Taiwan CDC: Statement/Update On Locally Acquired H7N7 Infection

 

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Just over a month ago Taiwan reported their first locally acquired human H7 infection (see Taiwan CDC: Human Infection with a Novel H7 Avian Virus), which according to early reports was due to a Eurasian H7 virus.

The patient (a man in his 70s) was hospitalized with fever and pneumonia on March 22nd, and remains hospitalized and in isolation, although his condition was said to be improving. The CDC reported:

Currently, 33 close contacts are under health monitoring and management, and 3 have been given preventative medication based on risk assessment. Tests were conducted on 6 family members, all of whom tested negative.

The following day, in a Taiwan CDC Update: Novel H7 Infection Identified as H7N7.  We also saw a letter to physicians posted on April 8th.  Today we've the first detailed update since then, which reports no further cases have been detected, and assesses the risk to the public as `low'.

Of note, however, is the revelation that the sequenced virus (from the patient) contained the PB2-627K mutation, which is associated with enhanced replication and pathogenicity in mammals (see A rapid review of the avian influenza PB2 E627K mutation in human infection studies).

Since no H7N7 viruses were detected among the birds tested, it is unknown if this mutation was already `fixed' in the avian host, or (as we've seen in other cases) developed spontaneously in the patient.  

While reassuring the public, the CDC notes it is ` . . .  not only closely monitoring genomic evolution but also convening expert meetings to focus on assessing the risk of cross-species transmission . . . '

The full translated update follows:

The first locally transmitted human case of H7N7 influenza A was detected in Taiwan. The agricultural and health authorities launched a joint epidemic prevention and control operation, completing a public health risk assessment that classified the risk as "low risk," and continue to implement epidemic monitoring and prevention and control preparations.
 

Release Date: 2026-05-05

The Taiwan Centers for Disease Control (CDC) announced today (April 5) that regarding the first locally transmitted case of H7N7 novel influenza A reported on April 2 involving a poultry farmer, the CDC has completed gene sequence comparison and analysis. Furthermore, after joint assessment of the overall impact by agricultural and health authorities, the public health risk rating for Taiwan is "low risk."

The CDC pointed out that the patient was discharged from isolation on April 3, and the 33 identified contacts completed health monitoring on April 6, with no confirmed cases of novel influenza A. There is no risk of the outbreak expanding.

This case was discovered due to the high level of vigilance of the hospital physician, who reported the case based on clinical symptoms, contact history, and preliminary test results, leading to confirmation of novel influenza A. Therefore, the CDC will award the reporting physician a NT$10,000 reporting bonus in accordance with Article 5, Paragraph 1, Item 1 of the Infectious Disease Prevention and Control Reward Regulations.

The CDC explained that this case was investigated and controlled through cooperation between health and agricultural authorities, based on the national integrated epidemic prevention action. Gene sequence comparison of the virus showed that it was most similar to the virus strain isolated from wild birds in Japan and South Korea in 2024, and all gene fragments originated from the Eurasian low pathogenic avian influenza virus gene pool, indicating that the virus is highly related to the virus circulating in wild bird populations. 

Further analysis showed that the virus's PB2 gene carries the E627K mutation (PB2 E627K). According to existing research, this mutation may enhance the virus's replication ability in mammalian cells. However, since it cannot be ruled out that this site is a mutation produced in humans after infection, and no virus with the same characteristics has been found in Taiwan recently, nor have any drug resistance-related mutations been detected, the current assessment is that the risk to the public is low. 

In addition, agricultural authorities actively completed sampling at other poultry farms of the case before the Qingming Festival holiday, expanded sampling at five poultry farms near the case, and cooperated with the Wild Bird Association to collect 92 wild bird specimens from the surrounding area, all of which did not detect avian influenza-related viruses.

