Hantavirus: Deadly Rat Disease Spreads to Humans in US UPSC

HANTAVIRUS

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A health alert has been issued in the state of Arizona, in the United States, after a rodent-borne hantavirus killed four people.
The virus spreads to humans through droplets from the urine, saliva, or faeces of the rats.

Details

Hantavirus

Hantaviruses are a group of viruses primarily carried by rodents.
They are known to cause serious illnesses in humans, including Hantavirus Pulmonary Syndrome (HPS) and Hemorrhagic Fever with Renal Syndrome (HFRS).
The disease manifestations and severity can vary based on the specific hantavirus and geographic region.

Transmission

Hantaviruses are typically transmitted to humans through inhalation of aerosolized particles from rodent excreta, such as urine, feces, or saliva.
Direct contact with infected rodents or their bodily fluids can also pose a risk.
In rare cases, particularly with the Andes virus in South America, human-to-human transmission has been documented.

Geographic Distribution

Old World Hantaviruses:Common in Europe and Asia, causing HFRS. Key viruses include Hantaan virus (HTNV), Seoul virus (SEOV), Puumala virus (PUUV), and Dobrava virus (DOBV).
New World Hantaviruses:Predominantly found in the Americas, causing HPS. Notable viruses include Sin Nombre virus (SNV) and Andes virus (ANDV).
Hantaviruses have been identified globally, though underreporting and underdiagnosis may occur, particularly in regions like Africa and Southeast Asia.

Clinical Syndromes

Hantavirus Pulmonary Syndrome (HPS):Characterized by flu-like symptoms initially, followed by rapid onset of severe respiratory distress due to fluid buildup in the lungs. Mortality can be high without prompt medical intervention.
Hemorrhagic Fever with Renal Syndrome (HFRS):Presents with fever, hemorrhage, and renal dysfunction. The severity ranges from mild to severe, depending on the viral strain.

Prevention and Control

There is no specific antiviral treatment for hantavirus infections.
Supportive care in a medical facility is critical, particularly for severe cases. Prevention focuses on minimizing exposure to rodent populations and their habitats.
Key preventive measures include:

Sealing up holes in homes to prevent rodent entry.
Proper sanitation to avoid attracting rodents.
Using protective equipment when handling rodent droppings or contaminated areas.

Virus

*Aspect*	*Description*
Definition	A virus is a microscopic infectious agent that can only replicate inside the living cells of organisms.
Structure	Consists of genetic material (DNA or RNA), a protein coat called a capsid, and sometimes a lipid envelope.
Classification	Classified based on nucleic acid type (DNA or RNA), symmetry (icosahedral, helical, complex), and envelope presence.
Replication Cycle	Involves attachment, penetration, uncoating, replication, assembly, and release. Can lead to lytic or lysogenic cycles.
Types of Viruses	DNA Viruses: Herpesvirus, Poxvirus, Adenovirus. RNA Viruses: Influenza, HIV, SARS-CoV-2.
Transmission	Spread through direct contact, airborne droplets, vectors (mosquitoes), and contaminated surfaces.
Host Range	Can infect animals, plants, fungi, bacteria (bacteriophages), and archaea.
Diseases Caused	Range from mild colds to severe diseases like AIDS, Ebola, Influenza, and COVID-19.
Prevention	Includes vaccination, antiviral drugs, hygiene practices, and quarantine measures.
Zoonotic Potential	Many viruses, like Influenza A, have zoonotic potential, meaning they can be transmitted from animals to humans.
Impact on Humans	Can cause acute infections, chronic infections, or asymptomatic cases.
Viral Evolution	Includes mutation, recombination, and reassortment, leading to new strains and potential pandemics.

