During which month(s) does dengue typically show peak incidence in India?

Explanation

## Seasonal Pattern of Dengue in India **Key Point:** Dengue in India shows peak incidence during the post-monsoon period (September to November), with a secondary rise in early monsoon months. ### Dengue Seasonality in India ```mermaid flowchart LR A["Jan-Feb<br/>Winter"]:::outcome --> B["Low transmission"] C["Mar-May<br/>Summer"]:::outcome --> D["Increasing trend"] E["Jun-Aug<br/>Monsoon"]:::outcome --> F["Rising cases"] G["Sep-Nov<br/>Post-monsoon"]:::outcome --> H["PEAK INCIDENCE"]:::urgent I["Dec<br/>Declining"]:::outcome --> J["Cases decrease"] ``` **High-Yield:** The post-monsoon season (September–November) is the highest-risk period for dengue epidemics in India. This is when: - Accumulated rainwater in containers provides optimal breeding grounds - Temperature and humidity remain favorable for viral replication - Vector population reaches its maximum - Most dengue outbreaks and deaths are reported during this window ### Epidemiological Basis | Season | Temperature | Humidity | Rainfall | Vector Activity | Dengue Cases | |--------|-------------|----------|----------|-----------------|---------------| | **Winter (Jan–Feb)** | Low | Low | Minimal | Minimal | Rare | | **Summer (Mar–May)** | High | Low | Absent | Increasing | Sporadic | | **Monsoon (Jun–Aug)** | Moderate | High | Heavy | Increasing | Rising | | **Post-monsoon (Sep–Nov)** | Moderate–High | High | Moderate | **Maximum** | **PEAK** | | **Early winter (Dec)** | Declining | Declining | Minimal | Declining | Declining | **Clinical Pearl:** Public health surveillance in India intensifies from August onwards to prepare for the anticipated post-monsoon surge. Vector control campaigns are strategically timed before September. **Mnemonic:** **PMSN** = Post-Monsoon Season = Notable dengue peak [cite:Park 26e Ch 12]