The Taiwan Centers for Disease Control (CDC) stated that, based on the spirit of national epidemic prevention unity, the CDC also launched a joint risk assessment team with agricultural and health authorities on April 1st to conduct a domestic risk assessment of the H7 subtype viruses (including H7N7, H7N2, H7N3, and H7N4). This risk assessment primarily referenced the framework of the US CDC's Influenza Risk Assessment Tool (IRAT). Team members collected supporting data and scores for ten risk factors and corresponding assessment questions, followed by a comprehensive evaluation. The results showed that the overall risk of the four H7 subtype viruses was low. While the possibility of sporadic local cases in the future cannot be ruled out, direct and indirect contact with animals remains the main transmission route. No evidence of sustained human-to-human transmission has been found, and the possibility of further community spread is extremely low.

In response to the detection of the key PB2 E627K variant in the first domestic H7N7 human infection case and concerns about the lack of herd immunity among the Taiwanese public to the H7 subtype of avian influenza, the Taiwan Centers for Disease Control (CDC) is not only closely monitoring genomic evolution but also convening expert meetings to focus on assessing the risk of cross-species transmission to ensure the disease prevention system can effectively address potential public health threats. Furthermore, the CDC is continuously strengthening the One Health inter-ministerial surveillance mechanism, maintaining surveillance in poultry farms and wild animals, closely monitoring genomic evolution, raising clinicians' awareness of the need for testing cases of pneumonia of unknown cause with a history of contact with poultry or livestock, and enhancing related prevention and control measures such as antiviral drugs.

In its global risk assessment of the H7 subtype of avian influenza, the World Health Organization (WHO) stated that the global H7 subtype of avian influenza is mainly prevalent in wild and domestic poultry populations. Although there have been occasional cases of human infection through contact with infected animals in the past, these cases have mostly presented with mild symptoms such as conjunctivitis or influenza-like illness. The Netherlands reported one death case in 2003. Given the potential impact on public health, close monitoring of human infections of this virus is crucial. Based on the current lack of evidence of sustained human-to-human transmission or community spread, the WHO assesses the threat to public health as remaining low. While sporadic human cases cannot be ruled out, the probability of human-to-human transmission is extremely low.

Argentina MOH: Statement and Special Report On Recent Hantavirus Activity

National Epidemiological Surveillance System (BEN) Week 16

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While the origins of the hantavirus infection currently spreading aboard a cruise ship in the Atlantic remain unknown, the ship embarked from an Argentine port on April 1st, making the Andes Virus a potential suspect.  

Yesterday, the Argentine MOH released a statement, which provides us with additional information on the ship's recent itinerary, along with a recap of hantavirus cases in the region.

First some (translated) excerpts from the statement:

The Ministry of Health is monitoring, along with international organizations, the hantavirus cases reported on the MV Hondius ship.

The national health ministry is maintaining a technical and epidemiological exchange with international and provincial authorities to gather official information on the confirmed cases on the Dutch-flagged cruise ship.

        (Excerpt) 

On May 2, our country's National Centre for Epidemiology received notification of a cluster of severe acute respiratory illnesses on board the cruise ship, including three deaths and one passenger with laboratory confirmation of hantavirus. The transmission route is currently unknown, and further testing is ongoing at the South African National Reference Laboratory to identify the strain and origin of the outbreak. The crew and passengers remain in isolation, and those affected have been transferred to receive the necessary medical care.

The vessel, which had departed from Montevideo, entered the port of Ushuaia on November 16, 2025. From there, it made several coastal voyages between Ushuaia, the Antarctic sector, and the islands of the South Atlantic.

On April 1, 2026, it set sail for South Georgia and the South Sandwich Islands, Saint Helena, and other points in the South Atlantic. The province of Tierra del Fuego reported no significant health-related events.

It is worth noting that Tierra del Fuego has no hantavirus and has not registered any cases since this disease was added to the list of notifiable events in our country in 1996. Its neighboring province, Santa Cruz, only registered one case in 2004. Currently, the Southern region is in a safe zone, with only 10 cases reported in Neuquén, Río Negro, and Chubut during the 2025-2026 season, which began on July 29 of last year.

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While the ship has been operating out of a region of the country without any history of hantavirus activity, it is always possible a passenger was exposed somewhere else prior to boarding the ship.

Yesterday the Argentine MOH released an update to their most recent Epidemiological bulletin, with a special focus on Hantavirus activity (and Mpox).  I've provided a translation of the hantavirus section below.

