’s National Centre for Infectious Diseases, local authorities said.
The pair shared a flight from Saint Helena to Johannesburg with the confirmed hantavirus patient who died in South Africa. While one man remains asymptomatic, the other is experiencing mild symptoms.
Authorities in Europe, Singapore and Saint Helena said the risk to the general public remained low.