Leptospirosis in the Andaman Islands, India

Leptospirosis is an emerging zoonosis. In the Andaman Islands during the early twentieth century, it occurred in the penal settlements of the British India Administration, mostly as Weil's disease, an acute febrile illness with hepato-renal complications. It was caused by leptospires belonging to groups Akiamy A and Andamans A. After the 1930s nothing further is known regarding the disease until the late 1980s, when Andaman haemorrhagic fever (AHF), a mysterious illness with the majority of cases presenting pulmonary involvement, appeared. AHF was later identified as leptospirosis and severe pulmonary haemorrhage was shown for the first time as a complication of leptospirosis from India. Leptospirosis continues to occur in the Islands annually. It generally presents as two separate clinical syndromes: the hepato-renal form, and the pulmonary form, which is associated with high case fatality rates ranging from 10 to 15%. Infections are due to a variety of serovars, Valbuzzi being the commonest. Leptospira interrogans sensu stricto has been the predominant infecting species. Doxycycline has been shown to confer a beneficial effect in reducing the clinical illness and mortality during outbreaks. The history of leptospirosis in the Islands, its epidemiology, clinical spectrum, characteristics of the isolates and control are reviewed and discussed in this article.