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Beware of the Hantavirus Threat! A Deadly Rodent-Borne Disease Lurking in Our Environment!
INTRODUCTION
Hantaviruses are a group of zoonotic viruses primarily transmitted through rodents and represent a significant global public health threat because they can cause severe diseases in humans, namely Hemorrhagic Fever with Renal Syndrome (HFRS) and Hantavirus Pulmonary Syndrome (HPS) (Jonsson et al., 2010). These diseases exhibit varying fatality rates, ranging from less than 1% in some mild forms of HFRS to more than 35% in certain HPS cases in Latin and North America (Vaheri et al., 2013). The World Health Organization (WHO) reports that thousands of HFRS cases occur annually, particularly in China, South Korea, and Russia, whereas HPS cases are predominantly reported in the Americas (WHO, 2023).
Hantavirus infection first gained global attention during an outbreak affecting more than 3,000 United States soldiers during the Korean War from 1951 to 1954. The disease was initially referred to as Korean Hemorrhagic Fever before the causative virus was successfully isolated in 1976 from the striped field mouse Apodemus agrarius near the Hantaan River in South Korea and subsequently named Hantaan virus (HTNV) (Lee et al., 1978). Since then, various hantavirus strains have been identified in different regions of the world.
Currently, more than 50 hantavirus species have been identified, with over 20 species known to be pathogenic to humans (Maes et al., 2019). Hantaviruses are classified as emerging zoonotic viruses due to their ability to re-emerge in new geographical areas as a consequence of ecological changes, urbanization, climate change, and increasing human interaction with wildlife (Klempa, 2018).
In Asia and Europe, hantaviruses generally cause HFRS, which is characterized by fever, thrombocytopenia, hypotension, hemorrhage, and acute renal impairment. In contrast, hantaviruses in the Americas more commonly cause HPS, which is characterized by severe pulmonary edema, acute respiratory failure, and cardiogenic shock with a high mortality rate (MacNeil et al., 2011). Early clinical manifestations often resemble those of other tropical diseases such as leptospirosis, dengue hemorrhagic fever, malaria, or influenza, making early diagnosis a major challenge, particularly in developing countries (Krüger et al., 2015).
The presence of rodents as the primary reservoirs of hantaviruses plays a crucial role in the epidemiology of the disease. Commensal rats such as Rattus norvegicus and Rattus tanezumi are commonly found in residential areas, markets, warehouses, ports, and agricultural land, thereby increasing the risk of human exposure to excreta from infected animals (Meerburg et al., 2009). Transmission generally occurs through inhalation of aerosols contaminated with rodent urine, saliva, or feces containing the virus.
In Indonesia, hantaviruses began to receive attention following the detection of hantavirus antibodies in humans and rodents in several regions, including Jakarta, Maumere, Semarang, Surabaya, and Serang (Ibrahim et al., 2019). Nevertheless, hantavirus surveillance and research in Indonesia remain very limited compared with other zoonotic diseases such as rabies, avian influenza, and leptospirosis. In fact, tropical climatic conditions, suboptimal environmental sanitation, high population density, and abundant rodent populations place Indonesia at considerable risk for future hantavirus outbreaks.
Therefore, enhanced preparedness through a One Health approach integrating human, animal, and environmental health is essential to anticipate future hantavirus threats.
VIRUS AND GENETIC CHARACTERISTICS
Hantaviruses belong to the genus Orthohantavirus, family Hantaviridae, and order Bunyavirales (ICTV, 2023). These viruses are negative-sense single-stranded RNA viruses possessing a tripartite genome consisting of Large (L), Medium (M), and Small (S) segments. The L segment encodes the RNA-dependent RNA polymerase, the M segment encodes the glycoproteins Gn and Gc, whereas the S segment encodes the nucleocapsid protein (N protein) (Plyusnin & Sironen, 2014).
The virus particles are spherical, approximately 80–120 nm in diameter, and enveloped by a lipid membrane. Due to the presence of this lipid envelope, hantaviruses are relatively sensitive to detergents, lipid solvents, heat, chlorine-based disinfectants, 70% alcohol, and ultraviolet radiation (CDC, 2024).
Phylogenetic analyses indicate that hantaviruses have a close evolutionary relationship with their reservoir hosts. Most hantaviruses are associated with specific rodent species, although recent studies have demonstrated the presence of hantaviruses in bats (Chiroptera), shrews, and moles (Soricomorpha), thereby expanding current understanding of the evolutionary history of these viruses (Guo et al., 2013).
Several hantavirus species are known to be pathogenic and capable of causing severe disease in humans with varying clinical manifestations. Hantaan virus (HTNV) is one of the best-known hantavirus species and is a major cause of severe HFRS in Asia, particularly in China and Korea. Seoul virus (SEOV) has a broader geographical distribution because its principal reservoir, Rattus norvegicus, is distributed worldwide, including in urban areas and ports. In addition, Dobrava-Belgrade virus (DOBV) is commonly found in the Balkans and Eastern Europe and is recognized for its relatively high fatality rate.
