?Chikungunya virus
Virus classification
Group: Group IV ((+)ssRNA) Family: Togaviridae Genus: Alphavirus Species: Chikungunya virus

Chikungunya is a relatively rare form of viral fever caused by an alphavirus that is spread by mosquito bites from the Aedes aegypti mosquito, though recent research by the Pasteur Institute in Paris claims the virus has suffered a mutation that enables it to be transmitted by Aedes Albopictus (Tiger mosquito). This was the cause of the actual plague in the Indian Ocean and a threat to the mediterranean coast at present, requiring urgent meetings of health officcials of France, Italy and Spain, but nothing seems to be moving that way. The name is derived from the Makonde word meaning "that which bends up" in reference to the stooped posture developed as a result of the arthritic symptoms of the disease. The disease was first described by Marion Robinson^[1] and W.H.R. Lumsden^[2] in 1955, following an outbreak on the Makonde Plateau, along the border between Tanganyika and Mozambique, in 1952. Chikungunya is closely related to O'nyong'nyong virus^[3].

Chikungunya is not considered to be fatal. However, in 2005-2006, 200 deaths have been associated with chikungunya on Réunion island and a widespread outbreak in Southern India (especially in Karnataka and Andhra Pradesh); see Recent outbreaks below.

Symptoms

The symptoms of Chikungunya (also called as Chicken Guinea) include fever which can reach 39°C, (102.2 °F) a petechial or maculopapular rash usually involving the limbs and trunk, and arthralgia or arthritis affecting multiple joints which can be debilitating. There can also be headache, conjunctival infection and slight photophobia. In the present epidemic in the state of Andhra Pradesh in India, high fever and crippling joint pain is the prevalent complaint. Fever typically lasts for two days and abruptly comes down, however joint pain, intense headache, insomnia and an extreme degree of prostration lasts for a variable period, usually for about 5 to 7 days.

Dermatological manifestations (data on file) observed in a recent outbreak of Chikungunya fever in Southern India (by Dr.Arun C. Inamadar, Dr.Aparna Palit, Dr. V V Sampagavi, Dr.N S Deshmukh,Dept of Dermatology, BLDEA's SBMP Medical College & Hospital, Bijapur, Karnataka, aruninamadar@rediffmail.com) are as follows: 1. Maculopapular rash 2. Nasal blotchy erythema 3. Freckle-like pigmentation over centro-facial area 4. Flagellate pigmentation on face and extremities 5. Lichenoid eruption and hyperpigmentation in photodistributed areas 6. Multiple aphthous-like ulcers over scrotum,crural areas and axilla. 7. Lympoedema in acral distribution (bilateral /unilateral) 8. Multiple ecchymotic spots (Children) 9. Vesiculobullous lesions (infants) 10. Subungual hemorrhage. Histopathological examination revealed perivascular lymphocytic infiltrate. There is no specific treatment for Chikungunya. The illness is usually self-limiting and will resolve with time. Symptomatic treatment is recommended after excluding other more dangerous diseases. Vaccine trials were carried out in 2000, but funding for the project was discontinued ^[4] and there is no vaccine currently available.

A serological test for Chikungunya is available from the University of Malaya in Kuala Lumpur, Malaysia.

Possible role for chloroquine in the treatment of Chikungunya: There is an interesting dialogue, mostly in French, about the possible use of chloroquine in the treatment of the arthralgia associated with Chikungunya.

1. A paper published in South Africa in 1984 concerning 10 cases of Chikungunya showed some effect of CQ in treating the symptoms of arthritis. Brighton SW. Chloroquine phosphate treatment of chronic Chikungunya arthritis. An open pilot study. S Afr Med J 1984 Aug 11;66(6):217-8.

The abstract of the paper: "Over 12% of patients who contract Chikungunya virus infection develop chronic joint symptoms. These symptoms respond only partially to the non-steroidal anti-inflammatory drugs. An open pilot study on the efficacy of chloroquine phosphate was carried out and 10 patients completed 20 weeks of therapy. Both the Ritchie articular index and morning stiffness improved significantly. In the patient's assessment, 7 out of 10 considered their conditions to have improved. On the basis of the doctor's assessment, 5 of the 10 had improved. These results justify further controlled blind trials of chloroquine in chronic Chikungunya arthritis."

2. From the University of Malaya: http://www.vadscorner.com/alphaviruses.html

"Treatment [of Chikungunya]:

Supportive care with rest is indicated during the acute joint symptoms. Movement and mild exercise tend to improve stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms. In unresolved arthritis refractory to aspirin and nonsteroidal antiinflammatory drugs, chloroquine phosphate (250 mg/day) has given promising results."

3. From the French government (in French): http://agmed.sante.gouv.fr/pdf/10/chicungu.pdf

"Dans le cadre de l'enquête mise en place pour identifier les molécules actives contre le virus du Chikungunya, des essais ont été réalisés en laboratoire sur des cultures cellulaires in vitro et ont montré une activité antivirale de la chloroquine (Nivaquine®) sur ce virus. L'Agence française de sécurité sanitaire des produits de santé (Afssaps) relève qu'il s'agit de tests préliminaires et qu'à ce stade, aucune donnée d'efficacité et de sécurité n'est disponible chez l'homme.

