|Year : 2022 | Volume
| Issue : 2 | Page : 152-155
Assessment of breeding sites and seroprevalence of dengue in an urban area of Puducherry – A community-based study
A Velavan1, Shashikala2, Patricia Anitha2, P Stalin1, R Arun Kumar1, Anil J Purty1
1 Department of Community Medicine, Pondicherry Institute of Medical Sciences, Puducherry, India
2 Department of Microbiology, Pondicherry Institute of Medical Sciences, Puducherry, India
|Date of Submission||04-Jul-2022|
|Date of Decision||02-Sep-2022|
|Date of Acceptance||03-Sep-2022|
|Date of Web Publication||23-Dec-2022|
Department of Community Medicine, Pondicherry Institute of Medical Sciences, Ganapathychettikulam, Kalapet, Puducherry - 605 014
Source of Support: None, Conflict of Interest: None
Background: Dengue virus infection is an important global public health issue. India is one of the high-burden countries with the resurgence of dengue in recent years. Surveillance based on hospital data can be misleading. Seroprevalence studies in the community are extremely useful in measuring the extent of transmission. This community-based study was done to identify the breeding sites of the Aedes mosquito and measure the seroprevalence of dengue infection in an urban area of Puducherry.
Methodology: A cross-sectional study was done for 6 months in an urban area of Puducherry to assess the breeding sites for dengue and to find the serological prevalence of dengue. House-to-house visits were done in the study area to collect details on sociodemographic data, environmental data, and breeding sites for dengue. Blood samples were obtained from all willing participants aged 9 years and above to detect specific immunoglobulin G antibodies to dengue virus by enzyme-linked immunosorbent assay.
Results: The seroprevalence of dengue infection was found to be 8.3%. Flower vase with water 72 (18%), animal water container 32 (8%), roof gutter/sunshades, 25 (6.3%), and open water storage tanks 18 (4.5%) were the most commonly prevalent breeding sites in the study area. The houses with potential breeding sites, such as roof gutters and sunshades, were significantly associated with the prevalence of dengue seropositivity among the study participants.
Conclusion: The seroprevalence was found to be relatively low in the study area and the potential breeding sites for dengue were identified.
Keywords: Breeding sites, dengue, seroprevalence
|How to cite this article:|
Velavan A, Shashikala, Anitha P, Stalin P, Kumar R A, Purty AJ. Assessment of breeding sites and seroprevalence of dengue in an urban area of Puducherry – A community-based study. J Curr Res Sci Med 2022;8:152-5
|How to cite this URL:|
Velavan A, Shashikala, Anitha P, Stalin P, Kumar R A, Purty AJ. Assessment of breeding sites and seroprevalence of dengue in an urban area of Puducherry – A community-based study. J Curr Res Sci Med [serial online] 2022 [cited 2023 Mar 20];8:152-5. Available from: https://www.jcrsmed.org/text.asp?2022/8/2/152/364503
| Introduction|| |
The global incidence of dengue has increased drastically, with 3.9 billion people at risk of infection. The actual number of dengue cases is underreported, and many patients are misclassified. One recent estimate indicates the occurrence of 390 million dengue infections per year, of which 96 million manifest clinically. The epidemiological patterns, including hyperendemicity of multiple dengue virus serotypes in many countries, are alarming and have a significant impact on both human health and the global and national economies. Dengue disease burden in India is one of the highest in the world. In India, the resurgence of dengue poses a major risk in recent years. In recent years, India has recorded over 1 lakh dengue cases annually, with a maximum of 188,401 dengue cases and 325 dengue deaths in 2017. The World Health Organization recommends surveillance as one of the key tools for preventing and controlling dengue. However, surveillance based on hospital data can be misleading for dengue due to the variations in manifestations of the disease. Seroprevalence studies in the community are extremely useful to measure the extent of transmission. In this context, the objective of this study was to measure the seroprevalence of dengue infection and to find the association between sociodemographic, and environmental factors with seropositivity for dengue virus among the study participants in a defined geographical area in Puducherry.
