Introduction
Dengue, an arthropod- borne viral infection transmitted by Aedes mosquitoes, is a public health problem in tropical and sub-tropical regions of the world. Dengue incidence and death are highest in children aged ≤15 years and case fatality rate is also highest in young children.1, 2 Dengue is ss-RNA and belongs to Flaviviridae family. It has 4serotype. The dengue virus genome is composed of 3 structural proteins, a membrane associated protein -M, an Envelop protein -E, and seven non-structural protein NS protein. NS1 has been shown to interact with the host immune system, known to evoke T cell response. In dengue virus infection, patients have a measurable level of NS1 protein in the blood, which are utilised as diagnostic markers of the infection.
Dengue viral infected person may be asymptomatic or symptomatic and clinical manifestations vary from undifferentiated fever to florid haemorrhage and shock. It is characterised by fever, headache, gastrointestinal disturbance, body pain and rash. More severe dengue is marked by increased vascular permeability, thrombocytopenia and haemorrhagic manifestation, fluid leakage into interstitial space result in shock, which without appropriate treatment may lead to death.3 The haematological effects observed are changes in blood counts, haemoconcentration due to plasma leakage, leukopenia because of decreased neutrophils near the end of the febrile phase, presence of atypical lymphocytes and relative lymphocytosis before shock, thrombocytopenia and changes in blood haemostasis with frequent presence of haemorrhagic manifestation.4 Biochemical and coagulation parameters include raised transaminases (SGOT>SGPT), elevated D-dimer, PT and APTT prolongation and hypofibrinogenemia.
Materials and Methods
Ethical Committee clearance was taken from the institution and informed consent was taken from the guardian of every patient who took part in this study. This prospective, Hospital- based study was conducted in the Department of Paediatrics, of a Tertiary Care Hospital of Eastern India from February 2019 to March 2020. All clinically suspected dengue infection as per the revised World Health Organization (WHO) guidelines 2009 in children of age between 1 to 12 years were screened. A detailed history and a thorough clinical examination were done in all the cases. Data was collected in a prewritten proforma. All the cases were subjected to following investigations: Dengue IgM capture ELISA, Haemoglobin (Hb), total count (TC), differential leukocyte count (DLC), Platelet count, Haematocrit (HCT), Serum Bilirubin, alanine transaminase (ALT), aspartate transaminase (AST), serum albumin, total proteins, Prothrombin time (PT) Activated partial thromboplastin time (APTT), Fibrinogen, D-dimer, urea, creatinine, ESR, CRP, Quantitative Buffy Coat for a malarial parasite, Urine RE/ME blood culture, chest x-ray, widal test, Ultrasound abdomen. Data were collected over a one-year duration then analysed over the next 6 months. Data analysis was done by using a suitable statistical technique.
Statistical analysis
The data were entered into the Microsoft excel enterprise 2007 spreadsheet. The analysis of the available data was done by using IBM SPSS Statistics for Windows, Version 22.0. Armonk, NY: IBM Corp. 2013 and Graph Pad Prism version 5. Statistical methods employed for data analysis was Descriptive statistics, Cross tabs, Chi-Square test for categorical outcomes. The level of significance was considered as 95% of confidence interval. So, P value ≤ 0.5 was considered as statistically significant.
Results
There were total of 123 patients admitted to our hospital during the study period. After exclusion 100 patients were enrolled for the study. Among 100 dengue patients, 85 were Dengue fever (DF), 11 were Dengue fever with warning signs (DFW) and 4 were severe dengue (SD). There were 56 male patients and 44 female patients with P-value >0.05. Among age groups 1 to 12 years, 21 were in 1- 3 years, 28 were in >3 to 6 years and max. i.e 51 were in >6 years of age. We found severity in > 6 years of age which was statistically not significant. (P- value .260 i.e >.05)
In our study, all the dengue patients i.e 100% had fever, only 4% presented with rash, 18% retroorbital pain, 21% body-ache, 28% headache, vomiting present in 52%. Pain abdomen was present in 21% including all 4 SD patients and 9 patients of DFW (P- value.000, <.05). 14% of dengue patients had generalized swelling (DF-4%, DFW- 6%, SD- 4%, P value .000, <.05), bleeding was present in 3 SD which is statistically significant. Among 100 dengue, hepatomegaly was present in only 16 patients, All the 4 SD had hepatomegaly and out of 11 DHF, 7 patients were found with enlarged liver (P-value .000 <.05), 4% developed ascites, 3% pleural effusion and 1% had oliguria. We had not found pallor, Jaundice, cyanosis, splenomegaly and lymphadenopathy which differ from many other studies. 64% had normal SBP and 21% had < 50th percentile as shown in the table number 2. 2 out of 4 SD presented with hypotension which was statistically significant (P-value < 0.05).
