French authorities in the Var department of Provence announced a case of Chikungunya fever in the town of Fréjus in late September 2010.
A 12 year old child had been bitten, locally, by a tiger mosquito and had been infected with the arbovirus Chikungunya. The child was being treated at his home.
The key word there is ‘locally’. French residents and others entering France from Africa or Asia find themselves infected with Chikungunya from time to time after being bitten abroad. But the Préfet of the Var, Hugues Parant, was informed that this case was autochtone – native to France.
The regional health agency in Provence, the Agence Régionale de Santé (ARS) de Provence Alpes Côte d’Azur confirmed that the child had been infected here in the south of France, not overseas.
The agency immediately took measures to try and eradicate the tiger mosquitoes which must be carrying the virus. They first made an assessment of the possible scale of the mosquitoes’ presence by investigating places recently visited by the child and then used insecticide in areas he’d frequented. Health professionals were alerted to be on the lookout for patients exhibiting possible symptoms of Chikungunya fever. Their efforts will not only treat potential patients effectively but help to trace the possible wider spread of the mosquitoes and eradicate them.
French authorities were aware during summer 2010 that the tiger mosquito aedes albopictus was present in the three Provence-Alpes-Côte d’Azur départements of Alpes-Maritimes, Var et Bouches-du-Rhône. Special vigilance was applied to the areas as it’s well known that aedes albopictus can transmit Chikungunya as well as Dengue fever. Two locally transmitted cases of Dengue fever were diagnosed in Nice (Alpes-Maritimes) earlier in September.
Chikungunya (or CHIKV) and Dengue fever present with similar symptoms: high fever up to 104°, aching, joint pain, rash and severe headache. The name Chikungunya is from the African Makonde language and means to lean downward or to be hunched. Then name relects the posture of patients suffering from joint pain. CHIKV fever lasts from two to five days and can be severe. The fever is followed by a joint pain (without swelling) which may last for weeks or months. Some badly infected patients have been known to suffer joint pain for years after infection with CHIKV.
There is currently no vaccine commercially available to protect against Chikungunya infection. In 2000, the US government paid for a vaccine trial which used live attenuated virus. (Attenuated viruses have been treated to reduce their virulence.) The results, written up for the American Journal of Tropical Medicine and Hygiene, showed that the trial vaccine gave protection to 85% of particpants in the study for at least a year. Nevertheless, CHIKV continues to infect people, mostly in Africa and Asia.
Differential diagnosis is important in order to treat CHIKV effectively. Symptoms can be mistaken for flu symptoms. In fact, many of the treatments which may be offered to patients with flu for fever, aches and joint pains are not suitable or effective for CHIKV sufferers. Anti-inflammatories such as aspirin, ibuprofen, naproxen and other non-steroidal anti-inflammatory drugs (NSAIDs) should not be given.
Chloroquine is winning approval as a treatment for Chikungunya symptoms. A University of Malaya study established that chloroquine was effective against arthralgic pain caused by CHIKV and not relieved by aspirin and other NSAIDs non-steroidal anti-inflammatory drugs (NSAIDs).
The French government and health authorities are bound to put serious effort into mapping, controlling and eradicating tiger mosquitoes in Provence. The local population, heavily dependent on tourism for their livelihoods, face a double threat from the infectious insects. Their physical and their financial health would suffer if the mosquito were allowed to spread, bringing infection to the south of France and driving wealthy tourists to spend their vacations in other destinations.
French authorities, in my experience, are pretty organised and pretty intelligent. They’re likely to respond to the mosquito problem in the south of France with a high degree of diligence, professionalism and expertise.
**Chikungunya virus was one of numerous infective agents that the United States researched as potential biological weapons in the post-World War II period.**