| Materials and Methods|| |
The study was carried out in the field practice areas of the urban health training center in Puducherry. It caters to a population of 12,687 individuals and 3072 families. All healthy individuals who are 9 years and above residing in the study area were included in the study. Assuming the seroprevalence for dengue immunoglobulin G (IgG) antibodies to be 58.8% based on a study by Shah et al. a sample size of 375 participants was calculated with an alpha error of 0.05 and an absolute precision of 5%. This was rounded off to 400. House-to-house visits were done in the study area, and the participants were recruited for the study by convenient sampling till we achieved the desired sample size. If any of the selected individuals were not available or did not consent to participate in the study, the next individual was approached. Data regarding demographic and environmental characteristics were collected from all eligible participants using a pretested and validated questionnaire and physical inspection of the surroundings of the house. Five milliliters of blood were collected from the adult study participants after getting the written consent. Children between 9 and 18 years were asked to sign an assent form along with written informed consent obtained from their parents or legal guardians and 3 ml of blood was collected. Samples were sent to the Microbiology laboratory of Pondicherry Institute of Medical Sciences for analysis. Clotted samples were centrifuged at 3000 rpm for 5 min to separate the serum. Serum was stored in labeled vials at 4°C. Dengue IgG antibody was detected according to the manufacturer's instructions using a commercially available enzyme-linked immunosorbent assay kit. (J. Mitraand Pvt. Ltd. New Delhi, India). The interpretation of the test was based on the cutoff value given by the manufacturer.
Data were entered into Microsoft excel with appropriate checks and analyzed using IBM SPSS Statistics for Windows, Armonk, New York, Version 20. The study results were expressed in numbers and percentages for categorical variables, and the Chi-square test was used to test the significance of association between independent variables with that of seropositivity and P < 0.05 was considered statistically significant.
The study was started after obtaining the approval of the Research and Institute Ethics Committee (IEC approval No: RC/18/38) of the Institute. The participant's information sheet was provided to all study participants, and the details of the study were explained to them. Informed written consent/assent was obtained from study participants as required before the survey.
| Results|| |
The demographic characteristics of the study participants such as age, gender, education, occupation, and socio-economic status are given in [Table 1].
The common breeding sites present in the study area are shown in [Figure 1].
|Figure 1: Assessment of breeding sites of Aedes mosquitoes (n = 400) *. *Multiple options|
Click here to view
A total of 33 (8.3%) individuals were positive for dengue IgG antibodies. Seropositivity was more among the age group of <20 years (10.7%) and 41–60 years (10.7%), while in the age groups of 21–40 years and >60 years, it was 6% and 6.2%, respectively. Among the males, 12 (9.2%) and among females 21 (7.8%) were seropositive for dengue antibodies.
The association between the presence of breeding sites and the seropositivity status of individuals residing in the household is shown in [Table 2].
| Discussion|| |
In this study, the study participants were representative of all age groups, including age groups <20 years and those more than 80 years. A majority of them studied up to primary or secondary school only. The common potential breeding sites for Aedes found among the household surroundings of the study participants were flower vases with water, roof gutters, sunshades with water stagnation, and animal water containers. Flower vase with water is a part of their cultural practice and are found in large numbers. Roof gutter/sunshade is invariably present in many of the houses, which stagnate rainwater and serve as a potential source of Aedes breeding. Animal water containers and open water storage tanks were other possible breeding sites identified during the survey. A similar study by Kamath et al. at Udupi reported that coconut shells and flower vases/pots with water were the common potential breeding sources for dengue in their urban study settings. This study revealed a seroprevalence of antibodies to dengue to be 8.3%. In 2017, a community-based survey done all over India by Murhekar et al. revealed that the overall seroprevalence of dengue antibodies was 48.7%. However, it varied from region to region, with the lowest seroprevalence in the Northeast (5%) and highest in the southern region (76.9%). The seroprevalence found in this study is relatively low as it is done in a small geographical area. However, a study done by Balamurugan et al. in Puducherry reported the seroprevalence of dengue to be 13.5% which is comparable. The seroprevalence was found to be higher in the age group of 41–50 years and <20 years among the study participants and among males. However, it was not statistically significant. Among the breeding sites found in the housing environment of the study participants, those houses with the stagnation of water in the roof gutter and sunshade were found to be significantly associated with the seropositivity of the inmate of the house. These breeding sites are commonly neglected and found in many of the houses in the study area. Thus, this study provides information on various breeding sites for dengue identified in this area and its association with seropositivity and areas to intervene by the local health authority.
Limitation of the study
This study was conducted in Muthialpet, a smaller area of urban Puducherry. Hence, generalizing and interpreting study results has to be done with caution. A larger study including urban residents representing a larger geographical area is recommended for further research.
| Conclusion|| |
The seroprevalence was found to be relatively low in the study area and the potential breeding sites for dengue were identified.
We would like to acknowledge our institute management for supporting this intramural-funded research. We are thankful to the field staff, laboratory technicians, and medical interns of our institute who helped in data collection, sample collection, transport, and processing of the samples. We thank the heads of the departments of community medicine and clinical microbiology for supporting this research project wholeheartedly.
Financial support and sponsorship
This research was done with the support of Intramural research funding by the Pondicherry Institute of Medical Sciences.
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2]