Caribbean mosquito-borne virus making its way to U.S.
The Aedes aegypti mosquito, a carrier of chikungunya
Photo by James Gathany of the Centers for Disease Control and Prevention
When Dr. Daniel Lattanzi went to Port au Prince, Haiti, in late May, he was met with more than 2,000 cases of the chikungunya virus.
“And the numbers are rising,” said Lattanzi, an obstretrician and gynecologist at UMPC-Pittsburgh hospital.
Chikungunya is unique, because unlike other vector-borne epidemics, the virus can be transmitted from mosquitoes to humans, or from humans to uninfected mosquitoes, but not between humans. There is no vaccine to prevent the illness.
After launching health rehabilitation centers in Haiti and a residency program in Guyana, Lattanzi, of Peters Township, is all too familiar with victims of the aching joints, fever and rash associated with the mosquito-borne virus, which can last between seven to 10 days.
On his last trip to Guyana in early June and on all his visits, Lattanzi exercised the necessary precautions when volunteering his medical services – applying chemical repellents such as DEET to his skin and Picaridian to his long sleeves and pants.
A number of U.S. states already treated patients, all of whom had traveled to the Caribbean.
The Centers for Disease Control issued a travel watch for those heading to Caribbean countries.
William B. Klimstra, a professor in the department of microbiology and molecular genes at University of Pittsburgh, has been researching a vaccine for the chikungunya virus since the 1990s. Klimstra said the study examines the virus’s effect on the immune system “to turn up the features that are good and turn down bad features.”
A vaccine would ease the mind of Caribbean voyagers, because the two mosquito species – Aedes aegypti and Aedes albopictus – that carry the virus are active throughout the day, rather than on a purely nocturnal schedule.
Isolated in Africa during the early 1950s, chikungunya is an African term which means “bends up.”
It references the joint pain that accompanies the virus and can linger for years afterward.
The disease spread to Asia during the 1960s and 1970s. European vacationers began carrying the virus home to southern Europe.
The virus mutated somewhere en route and plagued the region.
“The virus has become epidemic in southern Europe, which is what we are scared of happening in the U.S.,” Klimstra said, adding many fail to realize the danger is in the mutant form of the virus rather than the non-mutated virus concentrated in the Caribbean.
“(The viruses) are species specific,” Klimstra explained.
The Aedes aegypti, found in the Caribbean, can only thrive in southwestern climates of the United States – especially Florida – while the Aedes albopictus, found in Asia, can withstand harsher temperatures and can bring a mutated, more dangerous version of the infection to areas like Pennsylvania.
“There is a potential for it to come to Pittsburgh,” Lattanzi said.
However, Klimstra forecasts the virus petering out upon reaching the state, as happened with the spread of the dengue virus in 2009.
The vector-spread virus infected 50 million people but ground to a halt in the United States because of precautionary measures.
Joseph Conlon, technical adviser for the American Mosquito and Control Association, said the disease is likely to spread beyond international travelers returning to this country.
“The question is how far it would spread once it got here,” Conlon said. The next course of action, Conlon said, would be integrating mosquito management techniques.
But Klimstra said a full-scale epidemic is doubtful.
“It’s unlikely that it is going to overrun the country,” he said.