By November 2024, the World Health Organisation had documented more than 7.6 million dengue cases in 2024, comprising 3.4 million confirmed cases, over 16,000 severe cases, and more than 3,000 fatalities. Dengue has emerged as a global public health issue, particularly in numerous tropical and subtropical nations [1]. Dengue is an arboviral disease transmitted by mosquito vectors Aedes aegypti and Aedes albopictus, caused by the dengue virus (DENV). In the past 60 years, the dengue virus has disseminated to more than 130 nations, resulting in around 10,000 fatalities and 100 million symptomatic cases annually [2,3]. Furthermore, over 50% of the global population is susceptible to dengue transmission, predominantly in Asia, followed by Africa and America. It is a primary cause of mortality among youngsters in Southeast Asia[4].

Dengue is a disease caused by an arbovirus. Arboviruses are viruses conveyed by arthropods, as the World Health Organisation (WHO) delineated. The dengue virus (DENV) belongs to the Flaviviridae family and the Flavivirus genus. It comprises four serotypes: DENV1, DENV2, DENV3, and DENV4[5,6]. The pathogen is a virus characterized by a protective outer shell and a symmetrical structure resembling an icosahedron. Its diameter is around 50 nanometres [7, 8]. The DENV genome consists of a single positive-sense RNA strand, approximately 10.8 kb long. It comprises an open reading frame that encodes a singular polyprotein. The polyprotein is then broken into the structural proteins: capsid (C), membrane (M), and envelope (E), along with eight nonstructural (NS) proteins, specifically NS1, NS2A, NS2B, NS3, NS4A, NS2K, NS4B, and NS5. The structural glycoprotein E aids in cell identification and entrance, facilitating the fusion of the viral envelope with the cell membrane. Conversely, the NS proteins facilitate viral genome replication [9,10].

Children exhibit more distinctive traits, as diagnosing dengue and identifying its severe form are more challenging than in adults. DENV infection may manifest with symptoms varying from nonspecific fever to multiorgan failure accompanied by shock and/or hemorrhage. Infants in dengue-endemic regions are anticipated to be safeguarded from clinical sickness due to the transfer of maternal antibodies. Infants born to moms with a history of dengue infection are at an increased risk of experiencing more severe disease upon infection with a different DENV strain due to antibody-dependent enhancement[11-13]. There is limited knowledge regarding the symptoms of dengue in babies. Several published publications from India detail the clinical characteristics of neonates with dengue illness, primarily focussing on cases that arose during an outbreak. 

There are no specific treatments or vaccinations for dengue viral infection; therefore, the most effective method of controlling the disease is through vector management to prevent its transmission.[14]

This study aims to provide a thorough examination of the clinical epidemiological profile of dengue fever in children. This will enable clinicians to better comprehend the disease's magnitude and implications, thereby facilitating appropriate management strategies to mitigate morbidity and mortality

The study type was a retrospective, hospital record-based study. The study population was children between 0 and 15 years old admitted with dengue fever. They were diagnosed and classified per revised WHO 2009 guidelines in the pediatric Medicine Department of Rainbow Institute of Medical Sciences, Amaravathi, Maharashtra. India. The study period was from 1st January 2022 to 30th November 2022

Study technique

Patients were diagnosed by NS-1 ELISA test and /or IgM/IgG Mac ELISA test and classified according to revised WHO 2009 criteria.

Between January 1st, 2022, and November 30th, 2022, 765 children were admitted to our hospital with dengue fever. The maximum admissions occurred in August, followed by September.

 Of 765 cases, 495 (64.70%) were boys, and 270 (35.29%) were girls. Among the total admitted patients, the majority, 330 cases (43.13%), were in the age group of 5–10 years, 34.77% were in the 1-5 years age group, 118 cases (15.42%) were in the>10-15 years age group, and 51 cases (6.66%) were infants (Table 1).

Table 1: Represents the age and sex distribution of the dengue cases (n=765).

A higher incidence of dengue fever was seen in higher age groups because these groups have more outdoor activities and environmental exposure. The most common presentation was fever (100%) followed by Malaise (33.3%), rash (28.75%), Musculoskeletal pain (27.14%), Headaches and vomiting (23.14%), bleeding (14.37%), Oliguria (7.84%) seizures (5.22%), Retroorbital pain (3.66), Altered sensorium (3.66%) and Jaundice(1.96%) are the symptoms of severe dengue and its complications. (Table 2).

Table 2: Represents the Symptoms of dengue fever on admission

In the present study, most of the patients presented with warning signs (58.59%), followed by dengue without warning signs (28.75%) and the least presented with severe dengue fever (17.64%). Signs could be because these patients required hospital admissions and became part of the study. (Table 3).

Table 3: Represents the distribution of dengue fever in terms of severity.

Out of 765 cases, 294 (38.34%) cases of dengue fever presented with atypical manifestations like Dengue shock syndrome, Myocarditis, DIC, Encephalopathy, ARDS, Metabolic acidosis, Acute renal failure and Hyponatremia. Among them, Dengue shock syndrome was the leading presentation, seen in 140cases (18.3%), followed by Hyponatremia 40 cases (5.22%), Myocarditis and DIC 30 (4.18%), ARDS 24 (3.13%), Metabolic acidosis 6 (0.78%), and Acute renal failure in 4 cases (0.52%). (Table 4)

Table 4: Represents the distribution of dengue fever in terms of Complications.

