Knowledge, Attitudes, and Practices on the Use of Household Insecticide Products: Is the Awareness in Place?

Abstract

Insecticide application is one of the most important control measures for protection from mosquito bites. A descriptive, community-based cross-sectional survey involving 986 respondents was conducted to probe the knowledge, attitudes, and practices regarding household insecticide use in Selangor—the state that recorded the highest number of dengue cases in Malaysia. In this study, we classified the responses as either low (poor) or high (good) based on median cut-off points. Age, gender, ethnicity, and household income were found to be significantly associated factors relative to the respondents’ mosquito knowledge score, whereas no factors were significantly associated with attitudes toward the use of household insecticide. Practices, on the other hand, were associated with age and high attitude scores. Most respondents (71.4%) had good knowledge of mosquitoes. Conversely, 51.1% and 59.2% of respondents scored high on attitudes and practices, respectively, on the use of household insecticides. This study highlights the need to expand health promotion activities through social mobilization to raise awareness about vector-borne disease prevention and promoting positive attitudes and safe practices in the use of household insecticides.

knowledge, attitude, practice, community survey, insecticide

Dengue is one of the most prevalent public health issues in tropical and subtropical countries. Since the World Health Organization began tracking dengue cases worldwide, they have increased dramatically, threatening four billion people in 129 countries at risk of infection (World Health Organization 2020). Dengue fever, which is transmitted by Aedes (Stegomyia) aegypti (Linneus, 1762) and Aedes (Stegomyia) albopictus (Skuse, 1894), can sometimes develop into a severe form known as dengue hemorrhagic fever, can result in severe complications and even death in humans (Carneiro et al. 2017). There is currently no specific vaccine available to prevent the disease.

Malaysia has an extremely high prevalence of dengue fever, with significant outbreaks occurring frequently, particularly in urban areas. Dengue cases were recorded at 80,614 in 2018; this increased by 61.4% to 130,101 cases in 2019. Meanwhile, the number of cases in Selangor increased significantly in 2019 to 72,543 from 45,349 in the previous year [Ministry of Health Malaysia (MOH) 2020]. Strikingly, about half of the dengue cases reported in Malaysia are in Selangor and this is consistent across the two years. MOH recognizes dengue fever as a major public health issue and states that appropriate measures must be taken for prevention of disease outbreaks (Packierisamy et al. 2015). This includes vector control by the public involving the use of household insecticides as a disease prevention tool (WHO 2012). Nevertheless, a risk assessment on human-health risks from dengue and from the insecticides used to control mosquitoes should also be carried out to aid in the decision making by all stakeholders (Peterson et al. 2006).

In addition to the uses of mosquito bed nets and protective clothing, and the regular removal of stagnant water sources to prevent mosquito breeding, household insecticides such as mosquito repellents, mosquito coils, and mosquito mats have been commonly applied as the primary prevention approach for dengue. Most commercial household mosquito control insecticides contain pyrethroid chemicals, the synthetic derivative of pyrethrin (WHO 2005). These chemicals are known as Type 1 pyrethroids, which are known to be safe and have a low toxicity to humans. However, improper use of insecticide can harm the environment and human health (Thao et al. 2019).

In Malaysia, the Pesticides Control Division under the Department of Agriculture, Ministry of Agriculture and Food Industries is responsible for implementing and enforcing the Pesticides Act 1974. This division is also involved in the control of quality, effectiveness, and negative effects of pesticides imported and manufactured in the country through the registration process [Department of Agriculture Malaysia (DOA) 2021]. Nevertheless, despite these strict regulations, cases of intoxication or accidents could happen due to improper reading of labels (Okonya and Kroschel 2015, Moumouni et al. 2021) or improper storage of household insecticide (Barghash et al. 2016). In general, these insecticides are toxic not only to the target pest organisms, but also to nontarget organisms and humans due to their broad-spectrum toxicity (Barasa 2015, Meftaul et al. 2020). When insecticides are not used accordingly to the label instructions, they can have unintended negative effects (Attias and Cresti 2010, Thao et al. 2019). Noticeably, a total of 4,196 cases of unintentional pesticide poisoning were reported from 2006-2015 in Malaysia, of which accidental was the highest type of incidents at 91.8%, followed by occupational incidents at 5.2%. Correspondingly, the number of household insecticide poisonings was ranked fourth after herbicides, agricultural insecticides, and rodenticides (Kamaruzaman et al. 2020).

