What Are Arboviruses?

Arboviruses are a group of arthropod-borne viruses that are classified into certain members of the Meniviridae, Flaviviridae, Buniaviridae, and Sarnaviridae families. The main arboviruses classified in the genus Alphaviruses of the Meniviridae family are Eastern Equine Encephalitis Virus, Western Equine Encephalitis Virus and Venezuelan Encephalitis Virus, which are mainly distributed in Africa and the Americas. The genus Flaviviridae genus includes Japanese encephalitis virus, forest encephalitis virus, dengue virus, yellow fever virus, St. Louis encephalitis virus, West Nile encephalitis virus, and the like.

Arbovirus

The genus Flaviviridae and Alphaviridae have basically the same characteristics except for different nucleic acid structures and replication methods: 1. The virus is spherical, with a diameter of 40-70 nanometers, and the genome is a single positive-stranded RNA. 2. Capsid proteins are icosahedral symmetrical. The outer layer is a virus envelope and is sensitive to lipid solvents and sodium deoxycholate. Envelope mosaic virus glycoprotein. 3. It has a wide range of hosts and can proliferate in vertebrates and invertebrates. Arthropods can store and spread the virus for a long time. 4. The disease is obviously seasonal and endemic, mainly causing fever, encephalitis and hemorrhagic fever.

Bunyaviridae is the largest virus family in arboviruses. There are 13 known viruses, of which 4 viruses in the animal genus are related to human infections. , Hantavirus and Nairovirus including Xinjiang Hemorrhagic Fever virus. The nucleic acids of these viruses are single negative strand RNA ^[1]

There are more than 250 arboviruses (arthropod-borne viruses); at least 80 arboviruses with different immune characteristics can cause human infection. Arbovirus spreads among spinal animals through bites of insects (such as mosquitoes, cockroaches, flies, fleas, lice) and ticks. Birds are often the infectious agents of mosquitoes, which transmit the virus to

I. Japanese Encephalitis Virus:

1. Main biological traits:

There are three types of viral structural proteins: M, C and E, which are stable in antigenicity. The virus can agglutinate red blood cells of chicks, pigeons and geese in a pH range of 6.0 to 6.5, and can proliferate in primary cells such as hamster kidneys, young pig kidneys, and AP61 or C6 / 36 mosquito passage cells. For suckling rats.

2. Clinical significance:

Culex tritaeniorhynchus is a vector of transmission, forming a continuous cycle of mosquito animal mosquito. After human infection with the virus, most of them show recessive and mild infections, and a few patients show symptoms of encephalitis.

3 Microbiological examination:

(1) Isolation and identification:

Isolation and culture of neonatal rat primary cells and mosquito-passage cells were carried out by inoculation of suckling rats and golden hamster kidneys, and cross-neutralization test and hemagglutination inhibition test were used for identification. Cell cultures could also be identified with IFA. However, the isolation rate of clinical specimens is extremely low.

(2) Serological diagnosis:

The 2-ME sensitive hemagglutination inhibition test and IgM antibody capture ELISA test can be used for early diagnosis of JE; the complement-binding antibody titer is 4 times positive during the recovery period; the neutralization test is only used for epidemiological investigation.

(3) Rapid IFN diagnosis:

Encephalitis virus antigens in leukocytes are mainly present early in the course of the disease and can be used for early diagnosis.

Forest encephalitis virus

The transmission vector is hard ticks, which is a natural epidemic disease; mice and chicken embryos are sensitive to it; and the microbiological examination method is similar to that of JE virus.

Third, dengue virus

The media is

Intravenous ribavirin (in the United States, currently only aerosols are approved for use) (loading dose 2g, then 1g, once every 6 hours for 4 days, and then 0.5g, once every 8 hours for 6 days) Effectively treats Lassa fever, Rift Valley fever and Crimea-Congo hemorrhagic fever. The dose for treating renal syndrome hemorrhagic fever is described later. Treatment for most arbovirus infections is supportive, the same as for other viral encephalitis