In Northern Europe and Scandinavia, Puumala virus (PUUV) is the primary cause of a mild form of HFRS known as Nephropathia epidemica. Meanwhile, in North America, Sin Nombre virus (SNV) is the principal cause of Hantavirus Pulmonary Syndrome (HPS), a severe hantavirus infection affecting the lungs and associated with a high mortality rate. Andes virus (ANDV), commonly found in South America, also causes severe HPS and is of particular concern because it possesses limited human-to-human transmission capability, unlike most other hantaviruses.
Furthermore, Saaremaa virus (SAAV), identified in several European regions, is closely related to Dobrava-Belgrade virus and may cause milder forms of HFRS. The diversity of hantavirus species demonstrates that geographical distribution, animal reservoir species, and viral genetic characteristics strongly influence epidemiological patterns and disease severity in humans.
HTNV and DOBV are known to have relatively high HFRS fatality rates, whereas PUUV generally causes a milder disease manifestation known as Nephropathia epidemica (Vapalahti et al., 2003).
Seoul virus is of particular concern because its main reservoir, the domestic rat Rattus norvegicus, is distributed almost worldwide, including urban areas in Indonesia. This widespread distribution increases the potential for viral dissemination compared with other hantaviruses that are restricted to specific wildlife habitats (Lin et al., 2012).
Molecular studies in Indonesia have identified a novel hantavirus strain in Rattus tanezumi in Serang, Banten, referred to as Serang virus (SERV). This finding indicates that hantavirus genetic diversity in Indonesia remains incompletely understood (Ibrahim et al., 2019).
In addition to genetic mutations, hantaviruses may also undergo genetic reassortment through the exchange of genome segments between strains. This phenomenon has the potential to generate novel strains with altered virulence or transmission capabilities (Klempa, 2018).
EPIDEMIOLOGY AND GLOBAL DISTRIBUTION
Hantaviruses are distributed worldwide, and their geographical distribution is strongly influenced by the presence of rodent reservoirs. China has the highest number of HFRS cases globally, accounting for more than 90% of reported cases each year (Zhang et al., 2010). In Europe, cases are commonly reported in Finland, Sweden, Germany, Belgium, and the Balkan region.
In the Americas, the first major outbreak of HPS gained widespread attention in 1993 in the Four Corners region of the United States due to infection with Sin Nombre virus. Since then, numerous HPS cases have been reported in Argentina, Chile, Brazil, Bolivia, and Paraguay (MacNeil et al., 2011).
Andes virus in South America is unique because there is evidence of limited human-to-human transmission, unlike most other hantaviruses, which are generally not transmissible between humans (Martinez-Valdebenito et al., 2014).
Global climate change plays a significant role in rodent population dynamics. Increased rainfall enhances food availability, leading to rapid growth of rodent populations. This phenomenon was observed during the HPS outbreak in the United States, which was associated with the El Niño climate event (Yates et al., 2002).
Urbanization, deforestation, land-use changes, and agricultural expansion also increase human interaction with hantavirus reservoirs. Consequently, hantavirus is considered a zoonotic disease that is strongly influenced by ecological and environmental factors.
HANTAVIRUS SITUATION IN INDONESIA
Data regarding hantavirus in Indonesia remain limited; however, several studies have demonstrated the presence of hantavirus infection and antibodies in both humans and rodents. Serological surveys have identified antibodies against Seoul virus in rats captured in ports and urban areas of Jakarta, Surabaya, and Semarang (Kosasih et al., 2011).
A study conducted in Maumere, East Nusa Tenggara, identified hantavirus infection in patients presenting with symptoms resembling dengue hemorrhagic fever and leptospirosis. This finding suggests that hantavirus cases may have been underdiagnosed because their clinical manifestations closely resemble those of other tropical diseases (Ibrahim et al., 2019).
In Indonesia, several rodent species are known to serve as important hantavirus reservoirs and may act as sources of human infection. One of the most frequently identified species carrying hantavirus is Rattus norvegicus (the Norway rat), which is commonly found in urban areas, ports, drainage systems, and environments with poor sanitation. In addition, Rattus tanezumi, commonly known as the Asian house rat, is widely distributed in residential areas and has been reported to harbor various hantavirus strains in several regions of Indonesia. Another important species is Bandicota indica (the greater bandicoot rat), which generally inhabits rice fields and agricultural land, thereby increasing exposure risks among farmers and rural communities.
Meanwhile, Mus musculus (the house mouse) has also been reported to carry hantavirus, although its role as a primary reservoir remains under investigation. The presence of these various rodent species in residential areas, agricultural settings, and food storage facilities indicates that human interaction with hantavirus reservoirs in Indonesia is relatively high, particularly in regions with dense rodent populations and inadequate environmental sanitation.
High population density, poor environmental sanitation, inadequate waste management systems, and frequent urban flooding further increase the risk of hantavirus-carrying rodent proliferation and disease transmission.
Moreover, Indonesia is recognized as a megabiodiversity country with numerous wildlife mammal species that may potentially serve as reservoirs for novel viruses. Therefore, active surveillance of wildlife and rodent populations is essential to detect the possible emergence of new hantavirus strains.