Common rodents

*Common Name*	*Scientific Name*	*Physical Characteristics*	*Habitat*	*Diet*	*Unique Features*
House Mouse	Mus musculus	Small, light brown or grey fur, large ears, long tail	Human dwellings, fields	Grains, seeds, insects	Highly adaptable to various environments
Brown Rat	Rattus norvegicus	Large, brown or grey fur, blunt nose, long tail	Urban areas, sewers, fields	Omnivorous: grains, fruits, small animals	Known for spreading diseases like leptospirosis
Black Rat	Rattus rattus	Sleek, black or dark brown fur, pointed nose, long tail	Coastal areas, urban environments	Fruits, seeds, insects	Excellent climbers, often found in roofs
Guinea Pig	Cavia porcellus	Robust body, short legs, no tail, various fur colors	Domestic environments	Vegetables, hay, pellets	Commonly kept as pets, social animals
Capybara	Hydrochoerus hydrochaeris	Largest rodent, webbed feet, brown fur, small ears	Wetlands, riverbanks	Grasses, aquatic plants	Semi-aquatic, strong swimmers
Squirrel	Sciuridae family	Bushy tails, sharp claws, varied fur colors (grey, red, black)	Forests, urban parks	Nuts, seeds, fruits	Known for caching food, excellent climbers
Beaver	Castor canadensis	Large, flat tail, webbed feet, thick brown fur	Rivers, lakes, streams	Bark, leaves, aquatic plants	Known for building dams and lodges
Porcupine	Erethizon dorsatum	Covered in sharp quills, large body, slow-moving	Forests, grasslands	Leaves, fruits, bark	Uses quills as a defense mechanism
Hamster	Cricetinae subfamily	Small, stout body, cheek pouches for food storage, varied fur colors	Deserts, fields	Seeds, fruits, vegetables	Nocturnal, commonly kept as pets
Prairie Dog	Cynomys ludovicianus	Tan fur, black-tipped tail, small ears	Grasslands, prairies	Grasses, seeds, insects	Live in large colonies with complex burrow systems
Chinchilla	Chinchilla lanigera	Dense, soft fur, large ears, bushy tail	Andes mountains	Hay, pellets, dried fruits	Known for their incredibly soft fur, often kept as pets
Lemming	Lemmus lemmus	Small, short tail, thick fur, various fur colors (brown, grey)	Tundra, arctic regions	Grasses, mosses, berries	Known for population cycles and mass migrations
Gopher	Geomyidae family	Small, fur-lined cheek pouches, strong claws for digging, brown fur	Meadows, grasslands	Roots, tubers, plants	Create extensive burrow systems
Vole	Microtus genus	Small, stocky body, short tail, brown or grey fur	Meadows, forests, fields	Grasses, seeds, bark	Important part of the food chain, prey for many predators
Marmot	Marmota genus	Large, stocky body, bushy tail, brown or grey fur	Mountainous regions, grasslands	Grasses, flowers, insects	Hibernate during winter, live in colonies

Rodent-borne diseases

*Disease*	*Causative Agent*	*Symptoms*	*Transmission*	*Preventive Measures*
Hantavirus Pulmonary Syndrome (HPS)	Hantaviruses	Fever, muscle aches, fatigue, cough, shortness of breath	Inhalation of aerosolized particles from rodent droppings, urine, saliva; direct contact	Avoid contact with rodent excreta, seal entry points, clean areas infested by rodents safely
Leptospirosis	Leptospira bacteria	Fever, headache, muscle pain, chills, vomiting, jaundice	Contact with water, soil, or food contaminated with urine from infected animals	Avoid stagnant water, ensure rodent control, wear protective gear
Salmonellosis	Salmonella bacteria	Diarrhea, fever, abdominal cramps	Ingestion of contaminated food or water	Proper food handling, rodent control, sanitation
Rat-Bite Fever	Streptobacillus moniliformis, Spirillum minus	Fever, rash, vomiting, muscle pain, headache	Bites or scratches from infected rodents, contact with rodent secretions	Avoid rodent contact, clean bites/scratches, seek medical attention
Plague	Yersinia pestis bacteria	Bubonic: swollen lymph nodes, fever, chills; Septicemic: abdominal pain, shock; Pneumonic: respiratory symptoms	Flea bites, direct contact with infected animals or tissues	Flea control, avoid contact with wild rodents
Tularemia	Francisella tularensis	Fever, skin ulcers, swollen lymph glands, sore throat	Tick and deer fly bites, direct contact with infected animals, inhalation	Use insect repellent, avoid handling wild animals, cook game meat thoroughly
Lymphocytic Choriomeningitis (LCM)	Lymphocytic choriomeningitis virus (LCMV)	Fever, malaise, muscle aches, headache, nausea, meningitis	Inhalation of dust contaminated with rodent excreta, direct contact	Avoid contact with rodents, seal homes, maintain good hygiene
Bartonellosis (Cat Scratch Disease)	Bartonella bacteria	Fever, enlarged lymph nodes, pustule at scratch site	Scratch or bite from infected animals, flea bites	Avoid scratches/bites from animals, flea control
Murine Typhus	Rickettsia typhi, Rickettsia felis	Fever, headache, rash, muscle pain	Flea bites	Flea control, avoid contact with rodents

Sources:

NDTV

PRACTICE QUESTION

Q: Consider the following statements regarding Hantavirus:

Hantavirus infections in humans can lead to Hantavirus Pulmonary Syndrome (HPS) and Hemorrhagic Fever with Renal Syndrome (HFRS).
The primary mode of transmission of Hantavirus to humans is through direct contact with infected rodents or their urine and droppings.
There is a specific antiviral treatment available for Hantavirus infections, which significantly reduces mortality rates.

Which of the statements given above is/are correct?

a) 1 and 2 only
b) 2 and 3 only
c) 1 and 3 only
d) 1, 2, and 3

Answer: a)