Special Report: Hantavirus

On May 2, the Netherlands National Focal Point (NFP) notified the Argentine NFP of a hantavirus outbreak aboard a cruise ship with 147 passengers and crew from 23 different countries. The ship had departed from Ushuaia, Tierra del Fuego, on April 1 and was following a route through the South Atlantic with multiple stops. The ship is currently off the coast of Cape Verde, the country that will lead the response to the outbreak.

To date, a total of 6 cases have been identified, of which 3 have resulted in death. All passengers and crew are in isolation and maintaining the necessary social distancing to prevent further infections. Patients with compatible symptoms have been transferred to receive appropriate medical care. The National Ministry of Health is in contact with the National Epidemiological Surveillance Centers (NECs) of the countries involved to gather information on the cases' itineraries prior to boarding, the type of contact they had on the cruise ship, and the identification of close contacts. The National Institute of Infectious Diseases (ANLIS) "Carlos G. Malbrán" has also offered advice regarding laboratory diagnosis and the possibility of performing sequencing and genomic analysis of the samples.

Given this situation, the National Epidemiological Surveillance System (BEN) reports that since epidemiological week 13, 9 new cases have been reported nationwide, located in Buenos Aires Province (4 cases), Salta (3 cases), Jujuy (1 case), and Chubut (1 case). So far this year, 42 new cases have been reported, and since the beginning of the season (epidemiological week 27 of 2025), the total number of confirmed cases has reached 101.

The majority are concentrated in the Central region, with Buenos Aires Province reporting the most confirmed cases (42). However, the highest incidence rate corresponds to the Northwest region (0.60 cases per 100,000 inhabitants), where 36 confirmed cases have been registered, 83% of which are concentrated in Salta.

Regarding the cases reported in the Southern region, the National Epidemiological Surveillance System (BEN) reports that one of the confirmed cases in Río Negro corresponds to the town of Río Colorado, located outside the historically endemic areas for hantavirus. In this context, environmental investigations were carried out in this town and other neighboring areas, and four potential exposure sites were identified. No species known to be reservoirs of pathogenic hantavirus were captured, and the specimens obtained tested serologically negative. Based on these findings, the jurisdictions were recommended to implement periodic environmental monitoring to assess the composition of rodent populations during periods of peak abundance and to identify the environments associated with reservoir species.

Finally, during the current season, an intrafamilial cluster was recorded in the town of Cerro Centinela (Chubut), involving three related cases (cohabiting individuals) with sequential symptom onset dates.

Following notification of the index case, the province conducted an environmental focus study and recorded the presence of wild rodents known as hantavirus reservoirs. One of the captured specimens even tested positive for the hantavirus. The epidemiological characteristics of the event raised suspicion of person-to-person transmission, prompting genomic analysis of the human samples. The results indicated that the sequences corresponded to the Andes virus, with a 99.99% similarity among the three cases analyzed. The results of the genomic sequencing of the virus detected in the seropositive rodent are still pending.

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As the following MOH graphic illustrates, hantavirus activity tends to peak in the summer in Argentina (Nov-Dec-Jan), and reaches its nadir in the winter (May-Jun-Jul).  It is still fairly active in March and April.

We'll know a lot more once sequencing of the virus is complete, which will hopefully become available this week. 

Stay tuned. 

WHO DON: Update: Hantavirus Cluster Linked to Cruise Ship Travel, Multi-country

AI generated with Gemini based on WHO narrative

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It's been barely 40 hours since we first learned of the cluster of Hantavirus cases aboard a ship on a polar expedition cruise in the South Atlantic. The ship departed from Ushuaia, Argentina, on April 1st, and has made more than a half dozen stops (see map above), where passengers may have left the ship.

While the exact Hantavirus has not been identified, the ship's departure point suggests the Andes Virus, which is often found in rodents in South America. 

The Andes virus would be particularly concerning because it is the only Hantavirus with an established reputation for being transmissible between humans (see NEJM  “Super-Spreaders” and Person-to-Person Transmission of Andes Virus in Argentina).

Complicating matters, the incubation period for Hantavirus can run up to 8 weeks, with a 42-day monitoring period generally recommended.  Some cases can be mild, or even asymptomatic, but the CFR (case fatality rate) can reach 30%-60%. 