TRANSMISSION PROCESS AND PATHOGENESIS
Unlike most other members of the order Bunyavirales, which are transmitted by arthropods, hantaviruses are primarily transmitted through inhalation of aerosols contaminated with urine, saliva, or feces from infected rodents (CDC, 2024).
Human hantavirus infection generally occurs through exposure to infected rodents or environments contaminated with their excreta. The most common route of transmission is the inhalation of aerosolized viral particles originating from dried rodent urine, feces, or saliva mixed with airborne dust. Such conditions are frequently encountered when cleaning warehouses, abandoned houses, food storage areas, or locations heavily infested with rodents without adequate protective measures. In addition to airborne transmission, infection may also occur through direct contact with virus-containing rodent excreta via broken skin or mucous membranes.
In some cases, bites from infected rodents have also been reported as a potential route of hantavirus transmission to humans, although this mechanism is relatively rare compared with aerosol inhalation. The risk of infection further increases when food or water sources become contaminated with urine or feces from infected rodents. Moreover, exposure to contaminated environments, particularly in areas with poor sanitation, high rodent density, flooding, or waste accumulation, significantly increases the likelihood of hantavirus transmission in humans.
The virus enters the body through the respiratory tract and infects vascular endothelial cells. Endothelial damage leads to increased vascular permeability, resulting in edema, hypotension, hemorrhage, and organ dysfunction (Vaheri et al., 2013).
In HFRS, the kidneys are the primary organs affected. In contrast, in HPS, the lungs develop massive pulmonary edema leading to acute respiratory failure.
Immunological factors also play a crucial role in disease severity. An excessive immune response, often referred to as a cytokine storm, may exacerbate tissue damage and increase patient mortality.
CLINICAL MANIFESTATIONS
Hemorrhagic Fever with Renal Syndrome (HFRS)
Hemorrhagic Fever with Renal Syndrome (HFRS) is the most commonly reported form of hantavirus infection in Asia and Europe. The disease is caused by several hantavirus species, including Hantaan virus (Hantaan orthohantavirus), Seoul virus (Seoul orthohantavirus), Puumala virus (Puumala orthohantavirus), and Dobrava-Belgrade virus (Dobrava-Belgrade orthohantavirus). The main manifestations of HFRS include increased vascular permeability, coagulation system disturbances, and acute kidney injury, which may progress to severe renal failure if not managed promptly and appropriately (Vaheri et al., 2013).
Clinically, HFRS generally progresses through five sequential phases of disease, although not all patients experience every phase completely. The first stage is the febrile phase, which lasts approximately 3–7 days and is characterized by sudden high fever, chills, severe headache, back pain, myalgia, nausea, vomiting, and generalized weakness. During this phase, facial and conjunctival hyperemia are commonly observed, accompanied by petechiae or mild hemorrhage resulting from vascular damage and thrombocytopenia. The early manifestations of HFRS often resemble influenza, leptospirosis, or dengue hemorrhagic fever, making early diagnosis particularly challenging in endemic regions (Krüger et al., 2015).
Following the febrile phase, the disease may progress to the hypotensive phase, during which capillary permeability increases significantly, causing plasma leakage from blood vessels into surrounding tissues. This condition results in a marked decline in blood pressure and may progress to hypovolemic shock. In severe cases, patients may develop systemic circulatory disturbances, tachycardia, and multiple organ dysfunction. Recent studies have demonstrated that cytokine storm plays an important role in exacerbating vascular endothelial damage during this phase (Lu et al., 2024).
The subsequent stage is the oliguric phase, which represents the critical phase of HFRS. At this stage, urine production decreases drastically due to acute kidney injury. Patients may develop elevated serum urea and creatinine levels, edema, hyperkalemia, and metabolic acidosis. In addition to renal impairment, some patients also exhibit more severe hemorrhagic manifestations, including hematemesis, melena, or pulmonary hemorrhage. Complications such as disseminated intravascular coagulation (DIC) and thromboembolism may also occur in severe infections (AccessMedicine, 2024).
If the patient survives the oliguric phase, the disease progresses to the diuretic phase. During this stage, renal function gradually improves, resulting in a marked increase in urine output, which may reach several liters per day. Although this phase indicates clinical improvement, patients remain at risk of dehydration and electrolyte imbalance due to excessive fluid loss. Therefore, careful monitoring of fluid and electrolyte balance remains essential.
The final stage is the convalescent phase, which may last for several weeks to months. Renal function gradually returns to normal; however, some patients may continue to experience proteinuria, hematuria, hypertension, or residual renal dysfunction over the long term. Recent studies have shown that post-HFRS renal damage may persist in certain patients, particularly in infections caused by highly virulent strains such as Hantaan virus and Dobrava virus (Lu et al., 2024).
