A New Pathogen in Paradise

A New Pathogen in Paradise

A new virus with a strange name recently emerged in the popular press and the public consciousness. On 19 December 2013, two confirmed cases of locally acquired chikungunyavirus (CHIK) were reported on the French Caribbean island of Martinique. The World Health Organization announced that this is the first time local transmission of this virus has been detected in the Americas.

 

CHIK is spread by the bite of infected mosquitos such as Aedesaegypti (the yellow fever mosquito) and Aedes albopictus (the Asian tiger mosquito).

 

In human infections, CHIK can cause a debilitating illness often characterized by headache, fever, fatigue, nausea, vomiting, muscle pain, rash, and joint pain. It is rarely fatal, but it can lead to chronic, debilitating joint pain. The virus was discovered in 1953 in Tanzania during an epidemic of dengue-like illness, and acquired its name from a local phrase that means ‘that which bends up.’ In other words, causes pain.

 

Since its discovery, the virus has been responsible for outbreaks in Kenya (2004), the French island of Reunion off East Africa (2005-06), and in other locations.  The Reunion outbreak resulted in 244,000 cases and 203 deaths.  A 2006 outbreak in India involved more than a million cases.  Travelers returning from Africa and Réunion also introduced the virus into parts of Europe.

Subsequent outbreaks in India likely were driven by the virus’ ability to adapt to the more aggressive tiger mosquito, and to acquire mutations that shortened the period of viral replication in the mosquito and thereby increased the viral load.  The end result was a fast-moving epidemic.

“These observations point to one important fact that the more the efficiency with which we contain the primary outbreak of this disease, the better we are able to prevent adaptive mutations in the virus and the emergence of severe infections and explosive epidemics,” notes a member of the Global Virus Network (GVN), Dr. E. Sreekumar, at the Rajiv Gandhi Centre for Biotechnology in Kerala, India.

There is no specific antiviral treatment available forchikungunya fever. Treatment is symptomatic and includes rest, fluids, and medicines to relieve symptoms of fever and aching such as ibuprofen, naproxen, acetaminophen, or paracetamol.(Aspirin should be avoided.)

 

Various research groups in the U.S. and Europe are working on a vaccine.  Recently, a group in the Netherlands reported on the production of a synthetic CHIK vaccine* that protected mice from infection and inflammation caused by the Réunion Island CHIK virus strain.

 

Like other viruses before it, CHIK has moved west into the Americas with the aid of tourists and international trade.  An effective vaccine would be an important tool in controlling this emerging virus.

* Effective Chikungunya Virus-like Particle Vaccine Produced in Insect Cells. Stefan W. Metz, Joy Gardner, CorinneGeertsema, Thuy T. Le, Lucas Goh, Just M. Vlak, AndreasSuhrbier, Gorben P. Pijlman. March 14, 2013. DOI: 10.1371/journal.pntd.0002124.

Global Virus Network Warns U.S. of Growing Measles Threat

Oct. 1, 2013 17:39 UTC

Global Virus Network Warns U.S. of Growing Measles Threat

BALTIMORE–(BUSINESS WIRE)– The Global Virus Network (GVN), a coalition of the world’s leading medical virology research centers working to prevent illness and death from viral disease, today warned the U.S. of a startling rise in measles cases particularly in the last couple of years. Measles were eliminated in the U.S. by 2000, but according to the U.S. Centers for Disease Control in the first eight months of 2013 the U.S. saw nearly 160 cases of measles – which many believe will rise as a growing number of parents choose not to vaccinate their children in which state law does not otherwise apply.

“Measles is a dangerous disease. We lose sight of the dangers because currently the disease is rare in the US and usually imported from other countries where measles is more prevalent,” explains Dr. Diane Griffin, GVN Center of Excellence Director and Alfred and Jill Sommer Professor and Chair, W. Harry Feinstone Department of Molecular Biology and Immunology, Johns Hopkins Bloomberg School of Public Health. Griffin continued, “While most cases resolve with no complications in 10-14 days, measles can cause diarrhea and ear infections, as well as other serious side effects – seizures, pneumonia and encephalitis, which can each lead to death. The most vulnerable in the US are those under the age of 12 to 15 months, when the measles vaccine is usually given. Infants are therefore at the highest risk. Those who do not vaccinate their own children place infants of other families at risk as well as their own children.”

As experts and leading researchers on all viral diseases, GVN Centers of Excellence are working to improve the measles vaccine and better understand the complications of measles for the global population. “There is still much to do in terms of improving vaccinations against measles. While the two dose regimen provides protection for populations when delivered appropriately, a single dose regimen would be ideal and for developing countries a vaccine that did not need refrigeration or require a needle and syringe would facilitate delivery,” notes Professor Griffin, whose own laboratory focuses on understanding how the body responds to the measles vaccine to provide protection. She explained further that research to develop a dry powder vaccine delivered by inhalation is one promising line of research. The dry powder vaccine uses the same safe live vaccine virus that is currently given by a shot, but is given through a face mask. This way trained medical personnel, refrigeration and needles and syringes are not required. The dry powder vaccine is effective in animal models and is currently being tested in humans.

For the looming situation in the United States, Professor Griffin encouraged all families to ensure that their children are properly vaccinated against measles. “We cannot sit back and wait for measles to once again take hold in the United States,” she warned.

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