Oropouche virus ‘massively underdiagnosed' in Latin America, new study suggests
Closely related to the Zika and Dengue viruses, Oropouche is transmitted by biting midges and mosquitoes. It poses a particular risk to pregnant women, having been linked to stillbirths and serious birth defects.
The virus was first detected outside of Brazil – where it is endemic – in October 2023, when it began spreading rapidly across other South American and Caribbean countries. Since then, over 20,000 cases and four deaths have been reported.
However, a new study published in The Lancet Infectious Diseases suggests that the virus may have been circulating across the region undetected since as early as 2001.
Researchers analysed 9,400 blood samples collected between 2001 and 2022 from patients in Bolivia, Colombia, Costa Rica, Ecuador, and Peru. They found that at least 6.3 per cent – nearly 600 individuals – had antibodies against Oropouche, indicating past infection.
There were significant regional variants, however; while antibodies were present in two per cent of samples from Costa Rica, they appeared in five per cent of samples from Ecuador and over 10 per cent of samples from the Amazon region.
People living in higher altitudes were also less likely to have experienced a previous Oropouche infection than those at warmer, lower altitudes – which offer more favourable conditions for the insects that transmit the disease.
'Our data show that Oropouche virus is massively under-diagnosed in Latin America,' said Professor Jan Drexler, head of the Virus Epidemiology Laboratory at the Institute of Virology at Charité and lead author of the study.
'We still know relatively little about the virus, the consequences of an infection, including on unborn babies, require further investigation and it's not yet clear whether there are parallels with the Zika virus,' he added.
The researchers said that Oropouche cases are often confused with dengue fever, which is widespread in Latin America, because they cause similar symptoms including high fevers, headaches, and muscle pain.
The study also found the El Niño phenomena – a naturally occurring weather pattern which creates warmer and wetter weather – significantly increases transmission of Oropouche, by creating conditions in which midges and mosquitoes can thrive. The 2023-2024 El Niño was one of the strongest on record, and was exacerbated by climate change.
'I think it's possible that Oropouche virus will become even more widespread in the future as climate change progresses,' Dr Drexler said.
The authors of the study say the findings emphasise the need for the development of an Oropouche vaccine, which currently does not exist.
They also recommend that healthcare workers in the Americas are better educated on the signs and symptoms of Oropouche virus, and that it should be considered when treating anyone with unexplained fevers, pregnancy complications, or in the case of unexplained death.
Protect yourself and your family by learning more about Global Health Security
Broaden your horizons with award-winning British journalism. Try The Telegraph free for 1 month with unlimited access to our award-winning website, exclusive app, money-saving offers and more.
Hashtags

Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Yahoo
a day ago
- Yahoo
World's deadliest animal is probably outside your Florida home right now. Protection tips
What's the world's most dangerous animal? Hint: It's plentiful in Florida and no, it's not an alligator, shark or python. According to the Centers for Disease Control the deadliest animal in the world is the mosquito. "The mosquito kills more people than any other creature in the world," the CDC said, noting the flying nuisance spreads such diseases as malaria, dengue, West Nile, yellow fever, Zika and chikungunya. The Florida Department of Health said there are 80 types of mosquitoes in the state, many of which transmit diseases. The agency tracks mosquito-borne illnesses — known as arboviruses — acquired locally and those contracted by people with a history of travel. Here's what you should know, including how you can protect yourself and your family. Mosquito-borne illnesses confirmed in Florida so far this year The latest report from the Florida Department of Health has confirmed the following cases of mosquito-borne illnesses in the state between Jan. 1 through Aug. 2: West Nile Virus: 5 asymptomatic blood donors Escambia: 5 Chikungunya: 4 cases in those with travel history Broward: 2 Lake: 1 Miami-Dade: 1 Dengue: 122 cases in those with travel history; 7 cases in non-Florida residents Bay: 1 Brevard: 2 Broward: 10 Clay: 1 Collier: 2 Duval: 3 Escambia: 1 Hillsborough: 6 Lake: 3 Lee: 4 Manatee: 1 Marion: 1 Miami-Dade: 63 Okeechobee: 3 Orange: 6 Osceola: 2 Palm Beach; 5 Pasco: 1 Pinellas: 3 Polk: 1 St. Johns: 1 St. Lucie: 1 Volusia: 1 Denque acquired in Florida: 8 cases Brevard: 6 Miami-Dade: 2 Malaria: 28 cases in those with travel history; 9 in non-Florida residents Alachua: 1 Brevard: 1 Broward: 3 Collier: 1 Duval: 1 Hillsborough: 1 Lake: 1 Marion: 2 Miami-Dade: 4 Nassau: 2 Orange: 3 Palm Beach: 3 Polk: 2 St. Lucie: 2 Volusia: 1 What mosquito-borne diseases are tracked in Florida? The Florida Department of Health tracks travel- and locally acquired cases of the followed mosquito-borne diseases: West Nile fever and West Nile encephalitis Eastern equine encephalitis virus St. Louis encephalitis virus Dengue virus Chikungunya virus Zika virus California encephalitis group viruses Malaria Florida has more than 80 types of mosquitoes. Here are 5 'most wanted' The Florida Department of Health said there are more than 80 different species of mosquitoes in Florida, compared to about 3,500 species in the world. While not all of them cause disease, here are five the agency lists as "Florida's most wanted": Aedes