Mosquito Borne Diseases

Zika fever, also known as Zika virus disease or simply Zika, is a mosquito-borne disease caused by the Zika virus. In many cases there are no symptoms, but it can present in a similar way to dengue fever. Symptoms might include fever, red eyes, joint pain, headache and a maculopapular rash. Women who are infected by Zika virus during pregnancy can bear children with serious health conditions, including microcephaly, which can cause life-long disabilities.

• Common symptoms
  • Fever
  • Rash
  • Conjunctivitis
  • Headache
  • Muscle and joint aches

First identified in Ugandan monkeys in 1947, then in humans in 1952, the Zika virus was virtually dormant for six decades. Global outbreaks in 2015 were recorded in Africa, the Americas, Asia and the Pacific. On 1 February 2016, the Public Health Emergency of International Concern.

Causes

Zika virus disease is caused by a virus transmitted primarily by Aedes aegypti mosquitoes. These mosquitoes bite during the day, usually just after sunrise and around sunset.

Most people with Zika virus infection do not develop symptoms; for those who do, symptoms tend to last for two to seven days. In some cases, women who are infected by Zika virus during pregnancy bear children with serious health conditions, including microcephaly, which can cause life-long disability.

It is possible to contract Zika in Africa, the Americas, Asia and the Pacific. Zika cases have been reported from more than 80 countries.

Because Zika virus infection often causes little or mild illness, it is difficult to quantify the incidence of infection. Since 2015, more than 900,000 suspected cases of Zika have been reported.

Zika can spread wherever Aedes aegypti mosquitoes are present. It is a virus transmitted between humans primarily by this mosquito, which is commonly found around homes and urban areas.

There is no treatment for Zika virus, other than rest, fluids and management of symptoms with common medicines. Symptoms of Zika virus infection are usually mild, and resolve within seven days.

There is no vaccine for Zika virus. Prevention relies on reducing exposure to mosquito bites, by removing mosquito breeding sites, using insecticides to suppress the mosquito population, and wearing protective clothing and repellents.

However, the World Mosquito Program's Wolbachia method is showing promising results internationally. It is helping to block the transmission of Zika, as well as other viruses transmitted by Aedes aegypti mosquitoes, such as dengue, chikungunya and yellow fever

Dengue fever is a mosquito-borne disease caused by the dengue virus. Symptoms typically begin three to fourteen days after infection. Common symptoms of dengue include fever, rash, nausea and aches and pains, lasting up to a week. Some people with dengue develop complications that can result in internal bleeding, shock and even death. Severe dengue requires careful monitoring in hospital. In recent decades, the global incidence of dengue has grown dramatically, with more than half of the world's population now at risk. Every year, approximately 36,000 people around the world die from dengue fever.

Common symptoms

• High fever
• Headache
• Vomiting
• Joint pain
• Rash

According to the World Health Organization, dengue fever is one of the top ten global health threats — it's also the most rapidly spreading. There has been a 30-fold increase in global incidence over the past 50 years.

Common symptoms of dengue include fever, rash, nausea and aches and pains, lasting up to a week. Some people with dengue develop complications that can result in internal bleeding, shock and even death. Severe dengue requires careful monitoring in hospital.

There are four serotypes of dengue virus, all of which can cause disease. Prior infection with one dengue serotype is a risk factor for developing later infections.

Causes

Dengue fever is caused by a virus transmitted primarily by Aedes aegypti mosquitoes. These mosquitoes bite during the day, usually just after sunrise and around sunset.

Symptoms typically last for two to seven days.

More than half of the world's population is at risk of dengue infection.

Each year, an estimated 390 million dengue infections occur around the world, resulting in up to 36,000 deaths

Dengue can occur anywhere that Aedes aegypti mosquitoes live. The most significant dengue epidemics in recent years have occurred in Southeast Asia, the Americas and the Western Pacific. Approximately 141 countries are affected.

Dengue spreads where Aedes aegypti mosquitoes are present. This mosquito is commonly found in and around homes, where it breeds in small water containers. When an Aedes aegypti mosquito bites someone with dengue, it can become infected and transmit the virus to another person when it bites again.

There is no specific medical treatment for dengue, which has flu-like symptoms. Monitoring for warning signs of severe disease is important. Urgent medical intervention is required if indications of shock or bleeding develop, as these complications can be lethal.

