{"id":19612,"date":"2025-03-19T08:00:50","date_gmt":"2025-03-19T08:00:50","guid":{"rendered":"https:\/\/interhospi.com\/?p=19612"},"modified":"2025-04-02T10:24:21","modified_gmt":"2025-04-02T10:24:21","slug":"oropouche-virus-warning-as-threat-spreads-beyond-the-amazon","status":"publish","type":"post","link":"https:\/\/interhospi.com\/oropouche-virus-warning-as-threat-spreads-beyond-the-amazon\/","title":{"rendered":"Oropouche virus: warning as threat spreads beyond the Amazon"},"content":{"rendered":"
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Oropouche virus: warning as threat spreads beyond the Amazon<\/h1>Oropouche<\/a><\/span>, virology<\/a><\/span>, Arboviral Disease<\/a>, Climate Change<\/a>, Editors' Picks<\/a>, Featured Articles<\/a> <\/span><\/span><\/header>\n<\/div><\/section>
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As global health authorities tackle with a host of established infectious disease threats, a previously obscure virus is steadily expanding its reach beyond its traditional Amazonian stronghold. Oropouche virus, first identified in Trinidad and Tobago in 1955, has emerged as a significant public health concern across South America and the Caribbean, with recent outbreaks reported in Bolivia, Brazil, Peru, and Cuba, including cases among travellers returning to Canada and the United States. Callan Emery<\/em> reports.<\/strong><\/p>\n

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The current situation<\/strong><\/h2>\n

Since late 2023, Oropouche virus disease has experienced a notable geographic expansion. According to the Pan American Health Organization (PAHO), between January and August 2024, more than 8,000 cases were reported across Peru, Brazil, Colombia, Bolivia, and Cuba. Some areas are seeing the virus for the first time, indicating a troubling pattern of spread.<\/p>\n

Brazil has been particularly affected, with 7,284 confirmed cases reported between January and July 2024, with the Amazon region accounting for 75.7% of these cases. Six states reported cases, while ten non-Amazonian states, including Bah\u00eda, Esp\u00edrito Santo, Santa Catarina, Pernambuco, and others, reported autochthonous transmission for the first time.<\/p>\n

\"Culicoides

Culicoides paraensis<\/em> – biting midge that can cause Oropouche infection<\/p><\/div>\n

The virus has also established a foothold in Bolivia (356 confirmed cases), Colombia (74 cases), Peru (290 cases), and Cuba, where health authorities declared the first Oropouche viral illness epidemic in May 2024 with 74 confirmed cases across two provinces.<\/p>\n

Of particular concern, Brazil reported two deaths in Bahia involving females aged 21 and 24\u2014the first documented fatalities in Brazil and the Americas caused by acute Oropouche virus infection. The patients experienced severe coagulopathy and liver involvement, which were determined to be the likely causes of their rapid deterioration.<\/p>\n

Why is it spreading now?<\/strong><\/h3>\n

The increased spread of Oropouche virus is linked to a convergence of environmental and human factors. Climate change has intensified rainfall and temperatures, which has expanded the habitats of the virus\u2019s vectors\u2014biting midges (Culicoides paraensis) and certain mosquito species including Culex quinquefasciatus.<\/p>\n

Meanwhile, human activities are reshaping the landscape of transmission. Deforestation and urbanisation have altered the natural habitats of vectors and hosts, creating new opportunities for interaction between them and humans, increasing the risk of spillover and transmission. As Okesanya et al. (2025) note in their comprehensive review, \u201cThese same characteristics have a significant impact on the habitats of the reservoir hosts, driving them to proximate areas of peri-urban and urban areas where the vectors are abundant.\u201d<\/p>\n

Construction projects, particularly in the Amazon region, have historically been associated with Oropouche outbreaks. A notable example occurred in 1961 when approximately 11,000 human cases were documented in Bel\u00e9m City, Brazil, coinciding with the construction of the Bel\u00e9m-Bras\u00edlia highway. The construction likely increased workers\u2019 exposure to infected vectors.<\/p>\n

Additionally, air travel has become a significant factor in the virus\u2019s spread. The prompt movement of individuals across regions with active virus circulation allows Oropouche to be transported to non-endemic areas, where it can potentially establish new transmission cycles if suitable vectors are present.<\/p>\n

The danger it poses<\/strong><\/h3>\n

While most Oropouche infections result in mild, self-limiting disease, several concerning developments warrant attention from public health officials and clinicians.<\/p>\n

The most alarming recent finding is the potential link between Oropouche virus infection during pregnancy and adverse outcomes including foetal death and congenital abnormalities. According to a PAHO Public Health Risk Assessment from August 2024, in Brazil, one foetal death and one miscarriage were reported in Pernambuco, as well as four cases of newborns with microcephaly possibly linked to Oropouche virus.<\/p>\n