In hematological profile, 50% patients had their Hb% in the normal range, 20% patients found anemic and 30% patient had high Hb% (SD- 3, DFW- 7, DF- 20, P value .013, <.05). > 40% PCV was found among 25% of the patients (SD-3, DFW- 6, DF- 16 P value .002, <.05), Leukocytosis WBC >11000 was found in only 4% and leukopenia WBC <4000 found in 22% of dengue fever. Only 1 out of 4 SD had leukopenia (P- value .870, >.05), neutropenia seen in 60% and neutrophilia in 17 %, Lymphocytes count >60%, found in 30 dengue patients (P- value >.05). 39 patients had platelet count < 1.5 lakh among them 3 patients (SD 2, DF 1) had platelet <50000, 17 patients (SD 1, DFW 4, DF 12) had platelet count between 50000 -1lakh, which was statistically significant P value .000, <.05. ESR and CRP was within normal range in 90 and 70 dengue patients respectively and found statistically not significant (P- value >.05). Table 3 depicts the hematological profile of dengue.
The liver function test was deranged in almost all of the dengue patients and it was 3 to 4 times maximally in DFW and SD. Only 28 patients had SGOT ≤40 IU and 72 patients had abnormal SGOT. 42 patients of DF had SGOT value between 40-80 IU i.e slightly raised. 4 out of 11 DFW, had between 81- 120 IU and 6 out of 100 had SGOT value more than 160 IU (2- DF, 2-DFW, 2-SD) P- value .000, <.05. The SGPT was normal in 59 patients. Almost all DFW and SD had abnormal SGPT profile. In out of 11 DFW 4 had less than 2 times, 4 had more than 2 times, 1 had > 3times and 1 had >4 times SGPT value (P- value .000, <.05). Only 4 patient had protein less than 5.6 (DFW-1, SD-3, P- value.000, <.05). Out of 100 patients hypoalbuminemia was found in only 11 patients (DF-3, DFW-4, SD-4, P value.000, <.05). So, we can say that hypoproteinemia and hypoalbuminemia was associated with dengue severity.
In the coagulation profile, we had monitored INR, APTT, D-dimer and Fibrinogen. 17 patients had PT> 16 (normal range of INR in our hospital lab 11-16). 12 out of 17 dengue patients belongs to DF (14.1%), 1 belongs to category DFW (9.1%), 4 dengue patients to SD (100%), P value <.000, <.05. Out of 100 patients aPTT >34 was seen in only 12 patients (5.9%- DF, 27.3%-DFW, 100%-SD) which was statistically significant. 39 Patients had fibrinogen level <200 (<150-5 and 150-200- 34). 100% of SD and 81.8 % of DFW had low fibrinogen which was statistically significant. Same like fibrinogen, D-dimer was also associated with dengue severity.100% of SD and 7 out of 11 DFW i.e 63.6% had D-dimer value >0.5 (P- value .000, <.05).
Discussion
Based on the WHO TDR 2009 dengue guidelines, the total number of cases analysed were 100, out of which 85(85%) were categorised as dengue fever (DF), 11(11%) DF with warning signs and 4 (4%) were cases of severe dengue (DHF/DSS). Non-severe dengue includes both DF and DFW and SD includes DHF/DSS. We had included age group from 1 to 12 years and maximum numbers of cases were seen in the age group >6 years of age (51%) and the least affected age group was 1-3 years of age (21%) which was similar findings to the many other studies like
Table 1
Showing age and sex distribution in DF, DFW and SD. (N=100)
Table 2
Showing clinical features in different category of dengue infection
Table 3
ShowingHaematological profile in different category of dengue infection (N=100)
Table 4
Showing LFT parameters in different category of Dengue Fever (N=100)
Table 5
Showing Coagulation Profile in different category of Dengue Fever (N=100)
Table 6
Descriptive analysis of different parameter in dengue fever
[i] Table 6 Representing Descriptive result of Demographic, clinical, Hematological, Biochemical and coagulation Profile of Dengue fever (DF), Dengue Fever with warning (DFW) and Severe Dengue (SD).
Ramana Sastry C.P.V et al. who found almost 50% were among 6-8 years age group.5 The mean age group in this study was 6.8. More involvement in children > 6years could be explained by the diurnal adaptation of Aedes mosquito in stored water.
These children spent their spare time more open field. This makes them prone to repeated attacks by Aedes mosquitoes. We could see that severity was also seen more in the age group >6 years but it was not statistically significant P value >.05. There was significant difference in male: female ratio in our study 1.2: 1 which was similar to other study as above but in Amrita Roy et al. finding was contrary to our study where the females were more affected in dengue fever than males.6 We had found female and male having equal chance to develop complication. This was probably due to more importance being given to the male children in the Indian society. Covered dress used by females may be another cause for fewer incidences.
Fever was present in 100% dengue patients, vomiting in 52%, headache in 28%, pain abdomen 21%, retroorbital pain 18%, generalized swelling in 14% and only 4% presented with rash. Persisting vomiting, pain abdomen, generalized swelling, bleeding, hepatomegaly, ascites, pleural effusion and oliguria mainly associated with severity of dengue which was statistically significant.