In general, the clinical manifestations of HFRS include high fever, headache, back pain, nausea, vomiting, petechiae, hypotension, oliguria, and acute kidney failure. The disease fatality rate is strongly influenced by the viral strain, the patient’s immune status, and delays in medical treatment. In mild infections caused by Puumala virus, the mortality rate is relatively low, whereas infections caused by Hantaan virus or Dobrava virus may result in fatality rates of up to 15% (Krüger et al., 2015). Recent systematic studies have further demonstrated that elevated creatinine levels, pulmonary infiltrates, increased hematocrit, and severe thrombocytopenia are important prognostic factors associated with increased mortality in HFRS patients (Tortosa et al., 2026).
Hantavirus Pulmonary Syndrome (HPS)
Hantavirus Pulmonary Syndrome (HPS), also known as Hantavirus Cardiopulmonary Syndrome (HCPS), is the predominant form of hantavirus infection found in North and South America. The disease is primarily caused by Sin Nombre virus and Andes virus. Compared with HFRS, HPS has a much more rapid and severe clinical course because it acutely affects both the pulmonary and cardiovascular systems (Moore & Griffen, 2024).
HPS usually begins with a prodromal phase lasting approximately 3–6 days. During this initial stage, patients experience high fever, severe myalgia particularly involving the thigh and back muscles, fatigue, headache, and gastrointestinal symptoms such as nausea, vomiting, abdominal pain, and diarrhea. These early manifestations are highly nonspecific and are often mistaken for influenza, COVID-19, or other viral infections. Following the prodromal phase, the patient’s condition may deteriorate rapidly within a short period of time.
The subsequent phase is the cardiopulmonary phase, which represents the most dangerous stage of HPS. During this phase, massive increases in pulmonary capillary permeability occur, allowing fluid to accumulate in the alveoli and causing noncardiogenic pulmonary edema. Patients begin to develop cough, progressive dyspnea, severe hypoxia, and acute respiratory failure. In severe cases, cardiogenic shock may occur due to myocardial depression and systemic circulatory dysfunction. Many patients require mechanical ventilation and intensive care shortly after the onset of respiratory distress (Ulloa-Morrison et al., 2024).
The primary pathogenesis of HPS is associated with an excessive immune response to viral infection of pulmonary endothelial cells. Immune system activation triggers the release of large quantities of inflammatory mediators, resulting in widespread vascular leakage. This condition leads to severe pulmonary edema, hypotension, and impaired tissue perfusion. Unlike typical bacterial pneumonia, pulmonary edema in HPS is primarily caused by capillary leakage rather than direct destruction of lung tissue by the virus (AccessMedicine, 2024).
The mortality rate of HPS is extremely high, approximately 35–40%, and may be even higher during certain Andes virus outbreaks in South America when patients do not receive timely intensive care (MacNeil et al., 2011). Recent studies have shown that poor prognostic factors in HPS include bilateral pulmonary infiltrates, early shock, elevated hematocrit, severe thrombocytopenia, and the need for mechanical ventilation during the early phase of illness (Tortosa et al., 2026).
Although most hantaviruses are not transmitted between humans, Andes virus is an exception because it possesses limited human-to-human transmission capability, particularly through close and prolonged contact. This finding has increased global concern regarding the potential for future hantavirus outbreaks, especially in regions with high rodent populations and significant environmental changes.
Overall, both HFRS and HPS demonstrate that hantavirus infection is a serious zoonotic disease with a broad clinical spectrum and high mortality. Therefore, early diagnosis, strengthened zoonotic surveillance, and increased public awareness regarding rodent exposure are essential measures for the prevention and control of this disease.
LABORATORY DIAGNOSIS
The diagnosis of hantavirus infection requires a comprehensive approach because the clinical manifestations are often nonspecific and resemble various other infectious diseases. Diagnosis cannot rely solely on clinical symptoms but must be combined with detailed patient history, including exposure to rodents or environments contaminated with rodent excreta, as well as appropriate laboratory examinations. Patient activities such as working in warehouses, agricultural areas, forests, flood-affected zones, ports, or environments with poor sanitation constitute important epidemiological information that may raise suspicion of hantavirus infection (Vaheri et al., 2013).
In the early stages of infection, hantavirus symptoms frequently resemble those of other tropical diseases such as leptospirosis, dengue hemorrhagic fever, malaria, typhoid fever, and respiratory infections caused by COVID-19. Patients generally present with high fever, headache, myalgia, nausea, vomiting, respiratory distress, or acute kidney injury. Therefore, laboratory confirmation plays a crucial role in establishing the diagnosis and determining appropriate clinical management (Krüger et al., 2015).
One of the most widely used diagnostic methods is serological testing using Enzyme-Linked Immunosorbent Assay (ELISA). This examination aims to detect IgM and IgG antibodies against hantavirus in patient serum. IgM antibodies usually appear during the acute phase of infection and indicate recent or active infection, whereas IgG antibodies develop later and may persist for a long period as evidence of previous exposure. ELISA is widely utilized because it has relatively high sensitivity and specificity and can be readily implemented in routine diagnostic laboratories (Jonsson et al., 2010). Recent studies have demonstrated that the use of recombinant antigens in ELISA can improve the sensitivity of early hantavirus diagnosis, particularly in patients with low antibody levels during the initial stage of illness (Jiang et al., 2024).
