The Predictors of the Severity of Dengue Fever: A Cross-Sectional Study in a Tertiary Care Center of Bangladesh

Abstract

Background: Dengue is an endemic disease for Bangladesh with occasional outbreak. Little is known about the predictors of severe dengue. Methods: This cross sectional study was conducted in the medicine department of Dhaka Medical College from April 2019 to March 2020. Total 199 consecutive patients were enrolled in this study. For the purpose of the analysis, dengue fever was classified as group I and dengue hemorrhagic fever and dengue shock syndrome was classified as group II. Results: The mean (SD) age of the study population was 28.5(12.1) and 87.4% were less than 40 years of age. The male and female ratio was about 3:1. Among the total study population, 149(74.9%) patients had DF, 46 (23.1%) had DHF and only 4 (2%) had DSS on presentation. Baseline demography and clinical presentation did not significantly differ between classical dengue and severe dengue. Previous history of dengue had low association with severity (RR, 95%CI, phi, P value; 1.2, 1.04-1.40, 0.25, 0.001).Most of the laboratory parameters were similar between the groups. The number of platelet count was significantly lower in DHF and DSS [median (IQR) 43500(16500-95250], than DF [median (IQR) 65000(33000-1170000, p-value 0.01] Conclusion: Previous infection with dengue virus and decreasing platelet count are the predictors of the severe dengue. Key word: Dengue Fever, Predictors of severe dengue. DOI: https://doi.org/10.3329/jdmc.v29i1.51175 J Dhaka Med Coll. 2020; 29(1) : 77-82 1. Dr. Mohammad Zaid Hossain, Associate Professor, Department of Medicine, Dhaka Medical College Hospital, Dhaka 2. Dr. Nusrat Sultana, Assistant Professor, Department of Virology, Dhaka Medical College. 3. Dr. Afroza Akbar Sweety, Assistant Professor, Department of Virology, Dhaka Medical College. 4. Dr. Reaz Mahmud, Assistant Professor, Department of Neurology, Dhaka Medical College, Dhaka, Bangladesh. 5. Dr. Mohammed Masudul Hassan Khan, Assistant Professor, Department of Medicine, Dhaka Medical College, Dhaka 6. Dr. Muhammad Faizur Rahman, Assistant Professor, Department of Medicine, Dhaka Medical College, Dhaka 7. Dr. Sadia Saber, Assistant Professor of Medicine, Bangladesh Medical College, Dhaka 8. Dr. Farzana Rahman, Assistant Professor, Department of Medicine, Dhaka Medical College, Dhaka 9. Dr. Khairul Islam, Junior Consultant, Department of Medicine, Dhaka Medical College, Dhaka 10.Dr. Forhad Uddin Hasan Chowdhury, Registrar, Department of Medicine, Dhaka Medical College, Dhaka 11.Dr. Mazharul Islam, Honorary Medical officer, Department of medicine, Dhaka Medical College Hospital, Dhaka 12.Dr. Nandita Paul, Senior Consultant, Department of Medicine, Mugda Medical College Hospital, Dhaka 13.Prof. Khan Abul Kalam Azad, Principal & Professor of Medicine, Dhaka, Medical college Hospital. Correspondence: Dr. Mohammad Zaid Hossain, Associate Professor, Department of Medicine, Dhaka Medical College Hospital, Phone: +8801713097627. E-mail: zhvalentino@gmail.com Received: 22-01-2020 Revision: 29-01-2020 Accepted: 21-03-2020 Introduction Dengue fever (DF) is the most common mosquito-borne viral disease in the world. Approximately 390 million people are affected worldwide every year, with around a 1% mortality rate of which 70% of the cases are predominantly in Asia1. On the other hand, the number of infected cases is rising exponentially over the years. Therefore, it has been a major public health threat to the world for several decades especially in the tropical and subtropical regions. In Bangladesh, the first official dengue outbreak occurred in 20002. Since then every year Bangladesh has faced a mild to severe outbreak. In 2019 dengue outbreak has been the largest with 101354 cases and 166 death3. Nonetheless, the more frequent and severe outbreak is predictable because of climate change, poor urban planning, and inadequate awareness among the population4. DF occurs due to the acute infection caused by four serotypes (DENV-1, DENV-2, DENV-3, and DENV-4) of the dengue virus5. The features of dengue patients may include