The Hantavirus Paradigm: Genomic Architecture, Epidemiological Dynamics, Diagnostic Advances and Mitigation Strategies

1. Introduction

Hantaviruses are enveloped, negative-sense, single-stranded RNA viruses belonging to the genus Orthohantavirus within the order Bunyavirales, family Hantaviridae. They are spread by direct or indirect contact with rodent reservoir hosts that are infected [1,2]. Because of this route of transmission and the fact that rodent host species are found all over the world, hantavirus is a pathogen that have worldwide epidemiological significance. A number of outbreaks have been documented in Asia, Europe, and the United States since hantavirus diseases were discovered, making it a significant emerging infectious disease [3,4].

Geographical location and viral type affect the range of diseases linked to hantavirus infection. Old World and New World hantaviruses are two categories for the viruses. New World hantaviruses are primarily found in North and South America and are linked to Hantavirus Pulmonary Syndrome (HPS), also referred to as Hantavirus Cardiopulmonary Syndrome (HCPS). Old World hantaviruses are primarily found in Europe and Asia and are linked to Hemorrhagic Fever with Renal Syndrome (HFRS) [5,6,7]. While HFRS, which mainly affects the kidneys and blood vessels, HCPS, a quickly progressing disorder affecting the heart and lungs. The viral strain and the host immunological response determine the disease’s severity. Although HFRS accounts for the vast majority of absolute case numbers worldwide, HCPS is one of the most acutely deadly acute viral respiratory infections due to its significantly higher case fatality rate, which approaches 30 to 40% in the absence of adequate supportive care [3,8,9,10,11].

2. Genome Structure of Hantavirus

Hantavirus virions range in size from 120 to 150 nm and have a spherical shape. They have a tripartite single-stranded negative-sense RNA genome and are spherical, enveloped viruses. The nucleoprotein (N), envelope glycoproteins (Gn, formerly G1, and Gc, formerly G2), and the L protein or viral RNA (vRNA)-dependent RNA polymerase (RdRp) are encoded by the three segments, S (small), M (medium), and L (large), respectively [2,5]. The multifunctional protein RdRp, which is involved in both viral genome transcription and replication, is encoded by the L segment. Similar to other members of the Bunyavirales family, the hantavirus RdRp uses a cap-snatching mechanism to effectively take over host translation machinery without encoding its own capping enzyme. This mechanism involves cleaving 5’ capped oligonucleotides from host cellular mRNAs and using them as primers for viral mRNA synthesis [2,12]. Since its enzymatic activity is necessary for viral replication, the RdRp is a significant pharmacological target for the development of antiviral drugs. It comprises conserved sequence patterns shared by RNA-dependent RNA polymerases across several virus families. The potential for broad-spectrum anti-hantaviral efficacy of RdRp-targeting medications is supported by the conservation of RdRp catalytic motifs among hantavirus species [12,13,14,15].

A single glycoprotein precursor (GPC) encoded by the M segment is co-translationally converted into two mature surface glycoproteins, Gn and Gc. Gn and Gc work together to create heterodimeric spike complexes that emerge from the viral envelope and carry out two vital tasks: recognition and binding of host cell receptors, mostly by Gn, and pH-dependent membrane fusion during viral entry into endosomes, mainly via Gc. The main antigens of interest for vaccine design are the Gn and Gc glycoproteins since they are the main targets of virus-neutralizing antibodies. The degree of cross-protective immunity induced by infection with one strain against heterologous strains is significantly limited by the degree of sequence divergence in Gn and Gc across hantavirus species, with amino acid identity between distantly related strains as low as 30 to 50%. The production of widely protective vaccines is severely hampered by this variety, which calls for careful immunogen design techniques such focusing antibody responses on conserved structural epitopes [16,17,18,19,20,21].

The S segment codes for the nucleocapsid (N) protein, which is the most widely expressed viral protein in cells that are infected. The N protein promotes RdRp activity, encapsulates and shields viral RNA within RNP complexes, and interacts with several host factors to alt the cellular environment during infection [2,22]. Additionally, the N protein is the predominant antigen for the humoral immune response; commercial serological diagnostic techniques are based on anti-N antibodies, which emerge early in infection and can be detected at or before the beginning of symptoms. Crucially, compared to the glycoproteins, the N protein is far more conserved among hantavirus species. This conserved immunodominance of the N protein enables the development of broadly cross-reactive serological assays that use recombinant N protein antigens to detect antibodies elicited by diverse hantavirus species, making it the preferred diagnostic antigen target globally [23,24,25].

