Chikungunya is a mosquito borne virus with a high fever phase lasting two to five days with a longer period of joint pain in the elbows, shoulders or knees. In some cases this pain has been known to persist for years. The threat of this disease has not reached alarming proportions in the U.S. at this time, but has the potential to spread across the country. A treatment for this particular virus has not been found at this time but some medications offer the possibility to reduce symptoms. Drinking fluids and getting plenty of rest are also recommended.
The typical incubation period for chikungunya is two to three days, but has been known to take up to 12 days after being infected before symptoms appear. Once bitten there are a number of symptoms; the first of which is usually a fever with a high temperature of 104 degrees F being common. An arthritis like ache occurs in the joints and sometimes a rash manifests on the body. Other symptoms can include nausea, headaches, conjunctivitis, and oddly enough a loss of taste. Inflammation of the eye may also occur with a sensitivity to light. An obscure swelling of the legs may also be present. As of yet, no known association with cardiovascular, renal (kidney), or hepatic (liver) abnormalities are present.
The associated fever will last for two or three days and abruptly ends. Other symptoms, however, such as insomnia, headache, joint pain, and a state of extreme weakness, may last from five to seven days. Joint pains of varying degree have continued in some patients for years, with age being a factor. Recovery from Chikungunya depends upon the age of those infected. Patients who are younger recover between five and 15 days; those of middle age may continue to feel the virus’s effects for a month or two. The elderly seem to take the longest to recover from the attack. The duration and intensity of the disease is less in the young and pregnant women. No undesirable effects are conspicuous in pregnant women after the infection period has passed.
Recent epidemics have documented long-term symptoms of this virus during acute cases of infection. During an outbreak in 2006, more than 50 percent of patients who were more than 45 years of age had long-term musculoskeletal pain and up to 60 percent presented with prolonged joint pain three years after being infected. These long-term symptoms are not a new phenomenon. During a chikungunya epidemic in Italy, 66 percent of those infected reported myalgia (muscle pain), arthralgia (joint pain) or asthenia (weakness) one year later.
Increased age and prior rheumatological disease are common predictors of these prolonged symptoms. However, the cause of these chronic problems is not fully understood at this point. Although not dangerous enough to cause deaths in humans, the symptoms are debilitating and this mosquito borne virus could pose a threat across the U.S. because uninfected mosquitoes that bite an infected person, then carry the virus.
There is some evidence from human and animal patients that chikungunya could initiate chronic infections with a viral antigen taking up residence in the host. This is borne out by studies with mice which have shown a viral RNA detected specifically in joint tissue for a minimum of 16 weeks after inoculation. The chikungunya virus persisted in a spleen of a non-human primate for at least 6 weeks.
Protection against contact with disease carrying mosquitos is the most effective method at this time. Insect repellents, window and door screens help to keep mosquitoes out of the house, but this has only a minimal effect as most contact by humans and mosquitoes occurs outside. Other methods of prevention include stopping mosquitoes from multiplying by draining water from house gutters, buckets, flower pots, pool covers or other containers where water can be collected. Empty pet’s water bowls and clean bird baths, discard old tires, and cover boats with tarps to prevent accumulation of water in them. Drain or empty plastic swimming pools, and keep large swimming pools properly chlorinated.
Another protective deterrent is the wearing of proper clothing: shoes, not flip-flops, socks, long-sleeved shirts, and long pants. Applying insect repellent before sunscreen is also recommended as is the application of repellents to clothing. Mosquito netting for children under two months of age may be an effective, protective measure. It is important to read the labels and instructions on insect repellents as there are some insect repellent products which are not suitable for children. These products do list their ingredients such as DEET, Picardin, and oil of lemon eucalyptus and they are approved by the U.S. Environmental Protection Agency.
The East Coast and parts of some Southern states have reported the highest number of cases of chikungunya in the U.S. as of June 16. States reporting cases include the commonwealth of Virginia, North Carolina, Tennessee, Florida, and the U.S. Virgin Islands. According to the Center for Disease Control (CDC) as of June 10, 2014, a total of 39 cases of chikungunya have been reported. The Caribbean Islands is the location cited for these 39 infections. More than 130,000 cases in the Caribbean Islands have been reported in 2014. Dr. William Schaffner, an infectious disease specialist at Vanderbilt University Center, stated the virus will take a while to establish itself in this country. He added that there is no way however, to isolate the population from mosquitoes. A warning issued by the CDC states that there is always the risk of infected travelers spreading the illness across the U.S. A person infected in the Caribbean, for example, who returns to his or her home state who is then bitten by a mosquito has now transferred the virus to another mosquito, thereby insuring the spread of the disease to other parts of the country. States currently being monitored by the CDC for new cases of chikungunya are; California, New York, Arkansas, Connecticut, Puerto Rico, Nevada, Maryland and Minnesota.
Europe, Asia and Africa are other prominent places of chikungunya infections, which is caused by the Aedes Mosquito. Spreading rather quickly, the chikungunya mosquito borne virus may become this summer’s first major threat in the United States. The first cases of the disease were reported in the Americas in late 2013. The number of cases confirmed by the Caribbean Public Health Agency climbed from 100,000 in early June to more that 135,000 by the beginning of this week. A little more than half of those cases originated in the Dominican Republic.
By Andy Towle