In addition to ELISA, the Immunofluorescence Assay (IFA) is also commonly used to detect hantavirus-specific antibodies. This technique utilizes fluorescent-labeled antibodies to identify patient antibodies directed against viral antigens. IFA possesses high sensitivity and may help confirm ELISA results, particularly in cases with equivocal serological findings. However, this method requires more specialized laboratory facilities and interpretation by experienced personnel (Vapalahti et al., 2003).
Molecular detection using Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) has become an important diagnostic method, especially during the early phase of infection when antibodies have not yet developed optimally. RT-PCR can directly detect viral genetic material from blood, serum, tissues, or other clinical specimens. This method is highly useful for early diagnosis, viral strain identification, and epidemiological surveillance. The development of real-time PCR has further enabled more sensitive viral detection, shorter examination times, and viral load quantification, which may assist in assessing disease severity (Klempa, 2018).
In recent years, multiplex real-time PCR technology has advanced rapidly and now enables simultaneous detection of multiple pathogens with similar clinical manifestations, including hantavirus, Leptospira, dengue virus, and SARS-CoV-2. This approach is particularly important in tropical countries such as Indonesia, where many infectious diseases exhibit overlapping clinical features (Temmam et al., 2024).
Virus isolation remains the gold standard in virological research because it allows complete viral characterization. However, this procedure is rarely performed in routine laboratories because it requires biosafety level-3 (BSL-3) facilities due to the high risk of laboratory-acquired infection. Virus isolation is generally conducted for research purposes, vaccine development, and pathogenesis studies (CDC, 2024).
Furthermore, advances in genome sequencing technology have contributed significantly to understanding hantavirus epidemiology and evolution. Genome sequencing enables the identification of novel strains, analysis of genetic mutations, and investigation of phylogenetic relationships among viruses from different geographical regions. Next-generation sequencing (NGS) technology is increasingly being utilized in zoonotic surveillance because it allows rapid and accurate detection of novel viruses, including previously unidentified hantaviruses (Maes et al., 2019).
Hematological and clinical biochemical examinations also provide important clues in the diagnosis of hantavirus infection. Most cases demonstrate thrombocytopenia due to increased platelet destruction and vascular dysfunction. Leukocytosis commonly occurs as part of the systemic inflammatory response, whereas hemoconcentration develops due to plasma leakage from blood vessels. In patients with HFRS, elevated serum creatinine and urea levels are important indicators of acute renal impairment. In addition, increased hematocrit, proteinuria, hematuria, and electrolyte disturbances are frequently observed during severe phases of the disease (Vaheri et al., 2013).
In HPS, laboratory findings often include severe hemoconcentration, thrombocytopenia, leukocytosis with left shift, and elevated lactate levels resulting from tissue hypoxia. Chest radiographic examination may also reveal bilateral interstitial infiltrates and rapidly progressing noncardiogenic pulmonary edema (MacNeil et al., 2011).
The differential diagnosis of hantavirus infection is broad because its clinical manifestations resemble numerous other infectious diseases. Leptospirosis is one of the primary differential diagnoses because it is also rodent-borne and may cause fever, renal failure, hemorrhage, and hepatic dysfunction. Dengue hemorrhagic fever is likewise difficult to distinguish from hantavirus infection because both conditions may produce thrombocytopenia, hemoconcentration, and hemorrhagic manifestations. In addition, severe malaria, bacterial sepsis, typhoid fever, scrub typhus, and COVID-19 should also be considered in the differential diagnosis, particularly in patients presenting with acute febrile illness and respiratory symptoms (Krüger et al., 2015).
The major challenges in hantavirus diagnosis in developing countries are mainly related to limited molecular laboratory facilities, low clinician awareness of the disease, and inadequate integrated zoonotic surveillance systems. Many hantavirus cases are likely underdiagnosed or misdiagnosed as dengue or leptospirosis. Therefore, strengthening laboratory capacity, improving clinical awareness, and integrating surveillance through a One Health approach are essential steps to enhance early detection of hantavirus infection in Indonesia and other tropical countries.
IMPACT OF CLIMATE CHANGE AND ENVIRONMENTAL FACTORS
Global climate change and environmental degradation have a profound impact on the dynamics of hantavirus transmission in various parts of the world. Changes in temperature, rainfall patterns, humidity, and ecosystem disturbances directly affect rodent populations, which serve as the primary reservoirs of hantaviruses. Increased environmental temperatures and heavy rainfall can enhance the availability of natural food sources for rodents, such as seeds, vegetation, and other food resources, thereby accelerating reproduction and increasing rodent population density. These conditions increase the likelihood of contact among rodents and enhance viral circulation in nature. Ecological studies have demonstrated that seasonal climate fluctuations are strongly associated with increases in hantavirus reservoir populations and subsequent rises in human cases several months later (Luis et al., 2010). In addition, warmer winters resulting from global warming are known to prolong rodent activity periods and increase opportunities for viral transmission throughout the year (Sipari et al., 2022).