3. Viral Replication Cycle

The viral Gn glycoprotein binds to particular cell surface receptors to start the intricate, multi-step process of hantavirus entrance and replication into host cells. Beta-3 integrins more precisely, alphav-beta3 on endothelial cells and alphaIIb-beta3 on platelets are used as major entry receptors by pathogenic hantaviruses, including both severe HFRS-causing Old World strains and HCPS-causing New World strains [7,26,27,28]. After receptor binding, they are internalized by clathrin-mediated endocytosis. Virions then move through the endosomal compartment to late endosomes and lysosomes, where the increasingly acidic pH causes conformational changes in the Gc glycoprotein that facilitate the fusion of the viral and endosomal membranes. The three viral RNP complexes are then released into the cytoplasm. Transcription and Translation occur at the endoplasmic reticulum Golgi intermediate compartment or at the location where RNPs are released. Viral transcription and replication are carried out by the viral polymerase RdRp, which has transcriptase, replicase, and endonuclease activities. RdRp cleaves cellular mRNA to create capped primers, which starts transcription. [2,16,29,30,31,32,33].

It has recently been proposed that cellular endonucleases also contribute to the production of capped primers by cleaving cellular mRNAs whose cap-structures are shielded from degradation by the viral N protein that is specially linked to them. These capped primers then start the transcription of viral mRNAs [2]. S segment derived mRNA serves as a template for the N protein. M segment derived mRNA produces GPC on the ER membrane-bound ribosomes. G1 and G2 glycoproteins are transported from the ER to the Golgi complex or to the plasma membrane where assembly takes place. The Golgi is where Old World hantaviruses assemble, whereas the plasma membrane is where New World hantaviruses assemble. Processed Gn and Gc glycoproteins are integrated into developing viral envelopes during virion assembly, and mature virions bud into the Golgi lumen prior to being released by exocytic vesicles. In permissive cell types, the full replication cycle can be finished in 24 to 48 hours, producing hundreds of offspring virions [2,34,35,36]. Decay-accelerating factor (DAF/CD55), heparan sulfate proteoglycans on the cell surface, and the complement receptor gC1qR are among the numerous additional attachment factors and co-receptors that are implicated in hantavirus entry, according to emerging evidence. Each of these factors contributes to viral attachment and entry in a cell-type and strain-specific manner. Finding new targets for entry-inhibiting antiviral medications and comprehending the cellular tropism of various hantavirus strains could both benefit from an ongoing research project that aims to fully understand each strain’s receptor usage profile [2,18,37].

4. Epidemiology of Hantavirus

4.1. Global Burden and Disease Distribution

Hantaviruses are enzootic viruses that cause long-term, usually asymptomatic infections in rodent reservoirs. Human disease arises as an unintentional spillover event rather than as part of the virus’s natural transmission cycle. Although case fatality varies greatly by geography and virus species and can reach as high as 50% in the most severe presentations, global estimates place the annual burden at 10,000 to over 100,000 infections worldwide, with the biggest burden centered in Asia and Europe [8,38,39,40].

4.2. Old World Epidemiology: Hemorrhagic Fever with Renal Syndrome (HFRS)

HFRS is found in a distinct endemic belt that extends from Norway in the west to China, Korea, and Japan in the east, via Sweden and Finland. The majority of this burden falls on China: surveillance evaluations estimate that there are over 100,000 HFRS cases reported each year in Europe and Asia, with about 90% of those cases occurring in China [41,42]. While further time-series modeling and spatial analysis of Chinese CDC data from 2004 to 2015 show a typically decreasing but still significant incidence trend. The virulence of the causative agents varies by lineage: Puumala virus (PUUV), endemic in northern Europe and carried by the bank vole, usually causes a milder syndrome known historically as nephropathia epidemica, with mortality rate closer to 0.1–0.2%, while Hantaan virus (HTNV) and Dobrava virus (DOBV) produce the most severe disease, with case fatality of about 5–10% [43,44,45]. European incidence has trended downward in recent years: 1,885 hantavirus infections were reported across the European Region in 2023 (0.4 per 100,000 population), the lowest rate observed in the 2019–2023 window [43,46].