For diagnosis, S. IgM was positive in 277 patients. NS1 antigen test was positive in 430 patients, and IgG was positive in 58 patients. In the present study, NS-1 antigen assay and serum IgM and IgG assay have been done in all suspected patients to compare the sensitivity of the test with the duration of illness. Out of 320 patients admitted on the 1-3 days of fever, most patients had positive NS1 antigen test 220, 101 patients had IgM, and 20 had IgG positive. In patients admitted on 4-6 days of fever, approximately 210 patients had NS1 positive reports, 74 had positive serum IgM reports, and eight had IgG positive. So, the sensitivity of NS1 antigen is higher in the initial 4-5 days of fever. (Table 5)

Table 5 Represents the Correlation between the duration of fever and serological diagnosis.

Radiological abnormalities were seen in a few out of 765 patients; Ascites were seen in 7.84% of patients, 9.01% of pleural effusion and 1.96% of Pseudo thickening of gall bladder walls. (Table 6)

Table 6: Represents the radiological abnormalities in patients

Dengue is a significant global health issue widespread in tropical and subtropical regions. This study delineates the clinical characteristics of dengue fever in pediatric patients admitted to SIMS and RC General Hospital in Bangalore, Karnataka, India. Since the initial verified incidence of dengue in India in the 1940s, sporadic reports have emerged from Delhi, Ludhiana, Mangalore, Vellore, and various other states. The diagnosis is based on the clinical profile; however, they may exhibit diverse manifestations [15].

The incidence of dengue fever has consistently risen throughout the years, particularly among children. This results from fast urbanization, characterized by haphazard development and inadequate sanitary systems, which create optimal breeding conditions for mosquitoes. The heightened awareness among healthcare professionals following the initial outbreak and the availability of diagnostic tools have led to a rise in diagnoses [16].

An outbreak of dengue disease has been recorded during the pre-monsoon and monsoon seasons, attributed to water stagnation following rainfall that promotes vector breeding. This underscores the preventive actions against dengue fever that should be implemented during water stagnation following initial rain and after monsoon season [17].

Among the age and sex groups, most cases were in the age group of 5-10 years, with 43.13%, followed by 1-5 years, with 34.7%. And only 6.6% were in the <1 year age group, which was similar to previous studies conducted by Alam et al.[18]

The most common presentation was fever (100%) followed by Malaise (33.3%), rash (28.75%), Musculoskeletal pain (27.14%), Headache and vomiting (23.14%) bleeding (14.37%), Oliguria (7.84%) seizures (5.22%), Retroorbital pain (3.66), Altered sensorium (3.66%) and Jaundice (1.96%). A similar study was conducted by Selvan et al.[19] In their study, the most common presentation was fever (100%) followed by vomiting (71.1%) followed by rash (55.1%), abdominal pain (47.2%), body ache (45.7%) and headache (40.9%).  Nonspecific symptoms like cough/rhinitis (44.9%) and malware were also found in many patients. In the current study, most of the patients presented with warning signs (53.9%), followed by dengue without warning signs (28.75%) and the least presented with severe dengue fever (17.64%). Our findings are similar to the study conducted by Tripathy et al.,[20]  In the present study, atypical manifestations like Dengue shock syndrome, Myocarditis, DIC, Encephalopathy, ARDS, Metabolic acidosis, Acute renal failure and Hyponatremia. Among them, Dengue shock syndrome was the leading presentation, seen in 140cases (18.3%), followed by Hyponatremia 40 cases (5.22%), Myocarditis and DIC 30 (4.18%), ARDS 24 (3.13%), Metabolic acidosis 6 (0.78%), and Acute renal failure in 4 cases (0.52%). Our findings are similar to the findings of Vinaykumar et al.[21] In the current study, out of 320 patients admitted on the 1-3 days of fever, most of the patients had positive NS1 antigen test 220 and 101 patients had IgM, 20 patients had IgG positive. In patients admitted on 4-6 days of fever, approximately 210 patients had NS1 positive reports, 74 had positive serum IgM reports, and eight had IgG positive. So, it can be concluded that the sensitivity of NS1 antigen is higher in the initial 4-5 days of fever, and our findings are similar to  Pothapregada et al.,[22] Radiological abnormalities were seen in few patients out of 765 patients; Ascites were seen in 7.84% of patients, 9.01% of pleural effusion and 1.96% of Pseudo thickening of gall bladder walls in the present study. Our findings are similar to the survey conducted by Dhingra et al., [23].

Dengue fever is a prevalent and avoidable vector-borne disease, particularly during the monsoon and post-monsoon seasons; therefore, preventive measures should be implemented vigorously from the commencement of the monsoon. It is prevalent among both genders and can impact individuals of any age demographic. However, younger age groups, particularly newborns, are more susceptible to developing severe dengue, resulting in high mortality. Atypical presentations can alter the disease trajectory and potentially postpone diagnosis; therefore, doctors in endemic regions must recognize the diverse clinical presentation of dengue infection to ensure effective and timely therapy of this serious and often lethal illness.

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