Frequency and trend of dengue fever in a tertiary care hospital in Kancheepuram, Tamilnadu: three-year retrospective study

INTRODUCTION

Dengue is vector borne viral infection transmitted by bite of mosquitoes mainly affecting tropical and subtropical regions of the world.¹ Dengue virus has four serotypes (DEN 1-4) among which serotype DEN 2 is most common in India.² The Dengue name is derived from the word ‘Ki denga pepo’, which means sudden seizure by the demon in the Swahali language.³ Benjamin Rush called dengue fever as break bone fever after the 1780 tragic epidemic in Philadelphia.⁴ Dengue fever causes a significant morbidity and mortality in the tropical regions and nearly 2/5^th of the global population living in high risk areas for dengue infection.⁵ Global prevalence of dengue fever is increasing over the years and it is endemic in nearly 100 countries.^6,7

Majority of dengue fever cases presents as a self-limiting illness and rarely they go in for severe complications like dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS).⁸ The two factors which are associated with increased severity of dengue infection are secondary dengue infection and infection with virulent viral strain.⁹ Early diagnosis of the dengue infection remains the cornerstone for treatment and prevention of dreadful complications like DHF and DSS.^10,11 Till date there is no vaccine or specific anti-viral drug to treat dengue infection and hence vector control remains the only option to bring down he burden from the disease.^12,13

In India the firs epidemic was reported in 1780 in the metropolitan city of Chennai in Tamil Nadu.¹ Dengue fever is endemic in 34 states/UT of India. During 2009-2017 in India 683,545 dengue cases and 2,576 dengue deaths were reported as per the national vector borne disease control program surveillance data.¹⁵ Case fatality rate due to dengue is more than 1 over the last decade.¹⁶ In Tamil Nadu during 2018, overall 4,486 people were affected by dengue and 13 deaths were also reported.¹⁷

With this background this three-year retrospective study was planned in Kancheepuram district of Tamil Nadu with the objectives to describe the frequency and distribution of dengue infection and to determine the association between dengue infection and selected variables.

METHODS

It was a hospital based retrospective observational study conducted for a period of 3 months (January 1^st 2018 to March 31^st 2018).

Study area

The study was conducted in Sree Balaji medical college and hospital in Kancheepuram district, Tamil Nadu which is tertiary care teaching hospital.

Study population

Dengue patients belonging to all age group were chosen as the study participants.

Sampling method

Dengue patient’s records from the medical records department of the hospital were selected using universal sampling method.

Sample size

In the three-year time period 340 dengue patients were admitted in the hospital and they all were taken as study samples.

Data collection

Records of 340 dengue patients obtained from medical records department of the hospital were reviewed for the period of 3 years (2015 -2017). Dengue was diagnosed in the hospital by ELISA. Details about Socio-demographic features, type of dengue, and platelet count at the time of admission were taken from the records.

Statistical analysis

The data was entered in Microsoft excel and analysed using SPSS 22 version. Descriptive and analytical statistics were used to explain the study variables.

Ethical approval

The study was approved by the Institutional Ethics Committee, Sree Balaji Medical College and Hospital.

RESULTS

Frequency distribution of dengue infection

Among the study participants 240 (74.5%) were males and 100 (25.5%) were females. Table 1 shows majority of the dengue patients belonged to 20-40 years of age 168 (48%).

With respect to socio economic status nearly 63% of dengue cases belonged to lower class and 27% belonged to middle class. In this study, 306 (90%) patients were of the classical dengue type and 34 (10%) patients belong to DHF type.

Sex wise distribution of dengue infection

In this study Figure 1 depicts the sex wise distribution of dengue infection. Nearly 74.5 % of the patients were males and 25.5% were females. Among classical dengue cases 70% (213) were male and 30% (97) were females. Also among DHF cases 79% (27) were males and 21% (7) were females respectively

Trend of dengue infection

In the three-year study period more number of cases were reported in the year 2017 (61.7%) and followed by 2015 (30.3%) which is similar to the national level dengue statistics. During 2016 there is a significant drop in the no of reported dengue fever cases accounting for only 18% of the total, shown in Table 2.

Trend of dengue infection over the three years period is represented in Figure 2. It clearly shows that there is an increase in the dengue cases after the months of June and July and also there is highest peak in the cases following the rainy seasons (September-November). During the January to May months there is the drop in the reported cases.