4.3. New World Epidemiology: Hantavirus Cardiopulmonary Syndrome (HCPS/HPS)

HCPS is geographically limited to the Americas, where about 300 cases are diagnosed each year; nonetheless, its mortality is significantly higher than that of its Old-World equivalent. The majority of cases in North America are caused by the Sin Nombre virus (SNV), which is carried by the deer mouse (Peromyscus maniculatus). Less than 1,000 cases have been reported overall in the United States [10,38]. The predominant agent in South America is the Andes virus (ANDV), which is primarily carried by the long-tailed pygmy rice rat (Oligoryzomys longicaudatus). Since the virus’s characterization following the 1995 Patagonian outbreak, more than 1,200 cases have been confirmed in Argentina alone, with an estimated 4,000 HCPS cases reported throughout South America [47,48,49]. The Bayou virus, Black Creek Canal virus, and New York virus are less prevalent New World agents linked to sporadic disease. Each of these viruses has a unique rodent reservoir, and the main way that humans are exposed to them is through inhaling aerosolized viral particles from infected rodent excrement [47]. Through 2025–2026, there was a noticeable increase in HCPS activity in the Americas. In eight countries (Argentina, Brazil, Bolivia, Chile, Panama, Paraguay, the United States, and Uruguay), the regional PAHO/WHO alert from December 2025 reported 229 confirmed cases and 59 deaths, with a regional case fatality rate of 25.7% that was primarily focused in the Southern Cone [38,50]. Most recently, a multi-country cluster traced to cruise ship travel emerged in 2026: seven cases (two laboratory-confirmed and five suspected) were identified among 147 passengers and crew, including three deaths, with rodent exposure aboard the vessel considered unlikely and limited person-to-person ANDV transmission via close, prolonged contact regarded as the more probable route [51,52,53].

4.4. Seroprevalence of Hantavirus

A pooled global seroprevalence of 2.93% (95% CI 2.34–3.67%) was estimated by a systematic review and meta-analysis of 40 years of seroprevalence studies, including 110 studies, 81,815 observations, and 3,207 seropositive events through January 2024. Regional estimates were 2.43% in the Americas (61 studies), 2.98% in Europe (33 studies), and 2.21% in Africa (6 studies). Regional point estimates ranged from 2.43% to 6.84% overall [40,54]. After the Hantaan virus was isolated in 1978, indigenous African hantaviruses were not molecularly identified for almost thirty years. The first indigenous African hantavirus to be confirmed molecularly was Sangassou virus, which was discovered in Guinea in 2006 and later isolated in cell culture in 2012. Following this, a thorough search resulted in the molecular identification of additional novel hantaviruses in rodents, shrews, and bats, extending the known reservoir host range beyond the rodent-only systems reported in Asia, Europe, and the Americas [55].

A human seroprevalence of 1.0% (n = 1,442) was found in the South African Cape region. Human seroprevalence data are still sparse but suggestive of genuine, geographically uneven exposure. In Madagascar, seroprevalence was significantly greater in the vicinity of forest environment, with 7.2% seropositivity found at locations close to Moramanga forest as opposed to the lower national average [55,56]. According to a recent Africa CDC knowledge analysis, the continent’s poorly characterized epidemiology is caused by fragmented surveillance, inadequate One Health systems, conflicting public health priorities from viral hemorrhagic fevers, HIV/AIDS, malaria, and tuberculosis, as well as limited intensive care capacity. These factors are exacerbated by climate variability, flooding, drought, deforestation, and urbanization that change rodent ecology and human exposure risk [57].

5. Transmission of Hantavirus

5.1. Primary Route: Inhalation of Aerosolized Rodent Excreta

All pathogenic hantaviruses primarily spread through the respiratory system. Inhaling aerosolized viral particles from dried rodent urine, feces, or saliva is the main way that humans become infected. This process is vividly explained in mechanistic terms: rodents carrying the virus excrete the virus in urine and feces, air currents aerosolize these excretions, and the particles are then inhaled into the lungs, causing severe pulmonary disease. Because this pathway relies on the disruption of contaminated material rather than the virus’s active host-seeking behavior, rodent or human action like sweeping or vacuuming can easily release the virus into the air in small places [1,58,59].

5.2. Secondary Routes

In addition to aerosol inhalation, there are a number of less frequent but well-researched pathways. People can contract an infection by consuming food tainted with rodent droppings, urine, or saliva. They can also contract an infection if an infected rat’s feces, urine, or saliva gets into their eyes, nose, or mouth. Direct inoculation is even less common; the virus can occasionally enter the body through incisions, the eyes, or, very infrequently, a rodent bite or scratch. Although none of these secondary routes come close to the epidemiological significance of airborne exposure, they are still clinically significant in case investigations [1,60,61,62].

5.3. Transmission Dynamics Within Rodent Reservoir Populations

In nature, hantaviruses are maintained through constant horizontal transmission between rodents, which is influenced by host immunology and demographics. Proinflammatory and antiviral responses are diminished while regulatory immune responses are increased at viral replication sites, sustaining persistent, asymptomatic infection in the reservoir. Additionally, host factors like sex steroids, glucocorticoids, and genetic background influence susceptibility. Newborn rodents from persistently infected, seropositive mothers are protected from infection by maternal antibodies transferred across the placenta and through lactation, but this protection wanes as the juveniles get older. After that, they are vulnerable to horizontal transmission from other infected adults, usually through aggressive encounters, shared burrows, or contaminated nesting material [39,59,63].

