Arnab Kumar Mandal1, Tapati Mondal1*, Puronjay Saha1,
Poulami Saha2, Arup Roy3 and Pratip Kumar Kundu1

1Department of Microbiology, Malda Medical College & Hospital, Malda, West Bengal, India.
2Department of Microbiology, JNMC, Aligarh Muslim University, Aligarh, UP, India.
3Departmnet of Microbiology, Regional Institute of Medical Science, Imphal, Manipur, India.

Abstract

Dengue is the most common and widespread arboviral infection in the world today. It is an increasingly prevalent tropical arbovirus infection with significant morbidity and mortality. Dengue fever is a recurrent problem in West Bengal.The purpose of this study is to present a comprehensive report on the diagnosis of Dengue fever cases with age and sex preponderance, data available from January 2013 to December 2016 at Malda Medical College, Malda, West Bengal. This is a cross-sectional investigative study done at Malda Medical College. In suspected Dengue fever cases, serum samples were tested for presence of Dengue NS1 antigen and presence of Dengue specific IgM antibodies by IgM antibody capture enzyme linked immunosorbent assay (MAC ELISA), strictly following the manufacturer’s protocol.On the year 2013, 2014, 2015 and 2016 Dengue confirmed cases were 25, 33, 68 and 1102 respectively. The number of Dengue cases in 2016 clearly outnumbered the Dengue cases in 2013, 2014 and 2015. In our study the highest numbers of cases were recorded in the age group 11 to 30 years and males were more affected than females. The majority of the cases were reported during the monsoon and post monsoon seasons.Dengue is increasing its geographical areas mostly everywhere now and this Dengue epidemiology demands efforts and support for controlling the disease effectively.

Keywords: Dengue, 4 years analysis, Malda, West Bengal

Introduction

Dengue is the most common and widespread arboviral infection in the world today. It is an increasingly prevalent tropical arbovirus infection with significant morbidity and mortality.1 In recent times Dengue fever is getting attention in medical and social fields in developing countries especially in South East Asia.2Presently, about 40% of the world’s population is at risk and there are 50 to 100 million cases every year. An estimated 500000 people with severe dengue require hospitalization each year and about 2.5% of those affected die.3According to WHO, nearly 75% of global burden of dengue fever are in south east regions and western pacific region.4Dengue infection has been known to be endemic in India for over two centuries.5 This emerging disease in India extending from urban area to semi urban and rural areas.4Dengue fever causes a major health, social and economic trouble on the populations of widespread areas.6Symptoms include fever, headache, retro orbital pain, muscle and joint pain and a characteristic skin rash, the disease may develops into the life threatening Dengue haemorrhagic fever (DHF) and Dengue shock syndrome (DSS).7 Dengue is transmitted mainly in India by Aedesaegypti mosquito and also by Aedesalbopictus. Dengue fever is a recurrent problem in West Bengal.8The purpose of this study is to present a comprehensive report on the diagnosis of Dengue fever cases with age and sex preponderance, data available from January 2013 to December 2016 at Malda Medical College, Malda, West Bengal.

Materials and Methods

This is a cross-sectional investigative study included the patients who attend the OPD (out patient department) and admitted in IPD (in patient department) ofMalda Medical College,Malda with suspected cases of Dengue fever. Dengue fever patients typically develop sudden onset of high grade fever. Hence, fever cases of all age groups and either sex attending the (all the year round) Malda Medical College, were selected as per WHO criteria (An acute febrile illness with ≥2 of the following manifestations: headache, retro-orbital pain, myalgia, arthralgia, rash and haemorrhagic manifestation) and tested on referral microbiology laboratory, Department of Microbiology, Malda Medical College. Blood samples from suspected acute Dengue fever cases ≤4 days duration were tested for Dengue NS1 antigen and blood samples of suspected Dengue fever cases at least 5 days duration were tested for Dengue specific IgM by MAC ELISA test kit prepared by National Institute of Virology, Pune, India.

