MINNEAPOLIS – A study published Wednesday in the journal Neurology reveals that the mosquito-borne Chikungunya Virus (CHIKV) is a substantial cause of Central Nervous System disease (CNS), which begins with an inflammation of the brain, known as encephalitis.

Researchers analyzed data from an outbreak occurred between September, 2005, and June, 2006, on La Réunion Island in the Indian Ocean, which resulted in 57 patients diagnosed with CHIKV linked to CNS disease. Of all cases, 24 were associated to encephalitis, affecting at most young children and the elderly. Of every 100,000 persons, 187 patients with inflammation of the brain were below 1 year and 37 over 65 years.

The name chikungunya comes from Tanzania, where the disease was first identified in 1952. Credit: Nutrition Review.
The name chikungunya comes from Tanzania, where the disease was first identified in 1952. Credit: Nutrition Review.

These numbers combined were much higher than those accumulated in the United States in these age categories, in terms of encephalitis. Although there were more young children affected by the disease, less severe outcomes were reported in infant than in adults. Therefore, infants were more likely to survive after developing encephalitis linked to CHIKV.

This was an alarming epidemic of a modified strain that led to more serious outcomes than previous outbreaks of the virus, study authors reported. It was even greater than the epidemic reported with the West Nile virus in the U.S. that occurred from 1999 to 2007. The globally spread of Japanese encephalitis was also outweighed by the outbreak on La Réunion Island.

The paper, published on behalf of the American Academy of Neurology, states that symptoms differed from one age group to another. Infants were more likely to have fever before the hospitalization, behavioral changes and skin rash. On the other hand, adults presented more frequently focal neurological signs, coma, impaired consciousness, seizures and death. As for the overall death rate for brain inflammation associated with CHIKV, it was 17 percent, whereas 35 to 45 percent of survivors presented persistent disability.

Chikungunya has been spreading all over the globe

The Chikungunya virus is native to the studied region. However, travelers can get infected by the bug as they pass through. This has led to outbreaks in the Caribbean Islands, Africa and Asia. Since September this year, over 7,000 cases have been registered in Mexico. In the United States there has been only on case locally transmitted and it was in reported in Florida, in July.

“Since there is no vaccine to prevent chikungunya and no medicine to treat it, people who are traveling to these areas should be aware of this infection and take steps to avoid mosquito bites, such as wearing repellent and long-sleeves and pants if possible,” remarks study author Dr. Patrick Gérardin, with the Central University Hospital in Saint Pierre, Reunion Island.

According to the Centers for Disease Control and Prevention (CDC), the most common signals of an infection transmitted by the mosquito-borne Chikungunya Virus include fever, joint and muscle pain, joint swelling and skin rash. Generally, most patients recover after a week of becoming infected. However, researchers point out that some people might develop further pain for months or even years.

Source: Neurology Advisor