Knowledge Nugget | From Hantavirus to COVID-19: Understanding viral diseases in news

In this context, let’s know about the hantavirus and other viral diseases that have been in the news.

Key Takeaways:

1. Named after the Hantan River in South Korea, hantavirus is a family of rodent-borne viruses that can cause serious illness and death in humans. However, the virus-carrying rats and other rodents do not fall ill to the virus.

2. Human infection primarily occurs through contact with the urine, faeces, or saliva of infected rodents or by touching contaminated surfaces. It is also possible to get the infection by breathing air that contains viral particles stirred up from these droppings, according to the US Centers for Disease Control and Prevention (CDC).

3. These viruses are generally not known to spread between people. However, some human transmission was recorded for the Andes strain, found in Argentina and Chile. The people on the ship are suspected to have been infected by the Andes hantavirus.

4. The type of virus varies depending on the region, and each hantavirus is specific to a different rodent host.

(i) Hantavirus pulmonary syndrome (HPS) is endemic to the Western Hemisphere and caused by New World hantaviruses. These are the deadlier of the two variants, killing a third of those who develop respiratory symptoms. The disease progresses from flu symptoms and fatigue to diarrhoea, vomiting and severe respiratory issues.

(ii) Haemorrhagic fever with renal syndrome (HFRS) is another group of illnesses caused by so-called Old World hantaviruses, found primarily in Europe, Africa and Asia. HFRS is known to affect around 150,000 people annually, killing between one and 15% of the infected. Among these, the Hantaan and the Dobrava strains cause the most severe impact, while the impacts of Seoul, Saaremaa, and Puumala virus infections are comparatively moderate.

5. Notably, Hantavirus rarely transmits from one person to another, which means in most cases infected persons have individually come in contact with the urine, faeces, or saliva of infected rodents or by touching contaminated surfaces.

6. Symptoms of hantavirus: In the case of HPS, flu-like symptoms present within one to eight weeks after exposure, and may include fatigue, fever, and muscle aches early on. As the disease advances, the affected person may experience respiratory difficulties such as shortness of breath and chest tightness as the lungs fill with fluid. The CDC estimates that 38% of people who develop respiratory symptoms may die from the disease.

— Symptoms of HFRS appear within one to six weeks of exposure to infected rodents, progressing from sudden fever with intense headaches and nausea. The disease progresses in phases, with low blood pressure, renal failure and internal bleeding becoming increasingly likely.

7. There is no known cure or treatment for HPS, and early detection and treatment are crucial, but some antivirals have helped manage the symptoms. Patients with severe breathing difficulties may need respiratory support like a breathing tube, while dialysis may become necessary as the disease advances.

Other viral diseases

1. Nipah virus: Nipah is a viral infection that mainly affects animals such as bats, pigs, dogs, and horses. Being zoonotic, it can jump to humans who come in contact with the infected animals and cause serious disease. 

— Nipah can spread to humans after close contact with infected animals or secretions containing the virus on fruit trees, fruits, date palm sap, juice or toddy. It can spread from human to human through close contact at home or in hospitals. It can spread from handling dead bodies of those with Nipah

— According to the US Centers for Disease Control and Prevention (CDC), its symptoms are fever, headache, cough, sore throat, difficulty in breathing, and vomiting. In severe cases, disorientation, drowsiness, seizures, encephalitis (swelling of the brain) can occur, progressing to coma and death. Notably, there are no antivirals and there is only symptomatic management.

2. Mpox: Previously known as monkeypox, Mpox is a self-limiting viral infection caused by mpox virus (MPXV). The most common symptoms of mpox include fever, headache, muscle aches, back pain, low energy, and swollen lymph nodes, along with pox-like rashes that last for two to three weeks. It is a self-limiting disease but can lead to death, especially among children and those with weak immune systems.

— According to WHO, there are two broad clades of the Mpox virus: clade I and II. Clade I leads to more severe disease and death than clade II in the populations where it is endemic.  

— Mpox spreads from person to person mainly through close contact with someone who has mpox.  Someone who comes into physical contact with an animal that carries the virus, such as some species of monkeys or a terrestrial rodent (such as the tree squirrel) may also develop mpox.

3. Ebola: It is a virus that can spread quickly and can be fatal in up to 90% of cases. Symptoms include fever, vomiting, diarrhoea, muscle pain and at times internal and external bleeding and can start to occur between two and 21 days from infection, according to WHO.

— The virus is most often spread by close contact with bodily fluids of people exhibiting symptoms and with contaminated objects such as sheets.

4. Zika: A mosquito-borne disease—Zika virus— mainly occurs in tropical and subtropical areas of Africa, the Americas, Southern Asia, and the Western Pacific.

— It is infected by Aedes species mosquitoes, which are the same ones that spread dengue and chikungunya viruses, and bite during the first week of infection. It is primarily transmitted through mosquito bites, sex, and breastfeeding.

Here’s how the Zika virus spreads (Source: CDC)

5. COVID-19: Coronavirus disease (COVID-19) is an infectious disease caused by the SARS-CoV-2 virus. The most common symptoms of COVID-19 are fever, chills, and sore throat.

BEYOND THE NUGGET: What is the ‘One-health’ approach?

1. According to the World Health Organisation website, One Health is an integrated, unifying approach that aims to sustainably balance and optimize the health of people, animals and ecosystems.

2. It recognizes that the health of humans, domestic and wild animals, plants, and the wider environment (including ecosystems) are closely linked and interdependent.

3. While health, food, water, energy and environment are all wider topics with sector-specific concerns, the collaboration across sectors and disciplines contributes to protect health, address health challenges such as the emergence of infectious diseases, antimicrobial resistance, and food safety and promote the health and integrity of our ecosystems.

4. By linking humans, animals and the environment, One Health can help to address the full spectrum of disease control – from prevention to detection, preparedness, response and management – and contribute to global health security.

5. The approach can be applied at the community, subnational, national, regional and global levels, and relies on shared and effective governance, communication, collaboration and coordination. Having the One Health approach in place makes it easier for people to better understand the co-benefits, risks, trade-offs and opportunities to advance equitable and holistic solutions.

Post Read Question

Consider the following statements: (UPSC CSE 2017)

1. In tropical regions, Zika virus disease is transmitted by the same mosquito that transmits dengue.

2. Sexual transmission of Zika virus disease is possible.

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

(Sources: What to know about the Hantavirus outbreak aboard Canary Islands-bound ship, Knowledge Nugget | What must you know about Nipah virus for your UPSC Exam?, Why Ebola is now an international emergency, UPSC Issue at a Glance: Mpox outbreak)

🚨 Click Here to read the UPSC Essentials magazine for April 2026. Share your views and suggestions in the comment box or at manas.srivastava@indianexpress.com🚨 

Subscribe to our UPSC newsletter. Stay updated with the latest UPSC articles by joining our Telegram channel – Indian Express UPSC Hub, and follow us on Instagram and X.