Bulletin of the World Health Organization

Estimated global incidence of Japanese encephalitis: a systematic review

Grant L Campbell, Susan L Hills, Marc Fischer, Julie A Jacobson, Charles H Hoke, Joachim M Hombach, Anthony A Marfin, Tom Solomon, Theodore F Tsai, Vivien D Tsu & Amy S Ginsburg

Volume 89, Number 10, October 2011, 766-774E

Table 3. Estimated annual incidence and case frequency of Japanese encephalitis (JE) by incidence group and age stratuma

IG Description Countries/regions 0–14 years of age
≥ 15 years of age
All ages
Endemic area(s) population
(millions)
Incidenceb Frequency Endemic area(s) population
(millions)
Incidenceb Frequency Endemic area(s) population
(millions)
Incidenceb Frequency Percentage of totalc
A Historically high-incidence areas with long-standing, high-quality vaccination programmes Japan, Republic of Korea, China (Taiwan) 28.5 0.003 1 170.0 0.003 5 198.5 0.003 6 < 0.1
B Extremely low-incidence areas; rare human cases; minimal or no vaccination programmes Australia, India (lowest-incidence stratum), Pakistan, Russian Federation, Singapore 28.0 0.001 0 61.5 0.004 2 89.5 0.003 2 < 0.1
C1 Historically high-incidence areas with expanding vaccination programmes China (higher-incidence stratum) 200.0 12.7 25 387 825.7 1.0 8462 1025.7 3.3 33 849 49.9
C2 Historically medium-incidence areas with expanding vaccination programme China (lower-incidence stratum) 53.9 0.04 21 222.7 0.003 7 276.6 0.01 28 < 0.1
D High-incidence areas with nascent or no vaccination programmes Cambodia, Indonesia (higher-incidence stratum), Lao People's Democratic Republic, Malaysia (Borneo except Sarawak), Myanmar, Philippines, Timor-Leste 65.4 10.6 6927 146.4 0.7 990 211.8 3.7 7917 11.7
E Medium-incidence areas with no vaccination programmes Indonesia (lower-incidence stratum), Malaysia (peninsular), Papua New Guinea 58.9 5.3 3122 154.6 0.34 523 213.5 1.7 3645 5.4
F Historically high-incidence areas with expanding vaccination programmes Nepal (higher-incidence stratum); India (highest-incidence stratum) 135.7 5.1 6861 305.4 1.8 5489 441.1 2.8 12 350 18.2
G Low-incidence areas with minimal or no vaccination programmes Bangladesh, Bhutan, Brunei Darussalam, Nepal (lower-incidence stratum) 43.0 2.5 1086 92.8 0.3 272 135.8 1.0 1358 2.0
H Historically medium-to-high-incidence areas with expanding vaccination programmes India (medium-incidence stratum), Malaysia (Sarawak), Sri Lanka, Thailand, Viet Nam 151.1 4.7 7063 387.0 0.3 1009 538.1 1.5 8072 11.9
I Historically medium-to-high-incidence area with expanding vaccination programme Democratic People's Republic of Korea 4.6 12.6 586 15.7 0.5 84 20.3 3.3 670 1.0
Total (JE-endemic areas only) 769.2 6.6 51 054 2381.7 0.7 16 843 3150.9 2.2 67 897 100
Overall incidence (endemic + non-endemic areas)b 5.4 0.6 1.8

IG, incidence group.

a Total population (endemic + non-endemic areas) aged 0–14 years is 1000.9 million; aged ≥ 15 years, 2692.7 million; and combined, 3693.6 million (country-specific data not shown).

b Per 100 000.

c Total frequency divided by 67 897 times 100.

Note: See text for assumptions.