Epidemiological Trends and Seasonal Patterns of Dengue Virus Infection in a Tertiary Care Centre in Warangal Telangana from 2022 to 2025

Imagine the world of public health as a giant, bustling city where invisible invaders are constantly trying to sneak in. One of the most notorious of these invaders is the Dengue virus, a tiny troublemaker that lives in the tropics and subtropics. It doesn't travel alone; it hitchhikes on the backs of mosquitoes, specifically the Aedes mosquito, which loves to bite during the day. Think of these mosquitoes as tiny, flying delivery drones that accidentally drop off a fever-causing package whenever they land on a person. When the weather gets hot and rainy, these "delivery drones" multiply like crazy, turning a quiet neighborhood into a chaotic delivery hub. Scientists care deeply about tracking these patterns because knowing when and where the mosquitoes are most active is like having a weather forecast for a storm—it helps hospitals and communities prepare their shields before the rain starts pouring.

This specific study is like a detective story set in Warangal, a city in the Indian state of Telangana. The researchers, working at a major hospital (a "tertiary care centre"), decided to look back at the last four years of medical records, from 2022 to 2025. They weren't guessing; they were looking at hard evidence from blood tests that confirmed exactly who had the virus. Their goal was simple but crucial: to figure out the rhythm of the Dengue virus in their city. Does it hit randomly? Does it follow the seasons? And who gets hit the hardest? By treating the hospital data like a giant puzzle, they wanted to map out the virus's habits so that future outbreaks could be predicted and stopped in their tracks.

The Four-Year Dance of the Virus

The researchers gathered data on 3,484 people who were confirmed to have Dengue during this period. If you imagine these cases as drops of water filling a bucket, the flow wasn't steady. It came in waves. The year 2023 was the biggest wave, with 1,091 cases (which is 31.31% of the total). The year before, 2022, had 723 cases (20.75%), and 2024 saw 956 cases (27.44%). By 2025, the numbers dropped back down to 714 cases (20.49%). This pattern suggests a "cyclical" trend, meaning the virus tends to have a big party one year, calm down a bit the next, and then maybe get rowdy again later. It's not a straight line up or down; it's a heartbeat that pulses with intensity.

The Seasonal Surge: When the Mosquitoes Strike

The most striking discovery was about when these infections happened. The virus has a very strict schedule. The researchers found that the vast majority of cases—73.45% of all of them—happened during just four months: August, September, October, and November.

Think of the year as a calendar with two distinct zones. From January to July, the city was relatively quiet, with only 640 cases (about 18.37% of the total) occurring during this "low-transmission" window. The quietest month was April, with only 65 cases. But once the monsoon rains arrived and the heat settled in, the virus exploded.

The peak of the party was September. In just that one month, 923 people got sick, which is 26.49% of all the cases seen over the entire four years! October was the runner-up with 643 cases (18.46%). The statistical tools used by the researchers (a "Chi-square test") showed that this clustering wasn't a coincidence; the math was so clear that the chance of this happening by random luck was less than one in a thousand (p < 0.0001). The data suggests that the post-monsoon environment creates the perfect storm for mosquitoes to breed and spread the virus.

Who Gets Hit the Hardest?

The study also looked at who was in the hospital. It turns out that while the virus doesn't discriminate too much between boys and girls, it does have a preference for age.

• Gender: Slightly more males were infected (55.17%, or 1,922 people) compared to females (44.83%, or 1,562 people). The researchers noted that this might be because men in the area are more likely to be outside working or playing during the day when the mosquitoes are most active. However, the age distribution was almost the same for both boys and girls, meaning age is a bigger factor than gender.
• Age: The biggest victims were children. The group aged 0–10 years took the biggest hit, with 1,256 cases, making up 36.05% of all infections. When you add the teenagers (ages 11–20), who accounted for 658 cases (18.89%), you find that more than half of all sick people (54.94%) were 20 years old or younger.

This is a critical finding. It suggests that while adults might have built up some immunity from past encounters with the virus, children are walking into the danger zone with "pristine" immune systems that haven't seen the virus before, making them much more likely to get sick.

What This Means for the Future

The paper concludes that Dengue in Warangal is a predictable, seasonal beast. It doesn't strike randomly; it waits for the post-monsoon months, specifically peaking in September. It also targets the youngest members of the community the hardest.

The authors suggest that instead of waiting for the hospital to get overwhelmed in September, the community needs to act earlier. They propose that vector control (killing the mosquitoes) and education campaigns should start in May and June, right before the rains fully set in. By treating the school environments and neighborhoods as if they are preparing for a known storm, rather than reacting to a surprise attack, the region might be able to lower the number of sick children and keep the hospitals running smoothly. The study doesn't claim to have "solved" Dengue, but it has handed the community a very accurate map of where and when the danger lies.