Dataset Information

Epidemiological study of Japanese encephalitis virus in Vientiane, Lao PDR, in 1990s.

ABSTRACT: Phylogenetic analysis of Japanese encephalitis virus (JEV) was conducted using core-premembrane and envelope gene sequence data of two strains from Vientiane, Lao People's Democratic Republic, in 1993 and five from Okinawa, Japan, in 2002 and 2003, and previously published strains. The two Vientiane strains designated as LaVS56 and LaVS145 belonged to genotype 1 (G1) and the same subcluster of G1 as Australian strain in 2000, Thai strains in 1982-1985 and 2004-2005, and Vietnamese strain in 2005, but were distinct from the subcluster of recently distributing G1 strains widely in Asia including Okinawan strains and recent Lao strain in 2009. These clusters with own distinct distributions indicated involvements of different mechanisms and routes of spreading viruses and clarified that Australian G1 strain is from Southeast Asia, not from East Asia. Both Vientiane strains were antigenically close to P19-Br (G1, isolate, Thailand), but distinct from Nakayama (G3, prototype strain, Japan), Beijing-1 (G3, laboratory strain, China), and JaGAr#01 (G3, laboratory strain, Japan), demonstrated by cross-neutralization tests using polyclonal antisera. These results together with seroepidemiologic study conducted in Vientiane strongly suggest that diversified JEV cocirculated there in early 1990s.

SUBMITTER: Saito M

PROVIDER: S-EPMC4324949 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature

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Epidemiological study of Japanese encephalitis virus in Vientiane, Lao PDR, in 1990s.

Saito Mika M Soukaloun Douangdao D Phongsavath Khampe K Phommasack Bounlay B Makino Yoshihiro Y

TheScientificWorldJournal 20150128

Phylogenetic analysis of Japanese encephalitis virus (JEV) was conducted using core-premembrane and envelope gene sequence data of two strains from Vientiane, Lao People's Democratic Republic, in 1993 and five from Okinawa, Japan, in 2002 and 2003, and previously published strains. The two Vientiane strains designated as LaVS56 and LaVS145 belonged to genotype 1 (G1) and the same subcluster of G1 as Australian strain in 2000, Thai strains in 1982-1985 and 2004-2005, and Vietnamese strain in 2005 ...[more]

PMID: 25695095

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Project description:BACKGROUND:Central nervous system (CNS) infections are important contributors to morbidity and mortality and the causative agents for ~50% patients are never identified. The causative agents of some CNS infections have distinct spatial and temporal patterns. METHODOLOGY/PRINCIPAL FINDINGS:Here we present the results of a spatial epidemiological and ecological analysis of CNS infections in Lao PDR (2003-2011). The data came from hospitalizations for suspected CNS infection at Mahosot Hospital in Vientiane. Out of 1,065 patients, 450 were assigned a confirmed diagnosis. While many communities in Lao PDR are in rural and remote locations, most patients in these data came from villages along major roads. Japanese encephalitis virus ((JEV); n = 94) and Cryptococcus spp. (n = 70) were the most common infections. JEV infections peaked in the rainy season and JEV patients came from villages with higher surface flooding during the same month as admission. JEV infections were spatially dispersed throughout rural areas and were most common in children. Cryptococcus spp. infections clustered near Vientiane (an urban area) and among adults. CONCLUSIONS/SIGNIFICANCE:The spatial and temporal patterns identified in this analysis are related to complex environmental, social, and geographic factors. For example, JEV infected patients came from locations with environmental conditions (surface water) that are suitable to support larger mosquito vector populations. Most patients in these data came from villages that are near major roads; likely the result of geographic and financial access to healthcare and also indicating that CNS diseases are underestimated in the region (especially from more remote areas). As Lao PDR is undergoing major developmental and environmental changes, the space-time distributions of the causative agents of CNS infection will also likely change. There is a major need for increased diagnostic abilities; increased access to healthcare, especially for rural populations; and for increased surveillance throughout the nation.

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Dataset Information

Epidemiological study of Japanese encephalitis virus in Vientiane, Lao PDR, in 1990s.

Publications

Epidemiological study of Japanese encephalitis virus in Vientiane, Lao PDR, in 1990s.

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