5.4. Person-to-Person Transmission: The Andes Virus Exception

The Andes virus is unique among pathogenic hantaviruses due to its proven ability to transfer from person to person. The biological mechanism remains incompletely understood; one hypothesis holds that the virus is secreted into human saliva and transmitted through the respiratory tract via airborne particles released during breathing, coughing, or sneezing, while a competing explanation for why most other hantaviruses fail to spread between humans points to laboratory observations that these viruses appear to produce very few mature virus particles in the lungs of infected humans a constraint Andes virus may partly overcome A 2018–2019 outbreak in Chubut Province, Argentina, where person-to-person transmission of the Andes virus resulted in 34 confirmed illnesses, provides the strongest evidence for this mode of transmission [64,65,66,67,68].

5.5. Behavioral and Occupational Exposure Settings

Exposure risk is increased by activities involving rodent contact, such as cleaning enclosed or poorly ventilated spaces, farming, forestry work, and sleeping in rodent-infested homes. Exposure to poorly ventilated areas with active rodent infestations, as well as entering rarely opened or seasonally closed buildings with rodent activity, are recognized major risk factors. Since both environmental and limited person-to-person explanations were taken into account before close, prolonged human contact was determined to be the more likely route for that particular event, the 2026 multi-country cruise ship cluster demonstrated how ambiguous route attribution can be in practice even in a well-resourced investigation [69,70,71].

6. Pathogenesis and Clinical Manifestations

6.1. Target Cells, Tissue Tropism, and Viral Dissemination

Hantaviruses mainly infect endothelium cells after entering the human body, which increases capillary leakage and vascular permeability. Patients with hemorrhagic fever with renal syndrome frequently exhibit fever, hypotension, bleeding, and severe kidney damage [11,72]. However, Hantavirus infection is not limited to endothelium cells; in postmortem tissue, viral antigen or RNA has been detected in macrophages, dendritic cells, lymphocytes, neutrophils, megakaryocytes, platelets, and follicular dendritic cells. This extensive multicellular tropism explains the many organ system involvement that characterizes severe disease and adds to the systemic nature of hantavirus immunopathology [73,74,75].

The main location of viral replication and pathological disruption in HCPS is the pulmonary microvascular endothelium. Hantaviruses first infect the alveolar epithelium and pulmonary macrophages after inhaling infectious aerosols. From there, they spread through the blood and lymphatic systems to infect their primary target cells, which are the microvascular endothelial cells that line the capillaries of the organ systems most affected by each syndrome. Fever, exhaustion, and muscle soreness are the first symptoms that patients experience. These are followed by cough, pulmonary edema, and acute respiratory distress [76,77,78]. The non-cytopathic nature of hantavirus infection in endothelial cells is a distinguishing and frequently highlighted characteristic. Hantaviruses do not cause a discernible cytopathic effect in infected endothelium cell cultures, in contrast to numerous viral infections that kill the cells they infect. This basic finding was regularly replicated in several experimental setups and hantavirus strains. One of the key conceptual challenges in hantavirus biology is reconciling the severe and quickly progressing clinical illness of HCPS with the non-cytopathic infection phenotype [28,78,79].

6.2. Immunopathology: T- Cells, Cytokine Storm, and the Pathogen-Immunity Paradox

Immunopathology, in which the host’s own immune effector systems both cause the tissue destruction that characterizes the clinical condition and are required to eradicate the viral infection, is best shown by the immunological response to hantavirus infection. In order to eradicate infected endothelium cells and manage the viral burden, strong virus-specific CD8+ cytotoxic T lymphocyte (CTL) responses are quickly drawn to hantavirus replication sites in the lung and kidney. By specifically infecting pulmonary microvascular endothelial cells, pathogenic hantaviruses trigger both innate and adaptive immunological responses locally, including the recruitment of particular CD8+ T cells and mononuclear effector cells. Proinflammatory cytokines, including TNF-alpha, IL-6, and CCL2/MCP-1, are released in large quantities as a result of this immunological activation [80,81,82]. This vascular barrier dysfunction is primarily caused by IL-6 trans-signaling, which actively disrupts VE-cadherin and upregulates adhesion molecules, according to research. The proximate mechanism of the non-cardiogenic pulmonary edema that characterizes severe HCPS is not direct viral cytopathology but rather structural damage to the pulmonary alveolar epithelium and endothelium brought on by this immune-mediated process [83,84,85].

CD4+ T helper cells and B cell-mediated humoral immune responses also participate in hantavirus immunopathogenesis and protection. A consistent immunological characteristic of hantavirus disease is the quick emergence of high-titer virus-specific IgM and IgG antibodies, including neutralizing antibodies against Gn and Gc glycoproteins, within the first few days of symptomatic illness. This is linked to better clinical outcomes and suggests that the early humoral response helps restrict viral dissemination and moderates the severity of the immunopathological cascade [81,86,87,88,89].

