As a deadly hantavirus outbreak aboard the MV Hondius cruise ship leaves three dead and at least five infected, there is one question worrying Mumbaikars: could this rare rodent-borne virus ever reach India’s crowded cities?
What has caught global attention is not just the outbreak on the cruise ship itself but also the presence of the Andes strain—a rare form of hantavirus capable of limited human-to-human transmission under close contact conditions. With two Indian nationals among the crew members onboard, the incident has triggered concern and intense monitoring by international health agencies.
The cruise ship, which departed from Ushuaia, Argentina, on April 1 with 149 people onboard, turned into a high-risk containment challenge after multiple infections were reported in the middle of remote Atlantic waters, far from immediate medical access.
While Mumbai doctors stress that there is no immediate threat to the city, the incident is a stark reminder of how quickly rare infections can attract global concern in an era of international travel. Medical professionals told mid-day.com that the risk remains extremely low, and there is no immediate reason to panic. However, awareness is important, especially in cities with dense rodent populations and during monsoon season.
What is hantavirus?
Hantavirus is a rare viral infection spread mainly by infected rodents such as rats and mice.
Humans can get infected through:
• Rat urine, saliva, or droppings
• Breathing contaminated dust particles
• Cleaning closed or poorly ventilated spaces
• Exposure to rodent-infested areas
Experts stress that hantavirus does not spread easily between humans.
What symptoms should Mumbaikars watch for?
The early symptoms are quite non-specific and may feel like a regular viral infection initially.
Common symptoms include:
• Fever
• Body ache and muscle pain
• Headache
• Weakness and fatigue
• Nausea or vomiting
• Dry cough
In some patients, breathing difficulty and chest congestion can develop later, which may become serious if not treated in time.
Anyone with persistent fever and a history of rodent exposure should seek medical advice early.
The early signs of hantavirus usually mimic a case of influenza, which poses difficulties for early detection. Respiratory symptoms may be in the form of coughing, chest congestion, difficulty breathing, and low blood oxygen content, indicating infection of the lungs. In severe cases, lungs can accumulate fluids leading to respiratory distress, which needs intensive care therapy using a respirator. Any patient exhibiting breathing difficulties following exposure to rodents, dusty and closed areas requires immediate hospitalisation.
Origin, transmissibility and incubation period
Hantavirus was first identified in the Korean region several decades ago and different strains are now known across various parts of the world. The infection is primarily transmitted from rodents to humans and not through routine human contact.
The incubation period can vary from around one to six weeks after exposure. As symptoms can appear gradually and resemble many common infections, diagnosis can sometimes be delayed.
How is hantavirus diagnonised?
Diagnosing hantavirus infection is performed by analyzing blood samples for the presence of IgM and IgG antibodies or by detecting viral RNA using RT-PCR, During the early stages of infection. Imaging studies like chest X-rays and HRCT can show signs of lung inflammation and the presence of fluids. And low platelet levels and raised hematocrit values might aid in confirming the diagnosis. It is very important that the early identification of hantavirus infection as respiratory failure can happen very rapidly in serious cases.
Is there any immediate risk to Mumbai residents?
At the moment, there is no cause for panic in Mumbai and no confirmed large-scale threat related to hantavirus. However, as the virus is associated with rodents, people should remain cautious, especially during monsoon and in areas where rat infestation is common. Awareness and hygiene are far more important right now than fear.
Who is most vulnerable?
Higher-risk groups include:
• Elderly people
• Asthma or COPD patients
• Diabetics
• Heart disease patients
• Immunocompromised individuals
Children can also get infected, though symptoms may initially appear mild.
Has hantavirus ever been reported in India?
India has reported very few documented cases and there is no major outbreak history linked to hantavirus so far. However, because the symptoms overlap with many tropical infections commonly seen in India, mild or isolated cases may sometimes go unrecognised. That is why medical awareness and surveillance remain important.
While hantavirus exposure has been linked to India by the serological analysis of the people and rodents, confirmed cases are rare and probably underdiagnosed as well. Symptoms are mostly similar to dengue, leptospirosis, or severe viral pneumonia. A limited number of tests and a low level of awareness might be the reasons for not detecting hantavirus-associated respiratory infections in clinical settings.
Are Mumbai`s rats capable of carrying hantavirus strains?
Rodents anywhere in the world can potentially carry viruses, including hantavirus strains. Considering Mumbai has a dense rodent population in certain pockets, maintaining strong sanitation and pest-control measures is essential. At present, there is no evidence suggesting widespread hantavirus activity among Mumbai’s rodents.
