DENGUE FEVER IN CHILDREN: ROLE OF ULTRASONOGRAPHY

* Dr. Sujit Mulay 1 , Dr. C. S. Rajput 2 , Dr. Sudha Bhave 3 and Dr. Suresh Waydande 4 . 1. Junior Resident, Department of pediatrics, Bharati vidyappeth university medical College and Hospital, Sangli. 2. Professor, Department of pediatrics, Bharati vidyappeth university medical College and Hospital, Sangli. 3. Associate Professor, Department of pediatrics, Bharati vidyappeth university medical College and Hospital, Sangli. 4. Assistant Professor Department of pediatrics, Bharati vidyappeth university medical College and Hospital, Sangli. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History


ISSN: 2320-5407
Int. J. Adv. Res. 5 (3), 251-256 252 The etiologic agents include all four serotypes which belong to the genus Flavivirus in the family Flaviviridae. The principle vector is mosquito, AedesAegypti, which breeds largely indoors in clean waters mainly in artificial water containers, and feeds on humans in daytime [4].
The clinical manifestations of dengue vary with the age and immunity of the patient. It can present as 1) In apparent infection 2) non-specific febrile illness, 3) classic dengue fever, 4) dengue hemorrhagic fever, 5) Dengue shock syndrome (DSS) and 6) encephalopathy and fulminant liver failure [5,6]. Guzman et al. studied to show that most cases present as classic dengue fever (DF) with high fever, retro-orbital pain, severe myalgia/arthralgia, and rash. However, in some cases, illness progresses to life-threatening dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS), characterized by vascular leakage leading to hypovolemic shock and a case fatality rate up to 5% [7,8].
Hammond et al. [9] studied to show that preschool children and infants have rather more often nonspecific febrile illnesses while preadolescent children often develop fever and moreover younger children with DHF are known to experience more severe clinical outcome (e.g. higher case fatality ratio) than adults.
Early identification of patients at risk of developing severe dengue is critical to provide timely supportive care, which can reduce the risk of mortality to < 1% [10]. Distinguishing dengue from other febrile illnesses (OFIs) early in illness is challenging, since symptoms are non-specific and common to other febrile illnesses such as malaria, leptospirosis, rickettsiosis, and typhoid fever in dengue-endemic countries [11].
Positive serology (anti dengue antibody) is the mainstay in the diagnosis of DF. But serology takes approximately 7 days to give a positive result [12,13]. The diagnosis of DF is often delayed owing to time taken for availability of serology test results [14]. Ultrasonography (USG) is a cheap, rapid and widely available non-invasive imaging method [15,16]. Some authors concluded findings of hepatomegaly, pericholecystic edema, thickened gall bladder, ascites, pleural effusion (right sided/ both) and splenomegaly are early and significant markers of dengue, which can be confirmed by serology later on [17,18]. Several studies concluded that ultrasonography of the chest and abdomen can be an important adjunct to clinical profile in diagnosis DF and diagnosis can be made early in the course of disease compared with other modes of diagnosis [14]. It can be used as a first-line imaging modality in patients with suspected dengue fever to detect early signs suggestive of the disease prior to obtaining serologic confirmation test results, especially in a dengue fever epidemic area [17].
These findings may also occur in other viral infections and enteric fever but in other viral infections the historical profile, symptom complex evolution and physical findings do not mimic those of dengue fever [14]. Thus, the aim of present study was to evaluate the sonographic findings of dengue fever which may be useful as an early diagnostic tool.

Materials and Methods:-Study Type & Area:-
A prospective observational study was conducted at Department of Paediatrics of a tertiary care centre during July 2014 to August 2016.
Inclusion Criteria:-1. Patient between the age group of 0 -18 years. 2. Patients with confirmed diagnosis of dengue fever (positive test for NS1 antigen/IgM dengue/IgG dengue).
Exclusion Criteria:-1. Patient with serological test negative for dengue. 2. Patients having fever of more than 2 weeks duration.
Sample Size:-Consecutive type of non-probability sampling was used for the selection of study subjects. A total of 88diagnosed pediatric patients of Dengue fever admitted in our hospital were taken for study after informed consent from parents.

Study Methodology:-
All patients were admitted and treated as indoor patients. On admission, detailed history and complete physical examination findings were recorded. The vitals (temperature, pulse, respiration, blood pressure) of the patients were recorded on admission and thereafter till discharge.In all patients, complete blood count and serological tests for dengue (NS1 antigen/ IgM dengue/ IgG dengue) were carried out depending on duration of fever on presentation.
Following laboratory investigations were done in all patients on admission:-1. Dengue NS1 antigen test/ IgM dengue antibody/ IgG dengue antibody-depending on duration of fever on presentation. All the three tests will be done by the ELISA (enzyme linked immunosorbant assay) technique. 2. Complete blood count (CBC) including platelet count.