7. Clinical Features of Hantavirus

7.1. Hantavirus Cardiopulmonary Syndrome (HCPS)

7.1.1. Prodromal Phase

Most cases of HCPS appear two to three weeks after contact to infectious rodent materials, with an incubation period of one to five weeks. A constellation of non-specific constitutional symptoms, severe viral gastroenteritis, or other common febrile illnesses characterize the prodromal phase, which lasts roughly three to six days. This diagnostic challenge frequently causes delays in recognition and appropriate management [90,91]. Nearly all presenting symptoms include a high-grade fever, severe myalgia, and significant muscle pain, especially in the major muscle groups of the back, thighs, and abdomen. Most patients feel headache, lightheadedness, and severe malaise [92]. About 50 to 76% of HCPS patients experience gastrointestinal symptoms during the prodrome, such as nausea, vomiting, abdominal pain, and occasionally diarrhea; the presence of these symptoms in a feverish, myalgic patient from an endemic area significantly increases clinical suspicion for hantavirus [93,94]. Physical examination results during the prodromal phase are usually non-specific, and delayed diagnoses sometimes cause the patient to move to the cardiopulmonary phase before the necessary diagnostic procedures are finished [90,92].

7.1.2. Cardiopulmonary Phase

The most clinically perilous stage of the entire illness is the transition from the prodromal to the cardiopulmonary phase of HCPS, which can happen with frightening suddenness and sometimes within hours [95]. When plasma starts to leak from pulmonary capillaries into the interstitium and alveolar spaces at a rate that exceeds lymphatic drainage capability, this shift is marked by the development of dry cough, progressive dyspnea, and tachypnea [96,97]. Hypoxemia can develop from mild to severe respiratory failure within 24 hours of the onset of respiratory symptoms, requiring mechanical ventilation and intubation [95,98]. Concurrently, myocardial depression results in decreased cardiac output and cardiogenic shock, which exacerbates respiratory failure. This is caused by direct viral involvement of the myocardial endothelium and the cardiodepressant effects of cytokine-mediated cardiomyocyte malfunction [90,95]. Tachycardia, tachypnea, hypoxia with oxygen saturation below 90% on room air, and, in extreme situations, hypotension are physical signs of the cardiopulmonary phase [95].

7.1.3. Recovery: Diuretic and Convalescent Phases

Patients who make it through the cardiopulmonary phase may experience a remarkably quick and satisfying recovery. In certain patients, pulmonary edema can start to resolve 24 to 48 hours after the most severe respiratory symptoms appear. This is accompanied by spontaneous polyuria, which is the result of extravasated fluid being reabsorbed from the pulmonary and systemic interstitium. To avoid iatrogenic dehydration during this diuretic phase, careful fluid and electrolyte management is necessary [10,99,100]. The hallmark of convalescence is typically a slow functional recovery. The majority of survivors recover with little to no ongoing organ impairment. However, some patients especially those who experienced severe acute kidney injury during the acute illness develop lingering renal difficulties and may fit the criteria for chronic kidney disease, highlighting the significance of nephrological follow-up for HCPS survivors following hospital release [47,101].

7.2. Hemorrhagic Fever with Renal Syndrome (HFRS)

7.2.1. The Phases of HFRS

After an incubation period of one to eight weeks, HFRS often advances through clinical stages. The abrupt-onset high fever (38 to 40 degrees Celsius), severe headache, retroorbital pain, photophobia, severe lower back or flank pain indicating early renal involvement, and abdominal discomfort are the symptoms of the febrile phase, which lasts three to seven days. When combined with a history of rodent exposure, distinctive clinical features such as flushing of the face, neck, and upper chest, conjunctival suffusion, and the formation of petechiae on the palate and axillary skin folds should urge quick assessment of HFRS. Thrombocytopenia, proteinuria, hematuria, leukocytosis with left shift, and elevated serum creatinine are among the laboratory abnormalities during the febrile period [1,7,11,43,102,103].

The most serious stage of severe HFRS is the hypotensive phase, which lasts for hours to a few days and is brought on by extensive capillary leakage that lowers the volume of plasma in circulation. Laboratory signs include coagulopathy, increasing thrombocytopenia, and hemoconcentration (growing hematocrit despite declining total red cell mass). Petechiae, ecchymoses, melena, hematemesis, and epistaxis are examples of hemorrhagic symptoms that worsen as a result of thrombocytopenia, platelet dysfunction, and reduced vascular integrity [99,104,105]. Acute kidney failure, which manifests as oliguria or anuria, rapidly rising serum creatinine and urea, electrolyte abnormalities, including hyperkalemia and hyperphosphatemia, and fluid overload are the main features of the oliguric phase, which lasts three to seven days and sometimes overlaps with the hypotensive phase in certain patients. The greatest risk of death from uremic complications, pulmonary edema from volume overload, and cardiac arrhythmias linked to electrolytes occurs during this phase [104,105,106]. Renal tubular function is restored during the diuretic phase, which frequently results in dramatic polyuria of several liters per day. If fluid and electrolyte replacement is not carefully managed during this phase, there is a risk of fatal dehydration, hyponatremia, and hypokalemia [10,99].

