Overview of Arbovirus, Arenavirus, and Filovirus Infections

Arboviruses are arthropod-borne viruses. An arbovirus is not a single type of virus. Scientists apply the name arbovirus to over 250 different viruses from many different families of virus that are spread to people or animals by certain arthropods that feed on blood. Arthropods include insects (such as flies and mosquitoes) and ticks. At least 80 arboviruses cause disease in people.

Most arboviruses are transmitted by mosquitoes, but some are transmitted by ticks, one (Oropouche virus) is transmitted by midges, and others are transmitted by sand flies. Arboviruses are spread when an insect or tick bites an infected animal, then bites another animal or a person. Most arbovirus infections are not spread from person to person, perhaps because the amount of virus in human blood is inadequate to infect the arthropod vector. Exceptions include chikungunya disease and the flavivirus infections dengue Dengue Dengue is a mosquito-borne viral infection that causes fever, generalized body aches, and, if severe, external and internal bleeding (called dengue hemorrhagic fever). About 50 to 100 million... read more , yellow fever Yellow Fever Yellow fever is a mosquito-borne viral disease that occurs mainly in the tropics. Yellow fever occurs only in the tropical areas of Central Africa, southern Panama, and South America. Some people... read more , and Zika virus infection Zika Virus Infection Zika virus infection is a mosquito-borne viral infection that typically causes no symptoms but can cause fever, rash, joint pain, or infection of the membrane that covers the white of the eye... read more , which can be transmitted from person to person by mosquitoes. Also, Zika virus can be spread during sexual activity. Uncommonly, dengue, chikungunya, and Zika viruses have been spread by blood transfusion or organ donation or from mother to newborn at birth. Casual, everyday contact has not been shown to transmit arboviruses from person to person.

Many arboviruses that were once present in only a few parts of the world are now spreading. These viruses include chikungunya virus, Crimean-Congo hemorrhagic fever virus, Japanese encephalitis virus, Rift Valley fever virus, West Nile virus West Nile Virus Infection West Nile virus infection is a viral disease spread primarily from mosquitoes to people. Most people have mild or no symptoms, but some people develop a severe infection that affects the central... read more , Ross River virus, and Zika virus. These viruses are spreading partly because climate change has resulted in more areas where the mosquitoes that spread the viruses can live. Also, travelers may be infected in areas where the virus is common, then return home and be bitten by a mosquito, which spreads the virus to other people.

Chikungunya virus is spread by a certain species of mosquito called the Aedes mosquito. This virus was first identified in Africa but has recently spread to the Caribbean and Central, South, and North America. Chikungunya virus infection typically causes a fever and severe joint pain, often in the hands and feet. Infected people may also have a headache, muscle pain, joint swelling, or a rash. Most people feel better within a week, but joint pan can persist for months or sometimes even years.

Arenaviruses are spread by rodents. Infections caused by these viruses include lymphocytic choriomeningitis Lymphocytic Choriomeningitis Lymphocytic choriomeningitis is a viral infection that usually causes a flu-like illness, sometimes with rash, joint pain, or infections in other parts of the body. Most people become infected... read more , Lassa fever Lassa Fever and South American Hemorrhagic Fevers Lassa fever and South American hemorrhagic fevers caused by arenaviruses are viral infections that cause bleeding (hemorrhage) and organ malfunction. They often result in death. These infections... read more , Bolivian hemorrhagic fever (caused by Machupo virus), Venezuelan hemorrhagic fever (caused by Guanarito virus), and Argentine hemorrhagic fever (caused by the Junin virus). Lassa fever can also be spread from person to person through contact with body fluids (such as saliva, urine, feces, or blood). Arenavirus infections are relatively common in people in some areas of the world and can cause severe disease.

Filoviruses can cause severe hemorrhagic fever Hemorrhagic Fevers Overview Hemorrhagic fevers are serious viral infections characterized by bleeding (hemorrhage). Hemorrhagic fevers can be caused by many different types of virus. Depending on the type of virus, these... read more in people and other primates (such as apes and monkeys). So far, only two members of this group of viruses have been identified:

How these viruses first spread to people has not been identified. However, experts think that the first person was infected by handling or eating an infected animal, such as a fruit bat or primate. These viruses spread readily from person to person.