Analysis of Environmental Factors with Dengue Hemorrhagic Fever in Guntur, Demak, Indonesia

Guntur district is one of the districts that is classified as endemic for dengue fever in Demak, Indonesia. In the last three years, there have been consecutive cases or deaths due to Dengue Hemorrhagic Fever (DHF). Based on the epidemiological triangle concept, the emergence of dengue fever can be caused by an imbalance between host (human) factors, the agent as the cause, and the supporting environment. Environmental factors facilitate contact with agents consisting of the physical, social and biological environment. The physical environment that influences the occurrence of dengue fever cases includes house layout, type of container, frequency of draining the container, availability of lids on containers, altitude and climate. DHF cases in Guntur District in 2022 were 67 cases (IR 0.8 per 1,000 population). The case sample in this study was 86 respondents consisting of 43 case groups and 43 as controls. Sampling was taken in Guntur, Demak, Indonesia. The results showed that the factors having influence on the DHF were landfill materials, landfill volume, landfill availability, frequency of landfill draining, and the presence of larvae. The risk factors for dengue fever are the material of the water reservoir, the frequency of draining the water reservoir, the volume of the landfill, and the presence of larvae. People who used cement/soil landfill materials had a 3.529 greater chance of contracting dengue fever. People with less reliable behavior in draining landfills had a 5.569 times greater chance of contracting dengue fever, and people whose water reservoirs containing larvae had a 17.939 times greater chance of contracting dengue fever.

INTRODUCTION

The distribution of dengue fever cases in Indonesia in 2021 is in 34 provinces in Indonesia, with a total of 73,518 cases, with an incidence rate of 27 per 100,000 population, 747 deaths and a case fatality rate of 0.96%¹¹.Dengue Hemorrhagic Fever (DHF) cases in Central Java Province are spread across 35 districts/cities with a total of 4,470 cases with an incidence rate of 12.2 per 100,000 population, the IR of DHF in Central Java is lower than the national target (<51/100,000 population), while the death rate occurred in 25 districts/cities with a total of 141 deaths with a case fatality rate of 2.7%, this figure is still higher than the national target (<1%)²².

Based on data from the Demak District Health Service in 2022, dengue fever cases amounted to 305 cases (IR 22.5 per 100,000 population) with 3 deaths (CFR: 1.1), this case is the highest case in the last 5 years, namely in 2021 cases DHF was 67 cases (IR 5.77 per 100,000 population) with 0 deaths (CFR: 0), in 2020 there were 107 cases (IR 9.35 per 100,000 population) with 0 deaths (CFR: 0), in In 2019 there were 168 (IR 14.94 per 100,000 population) with a death toll of 2 cases (CFR: 1.19) and in 2018 there were 42 cases (IR 3.61 per 100,000 population) with a death toll of 1 case (CFR: 2, 38)³³.

Based on the epidemiological triangle concept, the emergence of dengue fever can be caused by an imbalance between host (human) factors, the agent as the cause, and the supporting environment. Environmental factors facilitate contact with agents consisting of the physical, social, and biological environment⁴⁴. The physical environment that influences the occurrence of dengue fever cases includes house layout, type of container, frequency of draining the container, availability of lids on containers, altitude, and climate. The social environmental factor that influences the occurrence of dengue fever cases is population density. Increasing population density will increase contact between vectors and humans, thereby increasing the risk of dengue fever transmission⁵⁵. Biological factors, namely the presence of mosquito larvae and breeding places⁶⁶.

Guntur District is one of the districts classified as endemic for dengue fever in Demak Regency, namely a district where in the last 3 years there have been consecutive cases or deaths due to Dengue Hemorrhagic Fever. DHF cases in Guntur District in 2022 were 67 cases (IR 0.8 per 1,000 population)²². With a larvae free rate of 64%, this figure is still far from the national target of ≥95%. Behavior that does not pay attention to environmental cleanliness, such as a lack of awareness of draining the bathtub at least once a week, the behavior of hanging clothes, lots of unused trash/containers around the house that can hold water, and dark conditions in the house due to people's habits of not even opening windows. having no windows in the house is one of the factors behind the low larvae-free rate in Guntur District. The large number of second-hand goods collection businesses and the large number of empty houses have also played a role in increasing dengue cases in Guntur sub-district. Based on the description above, the problem in this research can be formulated, namely identifying environmental factors related to the incidence of Dengue Fever, as well as spatially assessing rainfall factors with the incidence of Dengue Fever in Demak Regency.

This research aims to analyze environmental factors (container material, frequency of draining containers, availability of container lids, container volume, and presence of larvae) with the incidence of dengue fever in Guntur, Demak, Indonesia.

MATERIALS AND METHODS

This type of research was observational with a case control design which aimed to determine the relationship between environmental factors (container material, frequency of container draining, availability of container lids, container volume, and presence of larvae) with the incidence of dengue fever in Guntur District. In this study, an analysis of the relationship between the independent variables (the environmental factors) and the dependent variable (DHF incidence) was carried out using the chi-square correlation test and spatial-temporal analysis using Geographic Information Systems (GIS).

The samples in this study were calculated using the Lemeshow formula which resulted in 86 samples consisting of 43 as case groups and 43 as control groups. Statistical tests of the relationships used the chi-square test and the spatial tests used the overlay mapping model.

RESULTS

This research was located in Guntur, Demak, Indonesia. This research was carried out on 14-19 August 2023.

Table 1.Univariate Analysis of The Environmental Factors Affecting The DHF Incidence

Characteristics	Case		Control
	N	%	N	%
Landfill materials
Cement and soil	30	69.17	17	39.53
Ceramics and plastic	13	30.23	26	60.47
Landfill Volume
> 50 liters	30	69.77	17	39.53
≤ 50 liters	13	30.23	26	60.47
Availability of landfill cover
Available	38	88.37	40	93.02
Not Available	5	11.63	3	6.98
Landfill Draining Frequency
>1 week	33	76.74	16	37.21
<1 week	10	23.26	27	62.79
The existence of larvae
Positive	37	86.05	11	25.58
Negative	6	13.95	32	74.42

Table 2.Bivariate Analysis

Characteristics	p	OR (95%Cl)
			1. Landfill materials	0.004	13.529 (1.445-8.619)
2. Landfill Volume	0.004	0.283 (0.116-0.692)
3. Availability of landfill cover	0.356	0.570 (0.127-2.551)
4. Landfill Draining Frequency	0.000	5.569 (2.176-14.251)
5. The presence of larvae	0.000	17.939 (5.962-53.975)