Climate change also affects rodent migration patterns and geographical distribution. Natural habitats affected by drought, wildfires, or environmental degradation force rodents to move closer to human settlements in search of food and shelter. This condition increases interactions between humans and hantavirus reservoirs. Recent studies have shown that land-use changes, agricultural expansion, and biodiversity loss are closely associated with increased prevalence of rodent-borne diseases. When natural predators decline and ecosystem structures are altered, rodent populations may increase dramatically, thereby elevating the risk of zoonotic disease transmission (Teitelbaum et al., 2025).
Rapid deforestation and urbanization occurring in many tropical countries further exacerbate this situation. Forest clearing for agriculture, mining, and residential development causes fragmentation of wildlife habitats and forces rodents to adapt to human environments. In urban areas, poor sanitation, high population density, and waste accumulation create favorable conditions for increasing rat populations. These factors are highly relevant to hantavirus epidemiology because major viral reservoirs, such as Rattus norvegicus and Rattus tanezumi, are capable of living in close proximity to humans in both urban and rural environments (Jonsson et al., 2010).
Flooding caused by extreme climate events is also an important risk factor in the spread of rodent-borne zoonotic diseases. Floods force rats out of their burrows and into human residential areas. Floodwaters may carry rodent urine, saliva, and feces containing the virus, thereby expanding the extent of environmental contamination. In addition to increasing the risk of leptospirosis, several studies have shown that flooding disasters may also increase human exposure to hantaviruses, particularly in areas with poor sanitation and high rodent density (Diaz, 2015). Recent research regarding the impact of extreme flooding in Brazil in 2024 demonstrated that climate change and inadequate sanitation accelerated the spread of various zoonotic diseases through environmental contamination and increased human contact with animal reservoirs (Ziliotto et al., 2024).
Global environmental changes also increase the risk of the emergence of novel hantavirus strains. Genome sequencing technology and next-generation sequencing (NGS) have revealed the presence of numerous previously unidentified hantaviruses in rodents, bats, and other small mammals in different regions of the world. Recent phylogenetic studies have shown that hantavirus evolution is strongly influenced by ecological dynamics of reservoir hosts and environmental changes that bring together animal species previously separated geographically (Guo et al., 2013). Furthermore, artificial intelligence (AI)-based modeling and early warning systems are increasingly being utilized to predict potential hantavirus outbreaks based on climate data, rodent density, vegetation patterns, land surface temperature, and satellite-derived rainfall information. A recent study in Germany successfully developed a machine learning-based spatial prediction system capable of estimating the risk of Puumala hantavirus outbreaks several months before increases in human cases occur (Kazasidis et al., 2024).
In South America, climate-based modeling approaches combined with rodent surveillance have also begun to be implemented to anticipate outbreaks of Hantavirus Pulmonary Syndrome (HPS). Research conducted in Argentina demonstrated that synchronized increases in rodent populations resulting from climate variability may serve as an early indicator of impending hantavirus outbreaks in humans. Such systems are expected to support the development of ecology- and climate-based early warning systems to prevent large-scale increases in human cases (Ferro et al., 2024).
As a tropical country, Indonesia possesses ecological conditions that strongly support rodent proliferation and the spread of rodent-borne zoonotic diseases. High rainfall, elevated environmental humidity, rapid urbanization, inadequate sanitation, and increasing flood frequency associated with climate change make Indonesia highly vulnerable to an increased risk of hantavirus transmission. In addition, the country’s rich biodiversity and extensive land-use changes further increase the likelihood of novel interactions between humans and viral reservoirs. These conditions demonstrate that the impact of climate change on hantavirus is no longer merely a theoretical threat, but a real and growing challenge requiring strengthened zoonotic surveillance, ecological monitoring of rodent populations, technology-based early warning systems, and integrated implementation of the One Health approach to protect public health in the future.
PREVENTION AND CONTROL
The prevention and control of hantavirus infection require a comprehensive and sustainable approach because the disease involves complex interactions among humans, animals, and the environment. In recent decades, the One Health concept has increasingly been recognized as one of the most effective strategies for controlling zoonotic diseases, including hantavirus infection. This approach emphasizes the importance of cross-sectoral collaboration among human health, animal health, environmental health, academic institutions, laboratories, governments, and communities to reduce the risk of zoonotic disease transmission in an integrated manner (Destoumieux-Garzón et al., 2018).
The primary reservoirs of hantaviruses are wild and domestic rodents that can carry the virus without showing clinical signs. Therefore, rodent population control constitutes a fundamental measure in disease prevention. Such control should not rely solely on traps or rodenticides but also incorporate ecological approaches aimed at reducing rodent habitats and food sources around human settlements. Poorly maintained environments, waste accumulation, inadequate drainage systems, and unhygienic food storage facilities are major factors supporting increases in rodent populations (Meerburg et al., 2009).
Improvement of environmental sanitation is another essential strategy in hantavirus control. Poor sanitation increases the likelihood of human exposure to rodent urine, saliva, and feces containing the virus. Homes and workplaces should be maintained in a clean, dry, and well-ventilated condition to minimize rodent infestation. Sealing gaps in walls, floors, roofs, and drainage systems is also critical to prevent rodents from entering houses or food storage buildings. In addition, proper waste management should be prioritized because organic waste accumulation frequently serves as a major food source for rats in both urban and rural areas (Centers for Disease Control and Prevention/CDC, 2024).
