Tag Archives: Nile

West Nile Virus Identified in British Mosquito for the First Time

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A fragment of the virus has been identified in Aedes aegypti mosquitoes in Nottinghamshire, UK

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The West Nile virus, marking the first potential fatal mosquito-borne disease in the UK, has been identified for the first time.

The UK Health Security Agency (UKHSA) has announced that its research collaboration with the Animal and Plant Health Agency has Afa successfully identified a “fragment” of the virus in Aedes aegypti mosquitoes collected from the marshlands along the Idol River in Nottinghamshire in July 2023, indicating that these insects are carriers of pathogens.

According to Alanfolly from Apha, the virus was discovered somewhat by chance during routine testing by his team. He notes that further screenings will take place around that area later this year. Interestingly, Nottinghamshire typically does not fall into Afa’s primary testing regions, which are mostly centered in southern and eastern England, where warmer climates increase the likelihood of infections such as West Nile.

Humans and horses can become infected with the West Nile virus through mosquito bites. Approximately 20% of infected individuals exhibit symptoms such as fever, headaches, body aches, vomiting, and diarrhea. In rare instances, the virus can lead to severe inflammation of the brain and spinal cord, which can be fatal. Currently, there are no approved vaccines for humans.

UKHSA has reported the virus’s presence only in two mosquito samples, with no current evidence suggesting that humans or horses are infected in the UK. The organization’s assessment indicates a very low risk to the public, but healthcare professionals are advised to test encephalitis patients for unexplained causes.

“This is the first identification of the West Nile virus in British mosquitoes, though it doesn’t come as a surprise given the virus’s ongoing spread across Europe,” stated Meera Chand from UKHSA.

The West Nile virus has been increasingly observed in Africa, Europe, and North America. In Europe, recent years have seen its northern spread, reaching the Netherlands in 2020.

Factors contributing to the spread of the West Nile virus include elevated spring and summer temperatures, summer droughts, and milder winters, all of which are becoming more prevalent in Northern Europe. Although APHA has not detected the West Nile virus in mosquitoes or birds for 2024, the recent warm weather in the UK could change that. “We had an unusually warm May,” Folly noted. “If there is another case, we may see it in the coming weeks. This is just the beginning; more cases could follow.”

British researchers have been vigilant for the West Nile virus since 2020 when a related mosquito-borne virus (USUTU) was first found in London. The West Nile virus shares similar transmission characteristics with USUTU and requires comparable environmental conditions.

“I wouldn’t be surprised at all,” stated Matthew Baylis from the University of Liverpool. “I’ve been expecting this to happen every year. I believe that the West Nile virus will eventually be detected in the UK.”

He suggested that the virus likely arrived in the UK via birds and is probably circulating among various mosquito species in the region. However, he reassured that there is no immediate cause for alarm. “The risk remains low for most people. While a few horses are susceptible to West Nile disease, it’s quite rare,” he added.

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Source: www.newscientist.com

The Death of a Blackbird highlights the looming danger of the West Nile virus in the UK

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Blackbird numbers have decreased in the UK as the USUTU virus has taken hold

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The deadly virus is killing Blackbirds all over the UK. Beyond the risks for birds, its spread indicates that mosquito-borne viruses are currently pose a threat to humans and animals in the country as a result of climate change.

The virus in question, USUTU, occurred in South Africa in 1959, but is now spreading in Europe. It caused fatal diseases in certain birds, especially black swans, and was first detected in the UK in 2020. In some parts of the country, the Blackbird population, the most notable London, has fallen by more than 40% since 2018. “I first noticed a decline when USUTU popped up,” he says. Hugh Hammer With British trust for ornithology.

Though catastrophic to bird life, USUTU poses low risks to humans and mammals. Human infectious diseases are rare and generally cause mild fever, but the arrival of the virus in the UK marked the first time by mosquito-borne viral zoonotic diseases (a disease that can be transmitted from animals to humans) that have appeared in domestic animal hosts. Virus experts are closely monitoring how well and fast the disease is spreading, as it could be a template for the future spread of other mosquito-borne diseases.

For example, the West Nile virus spreads just like USUTU and requires the same environmental conditions. “The same mosquitoes that can send USUTUs can usually send West Nile. [for Usutu] It can also serve as a host for West Nile.” Alanfolly at the British Animal and Plant Health Organization (APHA).

Humans can also contract the West Nile virus when bitten by mosquitoes, but the symptoms can be more severe than those of USUTU. Approximately 20% of infected people experience symptoms including fever, headache, body pain, vomiting and diarrhea. In rare cases, this virus can cause serious inflammation of the brain and spinal cord, which is fatal. There are no known human vaccines.

Climate change has helped accelerate the spreading of the West Nile virus through Northern and Eastern Europe. Research Showas the virus thrives in warm summer temperatures. In the Netherlands, USUTU was first detected in 2016, and the West Nile virus continued in 2020. British officials fear a similar pattern will unfold in their country. Demonstrating research The climate there is becoming more and more kind to mosquito-borne viruses. “The idea is if there's usutu here, West Nile is likely to come at some point and last, given the right conditions,” Folly says.