As of today's announcement from the WHO, there are now 2 confirmed cases, and 5 suspected cases; 3 have died, 1 remains hospitalized, and 3 remain aboard ship.

There are also another 140+ individuals aboard the ship who may have been exposed, along with an unknown number potential contacts on shore (including healthcare workers). All of which will present some significant challenges for public health agencies across multiple jurisdictions. 

In impressively rapid fashion the WHO has produced a detailed DON (excerpts below), providing us with both a risk assessment and WHO advice. While `. . . the WHO currently assesses the risk to the global population from this event as low. . . ',  this is a dynamic situation, and no one is taking it lightly. 

Some of the public health challenges ahead include:

• Exactly how, when, and where the three symptomatic cases will be medically evacuated from the ship (and any others that might subsequently fall ill)

• How disembarkation of the remaining passengers and crew - and their ongoing medical monitoring - will be handled. 

• Contact tracing - and health monitoring - of anyone that passengers may have had close contact with (now, and going forward) across multiple countries. 

I've reproduced large excerpts from the WHO DON below, but you'll want to follow the link to read it in its entirety.

Hantavirus cluster linked to cruise ship travel, Multi-country
4 May 2026

Situation at a glance

On 2 May 2026, a cluster of passengers with severe respiratory illness aboard a cruise ship was reported to the World Health Organization. The ship is carrying 147 passengers and crew. As of 4 May 2026, seven cases (two laboratory confirmed cases of hantavirus and five suspected cases) have been identified, including three deaths, one critically ill patient and three individuals reporting mild symptoms.

Illness onset occurred between 6 and 28 April 2026 and was characterized by fever, gastrointestinal symptoms, rapid progression to pneumonia, acute respiratory distress syndrome and shock. Further investigations are ongoing. The outbreak is being managed through coordinated international response, and includes in-depth investigations, case isolation and care, medical evacuation and laboratory investigations. 

Human hantavirus infection is primarily acquired through contact with the urine, faeces, or saliva of infected rodents. It is a rare but severe disease that can be deadly. Although uncommon, limited human to human transmission has been reported in previous outbreaks of Andes virus (a specific species of hantavirus). WHO currently assesses the risk to the global population from this event as low and will continue to monitor the epidemiological situation and update the risk assessment.

Description of the situation

On 2 May 2026, WHO received notification from the National International Health Regulations (2005) (IHR) Focal Point of the United Kingdom of Great Britain and Northern Ireland (hereafter referred to as the United Kingdom) regarding a cluster of severe acute respiratory illness, including two deaths and one critically ill passenger, aboard a Dutch-flagged cruise ship. On 2 May 2026, laboratory testing conducted in South Africa confirmed hantavirus infection in one patient who is critically ill and in intensive care. On 3 May, one additional death was reported. A further three suspected cases remain on board. As of 4 May, a total of seven (two confirmed and five suspected) cases, including three deaths, have been reported.

The vessel departed Ushuaia, Argentina, on 1 April 2026 and followed an itinerary across the South Atlantic, with multiple stops in remote and ecologically diverse regions, including mainland Antarctica, South Georgia, Nightingale Island, Tristan da Cunha, Saint Helena, and Ascension Island. The extent of passenger contact with local wildlife during the voyage, or prior to boarding in Ushuaia remains undetermined. The vessel carries a total of 147 individuals, including 88 passengers and 59 crew members. Onboard passengers and crew represent 23 nationalities. As of 4 May 2026, the vessel is moored off the coast of Cabo Verde.

Summary of cases:

Case 1: An adult male developed symptoms of fever, headache, and mild diarrhoea on 6 April 2026 while on board the ship. By 11 April, the case developed respiratory distress and died on board on the same day. No microbiological tests were performed. The body of the passenger was removed from the vessel to Saint Helena (a British Overseas Territory) on 24 April.

Case 2: An adult female, who was a close contact of case 1, went ashore at Saint Helena on 24 April 2026 with gastrointestinal symptoms. She subsequently deteriorated during a flight to Johannesburg, South Africa, on 25 April. She later died upon arrival at the emergency department on 26 April. On 4 May, the case was subsequently confirmed by PCR with hantavirus infection. Contact tracing for passengers on the flight has been initiated.

