Dengue in Adults: From Early Warning Signs to Hospitalization, Recovery, and Long-Term Impact

Dengue is among the fastest-spreading mosquito-borne viral infections globally, with a nearly 30-fold increase in incidence over the past five decades. In India, dengue is endemic in almost all states except, Ladakh, with cases peaking during the monsoon months (July-November) (1). According to data from the National Centre for Vector Borne Disease Control (NCVBDC), India has so far reported 6,927 dengue cases and 10 deaths in 2026 (2). Interestingly, a study conducted in India, confirmed the actual number of dengue cases may be up to 282 times greater than those officially reported by the National Vector-Borne Disease Control Program (3).

Dengue is no longer confined to seasonal outbreaks and continues to pose a substantial clinical and public health burden among adults in urban and semi-urban India (4).

Concurrent Infections in Dengue in Adults: A Clinical Consideration During the Monsoon Season

In India and other tropical regions, dengue frequently overlaps with other endemic infections, particularly malaria and enteric fever, during the monsoon and post-monsoon months. Emerging evidence suggests that dengue-malaria co-infection is not uncommon and may be associated with a more complicated clinical course due to overlapping manifestations such as thrombocytopenia, hepatic dysfunction, anaemia, and systemic inflammation (5, 6).

A recent meta-analysis reported a rising prevalence of malaria and acute dengue virus co-infection in endemic settings, underscoring the importance of considering concomitant infections in adults presenting with severe disease, persistent fever, or clinical features that appear disproportionate to the expected course of dengue (5). Similarly, co-existing enteric fever may further complicate the clinical picture and contribute to prolonged febrile illness and increased healthcare utilization (7).

For clinicians managing dengue in adults during seasonal outbreaks, awareness of potential co-infections may facilitate timely diagnostic evaluation and appropriate management, particularly in patients with atypical presentations, delayed recovery, or early organ involvement.

Establishing the Diagnosis in Adults

Dengue diagnosis in adults is based on NS1 antigen ELISA during the first five days of illness, followed by IgM ELISA beyond day 5, with PCR being useful for early molecular identification. Rapid diagnostic tests (RDTs) are deemed less accurate due to their varying sensitivity. (1)

Which Adults with Dengue Patients Are More Likely to Require Hospitalization?

"Although most adults with dengue experience a self-limited illness, progression to severe dengue is often preceded by identifiable clinical and laboratory warning signs that may help guide decisions regarding hospitalization and monitoring. Identifying patients at increased risk of clinical deterioration remains critical, particularly during the transition from the febrile to the critical phase.

Evidence suggests that older age, pre-existing comorbidities, persistent vomiting, abdominal pain, mucosal bleeding, rising haematocrit, progressive thrombocytopenia, and early evidence of organ involvement are associated with an increased likelihood of severe dengue and hospital admission (8,9). Comorbid conditions such as diabetes, hypertension, chronic kidney disease, cardiovascular disease, and chronic liver disease may further increase vulnerability to adverse outcomes and warrant closer follow-up during the acute illness (8).

Renal involvement is increasingly recognized as an important predictor of disease severity in adults. In an Indian tertiary-care study, acute kidney injury occurred in more than one-fifth of hospitalized dengue patients and was associated with significantly poorer outcomes, highlighting the need for early monitoring of urine output, volume status, and renal function in high-risk individuals (9).

Risk stratification based on clinical warning signs and evolving laboratory parameters may help clinicians identify patients who are likely to benefit from hospitalization before the onset of severe complications."

When and Why Is Hospitalization Required in Adults with Dengue?

Hospitalization in adults with dengue is primarily aimed at early recognition and management of complications that may emerge during the critical phase of illness, typically around defervescence. While most patients can be managed as outpatients with adequate hydration and follow-up, those who develop warning signs require closer monitoring because clinical deterioration can occur rapidly over a short period (10).