Pyrethroids present health hazards with both short- and long-term exposures (Peterson et al. 2006), and have been associated with a variety of health problems, including cancer (Burns and Pastoor 2018), endocrine (Balen et al. 2012), respiratory (Ho and Kuschner 2012), and other diseases. It causes tremors, hyperexcitability, and cellular damage by inducing numerous nerve action potentials and interfering with enzymes and receptors (Houk et al. 2011, Barasa 2015). As a result of household application of insecticdes, humans can be exposed to these insecticide chemicals via three main pathways: inhalation, ingestion, and dermal absorption (Achmadi and Pauluhn 1998, Li et al. 2016, Sim et al. 2020). Carpets and household furniture can accumulate residual insecticide chemicals, thereby increasing the risk of exposure through accidental inhalation and ingestion of insecticide vapors (Tang et al. 2018). Domestic insecticide use also allows insecticide chemicals to be released as aerosols into the home environment’s air and to fall to the floor as dust, exposing humans, especially children, directly or indirectly through hand-to-mouth behavior (Vesin et al. 2013, Glorennec et al. 2017).

Despite concerns about their toxic effects, household insecticides continue to be a primary option for domestic vector control efforts. Baseline data on community knowledge, attitudes, and practices (KAPs) about household insecticides is critical for facilitating public health education campaigns to maintain a healthy home atmosphere and to raise community concern about exposure. Accordingly, this study was conducted to access KAPs on the use of household insecticides among the communities in Selangor state.

Materials and Methods

Ethical Considerations and Consent

All participants were assured of the confidentiality of their responses and the anonymity of their involvement during enrollment. Written informed consent was obtained following a thorough description of the study. Participants were told that this study would be strictly for academic purposes. The study was approved by the University of Malaya Research Ethics Committee (UM.TNC2/UMREC-02).

Study Design and Respondent Selection

A cross-sectional survey was conducted within a community in each of the nine districts in Selangor (Fig. 1). Consenting participants completed an anonymous interview survey by assessing sociodemographic factors, knowledge of mosquitoes, knowledge of household insecticide use, and attitudes and practices concerning household insecticide use. One central point in a public area (e.g., shopping mall) was selected from each district followed by simple random sampling. A self-administered questionnaire was distributed to the respondents who agreed to participate in this study by signing the consent form. The respondents were aged between 18 and 60 years old and were randomly selected, according to their availability and willingness to participate in the study. The inclusion criterion was residence in the relevant community in Selangor, Malaysia. The number of respondents for this study was proportional to the total population size. The sample size for this study was determined based on the formula of Krejcie and Morgan (1970). We added 10% to the calculated sample size to compensate for missing data or non-responses (Itrat et al. 2008). The necessary sample size was 421 to achieve a power of 80%, a 5% margin of error, and 95% confidence intervals. The actual sample size was 986.

Fig. 1.

Data collection sites across nine districts in Selangor, Malaysia.

Study Instrument

A questionnaire was adapted and modified from Bass et al. (2001), Nalwanga and Ssempebwa (2011), and Chitra et al. (2013). A pilot study (n = 30) was carried out to determine the Cronbach’s alpha coefficient value to test the validity and reliability of the study tool. The alpha value was 0.809, so the questionnaire demonstrated high internal consistency (Henson 2001). The questionnaire had five sections. In the first section, the sociodemographic background of respondents was surveyed. In the second section, the knowledge of respondents regarding mosquitoes was investigated. The third section assessed the awareness of household insecticide use, type, brand, and active ingredients as well as the source of information on mosquitoes.

