Why chikungunya slips under dengue radar

Chikungunya spreads round the year and is as prevalent as dengue, NIV finds after redefining symptoms

Dengue and chikungunya are both mosquito-borne diseases and involve similar symptoms including high fever, headache, joint pain and rashes.

Chikungunya is as widely prevalent in India as dengue but tends to get overlooked or missed due to greater focus on dengue, a new study by the ICMR-National Institute of Viorology has found.

Cases of chikungunya were observed throughout the year while dengue spreads mainly during the monsoon, the study showed. Because of similar clinical symptoms, there is also greater difficulty in accurate diagnosis, Dr D T Mourya, director of NIV, main coordinator of the study said.

Dengue and chikungunya are both mosquito-borne diseases and involve similar symptoms including high fever, headache, joint pain and rashes. Dengue is much more dangerous. Last year, the National Vector Borne Disease Control Programme (NVBDCP) reported 1.9 lakh case of dengue cases and 67,700 of chikungunya. This year, 12,789 cases of chikungunya and 9,143 of dengue have been reported so far, but the latter count could jump in the ongoing monsoon.

NIV carried out a multi-site study as part of the Global Health Security Agenda, a partnership of over 50 countries. Data was collected between September 2016 and December 2017 from Sher-e-Kashmir Institute of Medical Sciences, Sawai Man Singh Medical College, King George’s Medical College, National Institute for Research in Tribal Health (Jabalpur) and Regional Medical Research Centres in Bhubaneshwar and Port Blair.

“Our study focused on generating more detailed information on the prevalence of dengue, chikungunya and cases of dual infections. The study also included detection of prevalence of Kyasanur Forest Disease (KFD) and Congo Crimean Hemorrhagic Fever (CCHF),” Pragya Yadav, principal investigator, told The Indian Express.
The researchers tested 6,479 patients with high fever. Of these, 1,068 tested positive only for dengue and 552 only for chikungunya. In 178 cases, patients tested positive for both diseases. “What we found surprising was that the prevalence of chikungunya was seen throughout the year, and in all seasons — pre-monsoon, monsoon and post-monsoon,” Yadav said.

For their study, the researchers also looked at a few additional symptoms that helped identify more positive cases for each disease. “Fever with vomiting or fever with breathlessness is not a typical symptom of dengue and chikungunya,” Yadav said. But including vomiting and other gastrointestinal symptoms increased detection.
For instance, using the NVBDCP case definition of dengue (fever with two or more symptoms like myalgia, arthralgia, headache and rash) the researchers could identify 706 cases of dengue. But inclusion of newer symptoms took the number of dengue positive cases for to 789. For chikungunya, the standard NVBDCP case definition led to detection in 516 cases, whereas using the modified case definition 644 patients could be detected.

“What is important is that the continuous presence of chikungunya and dengue positive cases suggest the presence of aedes vector of mosquito throughout the year in the community and not just during the monsoon season,” another researcher said.

Anuradha Mascarenhas

Anuradha Mascarenhas is a Senior Editor at The Indian Express, based in Pune. With a career spanning three decades, she is one of the most respected voices in Indian journalism regarding healthcare, science and environment and research developments. She also takes a keen interest in covering women's issues . Professional Background Education: A gold medalist in Communication and Journalism from Savitribai Phule Pune University and a Master’s degree in Literature. Author: She authored the biography At The Wheel Of Research, which chronicles the life and work of Dr. Soumya Swaminathan, the former Chief Scientist at the WHO. Key Focus: She combines scientific accuracy with storytelling, translating complex medical research into compelling public and human-interest narratives. Awards and Recognition Anuradha has won several awards including the Press Council of India's national award for excellence in journalism under the gender based reporting category in 2019 and the Laadli Media award (gender sensitivity -2024). A recipient of the Lokmat journalism award (gender category-2022), she was also shortlisted for the RedInk awards for excellence in journalism-2021. Her debut book At The Wheel Of Research, an exclusive biography of Dr Soumya Swaminathan the inaugural chief scientist of World Health Organisation was also nominated in the Popular Choice Category of JK Paper AUTHER awards. She has also secured competitive fellowships including the Laadli Media Fellowship (2022), the Survivors Against TB – New Research in TB Media Fellowship (2023) and is part of the prestigious 2025 India Cohort of the WomenLift Health Leadership Journey.” Recent Notable Articles (Late 2025) 1. Cancer & Specialized Medical Care "Tata Memorial finds way to kill drug-resistant cancer cells" (Nov 26, 2025): Reporting on a breakthrough for triple-negative breast cancer, one of the most aggressive forms of the disease. Discipline, diet and purpose; How a 97-year-old professor defies ageing'' (Nov 15, 2025) Report about Prof Gururaj Mutalik, the first Head of Department at Pune's B J Government Medical College who at 97 credits his longevity to healthy habits and a strong sense of purpose. 2. Environmental Health (The "Breathless Pune" Series) Long-term exposure even to 'moderate' air leads to chronic heart, lung, kidney issues" (Nov 26, 2025): Part of an investigative series highlighting that even "safe" pollution levels are damaging to vital organs. "For every 10 µg/m3 increase in PM2.5 level, there was 6-8% jump in medicine sales" (Nov 23, 2025): Using commercial data to prove the direct link between air quality and respiratory illnesses in Pune. 3. Lifestyle & Wellness News "They didn't let cancer, diabetes and heart disease stop them from travelling" (Dec 22, 2025): A collaborative piece featuring survivors who share practical tips for traveling with chronic conditions. At 17, his BP shot up to 200/120 mmHG; Lancet study flags why child and teen hypertension doubled between 2000 and 2020'' (Nov 12,2025)--A report that focusses on 17-year-old-boy's hypertensive crisis and reflects the rising global trend of high blood pressure among children and adolescents. 4. Scientific Recognition & Infrastructure For promoting sci-comm, gender diversity: IUCAA woman prof highlighted in Nature" (Nov 25, 2025): Covering the global recognition of Indian women scientists in gender studies and physics. Pune researchers find a spiral galaxy like the Milky Way from early universe'' (December 3, 2025)- A report on how Indian researchers discovered a massive galaxy that existed when the universe was just 1.5 billion years old , one of the earliest to have been observed so far. Signature Beat: Health, Science & Women in Leadership Anuradha is known for her COVID-19 reportage, where she was one of the first journalists to provide detailed insights into the Covishield and Covaxin trials. She has a dedicated interest in gender diversity in health and science, often profiling women researchers who are breaking the "leaky pipeline" in STEM fields. Her writing style is scrupulous, often featuring interviews with top-tier scientists and health experts from various institutions. ... Read More