Related Experiment Videos
Epidemiological, clinical, and virological features of influenza outbreaks in Pune, India, 1980
Abstract:
During the course of continuous surveillance of influenza in 1980 in Pune, India, which has a tropical monsoon climate, three outbreaks of acute respiratory infection (ARI) were investigated in March (hot season), in July-September (rainy season), and in November (cold season); sporadic cases during the interepidemic months were also studied. The first outbreak was associated with influenza A virus (H3N2), the second with influenza A viruses (H3N2) and (H1N1) and influenza B virus, but fewer influenza viruses were isolated during the third outbreak. The illnesses affected all age groups including infants and adults over 60 years of age, although the paediatric age group was mainly affected. The ARI outbreaks associated with the hot and cold seasons commenced at about the time the weather changed whereas the mixed influenza A (H3N2) and A(H1N1) outbreaks occurred in the middle of the rainy season.
Insights
Influenza outbreaks in Pune, India, occurred across different seasons, with influenza A (H3N2) and B viruses circulating. The study monitored acute respiratory infections (ARI) and their association with seasonal weather changes.
Area of Science:
- Epidemiology
- Virology
- Public Health
Background:
- Influenza surveillance is crucial for understanding viral circulation and disease burden.
- Pune, India, experiences a tropical monsoon climate, influencing seasonal disease patterns.
- Acute Respiratory Infection (ARI) outbreaks require continuous monitoring to identify causative agents.
Purpose of the Study:
- To investigate influenza outbreaks and associated acute respiratory infections (ARI) in Pune, India, during 1980.
- To determine the seasonality and viral etiology of ARI outbreaks.
- To analyze the relationship between weather patterns and influenza virus activity.
Main Methods:
- Continuous surveillance of influenza and ARI cases throughout 1980.
- Investigation of three distinct ARI outbreaks occurring in different seasons (hot, rainy, cold).
- Isolation and characterization of influenza viruses (A H3N2, A H1N1, B) from patient samples.
Main Results:
- Influenza A (H3N2) was linked to an outbreak in the hot season (March).
- The rainy season (July-September) saw co-circulation of influenza A (H3N2), A (H1N1), and influenza B viruses.
- Fewer influenza viruses were isolated during the cold season outbreak (November).
- ARI outbreaks coincided with seasonal weather changes, with mixed influenza A outbreaks during the rainy season.
Conclusions:
- Influenza viruses circulate in Pune, India, throughout the year, with distinct seasonal patterns.
- Weather changes significantly influence the timing and nature of ARI and influenza outbreaks.
- Paediatric populations were predominantly affected by these influenza outbreaks.