IASNOVA
Nipah Virus
– Nipah virus infection (NiV) is a viral infection caused by the Nipah virus.
– Symptoms from infection vary from none to fever, cough, headache, shortness of breath, and confusion. This may worsen into a coma over a day or two.Complications can include inflammation of the brain and seizures following recovery.
– The Nipah virus is a type of RNA virus in the genus Henipavirus.
– It can both spread between people and from other animals to people. Spread typically requires direct contact with an infected source.
– The virus normally circulates among specific types of fruit bats.
– As of 2019 there is no vaccine or specific treatment.
– Prevention is by avoiding exposure to bats and sick pigs and not drinking raw date palm sap.
– In May 2018, an outbreak of the disease resulted in at least 17 deaths in the Indian state of Kerala.
– The disease was first identified in 1998 during an outbreak in Malaysia while the virus was isolated in 1999.
– It is named after a village in Malaysia, Sungai Nipah.
– Pigs may also be infected and millions were killed in 1999 to stop the spread of disease.
Why in news?
Tripura Health Department in March 2019 issued a Nipah Virus alert after the death of five persons in a few villages of Bangladesh close to the Indo-Bangla international border.
West Nile Virus
– West Nile Virus is a disease which spreads from birds to humans with the bite of an infected Culex mosquito.
– Symptoms : include cold, fever, body ache, fatigue and nausea, with complications leading to meningitis and death.
– West Nile virus (WNV) is a single-stranded RNA virus that causes West Nile fever.
– It is a member of the family Flaviviridae, specifically from the genus Flavivirus, which also contains the Zika virus, dengue virus, and yellow fever virus.
– West Nile virus is primarily transmitted by mosquitoes, mostly species of the genus Culex, but ticks have also been found to carry the virus, although it is exceptional, and they are not likely to play a major role in the transmission of WNV.
– The primary hosts of WNV are birds, so that the virus remains within a “bird-mosquito-bird” transmission cycle.
Why in news?
A six-year-old boy from Kerala, who died after contracting the West Nile Virus (WNV), could be the first casualty of the disease reported from India, say experts in the Union ministry of health and family welfare.
Japanese Encephalitis
Description
– Japanese Encephalitis is a viral infection caused by RNA viruses belonging to the Flavivirus genus.
– It is a zoonosis – an animal disease that can spread to humans – primarily transmitted by evening biting Culex mosquitoes that feed on infected birds, pigs and other mammals passing the infection to humans living and working in rural areas around rice paddies and irrigation systems.
– Japanese encephalitis (JE) is an infection of the brain caused by the Japanese encephalitis virus (JEV).
– While most infections result in little or no symptoms, occasional inflammation of the brain occurs. In these cases symptoms may include headache, vomiting, fever, confusion, and seizures This occurs about 5 to 15 days after infection.
– JEV is generally spread by mosquitoes, specifically those of the Culex type.
– Pigs and wild birds serve as a reservoir for the virus.
– The disease mostly occurs outside of cities. Diagnosis is based on blood or cerebrospinal fluid testing.
– Prevention is generally with the Japanese encephalitis vaccine, which is both safe and effective. Other measures include avoiding mosquito bites. Once infected there is no specific treatment, with care being supportive. This is generally carried out in hospital. Permanent problems occur in up to half of people who recover from JE.
– The disease occurs in Southeast Asia and the Western Pacific.
– Children under 15 years of age seem to particularly susceptible to the infection. Outbreaks typically occur during or shortly after the rainy season in temperate regions and year-round in tropical regions (peak transmission during summer months).
Prevention
Use a repellent containing 20%-30% DEET or 20% Picaridin on exposed skin. Re-apply according to manufacturer’s directions.
If available, pre-soak or spray outer layer clothing and gear with permethrin.
Why in News?
The Health Department of Kerala in April 2019 pointed out that owing to the spike in Acute Encephalitis Syndrome (AES) cases in Malappuram, Kozhikode and Wayanad districts, there is an urgent need for conducting an epidemiological and entomological study.
AES which includes Japanese Encephalitis Virus (JEV), West Nile virus (WNV), Nipah (NiV), Kyasanur Forest Disease (KFD) and others is a group of clinical neurologic manifestation caused by wide range of viruses, bacteria, fungus, parasites, spirochetes, chemicals and toxins.
Kyasanur Forest Disease (KFD)
– Kyasanur forest disease (KFD) is a tick-borne viral haemorrhagic fever endemic to South India.
– The disease is caused by a virus belonging to the family Flaviviridae, which also includes yellow fever and dengue fever.
– The symptoms of the disease : include a high fever with frontal headaches, followed by haemorrhagic symptoms, such as bleeding from the nasal cavity, throat, and gums, as well as gastrointestinal bleeding.Other symptoms include vomiting, muscle stiffness, tremors, absent reflexes, and mental disturbances.
– There are a variety of animals thought to be reservoir hosts for the disease, including porcupines, rats, squirrels, mice and shrews.
– The vector for disease transmission is Haemaphysalis spinigera, a forest tick. Humans contract infection from the bite of nymphs of the tick.
– The vaccine for KFDV consists of formalin-inactivated KFDV.
– The disease was first reported from Kyasanur Forest of Karnataka in India in March 1957. The disease first manifested as an epizootic outbreak among monkeys killing several of them in the year 1957. Hence the disease is also locally known as “monkey disease” or “monkey fever”.
Why in News?
The Health Department of Kerala in April 2019 pointed out that owing to the spike in Acute Encephalitis Syndrome (AES) cases in Malappuram, Kozhikode and Wayanad districts, there is an urgent need for conducting an epidemiological and entomological study.
AES which includes Japanese Encephalitis Virus (JEV), West Nile virus (WNV), Nipah (NiV), Kyasanur Forest Disease (KFD) and others is a group of clinical neurologic manifestation caused by wide range of viruses, bacteria, fungus, parasites, spirochetes, chemicals and toxins.
