Envis Centre, Ministry of Environment & Forest, Govt. of India

Printed Date: Monday, January 27, 2020

Mosquitoes Information

JAPANESE ENCEPHALITIS.

 

jepanese Encephalitis (jp), commonly know as brian fever caused by flavivirus. Culex vishnui sub group mosquitoes are the principal vectors of JE. Comestic pigs and wild birds are act as amplifiers and also reservoirs of the virs . Infected mospuitoes then transmit the Japanese encephalities virus to humans and animals during the feeding process. Incubation period is nearly 5 to 15 days. More servere infection is marked by quick onset, headachine, high fever, neck stiffness, stupor,disorientation, coma, tremors, occasional convulsions(especially in infants) and spastic paralysis.JE Vaccinr is aviailable but expensive.

 

MALARIA

 

Malaria is a life-threatening parasitic disease transmitted by mosquitoes. Malaria causes 1.5 million to 2.7 million deaths each year, with an estimated 300 - 500 million cases annually. P. vivax and P. falciparum are the most common and falciparum the most deadly type of malaria infection. These pathogens are transmitted by Anopheline mosquites. Malaria symptoms appear about 9 to 14 days after the infectious mosquito bite, although this varies with different plasmodium species. Typically, malaria produces fever, headache, vomiting and other flu-like symptoms. Malaria call kill by infecting and destroying red blood cells (anaemia) and by clogging the capillaries that carry blood to the brain (cerebral malaria) or other vital organs. The main drugs available for use as prophylactics are Chloroquine, Mefloquine Doxycycline, Pyrimethamine, Sulfones.

 

DENGUE

 

Dengue fever is an acute febrile viral disease, primarily a disease of the tropics. Dengue viruses are flaviviruses and include four serotypes 1,2,3 and 4 (Dengue -1, -2, -3 and -4) which are transmitted by Aedes aegypti The incubation period is 4-7 days (range 3-14 days). Dengue fecer is characterized by sudden onset, fever of 3-5 days, intense headache, myalgia, anthralgic retro-orbital pain, anorexia, and rash. DHF caused by the same viruses, is characterized by increased vascular permeability, hypovolaemia and abnormal blood clotting mechanisms.

 

LA CROSSE ENCOPHALITIS

 

Etiologic agent is La Crosse virus - California serogroup virus in the family Bunyaviridae Virus cycles in woodland habitats between the treehole mosquito (Aedes triseriatus) and vertebrate hosts (chipmunks, squirrels). Approximately 70 cases reported per year. The target age group Children <16 years old. Frank encephalitis progressing to seizures, coma; majority of infections are subclinical or result in mild illness.

 

RIFT BALLEY

 

Rift Valley fever (RVF) is an acute, fever-causing viral disease that affects domestic animals (such as cattle, buffalo, sheep, goats, and camels) and humans. The disease is caused by the RVF virus, a member of the genus Phlebovirus in the family Bunyaviridae. The disease was first reported among livestock by veterinary officers in Kenya in the early 1900s. RVF is generally found in regions of eastern and southern Africa where sheep and cattle are raised, but the virus also exists in most countries of sub-Saharan Africa and in Madagascar.

 

EASTERN EQUINE ENCEPHALITIS

 

The main EEE transmission cycle is between birds and mosquitoes. The most important mosquito in maintaining the enzootic (animal-based, in this case bird-mosquito-bird) transmission cycle in Culiseta melanura. Horses can become infected with, and die from, EEE virus infection. Eastern equine encephalitis virus is a member of the family Togaviridae, genus Alphavirus. Symptoms range from mild flu-like illness to encephalitis (inflammation of the brain), coma and death.

 

YELLOW FEVER

 

Yellow fever occurs only in Africa and South America. In South America sporadic infections occur almost exclusively in forestry and agricultural workers from occupations exposure in or near forests. Yellow fever is a viral disease transmitted between humans by a mosquito. Yellow fever is a very rare cause of illness in travelers, but most countries have regulations and requirements for yellow fever vaccination that must be met prior to entering the country. Yellow fever vaccine is a live virus vaccine, which has been used for several decades. This vaccine is only administered at designated yellow fever vaccination centres. If a person is at continued risk of yellow fever infection, a booster dose is needed every 10 years.

 

ESTERN EQUINE ENCEPHALITIS

 

The main EEE transmission cycle is between birds and mosquitoes. The most important mosquito in maintaining the enzootic (animal-based, in this case bird-mosquito-bird) transmission cycle in Culiseta melanura. Horses can become infected with, and die from, EEE virus infection. Eastern equine encephalitis virus is a member of the family Togaviridae, genus Alphavirus. Symptoms range from mild flu-like illness to encephalitis (inflammation of the brain), coma and death.

 

MURRAY VALLY

 

MVE infection in humans is prevalent in Australia. A virus, designated Murray Valley encephalitis virus, was later isolated from fatal cases in an epidemic in 1951. Viruses have a natural endemic cycle, which involves water birds as the vertebrate host and Cules annulirostris as the major vector, in northern regions of Australia. Symptoms almost invariably include a sudden onset of fever; anorexia, headache, vomiting, nausea, diarrhoea and dizziness. Brain dysfunction may be experienced after a few days with lethargy, irritability, drowsiness, confusion, convulsions and ifts; neck stiffness can be expected, and both coma and death may ensue. There are no specific therapies to treat the dieseas.

 

ST. LOUIS ENCEPHALITIS

 

Etiologic agent is St.loius encephalitis virus,a flavivirus related to japanese encephalitis virus. Specifice mosquito vectors very regionally: Culex pipiens,Cx. Quinquefasciatus, Cx. Nigripalpus and Cx. tarsalis. Mosquitous become infected by feeding on birds infected with the St. Louis encephalitis vieus. Infected mosquitoes then transmit the St. Louis encephalitis virus to hurmans and animals during the feeding process. Mild infections occur without apparent sysptoms other than fever with headache. More server infection is marked by headache, high fever,neck stiffness, stupor, disorientation, coma, tremors, occasional convulsions (especially in infants) and spastic (but rarely flaccid) paralysis.

 

WEST NILE

 

The primary vector for WNV in the United States is the Culex pipiens mosquito that commonly breeds in urban areas and prefers to feed on birds. Mosquitoes acquire WNV when feeding on infected birds. The virus is than stored in the mosquito's salivary glands and transmitted to humans and other incidental hosts when the mosquito takes a blood meal. Humans and other domestic animals are considered "dead-end" hosts.

 

FILARAISIS

 

Lymphatic filariesis (LF) or elephantiasis is the most debilitating and desfinguring disease in tropical and sub tropical areas. The thread-like, parasitic filarial worms Wuchereria bancrofti, Brugia malayi and B.timori transmitted by Culex, Anophels and Mansonia mosquito species.These worms lodge in the lymphatic system and live for 4-6 year,producing millions of immature microfilariae that circulate in the blood. The disease usuallay is not life threatening, but it can permanently damage your lymph system and kindneys. diethyl Carbamazine Citrate (DEC) drug is available for for prevntion