Conventional strategies for dengue control rely heavily on reducing the number of water-holding containers that support mosquito breeding and using insecticides to suppress the mosquito population. However, it is challenging to achieve sustained reductions in mosquito numbers, and dengue outbreaks can still occur. Using personal repellents and wearing protective clothing can help to prevent mosquito bites

In contrast, the World Mosquito Program's Wolbachia method doesn't aim to reduce the mosquito population, rather to replace it with Wolbachia mosquitoes. This helps block the transmission of dengue, as well as other viruses transmitted by Aedes aegypti mosquitoes, such as Zika, chikungunya and yellow fever

The World Mosquito Program's research shows that in communities where high levels of Wolbachia mosquitoes are present, the incidence of dengue and other Aedes-borne diseases is significantly reduced.

Yellow fever is a viral disease of typically short duration. In most cases, symptoms include fever, chills, loss of appetite, nausea, muscle pains (particularly in the back) and headaches. Symptoms tend to improve within five days, however approximately 30,000 people around the world die from yellow fever every year. Yellow fever is an acute viral haemorrhagic disease transmitted by infected Anopheles or Aedes aegypti mosquitoes. The 'yellow' in the name refers to the jaundice that affects some patients.

Common symptoms

• Fever
• Headache
• Chills
• Back pain
• Fatigue
• Vomiting

Yellow fever is a viral disease of typically short duration In most cases, symptoms include fever, chills, loss of appetite, nausea, muscle pains (particularly in the back) and headaches. Symptoms tend to improve within five days; however, this disease claims the lives of approximately 30,000 people around the world every year. The 'yellow' in the name refers to the jaundice that affects some patients.

Causes

Yellow fever is caused by a virus transmitted primarily by Aedes aegypti mosquitoes. These mosquitoes bite during the day, usually just after sunrise and around sunset.

Symptoms typically improve within five days.

Yellow fever is endemic across Africa and Latin America.

Of the 47 countries affected, 13 in the Americas have the highest risk of outbreaks, including Brazil, Mexico and Colombia. The World Mosquito Program has begun work in these countries in an effort to end the spread of the disease.

While the urban transmission of yellow fever by Aedes aegypti mosquitoes has not been reported in Brazil since 1942, the risk of re-urbanisation of the disease remains. This mosquito species is found in most tropical and subtropical cities in the world, and they were the main carrier of yellow fever in the past.

According to the World Health Organization and the Pan American Health Organization, yellow fever causes 200,000 infections and 30,000 deaths annually.

Yellow fever can spread wherever Anopheles, Aedes aegypti and Haemogogus mosquitoes are present. There are three ways yellow fever can be transmitted. Our Wolbachia method provides protection against yellow fever transmitted by the Aedes aegypti mosquito, which is commonly found in urban settings, such as homes and urban areas.

Large outbreaks of urban yellow fever tend to occur when infected people introduce the virus into heavily populated areas with a high density of Aedes aegypti mosquitoes, and where most people have little or no immunity, due to lack of vaccination or prior exposure to yellow fever.

There is no treatment for yellow fever, other than rest and management of the fever with common medicines.

Safe and affordable, the yellow fever vaccine is the most important means to combat the virus.

The World Mosquito Program’s Wolbachia method could potentially help to reduce yellow fever transmission, as well as other viruses transmitted by Aedes aegypti mosquitoes, such as dengue , Zika and chikungunya.

Chikungunya is a viral disease transmitted to humans via infected Aedes aegypti mosquitoes. Symptoms typically include fever, joint pain, headache, muscle pain, joint swelling and rash. In most cases, a patient's condition will improve within a week, however occasionally the joint pain may last for months or even years. Chikungunya shares some clinical signs with Zika and dengue, leading to potential misdiagnosis in areas where these diseases are prevalent.

• Common symptoms
  • Sudden fever
  • Joint and muscle pain
  • Rash
  • Headache
  • Fatigue

First identified during an outbreak in Tanzania in 1952, chikungunya is a virus that is transmitted between humans by the Aedes aegypti mosquito. The word chikungunya comes from the Kimakonde language. It means ‘to become contorted’, as the disease causes debilitating joint pain that induces a stooped appearance.

Between 2014 and 2017, there was a large outbreak across the Americas, with more than 2.5 million suspected cases of chikungunya recorded in the Caribbean islands, Latin America and the United States. More than 600 deaths were attributed to this disease during this period.