Hantavirus is commonly associated with rodents such as rats and mice who tend to shed the virus in their urine, saliva, and feces. The primary risk is inhalation of these contaminated particles. For instance, in urban areas such as Mumbai, the risk factors include rodent exposure in dilapidated buildings, basements, garbage sites, and congested residential areas. While there have been no reports of a hantavirus pandemic in this locality, rodent-transmitted diseases are still an issue. People who clean dust-filled storage rooms or abandoned areas without wearing masks might end up inhaling the infected particles.
Can hantavirus be mistaken for dengue, flu, malaria or Covid-19?
Yes, very easily. In the early stage, hantavirus infection can mimic dengue, viral flu, malaria, leptospirosis, or even Covid-19 because symptoms such as fever, fatigue, headache, and body pain are common in all these illnesses.
Indeed, there are many infectious diseases that present similarly to hantavirus in India. Influenza, dengue, malaria, leptospirosis, and even the novel coronavirus can all mimic hantavirus, especially during the acute phase of illness, since their clinical features are quite similar. However, it is easier to tell the difference when there is a sudden onset of worsening pulmonary complaints. For example, patients may have trouble breathing, chest tightness, and low oxygen levels despite treatment for the suspected viral infection. Chest X-ray may also reveal changes that look like pneumonia. A thorough patient history regarding possible exposure to rodents and cleaning dusty rooms may help in differentiating the two.
What precautions should households take?
Basic hygiene and cleanliness play the biggest role in prevention:
• Keep homes and kitchens clean
• Avoid food waste accumulation
• Seal openings where rodents can enter
• Use gloves and masks while cleaning rodent-infested areas
• Avoid directly sweeping rodent droppings; disinfect the area first
• Ensure regular pest control, especially during monsoon season
People should remember that prevention begins with sanitation and awareness, not panic.
The prevention of rodent contact is perhaps the most critical precaution against contracting hantavirus as well as any other diseases associated with rodents. Storage of food in airtight jars and disposal of garbage regularly will help avoid attracting rats to residential houses. Storage rooms, kitchens, and basements need to be kept clean, dry, and well-ventilated. It should be noted that when sweeping dust from rodent droppings, one may inhale the infected particles in the process, which can result in illness. Therefore, disinfection of the location with the use of bleach solution or any domestic disinfectant agent should be performed first.
What animals carry hantavirus?
Rodents like rats mice deer mice, or cotton rats stand to be the main hosts of hantavirus. These animals release the virus through their urine, saliva, and feces. Most of the times, people get infected by breathing the virus that comes from these particles when a place is enclosed and not ventilated. Good housekeeping, getting rid of the rodents, and safe cleaning methods can be quite helpful to prevent the spread of this virus.
Is there a vaccine and a specific cure?
Presently, there is no vaccine or any specific antiviral treatment for hantavirus infections in India. Treatment mainly depends upon supportive measures and dealing with respiratory issues promptly.
As per pulmonary physicians, those cases of hantavirus where the involvement is serious may be treated with oxygen therapy, ICU treatment, ventilation management, and fluid balance maintenance since the condition might lead to respiratory failure.
Hospitalisation at the earliest is vital. As there is no specific treatment for hantavirus, preventive measures are highly significant. Staying away from rodents, keeping the surroundings clean, and visiting the doctor if one feels unexplained fever with breathlessness or chest problems are some of the best methods of protecting oneself from hantavirus infections. Annual vaccination against influenza may reduce impact of other respiratory viral infections (cross protection) and once in lifetime vaccination with Latest pneumococcal vaccine may also help in lowering the intensity / severity of pneumococcal pneumonia which is a known occurrence post viral respiratory infection.
These aren’t hantavirus-specific but in general help improving immunity against occurrence of severe respiratory infections. Keeping immunity good with high protein diet and balanced nutrition coupled with regular exercises cannot be overemphasised!
Are Indian hospitals equipped to detect hantavirus
As pulmonologists, we are aware of our expertise in dealing with severe respiratory infections, such as uncommon infections caused by viruses of the lungs. Since the diagnosis of the infection is not easily done in every Indian hospital because of the infrequent occurrence of this disease, specialised diagnostic centres can conduct tests for confirming the same if suspected clinically. The problem lies in the fact that the early symptoms of hantavirus infections mimic other common infections such as influenza, dengue, or even Covid-19 infections. Most patients reach out to pulmonologists after developing breathlessness, hypoxia, or any problems related to lungs.
Inputs shared by Dr Manjusha Agarwal, senior consultant – internal medicine, Gleneagles Hospital, Parel; Dr Samir Garde, consultant – interventional pulmonologist, SL Raheja Hospital, Mahim – A Fortis Associate, and Dr Ajay Shah, managing director of Neuberg Ajay Shah Laboratory, Mumbai
