By: Ebey P. Soman
Since its discovery in Tanganyika (modern day Mozambique and Tanzania in Africa) in 1952, Chikungunya virus outbreaks have been documented in Africa, South Asia, and Southeast Asia. Due to recent globalization and increased travel, infection has also spread outside of tropical regions and even into western nations (such as the United Kingdom). There is presently no cure, effective treatment, or vaccine for the virus, which makes it one of the few untreatable diseases in the world. Chikungunya fever is not directly life threatening, but has led to mortality in third world nations.
The name Chikungunya is derived from the Makonde language (spoken by the people of southeast Tanzania and northern Mozambique in Africa). It means, “…that which bends up,” describing the disease’s impact on human joints. Infected mosquitos, specifically the Aedes albopictus (the Asian tiger mosquito), transmit the Chikungunya virus. This is the same mosquito acting as the viral vector in the transfer of Yellow fever, Dengue fever, and the West Nile virus. Thus, the Chikungunya virus is an Arbovirus (arthropod borne) in the alphavirus genus of the Togaviridae family of viruses.
Once bitten by an infected mosquito, the virus has an incubation period of up to one week before the patient experiences signs and symptoms of an acute infection. These include rashes on the large parts of the body, symptoms of flu or fever, high body temperatures, and photophobia. The most discernible sign of this virus is the arthralgia that it induces in patients, usually affecting multiple joints in the outer extremities. Within a few days, the acute infection resolves, leaving the patient with most, if not all, the signs and symptoms they experienced during the acute infection for a prolonged period. The virus-induced multiple-joint arthritis tends to be the lasting effect of the virus, and usually presents as extremely inflamed and deformed joints. Case reports state that many patients experience the acute symptoms for years after the initial acute infection.
Unfortunately, untreated complications may lead to mortality. Patients usually experience high fevers and severe flu-like symptoms, and adequate rest and fluid rehydration is important. Often poor, many patients are unable to work, and cannot feed themselves or their families. Thus, these patients cannot maintain good diet, often starve, and develop hypoglycemia. Interruptions in diet and a lack of hydration may cause electrolyte imbalances; these predispose patients to serious complications, such as hypomagnesaemia-induced seizures.
Much like Dengue fever, Chikungunya can also induce thrombocytopenia in patients. Low platelet counts can increase the risk of internal bleeding. With thrombocytopenia and non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, patients may experience severe gastrointestinal bleeding. Both, complications from the virus and side effects of drugs used to treat the symptoms, can exacerbate problems and increase mortality.
The virus is usually not life threatening, but in third world nations where livelihood depends on manual labor, the pathogen elicits a heavy toll. Farmers or manual laborers suffer the most, as they are bedridden or their joints are too inflamed (and painful) for them to complete any work. The cost of providing healthcare for a sick family member also plays a role in depriving valuable time and resources; this most often destroys their livelihood. I personally saw this during the 2006-2007 Chikungunya outbreaks in Kerala, India. I traveled with a Disaster Relief Team from Peniel Revival Ministries, Inc., and visited many patients who were too poor to afford a few tablets of paracetamol (acetaminophen, Tylenol®). I could see the despair in patients’ eyes and clear evidence of starvation. Thus, in August of 2007, the Peniel Revival Ministries team assisted families in Vadaserikara Town in Kerala, and town officials helped to coordinate the event. This specific incident highlighted the great socioeconomic hardships that the virus brought to infected families, as well as the heavy toll these unlucky patients paid.
Scientists at the National Institute of Allergy and Infectious Diseases (NIAID) at the National Institutes of Health (NIH) are conducting a clinical trial to test a Chikungunya vaccine. So far, animal trials in rhesus monkeys demonstrated that treatment with non-infectious viral particles induced an appropriate immune response. Antibodies from the monkeys were then injected into mice and this surprisingly provided passive immunity against the virus, as well.
The fight against the Chikungunya virus may not seem like groundbreaking research, as it is restricted to tropical regions. However, since the 2007 outbreak in Italy, there is evidence that the virus may be changing and adapting itself to new environments. It is important for scientists to develop preventative medicine; thus, the Chikungunya vaccine research, if successful, may prove to be the keystone treatment of choice against other mosquito-borne viruses, such as Dengue fever. In the words of the NIAID Director Anthony S. Fauci, M.D., “If successful [the vaccine], this approach also might be used to develop vaccines against related mosquito-borne viruses, including those that cause Western, Eastern and Venezuelan equine encephalitis.”
On a more humanistic level, a vaccine will provide billions of people living in Africa and Asia with a certain level of protection against the Chikungunya virus. Moreover, perhaps we can eradicate the Chikungunya virus as we did with Polio in the United States.
Special thanks to Peniel Revival Ministries Inc. – Disaster Relief Trip 2007
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