8. Diagnosis

8.1. Differential Diagnosis

The non-specific early appearance of hantavirus disease is reflected in the wide differential diagnosis. Influenza A and B (the most common clinical mimic because of similar prodromal features), COVID-19 and other respiratory viral infections, community-acquired bacterial pneumonia (including Legionella pneumophila), Q fever (Coxiella burnetii), leptospirosis, plague (Yersinia pestis), other viral hemorrhagic fevers (such as dengue, Lassa, and Ebola in appropriate geographic settings), and non-infectious causes of ARDS [107,108]. Dengue hemorrhagic fever, leptospirosis, thrombotic thrombocytopenic purpura (TTP), hemolytic uremic syndrome (HUS), acute glomerulonephritis, immunoglobulin A nephropathy with macroscopic hematuria, and systemic vasculitis all share clinical and laboratory characteristics with HFRS. The epidemiological history of rodent exposure is the single most discriminating diagnostic feature for both syndromes. In patients from hantavirus-endemic areas, a history of plausible rodent contact within the 1–8 weeks prior to presentation significantly increases the pre-test probability of hantavirus disease and should prompt diagnostic testing. Perhaps the most effective way to reduce diagnostic delay is to train physicians at all levels in endemic places to routinely elicit rodent exposure histories in febrile patients. Human hantavirus infections should be diagnosed using laboratory testing, clinical data, and epidemiological data [11,103,109,110,111,112].

8.2. Laboratory Diagnosis

8.2.1. Serological Diagnosis

The main diagnostic in clinical practice and public health monitoring worldwide is the detection of hantavirus-specific IgM antibodies, or a fourfold or larger increase in IgG titres between acute and convalescent samples taken at least 14 days apart. IgM antibodies are detectable at the time of or very soon after symptom onset in the great majority of HCPS and HFRS patients, indicating the strong and temporally early humoral immune response that characterizes hantavirus infection. This is a crucial and clinically valuable feature of hantavirus serology [113,114,115,116].

The most popular and internationally standardized serological platform is the enzyme-linked immunosorbent test (ELISA), which uses recombinant nucleocapsid (N) protein as the antigen. Although there is little cross-reactivity between Old World and New World hantavirus groups with N protein antigens, the relative sequence conservation of the N protein within each group allows for the development of broadly reactive assays within each group, requiring the selection of regionally appropriate antigen panels [25,117,118,119]. Using whole-virus-infected cell substrates, immunofluorescence assay (IFA) offers a highly sensitive alternative serological platform. The other confirmatory diagnostic method is immunohistochemistry (IHC) of postmortem tissue, where the distinctive staining pattern of intense N protein antigen in morphologically intact endothelial cells is both pathophysiologically instructive and diagnostically specific, consistent with the previously discussed non-cytopathic infection phenotype [92,116,120,121,122,123,124].

8.2.2. Molecular Diagnosis: RT-PCR, qRT-PCR, and Next-Generation Sequencing

Hantavirus RNA can be directly detected during the viremic phase with excellent sensitivity and specificity using reverse transcriptase polymerase chain reaction (RT-PCR), which targets conserved areas of the S segment (encoding the N protein) or M segment (encoding the glycoproteins). RT-PCR can identify viremia in HCPS during the prodromal and early cardiopulmonary phases. As the disease moves into the convalescent phase and the humoral immune response neutralizes circulating virus, viral RNA falls below the detection limit. [125,126]. Viral load measurement is made possible by quantitative RT-PCR (qRT-PCR), which has clinical utility as a prognostic marker. Higher viremic loads at presentation are associated with more severe clinical courses and worse outcomes, and they may be used as a surrogate endpoint for assessing the effectiveness of antiviral medications in clinical trials. The likelihood of incidental hantavirus detection in patients who were not initially suspected of having the virus has significantly increased with the addition of hantavirus-specific RT-PCR targets to multiplex respiratory pathogen panels used for assessment of febrile respiratory illness, probably improving overall case ascertainment in clinical settings [127,128,129].

