April 7 is World Health Day, and the topic for 2014 is vector-borne diseases. The two most common vector–borne diseases in Anguilla are dengue and chikungunya. There is much concern in Anguilla at this time concerning chikungunya, so this article will focus on this disease.
What is chikungunya disease?
Chikungunya is a mosquito-borne viral disease first described during an outbreak in southern Tanzania in 1952. It is an RNA virus. The name ‘chikungunya’ derives from a word, in the Kimakonde Language, meaning “to become contorted”, and describes the stooped appearance of sufferers with joint pain (arthralgia).
Since 2004, chikungunya fever has reached epidemic proportions with considerable morbidity and suffering. In 2014, health officials in Anguilla have confirmed cases of the disease on the island. Chikungunya disease has also been confirmed in surrounding islands which include: St Martin /St Maarten, British Virgin Islands, Dominica, French Guiana, Guadeloupe, Martinique and St Barthelemy.
How do you get chikungunya disease?
The virus is transmitted from human to human by the bites of infected female mosquitoes. Most commonly, the mosquitoes involved are Aedes aegypti and Aedes albopictus, two species which can also transmit other mosquito-borne viruses, including dengue. These mosquitoes can be found biting throughout daylight hours, though there may be peaks of activity in the early morning and late afternoon. Aedes aegypti is very common in Anguilla.
After the bite of an infected mosquito, onset of illness occurs usually between four and eight days but can range from two to 12 days.
What are the symptoms and signs of chikungunya?
The vast majority of individuals suffering from this disease experience an abrupt onset of fever frequently accompanied by joint pain. Other common signs and symptoms include the following:
• muscle pain
• headache
• nausea
• fatigue
• rash
The joint pain is often very debilitating, but usually lasts for a few days or may be prolonged to weeks.
Most patients recover fully, but in some cases joint pain may persist for several months, or even years. Serious complications are not common. Often symptoms in infected individuals are mild and the infection may go unrecognized.
How is the diagnosis made?
If you have symptoms or signs of chikungunya disease you should seek medical attention. The diagnosis can be confirmed by special tests. The results of some of these tests usually take several days.
How is chikungunya treated?
There is no specific antiviral drug treatment for chikungunya. Treatment is directed primarily at relieving the symptoms, including the joint pain, using anti-pyretics, optimal analgesics and fluids. There is no commercial chikungunya vaccine.
Prevention and control
Prevention and control rely heavily on reducing the number of natural and artificial water-filled container habitats that support the breeding of the mosquitoes. This requires mobilization of affected communities. During outbreaks, insecticides may be sprayed to kill flying mosquitoes, applied to surfaces in and around containers where the mosquitoes land, and used to treat water in containers to kill the immature larvae.
For protection during outbreaks of chikungunya, clothing which minimizes skin exposure to the day-biting vectors is advised. Repellents can be applied to exposed skin or to clothing in strict accordance with product label instructions.
The community has a vital role to play in the prevention and control of this disease. The large number of derelict vehicles and other sources for breeding mosquitoes on the island are a cause for concern. Other breeding sites for mosquitoes include: tree holes and rock pools, in addition to artificial containers such as vehicle tyres, pots and pans, discarded cans, and saucers beneath plant pots.
We can do more as a community to decrease the breeding sites for mosquitoes which can result in preventing and or controlling both chikungunya and dengue disease in Anguilla.
Conclusion
Chikungunya is a viral disease transmitted to humans by infected mosquitoes. It causes fever and severe joint pain and many other symptoms. There is no cure for the disease and treatment is focused on relieving the symptoms. Preventing and controlling the vector that transmits the virus that causes chikungunya are crucial at this time. We must do more to decrease the breeding sites for these mosquitoes. There is no doubt that vector-borne diseases, such as dengue and chikungunya, are one of the greatest contributors to human mortality and morbidity in many countries, including Anguilla.
Ask Your Doctor is a health education column and is not a substitute for medical advice from your physician. The reader should consult his or her physician for specific information concerning specific medical conditions. While all reasonable efforts have been made to ensure that all information presented is accurate, as research and development in the medical field are ongoing, it is possible that new findings may supersede some data presented.
Dr Brett Hodge is an Obstetrician/Gynaecologist and Family Doctor who has over thirty years in clinical practice. Dr Hodge has a medical practice in The Johnson Building in The Valley (Tel: 264 4975828).