Communities should also be educated on safe methods for cleaning areas contaminated with rodent excreta. Many hantavirus infections occur due to inhalation of aerosols generated from dust contaminated with rodent urine or feces. Therefore, people are advised not to sweep or clean rodent droppings while dry, as this may aerosolize viral particles and increase the risk of inhalation. Contaminated areas should first be sprayed with disinfectants such as chlorine solution or 70% alcohol, followed by cleaning with gloves and damp cloths. This approach has been shown to effectively reduce the risk of hantavirus aerosolization in both household and occupational environments (CDC, 2024).
Furthermore, the public should be educated to store food in tightly sealed containers to prevent contamination by rodents. Open food storage may attract rats into residential areas and increase the risk of hantavirus transmission as well as other zoonotic diseases. Such educational efforts should be continuously implemented through community-based risk communication programs in order to sustainably improve public awareness regarding hantavirus threats.
Certain occupational groups are at higher risk of hantavirus exposure, including farmers, warehouse workers, sanitation personnel, forestry workers, wildlife researchers, military personnel, and laboratory workers. Therefore, the use of personal protective equipment (PPE) is essential to reduce exposure risk. The use of respirator masks, gloves, eye protection, and specialized work clothing is strongly recommended, particularly when working in areas with high rodent populations or when cleaning locations suspected of being contaminated with rodent excreta (Jonsson et al., 2010).
Strengthening integrated zoonotic surveillance is also a key component of hantavirus control. Surveillance should not only focus on humans but also include monitoring of rodent populations and other wildlife species that may serve as viral reservoirs. Serological and molecular monitoring in rodents can help detect hantavirus circulation before increases in human cases occur. A One Health-based surveillance approach enables cross-sectoral data integration, thereby facilitating earlier identification of potential outbreaks (Klempa, 2018).
Early detection of cases in both humans and animals is crucial to prevent wider disease transmission. Early diagnosis enables prompt medical management, which may significantly reduce mortality rates, particularly in cases of Hantavirus Pulmonary Syndrome (HPS), which can progress rapidly. In developing countries, the major challenges for early detection include limited awareness of hantavirus among healthcare professionals and inadequate molecular diagnostic facilities. Therefore, strengthening laboratory capacity, improving medical personnel training, and enhancing zoonotic disease reporting systems should become priorities in public health policy (Krüger et al., 2015).
In terms of specific prevention, hantavirus vaccine development has continued to advance. Several inactivated vaccines targeting Hantaan virus (HTNV) and Seoul virus (SEOV) have been used in China and South Korea and have demonstrated effectiveness in reducing HFRS incidence in endemic regions (Schmaljohn & Hooper, 2001). Recent studies have also focused on the development of DNA-based vaccines, mRNA vaccines, and recombinant vaccines targeting multiple hantavirus strains simultaneously. These next-generation vaccine technologies are expected to provide broader protection against hantaviruses with improved safety and immunogenicity profiles (Hooper et al., 2023).
Nevertheless, no hantavirus vaccine has yet been widely implemented on a global scale. The major challenges in vaccine development include the high genetic diversity of hantaviruses, their differing geographical distributions, and the limited vaccine market because most cases remain concentrated in specific regions. Consequently, prevention strategies based on environmental management and reduction of human-rodent contact remain the primary approaches for hantavirus control in many countries.
Climate change, urbanization, deforestation, and increasing human interaction with wildlife are expected to elevate the risk of hantavirus emergence in the future. Therefore, hantavirus control cannot be achieved through sectoral approaches alone but requires strong multidisciplinary collaboration through implementation of the One Health concept. This approach is particularly important for tropical countries such as Indonesia, which possess high biodiversity, abundant rodent populations, and significant environmental sanitation challenges.
ONE HEALTH APPROACH IN HANTAVIRUS ANTICIPATION
The One Health approach has become an essential strategy in the control of zoonotic diseases, including hantavirus infection, because these diseases emerge through complex interactions among humans, animals, and the environment. Hantavirus represents a clear example of a disease strongly influenced by ecosystem changes, rodent population dynamics, human activities, and environmental conditions that facilitate viral transmission. Therefore, hantavirus control cannot rely solely on medical interventions but must involve sustainable multidisciplinary and cross-sectoral collaboration (Destoumieux-Garzón et al., 2018).
The One Health concept emphasizes that human health is inseparable from animal health and environmental conditions. In the context of hantavirus, rodents serve as the primary viral reservoirs, while environmental changes such as urbanization, deforestation, land-use changes, and climate change affect the population dynamics of these reservoir hosts. When natural habitats are disrupted, rodents tend to migrate closer to human settlements in search of food and shelter, thereby increasing the risk of human contact with infected animal excreta (Jonsson et al., 2010).