The modern era in hantavirus diagnostics is represented by next-generation sequencing (NGS) and metagenomic techniques, which have revolutionary implications for public health and clinical care. From a single clinical sample, NGS allows for simultaneous pathogen-agnostic identification, full-genome characterization, strain typing, and phylogenetic analysis—capabilities that are extremely valuable in epidemic research. Portable nanopore sequencing platforms, which generate real-time sequencing data from small, low-power devices, are increasingly being modified and validated for field deployment and district-level laboratory use in low-resource settings, with the potential to bring hantavirus genome characterization capability to endemic regions currently completely dependent on sample shipment to remote reference facilities [130,131,132].

8.2.3. Emerging Point-of-Care Diagnostics

In order to bridge the gap between ELISA-dependent reference laboratories and field or rural settings, several organizations have validated lateral flow tests. The IgM/IgG lateral flow prototypes obtained 100% sensitivity and 97.5–99.3% specificity, according to a Brazilian prototype evaluation that evaluated 163 samples 10 from proven hantavirus patients, 103 from patients with associated febrile illnesses, and 50 healthy controls. HANTEC, a different point-of-care test, was created and field-validated with similarly good results: sensitivity of 87–100% and specificity of 97–100%, no cross-reactivity across a panel of eleven acute infections, detection across multiple hantavirus genotypes, and the capacity to operate without equipment or electricity, producing results in 10–15 minutes, specifically positioning it for epidemiological surveys and focused control measures in South America. Additionally, it is essential to create alternate molecular methods, such as the isothermal amplification approach [114,133,134].

9. Preventive Approaches Against Hantavirus

9.1. Environmental Control and Rodent Exclusion

The cornerstone intervention, supported by the CDC, PAHO, WHO, and occupational health regulatory bodies, is rodent control through active population reduction and environmental modification. The best methods for controlling rodents combine several mutually reinforcing strategies: mechanical exclusion, which entails sealing all holes, cracks, and structural penetrations in buildings that allow rodents to enter; removal of food and water sources that draw rodents to human-occupied spaces by storing food in metal or heavy plastic containers; reduction of harborage sites by removing clutter, debris, and dense vegetation near structures; and active population reduction by strategically using snap traps and rodenticides in infested areas. It is advised to regularly check buildings for indications of rodent activity prior to occupancy or use [38,60,135,136,137,138,139,140].

9.2. Occupational Safety Programs

Comprehensive occupational health programs are a proven strategy for minimizing work-related transmission, and hantavirus is a known occupational hazard for a variety of professions that operate in surroundings with elevated rodent populations. An alarming contemporary example of the avoidable human cost of insufficient occupational hantavirus precautions is the 2025 Paraguayan HCPS outbreak, which was centered in agricultural laborers with verified occupational rodent exposure. Regulations for hantavirus risk reduction have been established by OSHA in the US and comparable occupational health organizations in other nations. These regulations include requirements for hazard assessment, employee training, the provision of suitable PPE, and medical surveillance for workers with high-risk exposures [38,69,70,141,142].

9.3. Vaccine Development

Effective hantavirus vaccine development has long been a priority, but the recent outbreak occurrences significantly increased its visibility, there was little commercial interest. There is currently no approved hantavirus vaccine for use in the United States, Europe, or Latin America. However, inactivated whole-virus vaccines licensed in China and South Korea (Hantavax) were created particularly to combat the Seoul and Hantaan viruses and have been in use. However, the period of immunity they provide seems to be limited, their reported efficacy has been small, and they provide no protection against the New World hantaviruses that cause HCPS. These restrictions, together with the difficulty and expense of manufacturing inactivated whole-virus vaccines, have reduced their influence on the prevalence of hantavirus disease worldwide [21,80,143,144,145,146,147].

The COVID-19 pandemic response has sparked revolutionary advancements in mRNA vaccine technology, which have made it possible to build effective hantavirus vaccines utilizing contemporary platforms. The mRNA platform has several inherent benefits: it can quickly be redesigned in silico and produced without requiring live virus work; it can encode the Gn and Gc glycoproteins in precisely engineered prefusion-stabilized conformations that optimally display neutralizing antibody epitopes; and it can potentially encode antigens from several hantavirus strains in a single multivalent construct for wide geographic coverage [20,148,149,150,151,152]. Building on established industrial-scale mRNA manufacturing and regulatory infrastructure, moderna’s publicly confirmed 2026 mRNA hantavirus research program offers the commercial route for expedited clinical development, provided suitable research collaboration and public funding frameworks are established [143,150,153,154].

