Mosquitoes are the most lethal creature on the planet, killing and sickening millions each year. In addition some mosquito-borne diseases are rapidly spreading outside what was once considered their traditional geographic areas. One virus, the Zika virus, is considered an emerging pathogen, other viruses are mutating and are transmitted by mosquito species that did not previously transmit them. This following table lists the known mosquito diseases.
| Disease | Humanitarian Impact | Description | Symptoms |
|---|---|---|---|
| Chikungunya | Periodic outbreaks infecting from 10s of thousands to 100s of thousands of people. | Chickungunya is now found around the world, most recently appearing in the U.S. for the first time. The Chickungunya virus has mutated to use the Asian tiger mosquito (an invasive species) as a vector in addition to the more strictly tropical main vector, Aedes aegypti. Analysis of the virus’ RNA determined the genetic changes indicate increased virulence of recent strains. | The disease may be asymptomatic, but generally is not, as 72% to 97% of those infected will develop symptoms. Characteristic symptoms include sudden onset with high fever, joint pain, and rash. Other symptoms include headache, fatigue, digestive complaints, and conjunctivitis. Following the fever, strong joint pain or stiffness occurs; it usually lasts weeks or months, but may last for years. The joint pain can be debilitating, often resulting in near immobility of the affected joints. |
| Dengue Fever | More than one-third of the world’s population is living in areas at risk for infection. Dengue virus is a leading cause of illness and death in the tropics and subtropics. As many as 400 million people are infected yearly. | There are four types of dengue virus that can cause illness in humans. Dengue viruses are transmitted between humans by the bite of an infected Aedes mosquito. Dengue is rare in the U.S., but is common and a serious public health threat in warm sub-tropical and tropical areas of the world. Dengue fever is most common in urban areas and outbreaks occur commonly during the rainy season when mosquitoes breed heavily in standing water. | High Fever (106 F) (41 C)
Headaches Muscle, bone and joint pain, Pain behind eyes, widespread rash, Nausea and vomiting |
| Lymphatic Filariasis | Over 120 million people are infected, with about 40 million disfigured and incapacitated by the disease. | Lymphatic filariasis, commonly known as elephantiasis, is a painful and profoundly disfiguring disease. The disease is caused by three species of thread-like worms, known as filariae. Mosquitoes transmit Filariae when a mosquito with infective stage larvae feeds on blood. The Filariae parasites are deposited on the person’s skin and enter the body. The adult filariae live for several years in the human host. During this time, they produce millions of immature microfilariae that circulate in the peripheral blood and are ingested by mosquitoes that bite the infected human. | Broad range of clinical manifestations, varying from people with no evident clinical disease to those with lymphedema and/or severe disfigurement of the extremities and genitalia. There is a huge potential of overlap in these symptom complexes, although an individual may also experience each at different times during his or her lifetime. |
| Malaria | Over one million people die from malaria each year, mostly children under five years of age, with 90 per cent of malaria cases occurring in Sub-Saharan Africa. An estimated 300-600 million people suffer from malaria each year. More than 40 percent of the world’s population lives in malaria-risk areas. | Plasmodia parasites are transmitted between humans by the bite of an infected Anopheles mosquito. | Flu-like symptoms appear 8-30 days after a bite in fatigue, fever, nausea and chills. Malaria can result in anemia (a decreased number or red blood cells). The remains of the destroyed red blood cells clump together and cause blockages in the blood vessels. This can result in brain damage or kidney damage, which is potentially fatal. |
| Murray Valley Encephalitis Virus (MVEV) | Periodic outbreaks | Murray Valley encephalitis virus (MVEV) is maintained in a bird-mosquito-bird cycle spread by the Culex annulirostris mosquito. so far endemic to northern Australia and Papua New Guinea. The majority of MVEV infections are sub-clinical, meaning no outward symptoms. | Symptoms of severe disease are confusion, sleepiness, trouble speaking, lack of coordination, and brain infection. In very rare cases, long-term disability or death can occur. |
| Rift Valley Fever | Episodic outbreaks associated with heavy flooding | Rift Valley fever primarily affects domestic livestock however humans can also be infected by the bite of an Aedes mosquito. Human infections are generally mild but can be severe and include hemorrhagic fever, encephalitis or ocular diseases. | fever, generalized weakness, back pain, dizziness, and extreme weight loss at the onset of the illness. Rift Valley fever increases after flooding events. |
| Ross River Virus | Episodic outbreaks associated with heavy flooding and other water events | Once found only in Australia the Aedes mosquito has now spread Ross River virus to in the western Pacific islands of Fiji, Samoa, the Cook Islands, and New Caledonia. In 2010, the Ross River Virus was found to have made its way to the Aundh area in Pune, India and spread to other parts of the city. | Arthritis or joint pain, a rash on the limbs of the body, which often occurs roughly 10 days after arthritis begins. Lymph nodes may enlarge, most commonly in the arm pits or groin region |
| Saint Louis Encephalitis | Small number of cases in periodic outbreaks likely to have a fatal infection. | Spread by the Mansonia pseudotitillans mosquito and is found primarily in the United States. This is bird/mosquito cycle virus with the virus growing in both birds and mosquitos. | Fever and headache. More severe cases include headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, occasional convulsions and spastic paralysis. Fatality ranges from 3–30%. |
| West Nile Fever | 42,000 cases in the U.S. since 1999 | Wild birds are the host of West Nile fever which is then transmitted by mosquitoes. | Most of those infected have no symptoms. More severe cases cause flu-like symptoms |
| Yellow Fever | While there is a safe and effective vaccine, Yellow fever causes 200,000 infections and 30,000 deaths every year, nearly 90% of these occurring in Africa. | An acute infectious disease primarily of the tropics, caused by a virus and transmitted to man by mosquitoes of the genera Aedes and Haemagogus. | Headache, fever, chills, loss of appetite, nausea, and muscle pains and usually improve within five days. In some people within a day of improving, the fever comes back, abdominal pain and liver damage begins. These worsening symptoms increase the risk of bleeding and kidney problems. |
| Zika Virus | Considered an emerging pathogen, the virus was first isolated in 1947 from a rhesus monkey in the Zika Forest of Uganda. There are now statistics on infection rates | Zika spread outside Africa and Asia for the first time in 2007 and an outbreak was reported in Brazil in 2015. It is spread by Aedes aegypti, Aedes africanus, Aedes apicoargenteus, Aedes furcifer, Aedes luteocephalus and Aedes vitattus mosquioes and is now found in Brazil, Chile (specifically Easter Island), Colombia, El Salvador, Guatemala, Mexico, Paraguay, Suriname, and Venezuela. | Rash and joint pain. Zika was recently linked to birth defects, specifically microcephaly, which increased 10 fold in the last year in Brazil. |