Cases 1 and 2, had travelled in South America, including Argentina, before they boarded the cruise ship on 1 April 2026.

Case 3: An adult male presented to the ship's doctor on 24 April 2026 with febrile illness, shortness of breath and signs of pneumonia. On 26 April, his condition worsened. He was medically evacuated from Ascension to South Africa on 27 April, where he is currently hospitalised in an Intensive Care Unit (ICU). Laboratory testing on an extensive respiratory pathogen panel was negative; however, polymerase chain reaction (PCR) testing confirmed hantavirus infection on 2 May 2026. Serology, sequencing and metagenomics are ongoing.

Case 4: An adult female, with presentation of pneumonia, died on 2 May 2026. The onset of symptoms was on 28 April, with fever and a general feeling of being unwell.Three suspected cases have reported high fever and/or gastrointestinal symptoms and remain on board. Medical teams in Cabo Verde are evaluating the patients and collecting additional specimens for testing.

Public health response

Authorities from States Parties involved in the management of the event to date – Cabo Verde, the Netherlands, Spain, South Africa and the United Kingdom - have initiated coordinated response measures including:

• Ongoing engagement between WHO and the National IHR Focal Points of Cabo Verde, the Netherlands, South Africa, Spain and the United Kingdom, to ensure timely information sharing and coordination of response actions.
• WHO shared information about the events with National IHR Focal Points globally.
• Passengers onboard have been advised to practice maximal physical distancing and remain in their cabins where possible.
• Epidemiological investigations are underway to determine the source of exposure.
• The National IHR Focal Point of Argentina shared the passenger and crew lists with the National IHR Focal Points of the respective countries, according to each person’s nationality.
• In line with the Working Arrangement between the WHO Emergency Medical Team (EMT) Secretariat and the EU Emergency Response Coordination Centre (ERCC), the EMT Secretariat has launched formal discussions to support the clinical management and medical evacuation of symptomatic passengers.
• Logistic support has been provided, including sample collection items.
• Laboratory testing and confirmation of hantavirus infection have been conducted at the National Institute for Communicable Diseases (NICD) of South Africa. Serology, sequencing and metagenomics are ongoing.
• Additional laboratory samples from symptomatic passengers are being sent, with WHO support, to the Institut Pasteur de Dakar, Senegal, for testing.
• WHO has activated three-level coordination and is supporting national authorities in implementing risk-based, evidence-informed public health measures in accordance with the provisions of the IHR and related WHO technical guidance documents.

WHO risk assessment

Hantavirus cardiopulmonary syndrome (HCPS), also known as hantavirus pulmonary syndrome (HPS), is a zoonotic, viral respiratory disease caused by hantaviruses of the genus Orthohantavirus, family Hantaviridae, order Bunyavirales. More than 20 viral species have been identified within this genus. In the Americas, Sin Nombre virus is the predominant cause of HPS in North America, while Orthohantavirus andesense is responsible for most cases in South America.

Human Hantavirus infection is primarily acquired through contact with the urine, faeces, or saliva of infected rodents or by touching contaminated surfaces. Exposure typically occurs during activities such as cleaning buildings with rodent infestations, though it may also occur during routine activities in heavily infested areas. Human cases are most commonly reported in rural settings, such as forests, fields, and farms, where rodents are present, and opportunities for exposure are greater. HPS is characterized by headache, dizziness, chills, fever, myalgia, and gastrointestinal problems, such as nausea, vomiting, diarrhoea, and abdominal pain, followed by sudden onset of respiratory distress and hypotension. Symptoms of HPS typically occur from 2-4 weeks after initial exposure to the virus. However, symptoms may appear as early as one week and as late as eight weeks following exposure.