The fourth section consisted of questions assessing attitudes toward household insecticide use. The last section consisted of eleven questions assessing practices related to household insecticide use. Participants were also asked about the usage time and frequency, place of use and storage, and disposal method. The questionnaires were prepared in two languages: Bahasa Malaysia (the national language of Malaysia) and English.

Scoring System

The total scores for knowledge, attitudes, and practices were treated as continuous data and tested for normality. The scores of each variable were totaled, followed by the Kolmogorov Smirnov test of normality (Morgan et al. 2011, Field 2013, Mishra et al. 2019). Based on the normality test, the data was not normally distributed (P-value < 0.05), thus the median value for basic categorization was used (Chin et al. 2017, Sun et al. 2017). All values greater than or equal to the median scores based on knowledge, attitudes, and practices were defined as good, while all scores below the median were categorized as poor (Wijayanti 2015, Lugova and Wallis 2017, Chin et al. 2017).

A scoring system was used after the data was coded and entered into SPSS software. The score was one for correct answer, and zero for “don’t know” or the incorrect answer. The total knowledge score was summed up and classified according to the categories. The total score of knowledge of mosquitoes ≥ median (3) is an indicator of good knowledge whereas a total score less than the median (3) is indicative of poor knowledge. As the minimum total score answered by the respondents for mosquitoes was 0 and the maximum score was 6, the knowledge was categorized as poor: 0–2 and good: 3–6.

Attitude towards household insecticides consisted of nine aspects, and for each of the aspects, the respondents scored one for “agree,” and zero for “disagree”. Scores were summed, and a good attitude was indicated by a total score of greater than the median (6), and a poor attitude by a total score less than the median. For attitude, the minimum total score by the respondents was 0 and the maximum score was 9, thus the attitudes toward household insecticide was categorized as poor: 0–5, and good: 6–9.

Lastly, practices on household insecticide use consisted of 11 aspects, where a value of one was scored for the correct answer, and zero indicated the incorrect answer. Good practices are based on the total score of practices ≥ median (8), while poor practices are based on total score less than the median. From the survey, the minimum total score correctly answered by the respondents was 1 and the maximum score was 11, hence the practices on household insecticide use was categorized as poor were 1–7, and good were 8–11.

Statistical Analyses

The frequency distributions of demographic variables and KAPs were determined using descriptive analyses. The Chi Square test was used to determine any significant associations between demographic factors of respondents and the KAP domains, where P < 0.05 was considered significant. All significant variables (P < 0.05) in the univariate analysis (Chi Square) were then entered into multivariable logistic regression analyses using a simultaneous forced entry model (enter method), as there were no assumptions of which independent variables would create the best prediction equation. For knowledge of mosquitoes, the significant variables were age, gender, marital status, ethnicity, and household income, while for attitudes toward household insecticides, only total knowledge score of mosquitoes was significantly associated. For practices of household insecticides, the significant variables included age, type of house, total knowledge score of mosquitoes, and attitudes toward household insecticides.

The model fit was assessed using the Hosmer-Lemeshow goodness of fit (Lemeshow and Hosmer 1982). A significant test indicated that the model is not a good fit, and a nonsignificant test indicates a good fit. Multivariable logistic regression analyses were used to investigate factors associated with the scores of (1) total mosquito-related knowledge, (2) total attitudes toward household insecticide use, and (3) total practices related to household insecticide use. The relationship between KAPs was examined by using the Spearman coefficient correlation.

Results

Sociodemographic Characteristics

The details of the demographic characteristic of the studied respondents are summarized in Table 1. The largest number of respondents were aged between 18 and 29 years old (n = 433, 43.9%). There were more male respondents (n = 521, 52.8%) than females (n = 465, 47.2%). More than half the respondents were married (n = 589, 56.7%), and 839 (85.1%) of the respondents were Malay. There were more respondents with educational levels of secondary school and lower (n = 577, 58.5%) than those with tertiary educational levels (certificate, diploma, degree, and above) (n = 409, 415.5%). Moreover, many worked in the private sector (n = 367, 37.2%) and had average monthly household incomes less than RM 2,500 (n = 417, 42.3%).

