Study of a Leptospirosis Outbreak in Honduras Following Hurricane Mitch and Prophylactic Protection of the vax-SPIRAL® Vaccine

Abstract

Honduras was one of the Central American countries most severely hit by Hurricane Mitch. Torrential rains and heavy flooding created conditions conducive to a leptospirosis outbreak in the country. A group of Cuban scientists studied 68 patients from the Department of Cortés -one of the country's hardest hit areas -presenting clinical and epidemiological profiles indicative of leptospirosis. Blood and serum samples were taken from all subjects. A microscopic agglutination test (MAT) was used to identify Leptospira strains and to assess protection conferred by vax-SPIRAL ® (Cuban leptospirosis vaccine) against the isolated strain. Prevalence of leptospires in the kidneys and liver was also verified. A male predominance was found in the group aged 15-49 years. Municipalities in this Department with the largest number of cases were San Pedro Sula, La Lima, and Chamelecón. The most frequent symptoms included fever, headache, myalgia, and generalized discomfort. Over 80% of subjects reported presence of rodents in their homes, as well as contact with stagnant water and domestic animals. The strain isolated from positive blood cultures was from the Icterohaemorrhagiae serogroup, which was highly virulent in the animal model used. Protection was 100% in hamsters inoculated with vax-SPIRAL ® and subsequently challenged with the Honduran strain. Additionally, macroscopic analysis of organs from immunized animals that survived the challenge showed no signs of leptospirosis infection.