In this study 30 % dengue patients had Hb more than the normal value for their age. Among them 23.5% belonged to DF, 63.6% DFW and 75% in SD. 25 % patients had PCV value >40% which correspond to 18.8%, 54.5% and 75% to DF, DFW, SD respectively i.e more Hb and hemoconcentration indicate severity of dengue which was statistically significant. Similar findings were seen in Ramana Sastry C.P.V et al. and Amrita Roy et al. The percentage increase in haematocrit is an accurate indicator of vascular permeability and plasma leakage. In some DF patients the rise of PCV could have been due to dehydration as a result of poor intake and vomiting.7 There are no clear-cut guidelines for haemoconcentration in the Indian population.
74% patients had normal WBC count, 22% had leukopenia and only 4% had leukocytosis seen in this study population and leukopenia and leucocytosis was not associated with dengue severity (P- value >0.05). Similarly, Mishra et al. also reported that 58.76% of the cases had normal leukocyte count, while leucopoenia was seen in 25.77% and leukocytosis in 15.46% of the cases.8 In dengue neutropenia and lymphocytosis are more common than neutrophilia and lymphopenia. In our study maximum patients had normal WBC count, 60% had neutropenia and 84% had lymphocytosis but did not have any correlation with dengue severity. 39 patients had platelet count < 1.5 lakh among them 3 patients (SD 2, DF 1) had platelet <50000, 17 patients (SD 1, DFW 4, DF 12) had platelet count between 50000 – 1lakh , which was statistically significant P-value .000, <.05 similar to Kumar et al. who observed 14.1% of their patients had a platelet count <20,000 and low platelet count had significantly correlated with the severity of dengue. 9 ESR and CRP was within normal range in 90 and 70 dengue patients respectively and found statistically not significant (P value >.05) which was contrary to finding in study Atukuri SR et al. which depict that C-reactive protein had positive correlation in severe dengue, with significant P value (<0.0001), and non-severe dengue cases found to have no significant correlation. 10 Ho et al. in his study observed low CRP values (<20mg/dl) as a marker for dengue11, 12 which was similar to our findings where we had also found low CRP more.
The liver function test was deranged, SGOT>SGPT in almost all of the dengue patients and it was 3 to 4 times maximally in DFW and SD which was similar to the findings in Amrita Roy et al. kalenahaalli and Jagadishkumar et al. According to Shubhankar Mishra et al, Elevation of SGOT was significantly more compared to SGPT is more associated with severity of infection which coincides with others also. 13 Almost all DFW and SD had abnormal SGPT profile. SGOT raised more than SGPT in dengue may be due to involvement of myocytes. Very high levels of SGOT and SGPT indicate severity of the disease along with morbidity and mortality.
In the coagulation profile we had monitored PT, INR, APTT, D-dimer and Fibrinogen. Dengue fever is associated with transient coagulopathy during course of illness. PT and APTT prolongation may be due to impaired synthesis of the coagulation factor due to involvement of the liver. 100% of SD and 81.8% of DFW had low fibrinogen which was statistically significant which was similar to the study that used 125 I-fibrinogen 14, increased rates of consumption of fibrinogen were demonstrated in patients who had DHF both with and without shock or haemostatic abnormalities. A possible scenario is that dengue infection primarily activates fibrinolysis in the absence of a thrombotic stimulus, degrading fibrinogen directly and prompting secondary activation of various procoagulant homeostatic mechanisms. 15 In the study Kittiya Setrkraising,Chansuda Bongsebandhu-phubhakdi et al. showed significantly higher D-dimer levels in DHF patient compared with DF patient with the sensitivity of D-dimer in predicting DHF of 90%. 16 In our study 100% of SD and 7 out of 11 DFW i.e 63.6% had D-dimer value >0.5 (P- value .000, <.05). D-dimer was also found to be positively correlated with dengue severity in all stage of disease namely febrile, toxic and convalescent (P value <0.05). Detection of D-dimer in febrile stage of dengue infection may be beneficial for predicting the clinical course of the disease. It may help in the clinicians in predicting dengue severity before the patient progress into toxic stage so that close monitoring and proper management can be arranged.
Conclusion
Dengue is a mosquito-borne infection found in tropical and sub-tropical regions around the world. Series of clinical, hematological and biochemical changes occur during course of the illness. They could be used to identify the complications early and introduce effective management strategies, thus reducing morbidity and mortality.
Maximum of the patients present with simple dengue fever. We find age group > 6 years are more and age group <1-3 years are least prone to develop dengue fever. Male are slightly more effected than female but both Genders have an equal chance to develop complications. All dengue patients present with fever. Persisting vomiting, pain abdomen, generalized swelling, hepatomegaly and low Blood pressure is a prognostic indicator of dengue severity and monitoring of the child is of utmost importance. Severe dengue presents with the signs of plasma leakage i.e increased Hb % and PCV, thrombocytopenia which is statistically significant. Elevated transaminase > 3 to 4 times of its normal value associated with dengue severity which is also statistically significant.
In the coagulation profile, raised aPTT, PT, D-dimer and hypofibrinogenemia reflect progression towards complication. So, by using these biochemical parameters, we can segregate the complicated one and by providing adequate monitoring and treatment we can prevent mortality and morbidity associated with dengue fever.