Coagulation Profile 4. USG abdomen
Other investigations like liver function test, renal function test, S. electrolyte, X-ray chest/abdomen, blood culture, peripheral smear for malarial parasite were performed based on the clinical presentation. Based on the investigation results, patients were classified into 3 categories as per WHO guidelines: Dengue fever, Dengue Hemorrhagic fever and Dengue shock syndrome. All patients will be treated as per WHO guidelines-Dengue guidelines for diagnosis, treatment, prevention and control [19].

Discussion:-
Dengue has become a major international public health concern in recent years [20]. It is emerging as one of the most important mosquito borne diseases in India. Aedes aegypti mosquitoes that transmit the disease breed in manmade containers such as tanks, pitchers, discarded containers etc. in which water has stagnated for over a week. Thus, the success of control measures have become a reflection of sanitation and hygienic practices achieved. The cases of dengue peak in the monsoon season in most parts of the country but have become perennial in the southern states and Gujarat [21,22].
Dengue has myriad clinical manifestations with unpredictable evolution and outcome. The disease typically begins with an acute febrile phase lasting 2-7 days and is accompanied by flushing, generalized body ache, myalgia, arthralgia and headache. Increased capillary permeability reflected by progressive increase in hematocrit heralds the beginning of critical phase at around 3-7 days of illness. Severe hemorrhagic manifestations and shock secondary to plasma leakage may occur at this stage. Leukopenia and declining platelet counts are also seen preceding this stage [23]. Serological diagnosis is confirmatory of dengue and includes direct methods such as virus isolation and NS1 antigen detection and indirect methods such as IgM and IgG antibody detection [24].As serological diagnosis is not available in most of the places in a resource scarce country like India, sonography has an increasingly important role. Sonography is a readily available and cost-effective method for the diagnosis, which impacts the management of patients of dengue. The aim of present study was thus to evaluate the role of sonographic findings as early diagnostic modality in children with dengue fever. In present study, male predominance was seen with 63.6% male cases to 36.4% females with male to female ratio of 1.74:1. In a study by Hema M et al. [25], the sex ratio of male to female was 1.32: 1, while in that of Srinivasa et al. [26], it was 1.13:1. The sex distribution is also consistent with previous study findings that dengue fever occurs more in male sex [22,24,27].
We also observe thrombocytopenia in 78.4% cases while hemoconcentration and raised liver enzymes were observed in 48.9% and 68.2% cases respectively. In the study by Mittal Hema et al. [25], thrombocytopenia and hepatic enzyme derangement was present in 92.6% and 60% of the cases respectively. In the study by Narayanan M. et al. [31], serum SGPT levels were elevated in 59.7% of the total patients in whom the test was performed. Serum SGPT levels were elevated in 65% of DF, 63.6% of DHF and 66% of DSS patients. In the study by Aggarwal Anju et al. [32], serum SGPT levels were elevated in 57% of the patients in whom the test was performed.
The ultrasonographic findings showed hepatomegaly in 35 In the study by srinivasa et al. [26], 72% of the cases had ultrasound findings in the form of either hepatomegaly or gall bladder wall thickening.The ultrasound findings showed gall bladder wall thickening in 30.5%. In a study by Quiroz-Moreno et al. [33] gallbladder thickening was seen in 86% of the patients, Sai et al. [14] observed in 56% patients whileThulkar et al. in 35.1% [34]. Setiwan et al. attempted to investigate whether gall bladder wall thickening measured by ultrasonography can be used to predict the onset of severe dengue fever. It is found that a 255 thickness of 5mm is useful as a criterion for identifying DHF patients at high risk of developing hypovolemic shock [35].
In our study pleural effusion or ascites was apparent on clinical examination in some of the cases. But sonography helped in diagnosing all of them. Similarly 15 cases of hepatomegaly and 11 cases of splenomegaly could not be diagnosed by clinical examination but were diagnosed correctly by ultrasonography. So this study clearly demonstrates the importance of ultrasonography in the accurate and complete clinical evaluation of dengue fever. All the cases which went into hypotension and shock showed gall bladder wall thickening, with moderate to severe pleural effusion and ascites.

Conclusion:-
Abdominal USG should be used as a first-line imaging modality in all patients with suspected dengue fever to detect early signs suggestive of the disease along with obtaining serologic confirmation tests.