Chikungunya fever

From Ganfyd

(Redirected from Chickungunya fever)
Jump to: navigation, search

Another tropical mosquito-borne virus with no immunisation or cure: avoid bites

Chikungunya virus (CHIKV) is most commonly transmitted to humans through the bite of an infected mosquito, specifically mosquitoes of the Aedes genus, which usually bite during daylight hours.

Symptoms of infection, which generally come on three to seven days after being bitten, include the sudden onset of fever, chills, headache, nausea, vomiting, severe joint pain (arthralgias) and rash. Some symptoms typically last several weeks.

The illness is usually self limiting. Although rare, the infection can result in meningoencephalitis, especially in newborns and those with pre-existing medical conditions. Pregnant women can pass the virus to their fetus. Residual arthritis, with morning stiffness, swelling, and pain on movement, may persist for weeks or months after recovery. Severe cases of Chikungunya can occur in the elderly, in the very young (newborns), and in those who are immunocompromised. Chikungunya outbreaks typically result in several hundreds or thousands of cases but deaths are rarely encountered.

Chikungunya virus is most likely of African origin, though outbreaks occurred in the Americas in the 19th century.[1]

Recent outbreaks have occurred in islands in the Indian Ocean, Sub-Saharan Africa, India, South-east Asia, and the Philippines. A 2007 outbreak occurred in the the province of Ravenna in the Emilia-Romagna region of north-east Italy.[2][3]

Contents

Prevention

Vector control

There is no vaccine that protects against chikungunya virus.

Using protective measures to prevent being bitten by an infected mosquito is currently the only means available to an individual to reduce the risk of exposure.

The usual public health measures such as minimising open water are going to have to be revisited for a number of insect vectors that are extending their range very successfully including Aedes albopictus the vector of the recent outbreak strains.

Preventive treatments including vaccination

Potential preventive treatments include vaccination and the use of monoclonal antibodies.

Various approaches to vaccine development are being pursued (and similar approaches might work for other related viruses).[4][5]

Treatment

LogoKeyPointsBox.png

Usually self-limiting.

Treatment for chikungunya typically involves treating the symptoms and includes bed-rest, fluids and the use of non-aspirin analgesics during the phase of illness where the symptoms are most severe. Avoiding confusing it with early Rheumatoid arthritis and treating it with immunosupressives medicines is desirable.[6]

As a relatively recently emerged pathogen it is the subject of much research.[7]

Aetiology

The latest outbreak has been associated with:

  1. Genetic mutation of the viral genome[8]
  2. Aedes albopictus which worryingly has internationalised its distribution since 1980
    • Formerly found in Indian Ocean around southern Eastern Africa and Madagascar, South East Asia in a belt from India through Burma to Philippines and Borneo and in Japan and Manchuria
    • Now through out North Americia, Central Americia, much of South Americia, Southern Europe, Equatorial West Africa, China and Mongolia, Australia and New Guinea.

Epidemiology

Essentially now worldwide, with outbreaks in Brazil, Caribbean and Polynesia as of 2014. It started in Africa and is now endemic in the Indic ocean basin, the Indian subcontinent and the southeast of Asia. Outbreaks have occurred in Southern Europe. Its high attack rate and morbidity, despite low mortality can stretch any healthcare system.

A catch is that because of cross reactivity on immunology O’nyong-nyong virus, less likely to be tested for in travellers, may be missed.

References

This article is a work in progress. Please feel free to contribute to it.