aegypti, the yellow fever mosquito Larvae are found in water-holding objects found around the home and yard, such as flower vases, tires, toys, bottles, conch shells, cans, refrigerator drain pans, barrels, bromeliad plants, and other containers. Can be found in all of Florida except Panhandle counties. Diseases: Dengue, chikungunya, and Zika viruses. Aedes albopictus, the Asian tiger mosquito Larvae found in water-holding objects found around the home and yard, such as flower vases, tires, toys, bottles, cans, barrels, tree holes, bromeliad plants, and other containers. Found in all Florida counties. Diseases: Dngue, chikungunya, and Zika viruses. Culex quinquefasciatus, southern house mosquito Larvae are found in a variety of aquatic habitats, especially those with high organic content, including catch basins, ditches, containers, dairy lagoons, and others. Found in all Florida counties and are abundant throughout the state. Diseases: Dog heartworm, St. Louis encephalitis virus, West Nile virus. Aedes taeniorhynchus, Black salt marsh mosquito Larvae are found in salt marshes. Found in all Florida counties and are strong fliers that are major pests during summer and early fall. Disease: Dog heartworm. Psorophora ciliata, Gallinipper Larvae are found in ditches, containers, grassy pools, furrows of citrus groves, pasture areas. Found in all Florida counties. Diseases: None none. What attracts mosquitoes? While there's not much we can do about some conditions mosquitoes are attracted to — this is Florida — we should note mosquitoes are drawn to: Damp or humid areas Standing water Warm temperatures Dark, shady areas Carbon dioxide (your breath) Myth or magic? Do mosquito-repelling plants really work? Mosquitoes need standing water to lay their eggs. And they don't need much. Water in a bottle cap can provide an ideal breeding ground. Experts repeatedly encourage residents to empty flower pots, bird baths and any outdoor item that holds standing water — including bromeliads — to stop mosquitoes from breeding. Some residents share ideas to make outdoor living more bearable by selecting mosquito-repelling plants for their landscape, especially citronella and lavendar. But do they really work? 'Certain plants do contain mosquito-repelling compounds,' says Liah Continentino, environmental horticulture agent with University of Florida/IFAS Extension Monroe County. 'But unless you're extracting their oils and applying them like a spray, they're not doing much just sitting in your garden. 'Plants like eucalyptus, citronella, mint, basil, lavender and marigolds have oils that can deter mosquitoes. But the key word is 'oils.' These compounds need to be extracted and used in concentrated forms — like sprays — to be truly effective." In other words, mosquito-repelling plants are more myth than magic — at least when it comes to passive protection, UF said in a news release. So what can Florida residents do to minimize mosquitoes? Don't give up when it comes to enjoy Florida outdoor living. There are some things you can do and some do involve plants. Here are a few ideas: Reduce mosquito habitats 'This includes regularly emptying plant saucers, bird baths, pet water bowls and bromeliads, as well as any other water-holding plants. Refreshing bird baths and pet bowls with clean water several times a week and flushing bromeliad cups with a hose can help prevent larvae from developing,' said Jennifer Pelham, UF/IFAS urban horticulture agent and director of UF/IFAS Extension Martin County. Use plants in your landscape to attract mosquito predators "For dragonflies, which are highly effective mosquito hunters, they are drawn to native aquatic plants. For birds, include shrubs and trees that supply food, shelter and nesting areas,' said Lorna Bravo, urban horticulture agent with UF/IFAS Extension Broward County. Use fish to control larvae For water features that are permanent, such as ornamental ponds, UF/IFAS recommends adding mosquito-eating fish like Gambusia to naturally control larvae. Cover rain barrels with screens and refresh pet water bowls daily to prevent mosquito access. Encourage mosquito predators in your yard, including fish, dragonflies, fronts, birds and bats. What are the best mosquito repellents to use? According to the CDC, repellents with the following active ingredients "typically provide reasonably long-lasting protection": DEET Picaridin Oil of Lemon Eucalyptus or PMD "Products containing oil of lemon eucalyptus specifies that they should not to be used on children under the age of 3." IR3535 2-undecanone "Certain products containing permethrin are recommended for use on clothing, shoes, bed nets, and camping gear, and are registered with EPA for this use." Items that don't work to repel mosquitoes "There are many gimmicks for sale that do not work, so be an educated consumer and don't waste your money on impulse buys," the Florida Department of Health said. Some items that are not effective for reducing mosquitoes include: Mosquito plants Bug zappers Consumption of garlic, vitamin B, and bananas Repellent bracelets and wristbands Ultrasonic devices and cell phone apps Dragonfly mimics This article originally appeared on Florida Today: World's deadliest animal are mosquitos. 80 types in Florida Solve the daily Crossword


San Francisco Chronicle
2 days ago
- San Francisco Chronicle
Could chikungunya virus spread in the Bay Area? Here's what to know