Association between dengue infection and selected variables

As we can see from Table 3 there was a positive statistical significant association (p<0.0001) between dengue infection and male sex, lower socioeconomic status and platelet count at the time of admission. There is no statistical association between age and dengue infection (p=0.105) in this study.

*p value<0.0001 is highly significant statistically.

DISCUSSION

In present study 240 (74.5%) were males and 100 (25.5%) were females. Male preponderance of cases were also seen in studies by Antony et al (60.70% were males and 39.29% were females), Garg et al (67% were males and 33% were females) and Kumar et al (64.6% were males and 35.4% were females) but, female preponderance was seen in study by Padhi et al.^11,18-20 Majority of the dengue patients belonged to 20-40 years of age in our study which is similar to study by Antony et al (>20 years) and also it is discordant to studies by Padhi et al (11-20 years) and Garg et al (0-15 years).^11,18,19

Nearly 90% of the study participants belonged to classical dengue and only 10% were of DHF type. In Antony J study 97.65% classical dengue and only 2.35% were of DHF type and also Sharma did a study in Delhi in which 58.9% had classical dengue, 37.6% had DHF, and 3.38% had dengue shock syndrome.^18,21

Among the study participants there is an increase in the dengue cases after the months of June and July and also there is highest peak in the cases following the rainy seasons (September-November). This finding is consistent with studies by Gunasekaran et al, Bhat et al and Dash et al.^22-24 this trend is because of the increase in the breeding place for the vectors during the post monsoon period.

In present study the variables significantly associated with dengue infection are male sex, lower socioeconomic status and platelet count at the time of admission and about 67.9% of the dengue patients had a platelet count of <1 lakh mm³ at the time of admission which is similar to studies by Sirisena et al and Guzmán et al.^25,26

CONCLUSION

Results of the study clearly indicate that there should be proper education of the public through various available Medias and awareness campaigns. Majority of the cases were reported during the post monsoon period which warrants a coordinated action towards the vector control measures. Active participation from the public is an essential component to curb down the problem. There is also an urgent need to develop a vaccine which is effective against all 4 serotypes of dengue virus.

ACKNOWLEDGEMENTS

First of all, author would like to thank his college management and my department of community medicine for giving me this opportunity. He would like to extend his thanks to his department HOD and all his professors, associate professors and assistant professors for guiding him throughout the study. A special mention to all the co post graduates, friends and family members for helping him to complete the study.

Funding: No funding sources

Conflict of interest: None declared

Ethical approval: The study was approved by the Institutional Ethics Committee Sree Balaji Medical College and Hospital

