All of the following statements about Japanese Encephalitis are true, EXCEPT:
Not all individuals bitten by infected mosquitoes develop disease. The number of cases of Japanese Encephalitis recorded in nohern India per village (population 500 to 5000) were no more than 1 to 2. If number of cases is in excess of this expected frequency, it may suggest an epidemic. The vast majority of cases (about 85%) occur among children less than 15 years of age. The ratio of ove disease to inapparent infection varies from 1:300 to 1:1000. Thus cases of encephalitis represent only the tip of the iceberg compared to the large number of inapparent infections. Ref: Preventive and Social Medicine, by K.Park, 19th edition Page 238, 239
Two to Three cases per village may suggest an Epidemic
All individuals bitten by infected mosquitoes develop disease
Children are more frequently affected than adults
Ratio of inapparent to apparent infection is > 100:1