Sloth Fever: Everything You Need To Know (image:Pixabay)
A viral disease known as Oropouche virus or “sloth fever,” transmitted through mosquito bites, has been detected in the US. The virus was identified in American tourists returning from Cuba. The Oropouche virus has experienced a significant surge in outbreaks, starting in late 2023, with large-scale occurrences reported in the Amazon basin, as well as in new regions of South America, and in June 2024, Cuba reported confirmed cases of the virus, marking its expansion into new territories.
The World Health Organization (WHO) reported 8,078 Oropouche virus cases between January 1 and July 20, 2024, primarily in Brazil (7,284 cases, including 2 deaths), with additional cases in Bolivia (356), Peru (290), Colombia (74), and Cuba (74).
What Is Oropouche Virus ?
The Oropouche virus is an arboviral disease that is transmitted to both animals and humans through the bites of midges and mosquitoes. Since sloths are among the regular hosts of this virus, it received its colloquial name. It differs from other better-known vector-borne viruses like Dengue, Zika, Yellow Fever or Chikungunya because it is typically transmitted to humans by midges, Culicoides paraensis, rather than by mosquitoes.
What Are The Symptoms Of Oropouche?
The symptoms of the Oropouche virus infection are headache, joint stiffness, pain, and nausea, and in rare cases, it can be fatal, posing a significant risk, especially to pregnant women. Hence, it is difficult to diagnose an Oropouche infection only from symptoms; one needs to have a molecular laboratory diagnosis. A few cases may evolve into more severe forms, with neurological or hemorrhagic manifestations, but most cases are mild and resolve after seven or eight days.
How Long Has This Virus Been Around?
The Oropouche virus has a history spanning over six decades, with its initial discovery in 1955 in Trinidad and Tobago, followed by its detection in Brazil in 1960 through a sloth’s blood sample. Since the 1960s, the virus has caused intermittent outbreaks in humans within the vast Amazon region, which encompasses nine countries in South America, earning it the classification as a re-emerging virus due to its persistent circulation in this endemic region.
How Does The Virus Spread?
The Oropouche virus is primarily transmitted through the bite of infected insects, with the tiny midge species Culicoides paraensis being the main vector, finding its widespread presence across America. Additionally, other insects like the Culex quinquefasciatus and Ochlerotatus serratus mosquitoes may play a role in spreading the virus, although to a lesser extent.
The virus is not transmitted directly from person to person, but once it enters the bloodstream through an insect bite, it can rapidly disseminate throughout the body. It has the ability to cross the blood-brain barrier, allowing it to invade the central nervous system. Notably, the virus tends to concentrate in specific organs, particularly the brain and liver, where it can cause significant harm.
The CDC said it wants clinicians and public health offices to be aware of the virus and to test for suspected cases, and for travelers to protect themselves from insect bites.
The Pan American Health Organization has issued a health alert, recommending that individuals take preventive measures to protect themselves, including applying insect repellents, covering exposed skin, and utilizing fine mesh mosquito nets to minimise the risk of infection. Since there are currently no vaccines or specific treatments available for Oropouche virus, the most effective way to prevent infection is to take measures to avoid being bitten by midges and mosquitoes.
“The rapid spread of the virus across Europe and the US is likely attributed to a combination of factors, including increased international travel, climate change expanding the habitats of disease-carrying insects, and a lack of widespread immunity to this relatively new virus,” Dr Srinivasan told Indian Express.
(Nazwin Basheer has produced this article as part of a Timeline Internship Programme)
