Regional differences of leptospirosis in Sri Lanka: observations from a flood-associated outbreak in 2011.
Leptospirosis is known to be an important cause of weather disaster-related infectious disease epidemics. In 2011, an outbreak of leptospirosis occurred in the relatively dry district of Anuradhapura, Sri Lanka where diagnosis was resisted by local practitioners because leptospirosis was not known in the area and the clinical presentation was considered atypical. To identify the causative Leptospira associated with this outbreak, we carried out a cross-sectional study. Consecutive clinically suspected cases in this district were studied during a two-and-a-half-month period. Of 96 clinically suspected cases, 32 (33.3%) were confirmed by qPCR, of which the etiological cause in 26 cases was identified using 16S rDNA sequencing to the species level. Median bacterial load was 4.1 × 10(2)/mL (inter-quartile range 3.1-6.1 × 10(2)/mL). In contrast to a 2008 Sri Lankan leptospirosis outbreak in the districts of Kegalle, Kandy, and Matale, in which a predominance of Leptospira interrogans serovars Lai and Geyaweera was found, most cases in the 2011 outbreak were caused by Leptospira kirschneri. Seven (21.9%) confirmed cases had acute renal failure; five (15.6%) had myocarditis; severe thrombocytopenia (<20,000/uL) was seen in five (15.6%) cases. This outbreak of leptospirosis in the relatively dry zone of Sri Lanka due primarily to L. kirschneri was characterized by markedly different clinical presentations and low leptospiremia. These observations and data demonstrate the public health relevance of molecular diagnostics in such settings, possibly related to the microgeographic variations of different Leptospira species, but of particular value to public health intervention in what appears to have been a regionally neglected tropical disease.
Department of Community Medicine, Faculty of Medicine and Allied Sciences, Rajarata University, Saliyapura, Sri Lanka ; Tropical Disease Research Unit, Faculty of Medicine and Allied Sciences, Rajarata University, Saliyapura, Sri Lanka ; Division of Infectious Diseases, Department of Medicine, University of California San Diego, School of Medicine, La Jolla, California, United States of America.
Suneth B
SB
Agampodi
Tropical Disease Research Unit, Faculty of Medicine and Allied Sciences, Rajarata University, Saliyapura, Sri Lanka ; Department of Medicine, Faculty of Medicine and Allied Sciences, Rajarata University, Saliyapura, Sri Lanka.
Niroshan J
NJ
Dahanayaka
Teaching Hospital, Anuradhapura, Sri Lanka.
Anoma K
AK
Bandaranayaka
Teaching Hospital, Anuradhapura, Sri Lanka.
Manoj
M
Perera
Department of Medicine, Faculty of Medicine and Allied Sciences, Rajarata University, Saliyapura, Sri Lanka.
Sumudu
S
Priyankara
Tropical Disease Research Unit, Faculty of Medicine and Allied Sciences, Rajarata University, Saliyapura, Sri Lanka ; Department of Medicine, Faculty of Medicine and Allied Sciences, Rajarata University, Saliyapura, Sri Lanka.
Prasanna
P
Weerawansa
Division of Infectious Diseases, Department of Medicine, University of California San Diego, School of Medicine, La Jolla, California, United States of America.
Michael A
MA
Matthias
Division of Infectious Diseases, Department of Medicine, University of California San Diego, School of Medicine, La Jolla, California, United States of America ; Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru ; Departamento de Ciencias Celulares y Moleculares, Laboratorio de Investigación y Desarrollo, Facultad de Ciencias, Universidad Peruana Cayetano Heredia, Lima, Peru.
Joseph M
JM
Vinetz
D000328:Adult; D003430:Cross-Sectional Studies; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D004196:Disease Outbreaks; D005260:Female; D055868:Floods; D006801:Humans; D007919:Leptospira / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D007922:Leptospirosis / Q000453:epidemiology* / Q000382:microbiology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013188:Sri Lanka / Q000453:epidemiology
D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S