These complications mirror those observed in Zika virus infections, which caused widespread concern during previous outbreaks. Das Neves Martins et al. (2024) documented newborns with microcephaly in Brazil with potential vertical transmission of Oropouche virus, reinforcing the need for enhanced surveillance and protective measures for pregnant women.<\/p>\n

Additionally, neurological complications, although rare, have been documented. The virus has been detected in the cerebrospinal fluid of patients, and some have developed aseptic meningitis. There have also been cases of Guillain-Barr\u00e9 syndrome potentially associated with Oropouche infection under investigation.<\/p>\n

The fatalities reported in Brazil highlight another concerning aspect of Oropouche virus disease\u2014its potential to cause severe coagulopathy and liver involvement in some patients. While such severe manifestations appear to be rare, they demonstrate that the virus can occasionally cause life-threatening illness.<\/p>\n

From a public health perspective, the emergence of Oropouche virus in new geographic areas poses significant challenges. Healthcare systems in affected regions, particularly those already struggling with other endemic diseases like dengue, malaria, and Zika, face additional burdens. The similar clinical presentation of these diseases complicates diagnosis and may lead to misdiagnosis or underreporting of Oropouche cases.<\/p>\n

What can be done to stop it?<\/strong><\/h3>\n

Controlling the spread of Oropouche virus requires a multifaceted approach targeting both the vector and human exposure. Vector control measures remain a cornerstone of prevention efforts:<\/p>\n

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  1. Enhanced entomological surveillance<\/strong>: Strengthening monitoring of biting midge and mosquito populations can help identify areas at high risk for transmission.<\/li>\n
  2. Habitat modification<\/strong>: Reducing breeding sites for Culicoides paraensis by eliminating or treating organic debris, banana stems, and other decaying plant material can help control vector populations.<\/li>\n
  3. Targeted insecticide application<\/strong>: Strategic use of insecticides in areas with high vector density can reduce transmission risk.<\/li>\n<\/ol>\n

    Personal protective measures are equally important, particularly for individuals living in or travelling to affected areas:<\/p>\n

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    1. Use of fine-mesh mosquito nets<\/strong> on doors and windows to prevent entry of biting midges and mosquitoes.<\/li>\n
    2. Protective clothing<\/strong> that covers arms and legs, especially during peak biting times.<\/li>\n
    3. Application of effective repellents<\/strong> containing DEET or icaridin, and use of bed nets while sleeping.<\/li>\n<\/ol>\n

      For pregnant women or those planning pregnancy, the Public Health Agency of Canada recommends considering deferring travel to areas experiencing Oropouche outbreaks. If travel cannot be avoided, strict adherence to protective measures is essential.<\/p>\n

      Health systems strengthening is also crucial for responding effectively to Oropouche outbreaks:<\/p>\n

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      1. Enhanced surveillance systems<\/strong> to detect cases early and monitor the geographic spread of the virus.<\/li>\n
      2. Improved diagnostic capacity<\/strong>, including wider availability of polymerase chain reaction (PCR) testing for Oropouche virus.<\/li>\n
      3. Training of healthcare workers<\/strong> to recognise and appropriately manage Oropouche virus disease.<\/li>\n
      4. Cross-border collaboration<\/strong> to share information and coordinate response efforts.<\/li>\n<\/ol>\n

        Currently, there is no specific antiviral treatment or vaccine for Oropouche virus, highlighting the importance of prevention measures. However, research efforts are underway to develop both therapeutic options and vaccines.<\/p>\n

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        Understanding Oropouche virus disease<\/strong><\/h2>\n

        \u00a0<\/strong><\/p>\n

        Virology and transmission<\/strong><\/h4>\n

        Oropouche virus is an arbovirus of the genus Orthobunyavirus, belonging to the family Peribunyaviridae. The virus maintains both sylvatic (forest) and urban transmission cycles. In the sylvatic cycle, hosts include sloths, non-human primates, and certain birds, with forest mosquitoes like Aedes serratus and Coquillettidia venezuelensis serving as vectors.<\/p>\n

        In the urban cycle, humans are the primary amplifying host, with Culicoides paraensis (biting midges) and Culex quinquefasciatus mosquitoes serving as the main vectors. Biting midges are smaller than mosquitoes and can pass through conventional mosquito nets, requiring fine-mesh nets for effective protection.<\/p>\n

        Vertical (mother-to-child) transmission has recently been documented and is still under investigation, adding another dimension to the virus\u2019s transmission dynamics.<\/p>\n

        Clinical presentation and diagnosis<\/strong><\/h4>\n

        The incubation period for Oropouche virus is typically 3\u201310 days. The disease presents as an acute febrile illness with symptoms similar to other arboviral infections, making clinical diagnosis challenging.<\/p>\n

        Common symptoms include:<\/p>\n