Oropouche Fever

What is Oropouche Fever?

Oropouche Fever is an infectious disease caused by the Oropouche virus. The virus is common in Central and South America and causes large and explosive disease outbreaks. The virus was first isolated in 1955 and since that time there have been more than 30 major outbreaks, with more than half a million reported cases. The disease has similar symptoms to other common viruses (Dengue, Zika, and Chikungunya) so the precise number of infected people is difficult to determine. The virus is named after the Oropouche River in Trinidad and Tobago where it was first discovered.

How do you get Oropouche Fever?

The virus is transmitted through mosquito, tick and midge bites. When these insects become infected with the virus, the virus can be transmitted to animals (sloths, marsupials, primates, birds) and humans through the insect bite. Transmission to humans is primarily by the bite of the midge. The bite of the midge carrying Oropouche virus feels like a sharp prick and an irritation or lump may appear and last for a few hours or days.

No human to human transmission of this virus has been reported.

Susceptibility and Resistance

Oropouche Fever occurs most commonly during the rainy season when breeding sites for the insect hosts (stagnant water, marshes, decomposing vegetation etc.) are most widespread. The insect typically bites at dawn and dusk.

Deforestation and climate change may increase the spread of the virus by providing more reservoirs in which the insect host can breed, increasing the incidence of Oropouche Fever.

Incubation Period

The incubation period for Oropouche Fever is 4-8 days.

What are the Symptoms?

Symptoms of Oropouche Fever include the rapid onset of a high fever, headaches, muscle and joint pain, vomiting, dizziness, diarrhea, chills, sensitivity to light and weight loss. Although less common, a rash (similar in appearance to rubella), eye irritation and pain in the upper abdomen can occur. Meningitis-like symptoms may also occur.

Preventative Measures

Avoiding contact with infected midges, especially during the rainy season, is the primary preventative measure. Avoid insect breeding sites (swamps, stagnant water, marshes, decomposing vegetation etc.). Remove breeding sites (water filled habitats) if possible, use insect repellent containing 20 percent or more of DEET, wear protective clothing to cover exposed skin, use screens and bed nets and use insecticide to kill midge populations.

No vaccine is available.

Treatment

The patient should seek medical attention when he/she suspects that he/she has been in contact with an insect carrying the virus. The disease is identified by isolating antibodies to the virus in the blood of the infected individual. There is no specific treatment for Oropouche Fever, however, early contact with medical services and proper care for the patient’s symptoms (specifically pain management) are recommended. Most infected individuals recover after a few days.

Where Does It Commonly Occur?

Oropouche Fever is spread by the animals and insects that are hosts and vectors to the virus, therefore, the disease can be found wherever there are infected hosts. Outbreaks of the disease have been limited to Central and South America, with outbreaks reported in Brazil, Ecuador, Panama, Venezuela, Peru, and Trinidad and Tobago. The disease has been reported in both rural and urban environments and is endemic in many regions of the Amazon Rainforest.

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