Hantavirus infections are relatively uncommon globally. In 2025 (as of epidemiological week 47), in the Region of the Americas, eight countries reported 229 cases and 59 deaths with a CFR of 25.7%. [1] In the European Region, 1885 hantavirus infection reported in 2023 (0.4 per 100,000), marking the lowest rate observed between 2019 and 2023.[2] In East Asia, particularly China and the Republic of Korea, Hantavirus haemorrhagic fever with renal syndrome (HFRS) continues to account for many thousands of cases annually, although incidence has declined in recent decades.

Hantavirus infections are associated with a case fatality rate of <1–15% in Asia and Europe and up to 50% in the Americas. While there are no specific treatment nor vaccines for hantavirus infections, early supportive care and immediate referral to a facility with a complete ICU can improve survival.

Environmental and ecological factors affecting rodent populations can influence disease trends seasonally. Since hantavirus reservoirs are sylvatic rodents, transmission can occur when people come into contact with rodent habitats.

Although uncommon, limited human‑to‑human transmission of HPS due to Andes virus has been reported in community settings involving close and prolonged contact. Secondary infections among healthcare workers have been previously documented in healthcare facilities, though remain rare.

WHO currently assesses the risk to the global population from this event as low and will continue to monitor the epidemiological situation and update the risk assessment as more information becomes available.

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MOH Statements On Cruise Ship With Hantavirus Outbreak

 

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Over the past hour the ever diligent newshounds at FluTrackers have posted several new statements from Ministries of Health along the route of the m/v Hondious - which is dealing with an unusual outbreak of Hantavirus among its passengers (see earlier blogs here, and here).

As I mentioned in my last blog, the ship is currently positioned off the port of Praia, Cabo Verde, and local authorities are not permitting passengers to disembark.  There are reportedly two passengers in need of medical attention.

The (translated) statement from their MOH follows:

Health authorities are monitoring the situation of the cruise ship MV/NV Hondius with an outbreak of Hantavirus on board

The Ministry of Health informs that it has been following, from the very first moment, the situation of the cruise ship MV/NV Hondius, which entered the waters of Cape Verde on May 3, following the notification by international health entities of an outbreak of respiratory illness on board, with the occurrence of serious cases and deaths.

Following technical and epidemiological evaluation, the national health authorities decided not to allow the docking of the vessel in the Port of Praia, in application of the principle of precaution and in accordance with the International Health Regulation, in order to protect national public health.

The vessel carries 147 people including passengers and crew. Of this total, three people present symptoms and were properly evaluated and assisted by a health care team, currently being clinically stable.

Since then, the ship remains on the high seas under constant supervision from the health authorities. The necessary medical assistance is being provided by a team highlighted for the effect, consisting of specialist doctors, nurses, laboratory technicians and equally prepared measures for hospital responses for possible need for differentiated care Hospital Dr. Agostinho Neto.

The situation is being properly monitored through coordinated work between the National Health Directorate, local health facilities, INSP, maritime and port authorities, with support from WHO Cape Verde/AFRO, RSI Focal Points and authorities from the Netherlands and the UK.

This articulation has allowed for a swift, safe and technically appropriate response, ensuring patient clinical follow-up and preparation of all necessary precautionary measures, including possible medical evacuation by air ambulance of patients afterwards.

It is ensured that the situation is under control, there is no risk to the population on earth, so far. We remain vigilant and in close coordination with national and international entities, ready to take any additional measures that may appear necessary.

Information will be updated as the situation develops.

The National Health Directorate calls for serenity and reaffirms its commitment to transparency, safety and protection of health for all.

What is hantavirus ?

Hantavirus is an acute and serious infectious disease, transmitted by wild rodents (rats). Caused by the virus of the genus Orthohantavirus, the infection occurs mainly by the inhalation of urine particles, feces or saliva from those rats, which can develop into cardiopulmonary syndrome (severe shortage of air) or, less commonly, kidney syndromes.

Inhalation of contaminated particles — for example, during cleaning spaces with the presence of mice — is one of the most common forms of infection.

The other forms of transmission to the human species are:

👉Percutanea, by means of skin abrasions or rodent bites;

👉Contact of the virus with mucosa (conjunctival, mouth or nose), through hands contaminated with rodent excrements;

👉 Person-to-person transmission, reported, sporadically, in Argentina and Chile, always associated with the Andes hantaviruses.