An outbreak of chikungunya virus this summer has sickened more than 7,000 people in southern China, particularly in the city of Foshan. The virus is spread by Aedes aegypti and Aedes albopictus mosquitoes, which also transmit dengue and Zika viruses. These invasive mosquitos have expanded worldwide, including to California. Experts say that there's a low chance of chikungunya-infected mosquitoes spreading the virus to people in California, also known as local transmission. But it's not impossible — especially as climate change makes more of the state amenable to Aedes aegypti and Aedes albopictus. 'Global warming has enabled the spread of both of these mosquito species into new areas,' said Lark Coffey, a professor of pathology, microbiology and immunology at UC Davis, by email. Chikungunya virus typically causes mild symptoms, including fever and joint pain. But in some cases, this joint pain can be severe and persist for months. Through July, the European Centre for Disease Prevention and Control reported approximately 240,000 chikungunya cases and 90 chikungunya-related deaths worldwide in 2025. The virus' most likely path into California is via an infected traveler returning from an area with chikungunya virus transmission, Coffey said. U.S. health officials have issued a travel health notice for parts of China due to the chikungunya outbreak. All previously reported cases of chikungunya in California, including two this year as of July 1, have been associated with travel. But that hasn't been the case for dengue virus, which is spread by the same mosquitos. 'We have seen local transmission of dengue in California in the last couple years. Which, to me, implies that there's no reason we couldn't also have local transmission of chikungunya,' said Erin Mordecai, an associate professor of biology at Stanford University and a senior fellow in the Woods Institute of the Environment. 'The more chikugunya cases there are, the more likely it is.' Local transmission would involve multiple steps: an Aedes aegypti or Aedes albopictus mosquito biting a chikungunya-infected person, chikungunya virus incubating in the insect and then the mosquito going out and biting more people. The Bay Area may generally be a little too cool for transmission to readily occur. 'Temperature affects the entire life cycle of the mosquito and the virus,' Mordecai said. The cases of local dengue transmission occurred in the warmer climes of Southern California in 2023 and 2024. But climate change has made California warmer, and scientists expect the state to continue getting even warmer in the future. 'We expect mosquito development to increase (and) mosquito survival to increase,' said Lisa Couper, a disease ecologist and postdoctoral research fellow at UC Berkeley. An additional consideration is urbanization, as Aedes aegypti is 'really well-adapted to urban systems,' said Andy MacDonald, a disease ecologist and assistant professor in UC Santa Barbara's Bren School of Environmental Science and Management. 'It prefers breeding in, say, a small amount of water and some trash that's been discarded on the street.' In ongoing work, Couper and MacDonald have found that climate warming and urban expansion have increased the risk of local dengue transmission in California. 'We would expect these same factors to promote the suitability of chikugunya transmission,' Couper said. In the Bay Area, Aedes aegypti mosquitoes are present in Santa Clara and Solano counties. 'While there have been no local transmissions of chikungunya occurring in (Santa Clara) County as of now, the possibility remains, which is why we ask for the public's help in stopping this mosquito from spreading,' said Taylor Kelly, scientific technical services manager with the Santa Clara County Mosquito and Vector Control District, by email. That includes reporting black and white striped mosquitos, as well as mosquito bites that occur during the daytime. Experts also recommend using mosquito repellent and dumping standing water.
Yahoo
3 days ago
- Yahoo
Bangladesh dengue deaths top 100, August could be worse
Bangladesh dengue deaths top 100, August could be worse DHAKA (Reuters) -Bangladesh is experiencing a surge in dengue cases and deaths, with health experts warning that August could bring an even more severe outbreak of the mosquito-borne disease if urgent action is not taken. Dengue has killed 101 people and infected 24,183 so far this year, official data showed, placing a severe strain on the country's already overstretched healthcare system. A sharp rise in fatalities has accompanied the spike in cases. Nineteen people have already died of dengue so far in August, following 41 deaths in July — more than double June's 19 fatalities. "The situation is critical. The virus is already widespread across the country, and without aggressive intervention, hospitals will be overwhelmed," said Kabirul Bashar, an entomologist at Jahangirnagar University. "August could see at least three times as many cases as July, with numbers potentially peaking in September." Health officials are urging people to use mosquito repellents, sleep under nets, and eliminate stagnant water where mosquitoes breed. "We need coordinated spraying and community clean-up drives, especially in high-risk zones," Bashar said. Experts say climate change, along with warm, humid weather and intermittent rain, has created ideal breeding conditions for Aedes mosquitoes, the carriers of the dengue virus. While Dhaka remains a major hotspot, dengue is peaking across the country. Large numbers of infections are being reported from outside the capital, adding pressure to rural healthcare facilities with limited capacity to treat severe cases. Doctors warn that early medical attention is critical. Severe abdominal pain, vomiting, bleeding, or extreme fatigue should prompt immediate hospital visits to reduce the risk of complications or death. With the peak dengue season still ahead, health experts have stressed that community participation, alongside government-led mosquito control, will be critical in preventing what could become one of Bangladesh's worst outbreaks in years. The deadliest year on record was 2023, with 1,705 deaths and more than 321,000 infections reported.