Authors: KD Puspa, FD Hanifah, DF Mogsa, M Karyana (Health Administration, Working Team for Policy and Strategy for Controlling Infectious Diseases and Environmental Health, Center for Health Resilience System Policy, BKPK, Ministry of Health)
Amidst the frenzy of public attention to pandemics and popular diseases such as dengue or COVID-19, there is one health threat that is almost unheard of, but has the potential to be deadly: hantavirus.
It doesn't spread from person to person like influenza. It doesn't cause large outbreaks that immediately attract media attention. But that's precisely why hantaviruses are so dangerous. silent threat moving slowly in the shadows of our own environment. And even more worrying: Indonesia is not a hantavirus-free region.
An Invisible Threat: Hantavirus in Indonesia Is Not New
Many people think hantavirus is a rare disease from abroad. However, research shows that this virus has long been present in Indonesia, even since the 1980s. A comprehensive study conducted in several major cities found that the seroprevalence of hantavirus in humans in Indonesia reached around 11,6%. This means that in every 10 people, at least one has been exposed to this virus, although it may never have been diagnosed.
Furthermore, in rat populations, the primary reservoir, infection rates can reach 0–34%. This indicates that the virus is actively circulating in the environment, particularly in areas with high rodent densities.
In official Ministry of Health documents, hantavirus is referred to as an emerging zoonosis, a new disease that has emerged and has the potential to become a public health threat. The problem isn't simply whether this virus exists. The key issue is that we often don't realize its presence.
Why is Hantavirus Often “Invisible”?
In Indonesia, illnesses with fever symptoms are often immediately associated with dengue, typhoid, or leptospirosis. However, hantavirus has nearly identical initial symptoms: fever, muscle aches, nausea, and fatigue. As a result, many cases are likely misdiagnosed or missed altogether.
This phenomenon is known as “iceberg phenomenon”, which is visible only a small part, while the actual case is much larger under the surface.
Rat Viruses: An Often Overlooked Transmission Method
Hantavirus is not transmitted by mosquitoes or directly through food. It spreads through something we often take for granted: dust contaminated with rodent droppings.
This virus can enter the human body through airborne droplets containing particles of rat urine, feces, or saliva, direct contact with rodents, open wounds on the skin, and contaminated surfaces. National guidelines state that transmission primarily occurs through aerosolized excreta from rodents. In other words, a person doesn't need to be bitten by a rat to become infected. Simply being in an environment with rats and breathing contaminated air is sufficient.
Two Deadly Faces: HFRS and HPS
Hantavirus is not just one type of disease. It has two main manifestations, both of which are equally dangerous. First, Hemorrhagic Fever with Renal Syndrome (HFRS). It occurs mostly in Asia and Europe, attacking the kidneys and blood vessels with symptoms of fever, bleeding, and kidney failure.
Second, Hantavirus Pulmonary Syndrome (HPS). More common in the Americas, it attacks the lungs with symptoms of acute shortness of breath and respiratory failure. Case fatality rate (CFR) of hantavirus can be very high, even reaching up to 50% in some types of virus.
In Indonesia itself, the most frequently found virus is Seoul virus (SEOV), which is spread by house mice (rattus rattus and Rattus norvegicusBecause this type of rat lives in such close proximity to humans, the risk of transmission is much higher than for other zoonotic diseases that are limited to forests or wildlife.
Big City, Big Risk
Research in Indonesia shows that hantavirus is found not only in remote areas but also in large cities like Jakarta, Bandung, Semarang, and Denpasar. In one study, cases were even found in patients hospitalized in several major cities.
This demonstrates one important point: urbanization and population density actually increase the risk of hantavirus. Urban environments with poor sanitation, densely populated settlements, and suboptimal waste management create ideal habitats for rats.
An Increasingly Real Threat: The Latest Global Dynamics
In recent years, the world has begun to focus on hantavirus again. Several global reports indicate an increase in cases in East Asia and Europe. outbreaks Sporadic outbreaks in the United States, as well as links to climate change and urbanization. Climate change affects rodent populations, increasing their reproduction and expanding their habitats. Meanwhile, urbanization increases contact between humans and viral reservoirs.
Indonesia lies at the intersection of two risk factors: a tropical climate and high population density. This means the risk of hantavirus is not decreasing, but potentially increasing.
Why Should We Worry?
There are three main reasons why hantaviruses deserve serious attention in national health policy. First, underdiagnosed and underratedMany cases go undetected because the symptoms mimic other diseases. Second, the reservoir is abundant. Indonesia has at least 15 rat species confirmed to carry the virus. Third, the potential for fatality is high. The CFR can reach tens of percent in severe cases.
With this combination, hantavirus is not just a rare disease, but a systematic latent threat.
Important Lesson: Hantavirus is an Environmental Problem, Not Just a Disease
Unlike many other infectious diseases, hantavirus cannot be controlled with drugs or vaccines alone (neither of which has yet been widely approved).
Hantavirus control relies heavily on rodent population control, improved environmental sanitation, public education, and risk-based surveillance. The Ministry of Health's guidelines recommend an integrated reservoir control approach, improved environmental sanitation, and public risk communication. This demonstrates that hantavirus is a clear example of the One Health approach, linking human, animal, and environmental health.
What Should We Do?
Given the complexity of the hantavirus threat, policy responses cannot be partial. A systemic approach is needed. First, surveillance integration. Hantavirus needs to be included in syndromic surveillance systems (acute undiagnosed fever), not just disease-specific surveillance. Second, diagnostics should be strengthened. Serological and PCR testing should be expanded, especially in referral hospitals. Third, community-based rodent control. Rat control programs should be part of environmental health policies. Fourth, public education. The public needs to understand that sweeping a house full of rat dust without protection can pose an infection risk. Fifth, integration with existing programs. This approach can be synergized with Community-Based Total Sanitation (STBM), environmental health programs, and zoonotic control.
Conclusion: A Threat That Can No Longer Be Ignored
Hantavirus is not a new disease. It has long been around, but has been hidden in the shadows of other diseases. With increasingly strong scientific evidence, it is clear that this virus is already circulating in Indonesia, its reservoir is abundant, its diagnosis is still limited, and its impact can be fatal.
The question is no longer: is hantavirus present in Indonesia? But, to what extent have we not yet seen it?
If Indonesia does not begin strengthening environmental-based surveillance, diagnosis, and control, hantavirus has the potential to become the next “epidemiological surprise,” arriving unnoticed but with a major impact.
Closing Event
In the post-pandemic era, the world has learned one important lesson: health threats don't always come from the seemingly big, but rather from the overlooked. Hantavirus is one such threat. And like many other health threats, it presents us with a choice: act now or wait until it's too late.