Implementation of the One Health approach in hantavirus preparedness begins with strengthening integrated cross-sectoral surveillance systems. Surveillance should not only focus on human disease cases but also include monitoring of rodent populations, environmental conditions, and viral circulation in wildlife. This approach enables early detection of potential outbreak risks before widespread transmission occurs in humans. Integrated surveillance systems are particularly important because increases in rodent populations often serve as early indicators of heightened hantavirus transmission risk within a region (Meerburg et al., 2009).
Monitoring rodent populations is one of the major components of the One Health approach. Such monitoring aims to determine rodent population density, geographical distribution of reservoir species, migration patterns, and hantavirus infection rates among rodents. Rodent ecology research is highly important because each hantavirus species is generally associated with specific reservoir hosts. For example, Seoul virus is commonly associated with Rattus norvegicus, whereas Hantaan virus is primarily linked to Apodemus agrarius. Information regarding reservoir distribution greatly assists in mapping high-risk areas and developing more effective control strategies (Klempa, 2018).
In addition to rodents, recent studies have shown that several species of bats, shrews, and other wild mammals may also harbor hantaviruses or hantavirus-like viruses. Therefore, viral detection in wildlife has become an important component of modern zoonotic surveillance. Molecular technologies such as real-time PCR, genome sequencing, and next-generation sequencing (NGS) are increasingly being used to detect novel hantaviruses in wildlife before these viruses spread more widely to human populations (Guo et al., 2013). This approach is particularly important in addressing the threat of emerging infectious diseases resulting from increasing human interactions with wildlife due to global environmental changes.
Integration of human and veterinary health data is also a critical component of One Health implementation. Historically, disease data from human and animal health sectors have often been managed separately, thereby delaying early detection of zoonotic outbreaks. Through integrated cross-sectoral data systems, increases in disease incidence among rodents or wildlife can rapidly serve as early warning signals for the human health sector. Such data integration systems enable faster and more coordinated responses to potential hantavirus outbreaks (World Health Organization/WHO, 2023).
Strengthening zoonotic disease laboratories is another crucial aspect supporting the One Health approach. Hantavirus diagnosis requires laboratory facilities with adequate serological and molecular detection capabilities. Human and veterinary health laboratories need to be strengthened to ensure rapid, accurate, and safe viral identification. Furthermore, expanding biosafety level-3 (BSL-3) laboratory capacity is important because hantaviruses are classified as high-risk zoonotic pathogens (CDC, 2024).
Collaboration among governments, academic institutions, researchers, professional organizations, and communities also plays a key role in the success of the One Health approach. Governments have important responsibilities in developing zoonotic disease control policies, strengthening environmental sanitation regulations, and establishing integrated national surveillance systems. Meanwhile, academic institutions and research organizations contribute through epidemiological, virological, and rodent ecology research, as well as through the development of diagnostic methods and vaccines. Community participation is equally important because successful hantavirus control is strongly influenced by public hygiene practices and environmental management behaviors (Destoumieux-Garzón et al., 2018).
In Indonesia, implementation of the One Health approach in hantavirus control still faces numerous challenges. Laboratory- and ecology-based zoonotic surveillance systems are not yet fully integrated. Data regarding reservoir rodent distribution, the presence of local hantavirus strains, and the number of human cases remain very limited. In addition, coordination among ministries and institutions is often suboptimal, thereby reducing the effectiveness of early outbreak detection. This is particularly concerning because Indonesia faces a high risk of rodent-borne zoonoses due to its tropical climate, high population density, rapid urbanization, and persistent environmental sanitation problems in many regions.
Integration of data among the human health, animal health, forestry, agriculture, environmental, and research laboratory sectors is therefore essential to improve national preparedness against hantavirus threats. The development of ecological- and epidemiological-based early warning systems may assist governments in identifying high-risk areas before increases in human cases occur. This approach is also highly relevant in addressing the impacts of global climate change, which is predicted to increase the emergence risk of various new zoonotic diseases in the future (Carlson et al., 2022).
Thus, the One Health approach is not merely a theoretical strategy but a practical necessity for effective and sustainable hantavirus control. Strong multidisciplinary collaboration, integrated surveillance, laboratory strengthening, and increased public awareness constitute the main foundations for protecting human health against rodent-borne zoonotic threats such as hantavirus.
CONCLUSION
Hantavirus is an important zoonotic disease primarily transmitted through rodents and poses serious threats to human health. The disease may cause Hemorrhagic Fever with Renal Syndrome (HFRS) and Hantavirus Pulmonary Syndrome (HPS), both of which are associated with relatively high mortality rates.
Environmental changes, urbanization, flooding, and climate change contribute significantly to the increasing risk of hantavirus transmission. Indonesia possesses considerable vulnerability due to its large rodent populations, suboptimal sanitation conditions, and frequent human interaction with contaminated environments.
Strengthening surveillance systems, expanding molecular research, improving laboratory diagnostic capacity, enhancing public education, and implementing effective rodent control measures are essential steps in anticipating hantavirus threats in Indonesia.
An integrated One Health approach involving the human health, animal health, and environmental sectors represents the most effective strategy for preventing future hantavirus outbreaks.
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