What is sloth fever?Understand the Oropouche Virus

The Oropouche virus—known in some rarified circles for its potential lethality but more familiarly referred to as “sloth fever”—has finally reached the United States, causing great concern about the key facts that Americans ought to know.

The Florida health department announced on Tuesday that there have been 30 confirmed cases of Oropouche fever within the state, all related to travel to Cuba; another travel-related case has been reported in New York.

In an update Tuesday, CDC said at least three of the initial cases reported in the U.S. were hospitalized and the agency is in the process of formulating a strategy for swift detection and response to the virus.

At the beginning of this month, the Centers for Disease Control and Prevention released a health advisory to inform healthcare professionals and public health officials about a rise in the virus.

CDC indicated that from January 1 to August 1, 2024, over 8,000 instances of Oropouche virus disease were documented, which included two fatalities and five cases of vertical transmission linked to fetal death or congenital anomalies.

The countries that reported these cases include Brazil, Bolivia, Peru, Colombia, and Cuba.

The majority of cases have occurred in South America; however, infections are also emerging in regions where they have not previously been observed.

Although the disease has always been perceived to be mild, the agency argues that the need for improved monitoring is emphasized by its geographic spread and more severe cases. Thus CDCs are advising healthcare workers and public health officials to keep their eyes open for any new infections while warning expectant mothers against visiting affected areas.

What is Oropouche virus?

A locality in Trinidad and Tobago, where the virus was first detected in 1955, gave the Oropouche virus its name.

With over 500,000 recorded cases, the illness remains poorly understood, and the Lancet describes it as “an enigma of a threat.”

According to CDC about 60 percent of individuals who get infected experience the following general signs and symptoms: sudden fever, chills, headache, muscle pain as well as arthralgia that may seem similar to dengue and Zika fevers.

Irritation in the eyes, light sensitivity, vomiting, diarrhea, itchy skin, nausea and a feeling of unwellness are among other complications.

She mentioned that the life cycle and transmission dynamics are unclear and that the parasite appears to affect pregnant women.

This underscores the necessity for us to deepen our knowledge.”

How does Oropouche virus spread?

Humans primarily contract the virus through insect bites, especially from biting midges and certain mosquito species. This condition is native to the Amazon basin, transmitted in wooded areas through a cycle involving insects and various hosts.

Infected insects may bite travellers in these regions, who then carry the disease back to more urban areas.

The Pan American Health Organization reports that climate change and deforestation heighten the risk of humans interacting with infected insects.

The ongoing outbreak is expanding swiftly in nations where the virus is already prevalent, as well as in previously unaffected regions.Bolivia, Brazil, Colombia, Cuba, and Peru have documented instances of locally acquired infections.

No local transmission occurs in the U.S., but health officials have detected multiple cases in travellers returning from outbreak areas.

Dr. Erin Staples, a medical epidemiologist from the CDC’s Division of Vector-Borne Diseases, stated that they consider the current risk of ongoing local transmission in the continental United States to be low.

What’s happening now?

Experts say that shifts in the virus’s geographic spread suggest the involvement of new vectors in the transmission cycle. Staples emphasized the need for more information to accurately identify regions vulnerable to this issue.

We’re still learning about this virus, and we will be providing updates as soon as we have them.”

This year, health officials reported the first fatalities from the Oropouche virus, which can also transmit from mother to fetus.

Earlier this year, Brazil documented fatalities involving two young women who were otherwise in good health and not expecting. The Pan American Health Organization is currently investigating a third death involving a middle-aged man.

Some of these severe outcomes may be the result of more virus circulating, Staples said.

She stated, “With the increasing number of infections, we are observing rare and atypical clinical symptoms or fatalities. However, these are matters that the CDC is actively collaborating with our partners to investigate further.”

How can people protect themselves Oropouche virus?

At present there’s no vaccine available to protect against Oropouche virus nor is there an antiviral treatment for it. Laboratory tests can confirm cases but diagnostic laboratories do not offer such tests commercially. Moreover before one can confirm a diagnosis often it is important to rule out more common viruses like dengue. The timing is right therefore for mosquito bite prevention measures.

When mosquito activity peaks at dawn and dusk avoid outdoor activities. Hamilton advises wearing appropriate clothing and using strong mosquito repellent to reduce the risk of insect bites and infection.

The Centers for Disease Control and Prevention (CDC) has issued two travel warnings: The first one advises persons travelling to South America on taking “normal precautions” while the second one urges those visiting Cuba to adopt “enhanced precautions” against insect bite, as well as seeking medical assistance whenever necessary.

Experts advise new mothers to avoid pregnancy now, and the CDC suggests pregnant women consider postponing unnecessary travel to Cuba.