Serum samples were tested for presence of Dengue NS1 antigen and presence of Dengue specific IgM antibodies by IgM antibody capture enzyme linked immunosorbent assay (MAC ELISA), strictly following the manufacturer’s protocol.8, 9

Results

Table 1 shows, on the year 2013, 72 fever cases were tested for Dengue NS1 Ag of which 7 cases were positive and 110 fever cases were tested for DengueIgMAb of which 18 cases were positive. Total confirmed cases were 25. Table 2 shows, out of 25 Dengue confirmed cases, 16 were male and 9 were female. Male: female ratio was 1.7: 1.Table 3 shows, on the year 2014, 126 fever cases were tested for Dengue NS1 Ag of which 11 cases were positive and 202 fever cases were tested for DengueIgMAb of which 22 cases were positive. Total confirmed cases were 33. Table 4 shows, out of 33 Dengue confirmed cases, 23 were male and 10 were female. Male: female ratio was 2.3: 1. Table 5 shows, on the year 2015, 125 fever cases were tested for NS1 Ag of which 9 cases were positive and 587 fever cases were tested for IgMAb of which 59 cases were positive. Total confirmed cases were 68.Table 6 shows, out of 68 Dengue confirmed cases, 44 were male and 24 were female. Male: female ratio was 1.8: 1.  Table 7 shows, on the year 2016, 1859 fever cases were tested for NS1 Ag of which 433 cases were positive and 3216 fever cases were tested for IgMAb of which 669 cases were positive. Total confirmed cases were 1102. Table 8 shows, out of 1102 Dengue confirmed cases, 652 were male and 450 were female. Male: female ratio was 1.4: 1.

Table 1. Dengue suspected and Positive cases on the year 2013

Month Fever cases tested for Dengue NS1 Ag Dengue NS1 Ag ELISA Positive cases Fever cases tested for Dengue IgMAb Dengue IgM MAC ELISA Positive cases Total confirmed cases of Dengue
January 3 0 5 0 0
February 1 0 4 0 0
March 0 0 0 0 0
April 0 0 0 0 0
May 0 0 0 0 0
June 8 0 12 1 1
July 16 3 25 9 12
August 15 2 21 3 5
September 22 2 28 5 7
October 7 0 12 0 0
November 0 0 3 0 0
December 0 0 0 0 0
Total 72 7 110 18 25

 

Table 2. Age and Sex wise distribution of Dengue confirmed cases on the year 2013 Dengue confirmed cases

Age (Years)            Male             Female Total
0-10 1 0 1
11-20 8 3 11
21-30 2 3 5
31-40 2 2 4
41-50 1 0 1
51-60 1 1 2
>60 1 0 1
Total 16 9 25

 

Table 3. Dengue suspected and Positive cases on the year 2014

Month Fever cases tested for Dengue NS1 Ag Dengue NS1 Ag ELISA Positive cases Fever cases tested for Dengue IgMAb Dengue IgM MAC ELISA Positive cases Total confirmed cases of Dengue
January 1 0 6 0 0
February 0 0 2 0 0
March 0 0 0 0 0
April 0 0 0 0 0
May 0 0 3 1 1
June 12 0 19 0 0
July 14 1 26 3 4
August 17 1 27 1 2
September 24 2 31 3 5
October 22 3 35 4 7
November 28 4 42 10 14
December 8 0 11 0 0
Total 126 11 202 22 33

Table 4: Age and Sex wise distribution of Dengue confirmed cases on the year 2014 Dengue confirmed cases

Age (Years)            Male             Female Total
0-10 3 2 5
11-20 2 2 4
21-30 4 3 7
31-40 8 1 9
41-50 5 1 6
51-60 1 0 1
>60 0 1 1
Total 23 10 33

Table 5. Dengue suspected and Positive cases on the year 2015

Month Fever cases tested for Dengue NS1 Ag Dengue NS1 Ag ELISA Positive cases Fever cases tested for Dengue IgMAb Dengue IgM MAC ELISA Positive cases Total confirmed cases of Dengue
January 2 0 5 0 0
February 0 0 2 0 0
March 0 0 0 0 0
April 0 0 0 0 0
May 0 0 0 0 0
June 0 0 3 0 0
July 3 0 11 0 0
August 16 0 27 3 3
September 11 0 62 10 10
October 0 0 242 18 18
November 93 9 98 10 19
December 0 0 137 18 18
Total 125 9 587 59 68

Table 6. Age and Sex wise distribution of Dengue confirmed cases on the year 2015 Dengue confirmed cases

Age (Years)            Male             Female Total
0-10 9 5 14
11-20 10 7 17
21-30 11 7 18
31-40 7 1 8
41-50 4 1 5
51-60 2 1 3
>60 1 2 3
Total 44 24 68

