Updated estimation of the impact of a Japanese encephalitis immunization program with live, attenuated SA 14-14-2 vaccine in Nepal
| Autor: | Susan L. Hills, Sushil Shakya, Marc Fischer, Jagat Narain Giri, Shyam Raj Upreti, Rajendra Bohara, Ganga Ram Choudhary, Nicole P. Lindsey, Mukunda Gautam |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Male
Viral Diseases Pediatrics Geographical Locations 0302 clinical medicine Infectious Diseases of the Nervous System Medicine and Health Sciences Public and Occupational Health 030212 general & internal medicine Japanese encephalitis vaccine Child Vaccines education.field_of_study Incidence Incidence (epidemiology) Mortality rate lcsh:Public aspects of medicine Vaccination Vaccination and Immunization Infectious Diseases Neurology Child Preschool Epidemiological Monitoring Encephalitis Female Research Article Neglected Tropical Diseases medicine.drug medicine.medical_specialty Asia lcsh:Arctic medicine. Tropical medicine Infectious Disease Control Adolescent Death Rates lcsh:RC955-962 Immunology 030231 tropical medicine Population Vaccines Attenuated 03 medical and health sciences Nepal Japanese Encephalitis medicine Animals Humans Encephalitis Japanese education Disease burden Demography Immunization Programs Japanese Encephalitis Vaccines business.industry Public Health Environmental and Occupational Health Biology and Life Sciences Infant lcsh:RA1-1270 Japanese encephalitis Tropical Diseases medicine.disease Virology Age Groups People and Places Population Groupings Preventive Medicine business |
| Zdroj: | PLoS Neglected Tropical Diseases, Vol 11, Iss 9, p e0005866 (2017) PLoS Neglected Tropical Diseases |
| ISSN: | 1935-2735 1935-2727 |
| Popis: | Background Japanese encephalitis (JE) is a mosquito-borne disease that is associated with considerable morbidity and mortality in many Asian countries. The objective of this study was to describe the impact of the JE immunization program using SA 14-14-2 JE vaccine implemented in Nepal during 2006 through 2011. A previous assessment after the initial program implementation phase described a significantly lower post-campaign JE incidence compared to expected incidence; however, the previous evaluation had limited post-campaign data for some districts. Methodology/Principal findings JE and acute encephalitis syndrome (AES) data gathered through Nepal’s routine surveillance system from 2004 through 2014 were analyzed to assess the impact of the JE immunization program implemented in 31 districts. Expected incidence rates were determined by calculating the incidence of cases per 100,000 person-years in each district before the vaccination campaigns. This rate was applied to the relevant population after the vaccination campaigns, which provided the expected number of cases had the campaign not occurred. The observed incidence rate was the number of reported cases per 100,000 person-years post-campaign. Expected and observed JE and AES cases and incidence rates were compared. The post-campaign JE incidence rate of 0.7 cases per 100,000 was 78% (95% CI 76%–79%) lower than expected had no campaign occurred and an estimated 3,011 (95% CI 2,941–3,057) JE cases were prevented. The post-vaccination AES incidence of 5.5 cases per 100,000 was 59% (58%–60%) lower than the expected and an estimated 9,497 (95% CI 9,268–9,584) AES cases were prevented. Conclusions/Significance This analysis strengthens previous findings of the substantial impact of Nepal’s JE immunization program using SA 14-14-2 JE vaccine. Author summary In 2006, the Ministry of Health and Population in Nepal commenced a Japanese encephalitis (JE) immunization program using SA 14-14-2 JE vaccine, with mass campaigns conducted in selected districts, followed by introduction of JE vaccine into the routine childhood immunization program. JE and acute encephalitis syndrome data gathered through Nepal’s routine surveillance system from 2004 through 2014 were analyzed to assess the impact of this immunization program. Expected and observed JE and acute encephalitis syndrome cases and incidence rates were compared. Considerable impact on JE incidence was demonstrated and the results also suggested that a large proportion of acute encephalitis syndrome cases without laboratory confirmation are due to JE. The results support the belief that a JE immunization program will result in sizable reductions in the incidence of both laboratory-confirmed JE and clinical acute encephalitis syndrome cases. JE is a severe disease, and the program’s impact likely extended to reduction of rates of JE-related mortality and long-term disability. |
| Databáze: | OpenAIRE |
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