Dans ce contexte, l'Agence rappelle les indications et les conditions d'un bon usage de la Nivaquine®. La Nivaquine® est indiquée principalement dans le traitement préventif et curatif du paludisme. Elle aussi utilisée dans le traitement des symptômes de la polyarthrite rhumatoïde et dans le traitement du lupus. L'utilisation de ce médicament nécessite une prescription médicale."

Rough translation: "In the context of the search for molecules with activity against the Chikungunya virus, lab tests on cell cultures in vitro have shown that chloroquine (NivaquineR) has some antiviral activity against this virus. The French Agency of Health and Medicines Safety (AFSSAPS) points out that this involves preliminary tests and that at this stage, no information on the efficacy or safety in humans is available. In this context, the Agency reiterates the conditions of proper usage of Nivaquine (CQ ). Nivaquine/ CQ is indicated primarily for the prevention and treatment of malaria. It is also used in the symptoms of rheumatoid polyarthritis and of lupus. The use of this medication requires a prescription". (The rest of the statement reminds users of the hazards of over dosage with chloroquine, etc.)

Following a recent outbreak (2006) of the disease in Southern India, several homeopathy practitioners in the region have been handing out medicine that is supposed to prevent the disease. However, there have been no scientific studies to confirm the effectiveness of homeopathy against Chikungunya.

Epidemiology

Chikungunya was first described in Tanzania, Africa in 1952. An outbreak of chikungunya was discovered in Port Klang in Malaysia in 1999 affecting 27 people.

Recent outbreaks

In February 2005, an outbreak was recorded on the French island of Réunion in the Indian Ocean. As of May 18, 2006, 258,000 residents have been hit by the virus in the past year (out of a population of about 777,000). 219 official deaths have been associated with Chikungunya.

In neighboring Mauritius, 3,500 islanders have been hit in 2005 . There have also been cases in Madagascar, Mayotte and the Seychelles.

In 2006, there was a big outbreak in the Andhra Pradesh state in India. The initial cases were reported from Hyderabad and Secunderabad as well as from Anantpur district as early as November and December 2005 and is continue unabated.In Hyderabad alone an average practioner sees any where between 10 to 20 cases every day. Some deaths have been reported but it was thought to be due mainly to the inappropriate use of antibiotics and anti inflammatory tablets. The major cause of morbidity is due to severe dehydration, electrolyte imbalance and loss of glycemic control. Recovery is the rule except for about 3 to 5% incidence of prolonged arthritis. As this virus can cause thrombocytopenia, injudicious use of these drugs can cause erosions in the gastric epithelium leading to exsanguinating upper GI bleed (due to thrombocytopenia). Also the use of steroids for the control of joint pains and inflammation is dangerous and completely unwarranted. On average there are around 5,300 cases being treated everyday. This figure is only from public sector. The figures from the private sector combined would be much higher.

There have been reports of large scale outbreak of this virus in Southern India. At least 80,000 people in Gulbarga, Tumkur, Bidar, Raichur, Bellary, Chitradurga, Davanagere, Kolar and Bijapur districts in Karnataka state are known to have been affected since December 2005.

A separate outbreak of Chikungunya fever was reported from Malegaon town in Nasik district, Maharashtra state, in the first two weeks of March 2006, resulting in over 2000 cases. In Orissa state, amost 5000 cases of fever with muscle aches and headache were reported between February 27 and March 5, 2006 .

In Bangalore, the state capital of Karnataka (India), there seems to be an outbreak of Chikungunya now (May 2006) with arthralgia/arthritis and rashes. So also in the neighbouring state of Andhra Pradesh. In the 3rd week of May 2006 the outbreak of Chikungunya in North Karnataka was severe. All the North Karnataka districts specially Gulbarga, Koppal, Bellary, Gadag, Dharwad were affected. The people of this region are hence requested to be alert. Stagnation of water which provides fertile breeding grounds for the vector (Aedes aegypti) should be avoided. The latest outbreak is in Tamil Nadu, India - 20,000 cases have been reported in June 2006. Earlier it was found spreading mostly in the outskirts of Bangalore, but now it has started spreading in the city also (Updated 30/06/2006). More that 300,000 people are affected in Karnataka as of July 2006.

Reported on 29/06/2006, Chennai - fresh cases of this disease has been reported in local hospitals. A heavy effect has been reflected in south TN districts like Kanyakumari and Tirunelveli. Residents of Chennai are warned against the painful disease.

As of July 2006, nearly 50,000 people were affected in Salem, Tamil Nadu .

As of August 2006, nearly 1 lakh people were affected in Tamil Nadu. Chennai, capital of Tamil Nadu is one of the worst affected.

As of July 24, There are several cases of Chikungunya have been found in Madhya Pradesh too. The exact number of affected people is unknown.

Analysis of the recent outbreak has suggested that the increased severity of the disease may be due to a change in the genetic sequence, altering the virus' coat protein, which potentially allows it to multiply more easily in mosquito cells.