European Journal of Cardiovascular Medicine

Dengue is a arthropod borne acute viral illness caused by Flavivirus and transmitted by Aedes Aegypti mosquito and is characterized by biphasic fever, myalgia, arthralgia , rash and lymphadenopathy.
There are 4 distinct antigenic types of Dengue Virus-DEN 1, DEN 2, DEN 3, DEN 4. Infection by one serotype provides lifelong immunity against a particular serotype but doesn’t have cross protection against other serotypes.1
Dengue virus can be asymptomatic or present with severe manifestations like Dengue Hemorrhagic fever or Dengue Shock Syndrome.
The World Health Organization (WHO) has estimated that 2.5 billion
population and 124 countries are at the risk of dengue Infection resulting
in 100 million reported cases and 30,000 estimated deaths globally.2
In many regions where disease is endemic dengue triggers periodic
epidemics occuring every 2-4 years but India has experienced such epidemics annually for the last few decades.
The principal Diagnostic Modalities in endemic countries are Dengue NS 1 Ag and IgM antibody in early and later stage of illness respectively because of cost effectiveness ,good sensitivity and specificity . 3
Dengue cases could have missed because Dengue, with its diverse serotypes, may present with distinctive clinical features and lack of timely serological investigations being done .
In light of the evolving nature of Dengue, this research seeks to address critical gaps in our current knowledge, ultimately fostering advancements that can enhance our ability to mitigate the impact of Dengue across diverse populations by accurate identification of clinical signs and serological examination.

This is a hospital based Prospective observational study conducted in the Department of Pediatrics , Navodaya Medical College Hospital and Research centre over a period of 6 months from April 2023 to September 2023.
A total of 107 cases were included in the study after taking informed consent from the parents.
Clinically suspected dengue is Fever ≥38°C for less than 7 days with any 2 of the following- Nausea, Vomiting, Headache , Retro orbital pain or any warning signs like hypotension, Hemorrhagic manifestations.
WBC < 4,000 and Platelets count <1.5 lakh were considered as leukopenia and thrombocytopenia respectively.
Inclusion criteria-
• All children i.e.,less than 18 years of age with clinically suspected Dengue and NS1 Ag only or Both NS1 Ag and IgM positive cases. 
Exclusion criteria
• Children with Negative Dengue Serology
• Children with other coexisting infections.
Clinical features are classified into Category A – Probable Dengue, Category B – Dengue with warning signs and Category C -Severe Dengue
All clinically suspected Dengue cases were divided into two groups – 1) Group 1- Children with only NS1 Ag positive and 2) Group 2 - Children with both NS1 Ag and IgM positive.
The clinical manifestation, blood counts, the trend of counts were noted in all patients. These parameters were compared between the two groups.
Statistical analysis
Data was entered in MS Excel and analysed using SPSS software. Data is expressed in mean and frequencies in percentage. P value < 0.05 is considered significant.
Ethical clearance for the research is obtained by institutional ethical research committee.

Out of 107 cases 76 children were in Group 1 and 31 children in Group 2.
In our study it was found that majority of children were in between 5-10 years of age. In both Group 1 and Group 2 with 37(48.6%) in group 1 and 11(14.4%) in group 2 with male predominance in both the groups 40(52.6%) and 18(58.1%) in 1 and 2 group respectively.
Fig 1-Age wise distribution of cases in both subgroups .
0
5
10
15
20
25
30
35
40
Group 1
Group 2
56.50%

Fig 2-Gender distribution in different subgroups.
In the present study 24(22.5%) cases occurred during months of April – June and 83(77.5% ) cases from July to September.
In Category A symptoms All children presented with fever other clinical features were vomiting, myalgia and rash

Table 1 – Comparison of Clinical features in both sub groups
In Category B symptoms majority of children presented with abdominal pain followed by persistent vomiting and then clinical fluid accumulation.
In Category C, in Group 1- 6 cases presented with respiratory distress because of fluid accumulation ,4
cases in shock, 1 with severe bleeding manifestations and 1 in impaired consciousness whereas in Group 2 children- 2 cases presented in shock, 1 each in respiratory distress and bleeding manifestations

Table 2 – Categorical distribution of clinical Features.
In the laboratory parameters leukopenia, thrombocytopenia and hemoconcentration were noted. A more rapid fall in average platelet counts was observed in group 2 than in group 1 with minimum platelet count of 8,300 and 12,600 in group 1 and 2 respectively , average Hematocrit in group 1 is 33.6 and in group 2 is 34.9.
In Group I, 10 patients deteriorated from a lower category to a higher category whereas only 1 patient deteriorated from a lower category to a higher category in group II. Average duration of stay was 3 days in group 1 and 5 days in group 2 and Average duration of illness was 4 days in group I and 5 days in group II.
43.40%
Group 1
Males

In our study majority of the cases were in between 5-10 years of age which was similar to study conducted by Sinha et al 4 with slight male predominance which was similar to study findings done by Sahana K S et al 5 .In our study maximum cases 76% cases occurred during months of July to August which correlated with study conducted by Satish J V et al 6, this seasonal trend may be because of harvesting season for paddy and stagnation of water which serves as a breeding place for the vector.
Fever was the consistent complaint in both serological subgroups, other complaints were vomiting, generalized body ache and rash which was similar to study by Sabchareon A et al 7 Predominant bleeding manifestations were petechiae , epistaxis which was more in group 2 than group 1, In our study bleeding manifestation epistaxis correlated with study by Kulkarni et al 8 whereas in a study by Aggrawal et al 9 it was found hematemesis as the major bleeding manifestation.
More children in Group 1 - 10 cases deteriorated from lower to higher category than compared to group 2 were only 1 case deteriorated from lower to higher category.

Classical laboratory abnormalities of dengue like leukopenia, thrombocytopenia and hemoconcentration were observed in most of our study patients also which was similar in study by lokanatha et al 10 . However these findings were more in group 2 than in group 1.
A more rapid fall in average platelet counts was observed in group 2 than in group 1 which may be associated with bleeding manifestations in group 2.
Leukopenia was not associated with severity of dengue since it was associated with all categories of dengue which correlated with study by Saha k A et al. 11 Thrombocytopenia in dengue may be due to decreased production by the bone marrow, Ag -Ab mediated destruction or increased consumption because of increased platelet activating factors secondary to infection.
The more severe clinical and laboratory manifestations in group 1 who had only antigen positive in comparison to those who were also IgM positive may indicate a protective mechanism of the immune phenomenon.

In conclusion, this comparative study on clinical profiles within dengue serological subgroups provides valuable insights into the diverse manifestations of the disease. By examining distinct serotypes, we’ve identified variations in symptom severity, duration, and complications associated. Children with IgM negative may require more vigilant monitoring and care. However larger studies are needed to ascertain the same.