Estimation of the impact of a Japanese encephalitis immunization program with live, attenuated SA 14-14-2 vaccine in Nepal.
Wider availability of the live, attenuated SA 14-14-2 Japanese encephalitis (JE) vaccine has facilitated introduction or expansion of immunization programs in many countries. However, information on their impact is limited. In 2006, Nepal launched a JE immunization program, and by 2009, mass campaigns had been implemented in 23 districts. To describe the impact, we analyzed surveillance data from 2004 to 2009 on laboratory-confirmed JE and clinical acute encephalitis syndrome (AES) cases. The post-campaign JE incidence rate of 1.3 per 100,000 population was 72% lower than expected if no campaigns had occurred, and an estimated 891 JE cases were prevented. In addition, AES incidence was 58% lower, with an estimated 2,787 AES cases prevented, suggesting that three times as many disease cases may have been prevented than indicated by the laboratory-confirmed JE cases alone. These results provide useful information on preventable JE disease burden and the potential value of JE immunization programs.
Child Health Division, Ministry of Health and Population, Kathmandu, Nepal. drshyam@hotmail.com
Shyam Raj
SR
Upreti
Kristen B
KB
Janusz
W William
WW
Schluter
Ram Padarath
RP
Bichha
Geeta
G
Shakya
Brad J
BJ
Biggerstaff
Murari Man
MM
Shrestha
Tika Ram
TR
Sedai
Marc
M
Fischer
Robert V
RV
Gibbons
Sanjaya K
SK
Shrestha
Susan L
SL
Hills
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004672:Encephalitis, Japanese / Q000517:prevention & control*; D006801:Humans; D007223:Infant; D022321:Japanese Encephalitis Vaccines / Q000145:classification / Q000276:immunology*; D009390:Nepal / Q000453:epidemiology; D011159:Population Surveillance; D012189:Retrospective Studies; D014613:Vaccines, Attenuated / Q000276:immunology
D022321:Japanese Encephalitis Vaccines; D014613:Vaccines, Attenuated