The alert for an increase in hantavirus cases on an Antarctic expedition cruise once again focused attention on this zoonotic virustransmitted mainly by rodents and associated with serious health complications. It is not a single virus, but rather a viral family that can develop two main symptoms capable of compromising the lives of those who become infected.
This virus, which is still under scientific research, can also be transmitted from person to person. It is known that one of the hantavirus variants, called Andes virus (ANDV), would be responsible for this behavior. International media indicate that this variant would be responsible for the spread within the MV cruise ship Hondius.
The zoonotic virus has captured public attention after three deaths related to the outbreak were reported. Unlike COVID-19, a disease caused by SARS-CoV-2 and characterized by high transmission between people, the hantavirus It was already known and studied by science before the pandemic. It was in 1996 when researchers discovered that this virus could be transmitted from human to human.
The World Health Organization (WHO) highlights that the virus can cause cardiopulmonary syndrome in America due to hantavirus (SCPH), a disease known to cause respiratory conditions that can cause death in up to 50% of those who suffer from it.
Research on hantavirus has shown that the Andes virus strain is mainly found in South America and that its transmission between people is still limited. Despite this, doctors point out that it is a virus that needs to be taken care of.
What is known about the case?
So far, the WHO has reported two confirmed cases of hantavirus and five suspects, who remain under surveillance. Likewise, three deaths attributed to the virus have been reported and at least 149 people remain in quarantine inside the MV cruise ship. Hondius.
Nancy Sandoval, infectologist and vice president of the Pan American Association of Infectious Diseases, shared with Prensa Libre that, according to the data known so far, the alert for contagion on the cruise ship is due to the fact that it set sail from Ushuaia, in Argentine Patagonia, a region identified as endemic for the Andes strain of hantavirus.
In that region there is a record of the strain that can be transmitted from person to person, so surveillance is maintained to determine if the infections reported so far are derived from contact between rodents and humans or if there is transmission between people.
Identification of the exact serotype could help health authorities determine how to act against this spread.
Differences between hantavirus and SARS-CoV-2
Dr. Iris Cazali, infectious disease doctor and head of the Infectious Diseases Unit at Roosevelt Hospital, explained that there are great differences between both viruses, mainly because they belong to different families.
The doctor highlighted that both can cause severe respiratory diseases, but they differ in transmission, mortality and impact on global health. For example, SARS-CoV-2 is much more contagious, while hantavirus is more lethal.
Hantavirus transmission occurs from rodents to humans through contact with animal waste. On the other hand, SARS-CoV-2 is transmitted from person to person through respiratory aerosols and droplets, highlighted Cazali, who pointed out that both diseases come from different contexts. He highlighted that, although there is transmission of hantavirus between people, it is extremely rare and has only been observed with some particular strains, such as the Andes virus.
Another difference between both viruses is the incubation period, since that of hantavirus is one to six weeks, while that of SARS-CoV-2 is one to 14 days.
“The fatality rate of hantavirus is high. When hantavirus pulmonary syndrome occurs, mortality can be between 35% and 50%. In the case of COVID-19, mortality is much lower, between 1% and 2%,” highlighted the expert.
The infectologist Nancy Sandoval shared a table in which she exposes the main differences between both viruses, and shows how their characteristics make them different diseases, although they require care.
| Feature | Hantavirus | SARS-CoV-2 (COVID-19) |
| What is it? | Group of viruses transmitted mainly by wild rodents. | Coronavirus responsible for the COVID-19 pandemic. |
| viral family | Family Hantaviridae. | Family Coronaviridae. |
| natural reservoir | Rodents, especially infected wild mice. | Mainly humans these days; probably originated from animal reservoirs. |
| Main form of transmission | Inhalation of particles contaminated with rodent urine, feces or saliva. Less common due to bites. | Respiratory transmission between people through respiratory aerosols and droplets. |
| Is it easily transmitted between people? | In the vast majority of hantaviruses: No. Some South American variants can do so on a limited basis. | Yes and it has a high capacity for person-to-person transmission. |
| Risk contexts | Cleaning cellars, barns, closed houses, contact with weeds or rural areas infested by rodents. | Closed spaces, crowds, poor ventilation and close contact with infected people. |
| Incubation period | Approximately 1–6 weeks. | Generally 2–14 days. |
| Initial symptoms | Fever, severe muscle pain, fatigue, headache, gastrointestinal symptoms. | Fever, cough, sore throat, congestion, general malaise, loss of smell or taste (less common with recent variants). |
| Lung involvement | It can rapidly progress to severe respiratory failure and pulmonary edema. | It can cause viral pneumonia and severe acute respiratory syndrome in severe cases. |
| Cardiovascular compromise | Common in severe forms due to increased capillary permeability and shock. | Systemic inflammation, thrombosis and cardiovascular damage may occur. |
| Lethality | Generally higher than COVID-19, depending on the variant and access to intensive care, the mortality rate of Hantavirus Pulmonary Syndrome in Latin America ranges between 30 and 40%. | Much lower on average, although due to its high transmissibility it caused a large absolute number of deaths. |
| Disease frequency | Rare disease, generally associated with specific foci. | Global and highly frequent disease. |
| Diagnosis | PCR and specific serological tests for hantavirus. | PCR, antigen and serology tests for SARS-CoV-2. |
| Specific treatment | There is no widely effective specific antiviral; Management is mainly intensive support. | There are antivirals and targeted therapies in selected groups. |
| Vaccine available | There are no vaccines widely used in most countries. | Yes, there are multiple effective vaccines to prevent serious illness. |
| Main prevention | Rodent control and safe cleaning of contaminated spaces. | Vaccination, ventilation, respiratory hygiene and isolation when appropriate. |
Can hantavirus represent a greater threat to the population?
The hantavirus has become a topic of conversation in recent days, but the disease has been on the health scene for years. Dr. Iris Cazali stressed that it must be understood that this disease requires a mouse carrying the virus, and not just any mouse, but a rural one.
He added that the spread derives from contact with urine, feces and waste of these animals, which is why he highlighted the importance of taking precautions when cleaning places where the presence of rodents is suspected.
For his part, Sandoval highlighted that the hantavirus represents a real threat, although it does not seem to have pandemic behavior like SARS-CoV-2. However, he explained that it does represent a challenge for the health system.
As he explained, the danger of hantavirus derives from three factors: its high mortality when it is not diagnosed in time, the absence of specific treatment and the lack of robust protocols in the region’s health systems to quickly recognize and confirm it.
Sandoval added that Guatemala faces significant gaps regarding hantavirus, because it does not have confirmatory diagnostic tests within the routine public system, although it does have installed capacity to react and perform metagenomic sequencing if necessary. He also indicated that the capacity of intensive care units is limited and that first-contact health personnel rarely include hantavirus in the differential diagnosis of febrile symptoms with respiratory difficulty.
“What would protect us is not to wait for an outbreak to react, but to invest now in three things: active surveillance in ports and airports, diagnostic algorithms accessible to first-contact doctors, and an agile confirmation mechanism with international reference laboratories,” Sandoval recommended.
On May 6, eight people were reported infected in the hantavirus outbreak on the MV Hondius cruise ship, but as of May 7, nine were reported. (Free Press Infographic: EFE)