Table 7. Dengue suspected and Positive cases on the year 2016

Month Fever cases tested for Dengue NS1 Ag Dengue NS1 Ag ELISA Positive cases Fever cases tested for Dengue IgMAb Dengue IgM MAC ELISA Positive cases Total confirmed cases of Dengue
January 0 0 21 3 3
February 0 0 8 0 0
March 0 0 0 0 0
April 0 0 18 2 2
May 0 0 8 0 0
June 0 0 44 1 1
July 0 0 55 6 6
August 319 44 392 76 120
September 284 61 509 102 163
October 273 79 712 203 282
November 445 120 1284 239 359
December 538 129 165 37 166
Total 1859 433 3216 669 1102

Table 8. Age and Sex wise distribution of Dengue confirmed cases on the year 2016 Dengue confirmed cases

Age (Years)            Male             Female Total
0-10 86 76 162
11-20 200 113 313
21-30 171 94 265
31-40 85 86 171
41-50 53 47 100
51-60 41 28 69
>60 16 06 22
Total 652 450 1102

Table 9. Analysis of Risk Factors in total number of positive cases (n= 1228)

Risk Factors
Education Illiterate Primary Upper primary Secondary Higher Secondary Graduate
612 361 102 90 41 22
Occupation Student Housewives Unskilled labour Skilled labour Professional Others
94 42 656 408 20 08
Unhygienic environment around house Present Absent
1190 38
Indoor and Outdoor water containers to store water Present Absent
1228 0
Eliminate waters from artificial containers Daily Weekly Monthly
64 756 408
Screened doors and windows Present Absent
37 1191
Good air conditioning houses Yes No
88 1140
Using mosquito net Yes No
206 1022
Using mosquito repellents Yes No
0 1228
Wearing long-sleeved garments Yes No
97 1131
Activity around house Yes No
1186 42
Previous infection with a Dengue fever virus Yes No
22 1206

 

The number of Dengue cases in 2016 clearly outnumbered the Dengue cases in 2013, 2014 and 2015. The highest numbers of cases were in the age group11 to 30 years with a male preponderance. The majority of cases during the months of august to December indicating increased vector transmission in the monsoon post monsoon periods. Table 9 shows, analysis the risk factors of Dengue infection in total number of positive cases.

Discussion

Dengue is emerging as a major public health problem in India. It is one of the major public threats in West Bengal. The Dengue is gradually spreading to the rural areas of West Bengal.8In our study, on the year 2013, 72fever cases were tested for NS1 Ag of which 7 cases were positive and 110fever cases were tested for IgMAb of which 18 cases were positive. On the year 2014, 126fever cases were tested for NS1 Ag of which 11 cases were positive and 202fever cases were tested for IgMAb of which 22 cases were positive. On the year 2015, 125 fever cases were tested for NS1 Ag of which 9 cases were positive and 587fever cases were tested for IgMAb of which 59 cases were positive. On the year 2016, 1859fever cases were tested for NS1 Ag of which 433 cases were positive and 3216fever cases were tested for IgMAb of which 669 cases were positive. On the year 2013, 2014, 2015 and 2016 Dengue confirmed cases were 25, 33, 68 and 1102 respectively. The number of Dengue cases in 2016 clearly outnumbered the Dengue cases in 2013, 2014 and 2015. In our study the highest numbers of cases were recorded in the age group 11 to 30 years and males were more affected than females. This observation correlates with other studies.5, 8, 10, 11The majority of the cases were reported during the monsoon and post monsoon seasons, in accordance with the reported patterns of Dengue transmission, that correlates with other studies.8,12,13,14   Analysis the risk factors of Dengue infection like unhygienic environment around house, indoor and outdoor water containers to store water and time taken for elimination of water, screened doors and windows, good air conditioning houses, using mosquito net and repellents, wearing long-sleeved garments etc. The finding of our study similar to other study.15, 16

Fig. 1. Total confirmed cases of Dengue on the year 2013, 2014, 2015 and 2016

Conclusion

Dengue is a notifiable disease in India since 1996.7Dengue is increasing its geographical areas mostly everywhere now and this Dengue epidemiology demands efforts and support for controlling the disease effectively. Dengue fever sometimes leads to death without proper treatment and care. There is no vaccine and specific drug to control infection but it is curable with proper symptomatic treatment and efforts.6 Attention is therefore required for effective vector control measures. Dengue infections are mostly seen in monsoon and post monsoon season, hence preventive measures should be in full swing at the early onset of monsoons.

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