REFERENCES

1. 1. Patankar M, Patel B, Gandhi V, Shah P, Vegad M. Seroprevalence of dengue in Gujarat, Western India: a study at a tertiary care hospital. Int J Med Sci Public Health. 2014;3(1):16-9.
2. 2. Park K. Epidemiology of communicable diseases. In: Park's textbook of preventive and social medicine. 23rd ed. Jabalpur: Bhanot; 2015:246.
3. 3. Kumar M, Sharma R, Parihar G, Sharma M. Seroprevalence of dengue in central Rajasthan: a study at a tertiary care hospital. Int J Curr Microbiol Appl Sci. 2015;4(9):933-40.
4. 4. Ananthnarayan R, Panikar CKJ, Arboviruses. In: Ananthanarayan and Paniker’s Textbook of Microbiology, 8th ed. Hyderabad: Orient Longman; 2009:519.
5. 5. Arunasree B, Uma P, Rajsekhar B. Epidemiology of dengue fever in Srikakulam District, Andhra Pradesh. J Evol Med Dent Sci. 2015;4(27):4599-604.
6. 6. Kumar R, Tripathi P, Tripathi S, Alok Kanodia A, Venkatesh V. Prevalence of dengue infection in north Indian children with acute hepatic failure. Ann Hepatol. 2008;7(1):59-62.
7. 7. Flaviviruses. Chapter 149. In: Mandell, Douglas. Bennett’s principles and practice of Infectious Diseases. 7th Edition. Churchill Livingstone Elsevier; 2011: 1926-1950.
8. 8. Perumal A. A 3 year retrospective study on serodiagnosis of acute dengue infection in patients attending a tertiary care hospital in Chennai (2009-2011). Univ J Pre Paraclin Sci. 2016;2(6).
9. 9. Gubler DJ. Dengue, urbanization and globalization: the unholy trinity of the 21^st century. Trop Med Health. 2011;39(4):S3-11.
10. 10. Vijayakumar TS, Chandy S, Sathish N, Abraham M, Abraham P, Sridharan G. Is dengue emerging as a major public health problem. Indian J Med Res. 2005;121(2):100-7.
11. 11. Padhi S, Dash M, Panda P, Parida B, Mohanty I, Sahu S, et al. A three year retrospective study on the increasing trend in seroprevalence of dengue infection from southern Odisha, India. Indian J Med Res. 2014;140(5):660.
12. 12. Wilder-Smith A, Ooi EE, Vasudevan SG, Gubler DJ. Update on dengue: epidemiology, virus evolution, antiviral drugs, and vaccine development. Curr Infect Dis Rep. 2010;12(3):157-64.
13. 13. Lall H, Gupta P, Debbarma M, Sharma P, Ansari SK, Jais M, et al. Sero-prevalance of dengue in tertiary care hospital in Delhi. Int J Curr Microbiol Appl Sci. 2016;5(6):439-45.
14. 14. Kennedy RS. Some notes on an epidemic of dengue form fever among Indian troops, Calcutta. Ind Med Gaz. 1912;17:42.
15. 15. Ganeshkumar P, Murhekar MV, Poornima V, Saravanakumar V, Sukumaran K, Anandaselvasankar A, et al. Dengue infection in India: A systematic review and meta-analysis. PLoS Neglected Trop Dis. 2018;12(7):e0006618.
16. 16. Sood S. A hospital based serosurveillance study of dengue infection in Jaipur (Rajasthan), India. J Clin Diagn Res. 2013;7(9):1917.
17. 17. Dengue/DHF situation in India NVBDCP 2018 report. Available at: https://nvbdcp.gov.in/index4.php?lang=1&level=0&linkid=431&lid=3715 Accessed on: 28 December 2019.
18. 18. Antony J, Celine TM. A descriptive study on dengue fever reported in a Medical College Hospital. Sahel Med J. 2014;17(3):83.
19. 19. Garg A, Garg J, Rao YK, Upadhyay GC, Sakhuja S. Prevalence of dengue among clinically suspected febrile episodes at a teaching hospital in North India. J Infect Dis Immun. 2011;3(5):85-9.
20. 20. Kumar A, Rao CR, Pandit V, Shetty S, Bammigatti C, Samarasinghe CM. Clinical manifestations and trend of dengue cases admitted in a tertiary care hospital, Udupi district, Karnataka. Indian J Community Med. 2010;35(3):386.
21. 21. Sharma Y, Kaur M, Singh S, Pant L, Kudesia M, Jain S. Seroprevalence and trend of dengue cases admitted to a government hospital, Delhi- 5-year study (2006-2010): a look into the age shift. Int J Prevent Med. 2012;3(8):537.
22. 22. Gunasekaran P, Kaveri K, Mohana S, Arunagiri K, Babu BS, Priya PP, et al. Dengue disease status in Chennai (2006-2008): A retrospective analysis. Indian J Med Res. 2011;133(3):322.
23. 23. Bhat S, Sastry AS, Senthamarai S, Sivasankari S. Seroprevalence of dengue viral infection in patients attending to a tertiary care hospital in Kanchipuram, Tamil Nadu, India. Int J Res Health Sci. 2014;2(3):818-22.
24. 24. Dash PK, Parida MM, Saxena P, Abhyankar A, Singh CP, Tewari KN, et al. Reemergence of dengue virus type 3 (subtype-III) in India: Implications for increased incidence of DHF and DSS. Virol J. 2006;3:55.
25. 25. Sirisena PD, Noordeen F, Fernando L. A preliminary study on clinical profiles of dengue and dengue haemorrhagic fever suspected patients from two hospitals in the Western Province of Sri Lanka. Sri Lankan J Infect Dis. 2014;4(2):99-107.
26. 26. Guzmán MG, Vázquez S, Martínez E, Álvarez M, Rodríguez R, Kourí G, et al. Dengue in Nicaragua, 1994: reintroduction of serotype 3 in the Americas. Revista Panamericana de Salud Pública. 1997;1:193-9.