According to the WHO and Indian national guidelines, hospitalization should be considered in adults presenting with persistent vomiting, severe abdominal pain, mucosal bleeding, clinical fluid accumulation, lethargy, restlessness, hypotension, rising haematocrit with falling platelet counts, reduced urine output, or evidence of organ dysfunction (1,10). Admission may also be warranted in patients with significant comorbidities, advanced age, pregnancy, or inability to maintain adequate oral hydration and follow-up.

The principal objectives of hospitalization include serial clinical assessment, monitoring of haematocrit and platelet trends, optimization of fluid management, early detection of plasma leakage, and timely management of complications such as shock, severe bleeding, acute kidney injury, hepatic dysfunction, or cardiac involvement. In an Indian ICU-based study of severe dengue, nearly one-third of admitted patients died, underscoring the importance of early recognition and escalation of care in patients demonstrating poor prognostic indicators (11).

Appropriate hospitalization and vigilant monitoring during the critical phase remain central to reducing morbidity and mortality in adults with dengue.

Figure 1: Dengue Clinical Overview

Post Dengue Recovery and Quality of Life- Less Spoken Issues in the Real World

Adults may take a longer time to recover from dengue fever. Post-dengue fatigue syndrome is increasingly recognized as a long-term post-viral consequence characterized by debilitating exhaustion, muscular and joint pain, poor attention, sleep disturbance, mood abnormalities, and decreased daily functioning. According to a 2024 review in the Karnataka Medical Journal, 20-25% of hospitalized dengue patients have post-dengue tiredness syndrome, experiencing symptoms for months or years (12), which may likely hamper their productivity, interpersonal relationships, and overall quality of life.

Humanistic Economic and Social Burden in Dengue – Ramifications Beyond Clinic to Community

Prolonged recovery can affect physical productivity for weeks after infection, affecting work performance and daily functioning. This is especially concerning in economically productive age groups and among daily wage workers, because dengue-related productivity losses include loss of paid and unpaid work by both patients and caregivers (13).

Dengue imposes a substantial financial burden on adults and their families through medical expenses, hospitalization costs, lost productivity, and caregiver responsibilities. In a large urban cohort from Vellore, Tamil Nadu (74,587 individuals), the median direct medical cost was INR 4,357 for laboratory-confirmed dengue managed in outpatient settings, rising to INR 16,827 for hospitalized cases and INR 44,678 for severe dengue (14).

Another study reiterated that adults with severe dengue had the greatest hospitalization costs, with a median of ₹46,538, more than twice those of adults with less severe dengue. This research also pointed out that these estimates did not account for indirect costs like lost wages, travel, food, or lodging expenses, suggesting that the true economic burden of dengue in adults may be significantly higher in the real world (15).

Key Takeaway

Dengue in adults is increasingly associated with hospitalization-related challenges, particularly during the critical phase of illness. Early recognition of warning signs, identification of high-risk patients, timely hospitalization, and vigilant monitoring for complications remain central to improving outcomes. Beyond the acute illness, prolonged recovery and significant economic burden continue to reinforce dengue as a major public health challenge in India.

This information is solely intended for the use of Registered Healthcare Practitioner / Registered Medical Practitioner only. The information contained herein is based on the published medical literature and international recommended guidelines. The information provided is intended for educational purposes only, aimed at increasing awareness on dengue disease and not meant for promotion of any specific product. Registered Healthcare Practitioner / Registered Medical Practitioner shall apply their independent medical judgement for diagnosing or assessing or treating any patient. Takeda makes no representation or warranty concerning the information / content provided and assumes no responsibility for the accuracy of the information or content or opinion furnished or any outcome based on the application of such information. This material contains copyright protected information, content; the use of which is limited by law and this material cannot be reproduced, replicated, used, or modified by any person for their own use or further distribution.

TAKEDA and the TAKEDA logo are trademarks or registered trademarks of Takeda Pharmaceutical Company Limited.

Document number : C-ANPROM/IN/QDE/0203 ; Date of Preparation: June 2026