The period of transmittibility of hantavirus in humans is unknown. Studies suggest that the period of maximum coming would be a few days before the onset of signs/symptoms.

Already the incubation period of the virus, i.e. the period when the first symptoms begin to appear from the infection, is, on average, from 1 to 5 weeks, with variation from 3 to 60 days.

The first signs of infection are often mistaken for flu: fatigue, fever, and muscle aches. In some cases headaches, dizziness, chills and abdominal problems also occur.

However, the disease can progress quickly. Within a few days, more serious symptoms such as coughing, shortness of air and fluid accumulation in the lungs appear, which can lead to severe breathing difficulties.

Meanwhile, the government of St. Helena, a small island (pop. 4900) in the South Atlantic where the ship stopped in late April, has issued the following statement:

Suspected Hantavirus on MV Hondius
May 4th, 2006 

The public are advised that the Health and Social Care Portfolio have become aware of an evolving situation regarding a severe illness, affecting several passengers on the expedition vessel MV Hondius which recently visited St Helena between 22-24 April 2026.

The suspected cause is hantavirus, which is usually spread through contact with infected rodents, but may eventually pass from person-to-person. Symptoms can include fever, extreme fatigue (feeling more tired than usual), muscle aches, stomach pain, nausea, vomiting, diarrhoea or shortness of breath. Some people may develop severe breathing difficulty requiring hospital care.

Two passengers with minor symptoms came ashore and may have had some contact with members of our local community.

While the virus can be serious, no cases of this illness have been identified in St Helena and there is no significant cause for concern on the island at this time.

Public Health is working closely with the United Kingdom Health Security Agency (UKHSA) and other international partners to assess and manage the situation. A small number of people who travelled to St Helena on the MV Hondius or had very close contact with those who were showing symptoms, are being advised by Public Health to undertake a period of self-isolation as a precaution. St Helena Government (SHG) will provide full support to those who are asked to do so. A full risk-based contact tracing process is underway to identify and notify such persons.

The risk to the wider community is low and no additional precautions are necessary at this time. However out of the abundance of caution, should you experience a significant fever (>38°C), then you should contact the hospital on tele No 22500 for advice, but please DO NOT attend in person at the first instance.

For frequently asked questions about hantavirus, please visit: Hantavirus FAQ’s

The public are thanked for their support and cooperation during this time. Further updates will be provided on a regular basis.

#StHelena #Hantavirus #MVHondius

Lastly, South Africa MOH has issued this statement:

While the risks of transmission in these ports of call are low, they are not zero. And given the lengthy incubation period (1-5 weeks) of the virus, this is a going to require a protracted public health response.

WHO Statement On Hantavirus Cases Aboard Cruise Ship

 

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While we await further details on the (suspected) Hantavirus outbreak aboard a cruise ship in the Atlantic (see yesterday's blog), we have the following brief statement by the World Health Organization.

As of this posting, no DON has been published on this event, and that may not come for several days.  Sequencing of the virus will not only tell us more about its origin (is it the Andes strain?), it could also help define transmission dynamics aboard ship. 

While the WHO's messaging remains low-key, they are obviously taking this outbreak seriously, as they have notified their NFPs (National Focal Points) according to the IHR regulations. 

The BBC this morning is reporting that local authorities will not permit passengers to leave the ship in Cape Verde in order `to protect the public'.  It is not clear where or when the passengers will be allowed to disembark. 

Although human-to-human spread of the Andes virus has been documented (see EID Journal), the Andes Virus is not believed to transmit as easily as COVID, influenza, and many other respiratory viruses. 

Transmission likely requires close, prolonged exposure to respiratory droplets or other bodily fluids.

But there is still much we don't know about this virus, including its ability to spread asymptomatically. 

Studies have suggested (see Serological Evidence of Hantavirus Infection in Apparently Healthy People from Rural and Slum Communities in Southern Chile) that at least some infections are mild or asymptomatic.

A more recent 2025 study (see Virological characterization of a new isolated strain of Andes virus . . .), published in PloS NTD reported:

In this work, we described the isolation of the strain responsible for the largest ANDV PTP transmission outbreak, which occurred in the small town of Epuyén and began on November 2, 2018. This strain, ARG-Epuyén, exhibited a high capacity for PTP transmission, necessitating the implementation of quarantine measures to curtail further spread [8].