symptoms like fever, typically lasting for 5 to 7 days, with saddleback or biphasic curve manifested by a second phase fever lasting for one or two days. Headache, retro-orbital pain, muscular pain/ myalgia, joint pain/arthralgia, marked fatigue lasting for days to weeks are common. Other symptoms, such as rash, gastrointestinal symptoms including nausea or vomiting respiratory tract symptoms including cough, sore throat, and nasal congestion may appear depending on the pattern and severity of the disease1. Peripheral blood parameters are characterized by leucopenia (White Blood Cells (WBC) < 5000 cells/mm3), thrombocytopenia (< 150,000 cells/ mm3), rising hematocrit (5–10%). In Dengue Hemorrhagic Fever (DHF) plasma leakage occurs which is usually evidenced by ascites or pleural effusion. Additional laboratory findings include an elevated level of serum aspartate transaminase (AST), ALT. Decrease of Serum Albumin and S calcium levels are frequent in both adults and children with dengue fever3. The severity of the dengue fever varies from asymptomatic febrile illness to life-threatening Dengue hemorrhagic fever (DHF) or Dengue shock syndrome (DSS)5. The fatality of the dengue fever occurs largely in DHF and DSS. It has been observed that management in appropriate time can reduce the case fatality6. If the risk factors for the progression of the dengue fever are known, close monitoring of the susceptible patients will be possible. It will be helpful in reducing the case fatality in a costeffective way for the resource limited country like Bangladesh. Very little is known about the risk factors for the prediction of the severity of the Dengue fever. In this cross-sectional study we observed the clinical feature and the laboratory parameters of the Dengue fever. To determine the risk factors for the severity we compare the clinical features and different laboratory parameters among the different severity of dengue patient. Methodology This cross sectional study was carried out at the department of Medicine, of Dhaka medical college hospital from March 2019 to March 2020. The recruitment was limited to patients more than 18 years of age, both sexes with positive NS1 antigen or positive IgM antibody for dengue. Pregnant women and critical dengue patient were excluded from the study. Written informed consent was obtained from all the patients or from a legal representative where necessary. Ethical approval was taken from the ethical review committee of the respective institute. No priori sample size calculation and statistical power was determined. Total 199 patients were recruited according to mentioned inclusion and exclusion criteria. Procedure: A case record form was constructed to collect base line information, like demography, clinical features, and associated co-morbidities. Details physical examination was done. Clinical investigations which included complete blood count, blood sugar, serum creatinine, alanine aminotransferase(ALT), aspartate aminotransferase(AST), serum calcium, serum albumin was done in every patient during the admission or with in 24 hour of admission to know the baseline parameter. Repeated investigation was done according to patient need and as per physician’s decision. All the hematological investigations were done in the laboratory of DMCH using Beckman Coulter analyzer model AU480, USA. Dengue viral infection was classified according to National Guideline of Bangladesh3. Like dengue fever as typical signs symptoms of the dengue with NS-I antigen or IgM positivity without evidence of plasma leakage with or without hemorrhage. Dengue hemorrhagic fever as typical features mentioned above with evidence of plasma leakage (as evident by positive tourniquet test, 20% increase in hematocrit, presence of ascites or pleural effusion). Dengue shock syndrome as typical feature mentioned above and evidence of shock (narrow pulse pressure, less than 20 mm Hg and or hypotension) Statistical analysis: Statistical analysis was done by SPSS 23 version. Qualitative variables were expressed in n(%), normally distribute quantitative J Dhaka Med Coll. Vol. 29, No. 1. April, 2020