Estimating the Burden of Leptospirosis among Febrile Subjects Aged below 20 Years in Kampong Cham Communities, Cambodia, 2007-2009

Abstract

BackgroundLeptospirosis is an emerging but neglected public health challenge in the Asia/Pacific Region with an annual incidence estimated at 10–100 per 100,000 population. No accurate data, however, are available for at-risk rural Cambodian communities.MethodWe conducted anonymous, unlinked testing for IgM antibodies to Leptospira spp. on paired sera of Cambodian patients <20 years of age between 2007–2009 collected through active, community-based surveillance for febrile illnesses in a convenience sample of 27 rural and semi-rural villages in four districts of Kampong Cham province, Cambodia. Leptospirosis testing was done on paired serological samples negative for Dengue, Japanese encephalitis and Chikungunya viruses after random selection. Convalescent samples found positive while initial samples were negative were considered as proof of acute infection. We then applied a mathematical model to estimate the risk of fever caused by leptospirosis, dengue or other causes in rural Cambodia.ResultsA total of 630 samples are coming from a randomly selected subset of 2358 samples. IgM positive were found on the convalescent serum sample, among which 100 (15.8%) samples were IgM negative on an earlier sample. Seventeen of these 100 seroconversions were confirmed using a Microagglutination Test. We estimated the probability of having a fever due to leptospirosis at 1. 03% (95% Credible Interval CI: 0. 95%–1. 22%) per semester. In comparison, this probability was 2. 61% (95% CI: 2. 55%, 2. 83%) for dengue and 17. 65% (95% CI: 17. 49%, 18. 08%) for other causes.ConclusionOur data from febrile cases aged below 20 years suggest that the burden of leptospirosis is high in rural Cambodian communities. This is especially true during the rainy season, even in the absence of identified epidemics.

Assessing the performance of remotely-sensed flooding indicators and their potential contribution to early warning for leptospirosis in Cambodia

“…A cohort of villagers aged below 20 were followed during 2007–2009 by active, community-based surveillance for febrile illnesses in a convenience sample of 32 rural villages in four districts of Kampong Cham province, Cambodia [ 23 ]. A total of 2359 paired sera samples collected from febrile patients were randomly selected among 7162 fever cases who tested negative for other infectious diseases (dengue, Chikungunya, Japanese Encephalitis, Influenza, Respiratory Syncitial virus and Human Metapneumovirus) [ 23 ].…”

“…A cohort of villagers aged below 20 were followed during 2007–2009 by active, community-based surveillance for febrile illnesses in a convenience sample of 32 rural villages in four districts of Kampong Cham province, Cambodia [ 23 ]. A total of 2359 paired sera samples collected from febrile patients were randomly selected among 7162 fever cases who tested negative for other infectious diseases (dengue, Chikungunya, Japanese Encephalitis, Influenza, Respiratory Syncitial virus and Human Metapneumovirus) [ 23 ]. A total of 100 cases showed a seroconversion indicative of an acute leptospirosis infection, and defined by a second serum sample positive for anti- Leptospira IgM (PanBio Leptospira IgM ELISA kit) while the first serum sample, collected ten days earlier during the acute febrile phase of the disease, tested negative [ 23 ].…”

“…In Cambodia, a study estimated the annual incidence equivalent to half that of dengue, at 12.9 per 100,000 inhabitants aged below 20 years in Kampong Cham province during the 2007–2009 rainy seasons [ 23 ]. Another, hospital-based study of suspected leptospirosis cases found a seroprevalence of 29.0%; 14.4% with serological evidence of recent infection and 15.5% with evidence of previous leptospirosis infection [ 24 ].…”

Characterization of Leptospira isolates from humans and the environment in Uruguay

“…MAT was performed in all serum samples according to the standard technique with a two-step procedure 1 , 4 , 21 . Each serum was initially diluted 1:25 in saline and mixed with equal volumes of each of the 20 live cultures of Leptospira serovars that yield reactive results very frequently in the region and are able to promote cross-reactions.…”

Leptospirosis in French Historical Medical Literature: Weil’s Disease or Kelsch’s Disease?

“…2,3 Leptospirosis is difficult to identify in the tropical setting, where many other diseases with similar initial presentation cocirculate: dengue; Hepatitis A; yellow fever; schistosomiasis (Bilharzia); or blackwater fever (malaria). 4 Before becoming a neglected tropical disease, however, leptospirosis was a public health concern in now-developed countries. The French Royal Society of Medicine received 80 communications on "bilious epidemics" in France from 1782 to 1784 alone, many of which may have been leptospirosis outbreaks.…”