Andes virus: Not every outbreak is the next pandemic

 

NEWS of the recent Andes virus (ANDV) outbreak aboard the cruise ship MV Hondius has understandably raised public concern.

Reports of multiple deaths, coupled with discussions about passengers returning to their home countries after leaving the vessel, have revived anxieties many hoped had faded after the COVID-19 pandemic.

The reaction is understandable. Since 2020, reports involving unfamiliar viruses, overseas outbreaks, or international travel often trigger the same unsettling question: could this become another global pandemic?

From a virology and public health perspective, however, not every virus behaves the same way, and not every outbreak carries the same pandemic risk.

That distinction matters.

The Andes virus belongs to the hantavirus family, a group of viruses typically associated with rodents as their natural hosts.

Unlike SARS-CoV-2, which spreads efficiently through respiratory droplets and aerosols in everyday public settings, the Andes virus has a far more limited transmission pattern. It relies heavily on a specific rodent species found mainly in parts of South America to persist in nature.

This ecological dependence naturally limits how widely the virus can spread geographically, a key scientific difference often overlooked when people compare every outbreak to COVID-19.

The Andes virus is unusual among hantaviruses because limited human-to-human transmission has been documented. However, available evidence suggests such transmission is relatively rare and usually involves prolonged close contact, often within households or among family members.

It does not spread with the efficiency seen during the early stages of COVID-19, when brief encounters in enclosed spaces could lead to widespread transmission.

In simple terms, the Andes virus does not possess the same biological capacity for rapid community spread.

Another major difference lies in genetic behaviour. One of the greatest challenges during the COVID-19 pandemic was the coronavirus’ rapid mutation rate, which produced successive variants within relatively short periods. Hantaviruses, including the Andes virus, are generally more genetically stable.

From a public health standpoint, this is reassuring because it allows scientists and health authorities to predict viral behaviour more reliably while maintaining the effectiveness of existing diagnostic tools for longer periods.

None of this means the virus should be dismissed lightly.

Individuals infected with the Andes virus can develop Hantavirus Pulmonary Syndrome (HPS), a serious illness affecting the lungs and cardiovascular system.

Early symptoms often resemble common viral infections, including fever, muscle aches, headaches and fatigue, before progressing in some cases to breathing difficulties and severe respiratory complications.

However, there is an important difference between a virus capable of causing severe illness in individuals and one capable of overwhelming healthcare systems through explosive transmission.

COVID-19 became a global crisis not only because it caused severe disease, but because it spread extraordinarily quickly across populations. Hospitals worldwide faced sudden surges of patients within short periods, placing healthcare systems under immense strain.

At present, there is no strong evidence suggesting the Andes virus has the same capacity for widespread uncontrolled transmission.

Ecology also matters more than many people realise.

The rodent species most closely associated with the Andes virus does not exist in Malaysia, significantly reducing the likelihood of natural local transmission. In infectious disease science, understanding the relationship between a virus and its natural host is often just as important as monitoring reported case numbers

For this reason, current assessments by organisations such as the World Health Organisation and the Centers for Disease Control and Prevention continue to classify the broader global threat level as low.

Perhaps the more important lesson from situations like this is not fear, but perspective.

The COVID-19 pandemic taught societies to take infectious diseases seriously, and that awareness remains valuable. But it also conditioned many people to interpret every new outbreak through the lens of 2020.

In reality, viruses differ greatly in how they spread, mutate and sustain themselves within populations.

Public awareness is important. Panic is not.

As global disease surveillance improves, reports of emerging viruses will likely become more common, not necessarily because the world is becoming more dangerous, but because we are now far better at detecting and monitoring outbreaks than before.

The lesson from COVID is not to panic at every outbreak, but to understand each one on its own scientific terms. 

Dr Muhammad Amir Yunus is a molecular virologist at the Pusat Kanser Tun Abdullah Ahmad Badawi (PKTAAB), Universiti Sains Malaysia (USM).

The views expressed are solely of the author and do not necessarily reflect those of  MMKtT.

- Focus Malaysia.