The median reproductive number (the mean number of secondary cases caused by an infected person) was 2.12 before control measures were implemented and subsequently dropped to below 1.0 by late January.

Early intervention allowed for the collection of samples leading to the isolation of this new ANDV strain from an asymptomatic case. An early passage of this strain was sequenced, revealing only one amino acid difference from the virus recovered from the patient. Like the Andes/ARG strain, this strain was able to grow in a new host without needing adaptation [26].

All reasons why public health officials will want to proceed cautiously as they work to contain this outbreak. 

Brief Background on the Suspected Hantavirus Outbreak On A Cruise Ship (ex Argentina)

 

Note: The newshounds at FluTrackers are following media reports (see thread) of a hantavirus outbreak aboard a cruise ship (MV Hondius, bound from Ushuaia in Argentina to Cape Verde), where 2 or 3 passengers have reportedly died, and several more are apparently infected. 

While details are scarce, I've prepared a backgrounder on the virus, and what we currently know about today's events.  

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Hantaviruses - which are carried by rodents in many parts of the world - are contracted by humans primarily through the inhalation or ingestion of aerosolized rodent feces, urine, saliva.  While relatively uncommon, some of these viruses have demonstrated limited human-to-human transmission.

Some - like Europe's Puumala Virus - produce relatively mild illness, while others like North America's Sin Nombre Virus and the South American Andes Virus can carry a high fatality rate.

In 2019 we closely followed an unusually large outbreak in Argentina where over a period of 3 months, a total of 29 laboratory-confirmed cases of Hanta Pulmonary Syndrome (HPS), including 11 deaths - were reported in Epuyén, Chubut Province. 

The WHO DON report stated:

The index case had environmental exposure prior to symptom onset on 2 November, and subsequently attended a party on 3 November. Six cases who also attended the party experienced the onset of symptoms between 20-27 November 2018.

An additional 17 cases, all of whom were epidemiologically-linked to previously confirmed cases, experienced symptom onset between 7 December 2018 and 3 January 2019 (Figure 1). Potential human-to-human transmission is currently under investigation.

In that outbreak, the incubation period ran from 8 to 31 days.  The CDC notes incubation can run anywhere from 1 to 5 weeks, and some studies have suggested up to 8 weeks. 

Hantavirus in humans is almost always a dead-end infection, but in recent years the Andes virus (ANDV) has garnered a reputation for being a bit of an outlier.  

Following the above outbreak, the NEJM published “Super-Spreaders” and Person-to-Person Transmission of Andes Virus in Argentina, which warned: ANDV Epuyén/18−19 strain shows a facility (R>2) for sustaining continuous chains of transmission if no control measures are enforced. 

While we don't know if this hantavirus is the ANDV Epuyén/18−19 strain, the fact that it appears to have infected 5 or 6 passengers is a concern. 

The ship in question (HV Honidus) reportedly carries up to 174 passengers, and 74 crew, and departed Argentina in early April. This ship appears to have been on a `polar exploration cruise', then proceeding on to South Africa and Cape Verde.

While we don't have a solid timeline, according to media reports, in late April a 70 y.o. passenger died on board, and his 69 y.o. wife subsequently fell ill (she reportedly died in a Johannesburg hospital).

A third passenger has reportedly died (unconfirmed), and 3 more passengers are supposedly sick (1 hospitalized in Johannesburg),while two are in isolation awaiting the next port.

Given this is Sunday, there's very little in the way of official confirmation of these reports.  Hopefully we'll get more details in the next day or two. 

While more cases are possible - with appropriate control measures, this outbreak should be manageable - although the long incubation period will certainly complicate matters. 

For more on hantaviruses, you may wish to revisit:

Two Recent Studies On the Host Range of Hantaviruses In the United States

California: Mono County Reports 3rd Hantavirus Death

 EID Journal: Experimental Infection of Peromyscus Species Rodents with Sin Nombre Virus

MMWR: A Little Bit Of Seoul (Virus)