Organism

Oropouche fever is caused by an oropouche virus. This virus occurs in Panama and South America, and usually affects animals in forested areas, with humans being an accidental victim. Humans become infected when they enter forested areas, and indeed the infection was first recognised after an outbreak of feverish illness in workers building a new road through the jungle in Brazil.

Mode of Transmission

The virus is transmitted through the bite of a midge. It has the potential to cause explosive urban epidemics when midges spread from the forest to urban areas, particularly in the rainy season.

Regions Affected

As mentioned above, oropouche fever is found exclusively in South America and Panama.

Prevention

Infection can be prevented at an individual level by the use of insect repellents and mosquito nets. On a population level, outbreaks can be prevented by control of the insect vector, using insecticides, eliminating pools of stagnant water where midges may breed and avoiding excessive traffic between urban and forested areas.

Immunisation

None available.

Symptoms and Signs

Oropouche fever is an abrupt onset fever with chills, headache, muscle and joint pains and vomiting. Patients may develop symptoms of meningitis. In most cases the illness is self-limiting, although a minority of patients may have prolonged weakness and joint aches.

Tests

The infection can be diagnosed by detecting a specific antibody response to the virus. Antibody tests may be non-specific and fail to distinguish between similar viruses that may also cause fever in meningitis.

Treatment

There is no specific treatment, although agents to reduce symptoms such as Paracetamol and anti-inflammatory tablets may be used.

Complications and Outcome

This infection is usually self-limiting and complications are rare. Patients usually recover fully with no long term ill effects.