Background: In India, infectious diseases are the leading cause of mortality. Though, incidences are throughout the year but on peak during the specific season irrespective of the geographical region. Health sector need to manage the cases at least during peak of outbreaks.
Purpose: To determine the seasonal variation pattern outbreaks and cases.
Methodology: Database since 2010-2015 available at Website of IDSP, MoHFW, and Government of India was used. The diseases were classified as vector born, food & water born, vaccine preventable and a mixed category reporting fever only. Method of simple monthly average was used to obtain seasonal indices.
Result: Among the vector borne diseases, out of a total of 1496 outbreaks affecting 102109 persons, the deaths were 13.4/1000 cases; though, the outbreak of AES/JE was only 141 but CFR was 190.6/ 1000 cases contributing nearly half of the total deaths from vector borne diseases. The outbreaks of malaria were 328 affecting 28912 persons with CFR as 8.6/1000 cases. Dengue outbreak was highest (686) among the vector borne diseases affecting 70.8 persons per outbreak with CFR as 4.2/1000 cases. The outbreaks of food & water borne diseases were more than 3.5 times of vector borne diseases with CFR 4.9/1000 cases. The maximum outbreaks were of acute diarrhoeal diseases (2819) and lowest of cholera (378). Amongst vaccine preventable diseases, a total of 1592 outbreaks with maximum of measles followed by chicken pox and the lowest of mumps. Measles CFR was the highest (6.9/1000 cases). Vaccine preventable diseases excess outbreaks were seen during winter and spring seasons with peaks in March; while of vector born, food & water born and mixed class diseases during summer and autumn.
Conclusion: Infectious disease outbreaks follow seasonality; means either climate or temperature or both are associated; indicating appropriate preventive strategy well in time to combat excess outbreaks.
Outbreaks; Infectious diseases; Seasonal Indices; Seasonality.