In response to the threat, APHA launched a project in 2023 to track the emergence and transmission routes of USUTU and other mosquito-borne viruses in wild birds. Infrastructure to track this virus It is essential for the country to respond quickly to West Nile's arrival, Foley says. “Our real goal, or willingness from a government perspective, is to be able to detect these. [new viruses] We circulate animal populations before they can be transmitted to humans. ”

Reina Sikkema The University of Erasmus Medical Center in Rotterdam is studying the emergence of the Netherlands Ustus and the West Nile virus. The West Nile has not been detected since 2022,He believes the virus is circulating at low levels and is now being controlled by a relatively cool climate. “I believe it exists, but it takes the right situation to burn,” she says. Sikkema said detection of the West Nile in the UK is now inevitable, but he believes similar climatic factors can prevent the virus from spreading too widely.

However, the temperature rise in summer including Increased frequency of tropical nights – The UK's Met Office Weather Agency defines Sikkema that if the minimum temperature is not below 20°C, it could change photos of the UK, the Netherlands and other Northern European countries. “Mosquito-borne is not [just] On your Spanish holiday, or when you go to South America,” says Folly.

Like the potential risk of the West Nile virus to people, Folly says we shouldDon't forget what USUTU is doing to Blackbirds in the UK: “If 40% of humans die in Greater London, you'll know about it very quickly.”

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Source: www.newscientist.com

Las Vegas sees surge in mosquitoes carrying West Nile virus

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summary

  • A record number of mosquitoes in and around Las Vegas are testing positive for the West Nile virus as mosquito populations across the region soar.
  • Local health officials are urging residents to take precautions to avoid being stung.
  • The situation in Las Vegas is a case study as climate change expands the reach of vector-borne diseases.

Record numbers of mosquitoes are carrying the West Nile virus in and around Las Vegas, prompting local health officials to issue a public warning. Take precautions To avoid getting bitten.

West Nile virus causes fever, headache, vomiting and diarrhea and is fatal in about 1 in 150 cases. There is no vaccine or medicine to treat or prevent the mosquito-borne disease.

In recent weeks, 169 of more than 24,000 mosquito swarms tested for West Nile virus in 25 Southern Nevada ZIP codes tested positive, meaning at least one mosquito in the swarm was carrying the virus. The number of mosquitoes and positive swarms recorded this early in the season broke the regional records for both indicators set in 2019.

“The mosquito population is huge and we've already seen significant numbers of mosquitoes carrying the West Nile virus,” said Vivek Raman, environmental health inspector for the Southern Nevada Health Department.

Health officials also identified six swimming pools in the Las Vegas area where people had tested positive for the St. Louis encephalitis virus, a mosquito-borne disease that causes potentially fatal inflammation of the brain.

For decades, climate scientists and public health officials have warned that climate change could increase the range of various infectious diseases, particularly those transmitted by mosquitoes. The Las Vegas mosquito surge and regional increase in West Nile virus outbreaks provide an important case study in how climate affects human health.

Climate change will increase the global average temperature and precipitation, creating ideal conditions for mosquitoes, who breed in still, warm water. It will also lengthen the warm season, lengthening the mosquito season. These changes will Human exposure risk Even in places where no cases have been recorded before, there is an increased risk of contracting diseases such as West Nile virus.

The first case of West Nile virus was recorded in Las Vegas in 2004, five years after the first case in the United States was recorded in New York City in 1999. The most recent West Nile virus outbreak in Las Vegas was five years ago, when 43 people were infected, and area health officials fear the situation could get even worse this summer.

Spring weather is coming to Nevada and much of the Southwest. It gets warmer Summer heat waves have become more intense in recent decades. In Las Vegas, the average spring temperature is 6.2 degree increase since 1970This month, the city has already A week of record-breaking heatwave.

Rising temperatures in Southern Nevada are creating favorable conditions for mosquitoes, said Nishay Mishra, an assistant professor of epidemiology at Columbia University. Additionally, the state's ongoing drought has lowered groundwater levels throughout the Colorado River basin, including Lake Mead, which could unexpectedly benefit the insects.

“Mosquitoes typically breed in places that are moist and hot,” Mishra says, “but in Nevada, when small bodies of water dry up, they create shallow water that's perfect for mosquito breeding.”

Las Vegas' mosquito surge has been enormous: Last year, local health officials counted 6,000 mosquitoes in traps set across Clark County between April and June. This year, the number is already over 24,000.

Most of these mosquitoes are Culex mosquitoes, which are the primary vectors of the West Nile virus. But another mosquito species that doesn't carry the virus, Aedes aegypti, has also become common in Las Vegas. It was first spotted in the area in 2017, and Raman attributes its spread in part to climate change.

Along with climate, human behavior also plays an important role in the spread of vector-borne diseases. Culex mosquitoes and Culex pipiens mosquitoes breed in many Las Vegas backyards, the former breeding in small pools of water such as those left by sprinklers, and the latter often breeding along the surface of untended swimming pools.

Raman said the best ways to prevent infection are to empty water containers outside, take care of swimming pools, wear protective clothing and use bug repellent to prevent insect bites.

Louise Ivers, professor of global health and social medicine at Harvard Medical School and director of the university's Global Health Institute, said situations like the one in Las Vegas will become more common as infectious diseases continue to rise around the world due to climate change.

“We expect to see new infections, the resurgence of old ones, and changes in the transmission patterns of existing ones like West Nile virus,” Ivers said. “We may no longer be able to do things that we were previously free to do without worrying as much about protection from vectors like mosquitoes and ticks.”

Source: www.nbcnews.com