TAG: GS 3: SCIENCE AND TECHNOLOGY
THE CONTEXT: Brazil has reported the first-ever deaths from Oropouche fever, a mosquito-borne disease with symptoms similar to dengue. Severe cases are rare.
EXPLANATION:
- Two people in the Brazilian state of Bahia were the first people to die from Oropouche fever, the country’s health ministry reported recently.
- There have been no reports in the world’s scientific literature of deaths from the disease, Brazil’s health ministry reported.
Oropouche fever
- Oropouche is common in Latin America and the Caribbean.
- The virus was first detected in Trinidad and Tobago in 1955. But it has been detected in Europe.
- Oropouche virus disease is an arboviral disease caused by the Oropouche virus (OROV), a segmented single-stranded RNA virus that is part of the genus Orthobunyavirus of the Peribunyaviridae family.
- The virus has been found to circulate in Central and South America and the Caribbean.
- OROV can be transmitted to humans primarily through the bite of the Culicoides paraensis midge, found in forested areas and around water bodies, or certain Culex quinquefasciatus mosquitos.
- It is suspected that viral circulation includes both epidemic and sylvatic cycles.
- In the sylvatic cycle, primates, sloths, and perhaps birds are the vertebrate hosts, although a definitive arthropod vector has not been identified.
- In the epidemic cycle, humans are the amplifying host and OROV is transmitted primarily through the bite of the Culicoides paraensis midge.
- To date, there is no evidence of human-to-human OROV transmission.
- Italy reported its first-ever case of Oropouche in June 2024.
- It was also the first case ever to be detected in continental Europe.
How does Oropouche fever spread?
- Oropouche virus disease is transmitted through the bites of infected midges and mosquitos.
- Although the disease has long been circulating in Central and South America and the Caribbean, some countries have seen a sharp rise in diagnosed cases this year.
- The disease is spreading to other countries that have never detected cases of Oropouche fever before.
- On June 11, the WHO reported the first-ever outbreak in Cuba.
- “This is the first detection of the disease [in Cuba], therefore, the population is likely highly susceptible and there is significant risk of additional cases being detected,” the report noted.
Symptoms
- Oropouche fever is caused by the Oropouche virus, which is transmitted most often through the bite of the Culicoides paraensis midge.
- There is no evidence of human-to-human transmission of the disease — to date.
- Symptoms of the disease are similar to dengue and typically start between four and eight days after the bite.
- The onset is sudden, and symptoms usually include fever, headaches, pain, chills, joint stiffness and sometimes nausea and vomiting.
- Most patients recover in about seven days. According to the WHO, severe cases are rare.
- There is no specific vaccine or antiviral treatment available for the disease.
Climate effect on Oropouche
- Oropouche fever is an understudied illness, as the authors of a May 2023 paper published in the journal Infectious Diseases of Poverty noted.
- As a result, the disease’s epidemic potential and areas of likely spread remain “unexplored.”
- Although most cases of Oropouche fever thus far have been linked to tropical climate conditions, the authors noted that the lack of available data makes it difficult to draw precise conclusions.
- For example, some outbreaks have occurred outside the tropical conditions typically associated with transmission events.
- Although much remains unclear about the virus and its spread, the authors also noted that vegetation loss and deforestation appear to be associated with outbreaks of the disease.