Dengue in Adults: Rising Burden, Hidden Severity, and Impact of comorbidities- Dr Neha Gupta

National Dengue Day, observed every year on May 16, marks the Ministry of Health and Family Welfare's nationwide push to strengthen dengue awareness, prevention, and community participation. Dengue fever has evolved into a year-round public health issue in India, rather than a seasonal occurrence. According to official National Center for Vector Borne Diseases Control (NCVBDC) data, there were >1 million cases and 1,572 fatalities reported over last 5 years, (2021-2026). In partial data available for 2026 alone, 6,927 cases and 10 deaths have already been reported. (1)

It is noteworthy that recorded instances are an underestimation of the total dengue burden. A prior Indian study found that actual dengue cases were estimated to be 282 times higher than those officially reported by the national vector-borne disease control programme. (2) A population-based serosurvey across 240 clusters in 60 districts from 15 Indian states, estimating 8.8-12.9 million primary dengue infections among people aged 5-45 years, substantially above routine monitoring numbers. (3)

Young Adult Patients Form a Major Affected Population

A 2025 epidemiological investigation by Government Medical College, Patiala analyzed 63,569 suspicious samples from May 2024 onwards and discovered 29,876 dengue-positive patients, with a positivity rate of 47%. The study found that the 21–40-year age bracket had the highest proportion of cases, with males accounting for 64% of positives and rural areas accounting for 61%. (4) Dengue is a significant adult health concern, particularly among working-age populations, resulting in decreased productivity, wage loss, and financial hardships.

Seroprevalence and Serotype Shifts in Dengue Complicate Control

A 2024 systematic review and meta-analysis screened 178 studies and included 44 cross-sectional Indian studies to evaluate dengue seroprevalence across different geographic zones of India. The study found significant regional variation in seropositivity, indicating widespread silent dengue transmission and high background exposure among the Indian population. (5) Diverse serotypes hinder dengue care among adults. A retrospective cross-sectional study from eastern Uttar Pradesh conducted earlier in this decade revealed the circulation of many dengue serotypes, validating India's hyperendemic trend. (6) Another 2024 study from Bengaluru found a change toward DENV-3 dominance between April and July 2024, raising concerns because shifting serotype patterns can influence epidemic intensity and secondary infection risk. (7)

Dengue– Clinically Unpredictable Disease Course

Dengue in adults can rapidly progress during the crucial phase. A Tertiary-care research in Kerala with 153 confirmed dengue patients who presented early in fever; approximately 20%, developed severe dengue, and four deaths were reported. Petechiae, hypo-albuminemia, increased ALT, and elevated urea were found to be predictors of severity. (8) A 2025 North Indian prospective observational study included 158 confirmed dengue patients from tertiary-care facilities. It reported 11.4% mortality among recruited patients; altered sensorium, dyspnoea, decreased urine output, high creatinine, and elevated ferritin were all related with death. (9)

These findings reinforce that platelet count alone should not guide management. Warning signs, renal function, liver enzymes, serum albumin, haematocrit, urine output and mental status require close monitoring.

Dengue & Comorbidities in Adults – Double Trouble

Dengue among adults is increasingly influenced by India’s rising burden of metabolic disease. A 2025 Indian cross-sectional observational study included 350 serologically confirmed dengue inpatients and evaluated the association between dengue haemorrhagic fever severity and comorbidities. The study found that comorbid illnesses such as hypertension, diabetes, cardiovascular disease(CVD), and chronic liver disease(CLD) were associated with greater Dengue Haemorrhagic Fever (DHF) severity, DHF Grade 1 was seen in 62.6%, Grade 2 in 30.9%, and Grade 3 in 2.9% of patients; the association between DHF severity and these comorbidities was statistically significant (P ≤ 0.05), supporting closer monitoring of adults with underlying disease. (9)

Hypertension, diabetes, chronic kidney disease, cardiovascular disease and obesity can worsen endothelial dysfunction, inflammatory response, vascular leakage and fluid-management challenges. In such patients, even apparently uncomplicated dengue may progress rapidly.

Direct and Indirect Health Economic Burden Associated with Dengue

According to 2026 city-wide cohort research from Vellore, Tamil Nadu, hospitalization due to dengue causes a significant financial burden on households; the median direct medical cost for hospitalized cases is INR 16,827. However median cost for severe dengue cases was INR 44,678. Diagnostics, repeated blood tests, hospital stays, ICU care in severe instances, travel, caregiver time, and lost wages from missed workdays are among the costs. The authors also pointed out that India's actual dengue incidence is probably underestimated due to underreporting and deficiencies in private-sector surveillance. (10)

The impact of this economic burden is more significant in lower socioeconomic sections of the Indian society, where quality healthcare access, lack of education and awareness regarding relevant management measures, and overall inadequate resources further worsen outcomes.

Prevention Remains Essential but Suboptimal

Vector management, elimination of stagnant water, fumigation, repellents, window screens, and full-sleeved clothes are still vital. However, recurrent outbreaks despite these steps demonstrate that prevention is uneven and insufficient. Dengue management among adults in India currently necessitates more surveillance, early testing, enhanced private-sector reporting, and risk stratification for patients with comorbidities.

Despite increased awareness, timely recognition of warning signs in dengue remains suboptimal. Caution is especially important during the defervescence phase; the period when fever begins to subside, as this is the stage when severe dengue complications can emerge despite apparent clinical improvement. Although dengue may initially resemble common viral illnesses such as influenza, persistent vomiting, diarrhoea, abdominal pain, worsening weakness, or bleeding symptoms should prompt immediate medical attention, as these may indicate progression to severe dengue.

WHO recommends an integrated dengue prevention approach combining vector control, personal protective measures, community engagement, surveillance, clinical preparedness (11).

Fig 1- Dengue in Adults: Key Points

Key Messages

• Dengue fever among adults in India is characterized by increased incidence, significant under-reporting, high seroprevalence, fluctuating serotypes, unpredictable severity, and the growing influence of comorbidities.

• According to recent Indian studies, working-age adults are significantly affected; severe disease can occur in around one-fifth of hospitalized adult patients in some settings; and renal, hepatic, and inflammatory indicators may predict poor outcomes.

• Dengue care among adults must consequently go from platelet monitoring to organized severity evaluation, comorbidity screening, and early referral.

• WHO recommends integrated dengue prevention strategies including mosquito control, personal protection, community engagement

Disclaimer: The information contained herein is based on the published medical literature and international recommended guidelines. It is not intended to substitute the consultation with a healthcare provider/ registered medical practitioner and shall not be used for diagnosing or treating a health problem or disease. The information provided is aimed at increasing awareness on Dengue and it is not meant for promotion of any specific product. Registered Healthcare Practitioner / Registered Medical Practitioner shall apply their independent medical judgement for assessing or diagnosing or treating any patient. Takeda makes no representation or warranty concerning the information/content provided. The user/presenter of this presentation at his discretion may modify the contents as may be required in accordance with applicable references, laws and regulations. Any liability resulting from modification of slide set shall be the sole responsibility of user/presenter.

Document Number: C-ANPROM/IN/QDE/0168; Date of Preparation: May 2026