Chikungunya is caused by a virus transmitted primarily by Aedes aegypti mosquitoes. These mosquitoes bite during the day, usually just after sunrise and around sunset.

Chikungunya causes severe fever and debilitating joint pain, and shares some clinical signs with Zika and dengue, which sometimes leads to misdiagnosis in areas where these diseases are prevalent. Symptoms usually improve within a week; however, sometimes the joint pain may persist for months or even years.

Chikungunya is most prevalent in Asia, Africa, the Americas and the Pacific. It also occurs in warmer parts of Europe. Chikungunya cases have been reported from more than 100 countries.

Chikungunya occurs in sporadic outbreaks that are often separated by periods of more than 10 years, so it is difficult to assess the global burden of this disease, but the virus is widespread.

Between 53,000 and 330,000 cases are estimated to occur on average each year worldwide, but the 2014 epidemic in the Americas saw more than 1 million chikungunya cases reported in a single year.

Chikungunya spreads wherever Aedes aegypti mosquitoes are present. It is a virus transmitted between humans primarily by this mosquito, which is commonly found around homes and urban areas.

There is no specific antiviral drug treatment for chikungunya. Treatment primarily focuses on relieving symptoms with common medications.

There is no vaccine for chikungunya.

Prevention relies on reducing exposure to mosquito bites, by removing mosquito breeding sites, using insecticides to suppress the mosquito population, and wearing protective clothing and repellents.

However, the World Mosquito Program’s Wolbachia method is showing promising results internationally, helping to block the transmission of chikungunya, as well as other viruses transmitted by Aedes aegypti mosquitoes, such as Zika, dengue and yellow fever.

• Symptoms include fever, headache, nausea, vomiting, and tiredness.
• There are no vaccines to prevent or medicines to treat St. Louis encephalitis.
• You can reduce your risk by taking steps to avoid mosquito bites.

St. Louis encephalitis virus is spread to people by the bite of an infected mosquito. Most people infected with St. Louis encephalitis virus do not have symptoms. Those people who do become ill may experience fever, headache, nausea, vomiting, and tiredness.

Some people may develop neuroinvasive disease, such as encephalitis (inflammation of the brain) or meningitis (inflammation of the membranes that surround the brain and spinal cord). In rare cases, long-term disability or death can occur.

There are no vaccines to prevent or medicines to treat St. Louis encephalitis. Reduce your risk of infection by preventing mosquito bites.

• Western equine encephalitis (WEE) virus is spread through the bite of an infected mosquito.
• No human cases have been reported in the United States since the late 1990s.
• Most people with WEE virus infection do not get sick, though some will develop fever, headache, body aches, or confusion.
• There are no vaccines to prevent or medicines to treat WEE.
• Reduce your risk by taking steps to prevent mosquito bites.
• Western equine encephalitis is caused by a virus most commonly spread to people through the bite of an infected mosquito. Most people infected with western equine encephalitis virus do not feel sick. However, the virus can cause some people to develop symptoms of a febrile illness (fever) or severe neurologic disease.
• Western equine encephalitis virus has caused sporadic outbreaks of disease in horses and people from the late 1930s through the early 1980s in the United States. The last outbreak in the United States in people was in 1987, and since then, there have only been five cases of western equine encephalitis virus identified in the United States. The last reported case of western equine encephalitis occurred in 1999. Historically, the virus has been found in parts of North America, Central America, and South America.
• Risk of infection is highest during mosquito season, which starts in the summer and continues through fall. You can reduce your risk of infection by preventing mosquito bites.

• Symptoms include fever, headache, body aches, vomiting, diarrhea, or rash. Severe illness can affect the central nervous symptom and result in hospitalization or death.
• No licensed vaccines or medicines are available to prevent or treat West Nile virus disease (West Nile) in people.
• West Nile virus is most commonly spread to people through the bite of an infected mosquito. People get infected with the virus during mosquito season, which starts in the summer and continues through fall (typically June through October). The number of people diagnosed with West Nile typically peaks in late August to early September.
• Each year, about 2,000 people in the United States are diagnosed with West Nile, but this number is an underestimate as most people do not develop symptoms or attribute mild symptoms to other causes.
• Most people infected with West Nile virus do not develop any symptoms.
• Mild illness
• Some people develop mild illness with flu-like symptoms, such as fever with headache or body aches, joint pain, vomiting, diarrhea, or rash. Most people with mild illness recover completely, but fatigue and weakness can last for weeks or months