Estimated global incidence of Japanese encephalitis: a systematic review.

OBJECTIVE: To update the estimated global incidence of Japanese encephalitis (JE) using recent data for the purpose of guiding prevention and control efforts. METHODS: Thirty-two areas endemic for JE in 24 Asian and Western Pacific countries were sorted into 10 incidence groups on the basis of published data and expert opinion. Population-based surveillance studies using laboratory-confirmed cases were sought for each incidence group by a computerized search of the scientific literature. When no eligible studies existed for a particular incidence group, incidence data were extrapolated from related groups. FINDINGS: A total of 12 eligible studies representing 7 of 10 incidence groups in 24 JE-endemic countries were identified. Approximately 67,900 JE cases typically occur annually (overall incidence: 1.8 per 100,000), of which only about 10% are reported to the World Health Organization. Approximately 33,900 (50%) of these cases occur in China (excluding Taiwan) and approximately 51,000 (75%) occur in children aged 0-14 years (incidence: 5.4 per 100,000). Approximately 55,000 (81%) cases occur in areas with well established or developing JE vaccination programmes, while approximately 12,900 (19%) occur in areas with minimal or no JE vaccination programmes. CONCLUSION: Recent data allowed us to refine the estimate of the global incidence of JE, which remains substantial despite improvements in vaccination coverage. More and better incidence studies in selected countries, particularly China and India, are needed to further refine these estimates.

Disability from Japanese encephalitis in Cambodia and Viet Nam.

A cohort of Japanese encephalitis (JE) survivors in Cambodia and Viet Nam were assessed at least 4 months after hospital discharge in order to understand the extent of disability after JE. We used a simple assessment tool which focuses on the impact on daily life. In total, 64 disability assessments were conducted: 38 in Cambodia and 26 in Viet Nam. In Cambodia, 4 (11%) children had severe sequelae, suggesting the children would likely be dependent, 15 (39%) had moderate sequelae and 17 (45%) had mild sequelae. In Viet Nam, two (8%) persons had severe sequelae, five (19%) had moderate sequelae and eight (31%) had mild sequelae. In many JE-endemic areas there are no multi-disciplinary teams with sophisticated equipment to assess patients after JE disease. This assessment tool can assist with patient management and generate data to support the need for programmes to prevent disease and improve outcomes for survivors.

Schistosomiasis Consortium for Operational Research and Evaluation (SCORE): Its Foundations, Development, and Evolution.

The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) was established in late 2008 to conduct operational research that would inform practices related to the control and elimination of schistosomiasis. This article traces SCORE's beginnings and underpinnings. These include an emphasis on openness and contributing to the development of a cohesive schistosomiasis control community, building linkages between researchers and national programs, and focusing on answering questions that will help Neglected Tropical Disease program managers to better control and eliminate schistosomiasis. It describes the development and implementation of SCORE's multiple projects. SCORE began by drawing on advice from a broad range of experts by holding wide-ranging meetings that informed the priorities and protocols for SCORE research. SCORE's major efforts included large, multicountry field studies comparing multiple strategies for mass drug administration with praziquantel, assessment of approaches to elimination, evaluation of a point-of-care assay for field mapping Schistosoma mansoni, and increasing the sensitivity of a laboratory-based diagnostic. SCORE also supported studies on morbidity due to schistosomiasis, quantification of vector snails and the detection of schistosome infections in snails, and changes in schistosome population genetics under praziquantel drug pressure. SCORE data and specimens are archived and will remain available for future research. Although much remains to be carried out, our hope is that through the already published articles and SCORE results described in this supplement, we will have provided a body of evidence to assist policy makers in the development of judicious guidelines for the control and elimination of schistosomiasis.

A triple-drug treatment regimen to accelerate elimination of lymphatic filariasis: From conception to delivery.

The Global Programme to Eliminate Lymphatic Filariasis (LF) is using mass drug administration (MDA) of antifilarial medications to treat filarial infections, prevent disease and interrupt transmission. Almost 500 million people receive these medications each year. Clinical trials have recently shown that a single dose of a triple-drug combination comprised of ivermectin, diethylcarbamazine and albendazole (IDA) is dramatically superior to widely used two-drug combinations for clearing larval filarial parasites from the blood of infected persons. A large multicenter community study showed that IDA was well-tolerated when it was provided as MDA. IDA was rapidly advanced from clinical trial to policy and implementation; it has the potential to accelerate LF elimination in many endemic countries.

Evaluation of three immunoglobulin M antibody capture enzyme-linked immunosorbent assays for diagnosis of Japanese encephalitis.

Japanese encephalitis (JE) virus is a major cause of neurologic infection in Asia, but surveillance has been limited. Three JE immunoglobulin M (IgM) antibody capture enzyme-linked immunosorbent assay kits have recently been developed. The aim of this study was to evaluate their sensitivity, specificity, and usability using 360 acute-phase serum samples containing JE, dengue, or neither IgM antibody. The kits, manufactured by Panbio Limited, Inbios International, Inc., and XCyton Diagnostics Ltd, had high sensitivities of 89.3%, 99.2%, and 96.7%, respectively. The specificities were 99.2%, 56.1%, and 65.3%, respectively. When dengue IgM-positive samples were excluded, the kits had specificities of 98.4%, 96.1%, and 96.1%, respectively. The Panbio kit includes both JE and dengue antigens and appears to have an advantage in settings where dengue virus co-circulates, although further assessments in clinical settings are needed. This information is helpful in considering options for strengthening the laboratory component of JE surveillance.

Outcome and extent of disability following Japanese encephalitis in Indonesian children.

OBJECTIVES: The study aimed to assess outcome, including level of disability, following Japanese encephalitis (JE) in children in Indonesia. METHODS: A cohort of children diagnosed with laboratory-confirmed JE from January 2005 to August 2006 was followed-up, with disability measured at least 4 months after discharge from hospital. An assessment tool that can be used to rapidly determine practical level of disability and the likelihood that a child will be able to live independently after illness, the Liverpool Outcome Score, was used. RESULTS: Of 72 children with JE, determination of outcome was possible for 65 (90%). Sixteen died in hospital or before follow-up assessment (25%). Sixteen children (25%) had severe sequelae, indicating their function was impaired enough to likely make them dependent. Five (7%) had moderate sequelae and 12 (18%) had minor sequelae. The remaining 16 children (25%) were considered to have recovered fully. CONCLUSIONS: Half of the children with JE either died or were left with serious disabilities likely to impair their ability to lead independent lives, demonstrating the severe impact of JE. Immunization can effectively prevent JE, and an immunization program could avert some of the economic and social burden of JE disease in Indonesia.

Confirmation of Japanese encephalitis as an endemic human disease through sentinel surveillance in Indonesia.

Japanese encephalitis (JE) results in significant mortality and disability in children in Asia. In Indonesia, despite recognition of JE virus transmission, reports of human disease have been few and from limited geographic areas. Hospital-based surveillance for acute encephalitis syndrome (AES) and JE in children 15 years of age and under was undertaken in 15 hospitals in six provinces from 2005 to 2006. High- and low-risk provinces in geographically dispersed areas were included. Health center-based surveillance also was undertaken in one province. Eighty-two JE cases were confirmed among 1,496 AES cases detected. JE cases were confirmed in all provinces, but the proportion varied between 18% and 2% among provinces of different risk levels. Children younger than 10 years of age represented 95% of JE cases, and 47% of all cases either died or were disabled. The study shows JE is an endemic human disease across Indonesia. Immunization strategies are being considered.