Date: Thu 28 May 2015
Source: HCPLive [edited]
An outbreak of a Brazilian strain of cutaneous leishmaniasis (CL) in French Guiana among 24 visiting scientists has alarmed tropical disease experts at the US Centers for Disease Control and Prevention (CDC).
The CDC alerts US physicians to be aware of possible infection in travellers returning from the region. They also note that this strain responds differently to treatment than other strains.
The disease is caused by a protozoan parasite and transmitted by the bite of the sand fly. "The geographic extension of and numeric increase in _L. braziliensis_ cases in the Guiana ecoregion complex, as observed in the rest of South America, are worrisome, and continuous epidemiologic surveillance is needed," Guillaume Martin-Blondel, MD and colleagues at Toulouse University Hospital in Toulouse, France, wrote this month in the CDC's Emerging Infectious Disease journal. CL infection with _L. braziliensis_ "is emerging and has potential to disseminate," the team wrote.
The scientists, a multi-national group, were on a field mission in Saul, French Guiana in the Amazonian rainforest. 7 came down with symptoms a mean period of 19 days after they returned home. The disease results in ulcers mostly on lower limbs but also on upper limbs and ears. It can also cause nodular lymphangitis, adenitis, and superficial phlebitis. It can also cause ulcers in the mucous membranes of the lips, nose, soft palate or larynx.
Infection is confirmed by microscopic examination of skin scrapings to look for typical amastiotes, or by a positive Leishmania species PCR result.
Treatment is intramuscular meglumin antimoniate or intravenous liposomal amphotericin B. The Brazilian strain does not respond to pentamidine isethionate, the 1st-line treatment for another strain, _L. guyanensis_ CL. "Leishmaniasis is increasingly seen among travellers returning from Latin American countries, particularly from Bolivia, Belize and French Guiana," the CDC noted.
The transmission cycle of the parasitic disease involves reservoir hosts including dogs and rodents and is spread by sand fly vectors. "Changing human activities that affect these factors may have resulted in the emergence of species with distinct pathogenic potentials and responses to therapy," the authors wrote.
Until this outbreak, _L. braziliensis_ infection had been seen only in Argentina, Brazil, Panama and Venezuela. An increase in tourism and more development of the Amazon rain forest could be to blame for the spread of the infection, the team wrote.
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