More advanced than any other contemporary hantavirus vaccine platform are DNA vaccine options, in which plasmid constructs encoding hantavirus Gn and Gc antigens are administered intramuscularly and produced by host cells to produce immunological responses. Phase I human clinical trials assessing safety and immunogenicity are in progress, and USAMRIID has investigated the development of DNA vaccines against ANDV, SNV, and HTNV for military force protection purposes [155,156,157,158]. Although DNA vaccines have demonstrated manufacturing scalability and thermostability advantages over mRNA vaccines, they have historically produced lower immunogenicity in humans compared to small animal models. To achieve protective antibody titers, adjuvants or innovative delivery methods (such as electroporation or nanoparticle encapsulation) may be necessary. Other preclinical-stage alternatives include pseudovirus-based vaccine systems that use hantavirus surface antigens displayed on lentiviral or vesicular stomatitis virus backbones, and recombinant subunit vaccines that display Gn/Gc antigens in VLP or nanoparticle formats.

9.4. One Health Surveillance, Community Engagement, and International Frameworks

A true transdisciplinary One Health approach that incorporates human epidemiological surveillance, rodent population ecology monitoring, environmental surveillance, community engagement, and international coordination within a cohesive institutional framework is necessary for effective, sustainable hantavirus prevention at population scale. The 2026 MV Hondius outbreak, which revealed that an Andes virus cluster originating in rural South America can spread through international travel networks to produce multi-country cases within days, well within a single incubation period, unquestionably demonstrated the international dimension of hantavirus surveillance and preparedness. This incident highlights the need for improved global data exchange infrastructure, standardized case definitions, real-time molecular characterization capabilities at national reference labs, and cross-border contact tracing systems that can function within the framework of the International Health Regulations (IHR) [112,159,160,161].

10. Research Gaps and Future Direction

Despite the substantial advances in hantavirus science described in this review, a number of crucial knowledge and capacity gaps severely limit the ability to prevent, diagnose, and cure hantavirus disease. Closing these gaps should be a top priority for national public health agencies, international funding organizations for infectious disease research, and partners in the pharmaceutical industry. Below, we tried to talk about possible future paths. Accelerating Vaccine Development Through Clinical Translation.

10.1. Accelerating Vaccine Development Through

For hantavirus control, it is crucial to move potential vaccine candidates from preclinical success into clinical trials and ultimately licensing. The clinical success of the hantavirus vaccine depends on funding for Phase I/II human trials in at-risk populations, regulatory pathway clarity for hantavirus vaccine evaluation given the lack of established correlates of protection and the ethical impossibility of human challenge models, and international coordination between vaccine developers, funders, regulators, and public health authorities in endemic regions.

10.2. Developing Effective Antivirals for HCPS

Antiviral therapy, immunomodulatory therapy, and post-exposure prophylaxis for the hantavirus are unavailable globally. A systematic, well-funded translational research endeavor is required to advance promising drugs from in vitro identification into controlled clinical trials in endemic regions in order to close this gap. The most advanced preclinical candidates, favipiravir and other small-molecule RdRp inhibitors discovered by high-throughput screening, require extensive in vivo and efficacy studies before clinical consideration may be warranted. It is worthwhile to fully explore the potential of combination antiviral regimens that reduce the toxicity of individual medications while utilizing synergistic mechanisms.

10.3. Point-of-Care and Field-Deployable Diagnostics

For hantavirus-endemic areas without the capacity to conduct RT-PCR or reference-level serology, quick, field-deployable, and resource-appropriate diagnostics constitute a crucial unmet need. In order to achieve sensitivity and specificity comparable to laboratory ELISA at a fraction of the cost and operational complexity, commercially available lateral flow immunoassay (LFA) platforms for point-of-care hantavirus IgM detection need to be further optimized and rigorously validated in the field. Before point-of-care hantavirus diagnosis can be consistently incorporated into primary care settings, investment in multi-antigen LFA designs covering both Old World and New World hantavirus serogroups is required, along with head-to-head validation against ELISA gold standards in endemic-region patient populations.

10.4. Closing the Africa Surveillance Gap

The almost total lack of systematic human hantavirus surveillance in sub-Saharan Africa constitutes a significant and unacceptable gap in our understanding of the epidemiology and prevalence of hantavirus disease worldwide. It is urgently necessary to establish sentinel surveillance networks throughout Africa that are in line with current zoonotic disease surveillance platforms, along with systematic rodent ecological surveys and increased serological testing of febrile illness cases presenting to reference health facilities with unexplained renal or pulmonary syndromes. This will help determine the true extent of the African hantavirus epidemic and identify locally circulating strains that might need specialized diagnostic and vaccination strategies.

11. Conclusion

Hantavirus infections continue to be significant new zoonotic illnesses that have a big impact on world health. These infections are now well understood and controlled thanks to recent advancements in molecular diagnosis, epidemiological surveillance, and preventive measures. However, the danger of outbreaks is still increased by changing environmental conditions, growing rodent populations, and a lack of healthcare services. Reducing the incidence of hantavirus infections globally requires strengthening public health systems, raising awareness, improving monitoring programs, and developing treatments and vaccine development.