Table 1.

Socio demographic characteristics of the studied respondents (n = 986)

Socio demography	Frequency (%)
Age group (yrs)
18–29	433 (43.9)
30–44	359 (36.4)
45 and above	194 (19.7)
Gender
Male	521 (52.8)
Female	465 (47.2)
Marital status
Single	397 (40.3)
Married/Widowed/Divorced	589 (59.7)
Ethnicity
Malay	839 (85.1)
Indian	64 (6.5)
Chinese	60 (6.1)
Others	23 (2.3)
Highest educational level
Secondary school and below	577 (58.5)
Tertiary	409 (41.5)
Occupation category
Private sector	367 (37.2)
Government sector	354 (35.9)
Self-employed	158 (16.0)
Unemployed	107 (10.9)
Average monthly household income (MYR)
Less than 2,500	417 (42.3)
2,500–4,999	408 (41.4)
5,000 and above	161 (16.3)
Number of family members
1–3	349 (35.4)
4–6	501 (50.8)
>6	136 (13.8)
Type of house
Landed housea	701 (71.1)
High riseb	285 (28.9)

^aSingle house/Wooden house/Double storey/Bungalow

^bFlat/Apartment/Condominium

Knowledge of Mosquitoes

Table 2 shows the frequency (%) of responses for knowledge of Aedes and Culex (Say) mosquitoes. Most of the respondents knew that Aedes had black and white markings on the legs (n = 920, 93.3%), but most of them incorrectly gave the morphology of Culex (n = 579, 58.7%) as the respondents were not sure of the general color and shape of the abdomen of Culex mosquitoes. Only 460 (46.7%) respondents knew that container breeding Aedes bites occurred during the daytime, while 375 (38.0%) of the respondents knew the biting time of Culex. More than half the respondents (n = 650, 65.9%) answered that Aedes breeds in clean water, whereas 486 (49.3%) respondents stated that Culex breeds in polluted water. Most of the respondents were very familiar with dengue (n = 912, 92.5%) while filariasis was the least known disease (n = 200, 20.3%). Social media played an important role as a source of mosquito information. Television (n = 616, 62.5%) and the internet (n = 563, 57.1%) were the main sources, followed by health personnel (n = 494, 50.1%), friends and family (n = 451, 45.7%), and newspapers (n = 410, 41.6%). Overall, 71.4% (n = 704) of the respondents had good knowledge of mosquitoes.

Table 2.

Frequency distribution of respondents for knowledge of mosquitoes(n = 986)

Knowledge of mosquitoes		Frequency (%)
		Yes	No
Aedes has black and white markings on the legs		920 (93.3)	66 (6.7)
Culex has brown body		407 (41.3)	579 (58.7)
Aedes bites at night time		460 (46.7)	526 (53.3)
Culex bites during day time		375 (38.0)	611 (62.0)
Aedes breeds in the clean water		650 (65.9)	336 (34.1)
Culex breeds in drain or polluted water		486 (49.3)	500 (50.7)
Disease transmitted by mosquitoes	Chikungunya	437 (44.3)	549 (55.7)
	Dengue	912 (92.5)	74 (7.5)
	Filariasis	200 (20.3)	786 (79.7)
	Japanese encephalitis	230 (23.3)	756 (76.7)
	Malaria	396 (40.2)	590 (59.8)
Source of information on mosquitoes	Health personnel	494 (50.1)	492 (49.9)
	School/ university	314 (31.8)	672 (68.2)
	Television	616 (62.5)	370 (37.5)
	Friends & family	451 (45.7)	535 (54.3)
	Newspaper	410 (41.6)	576 (58.4)
	Internet	563 (57.1)	423 (42.9)
	Poster	231 (23.4)	755 (76.6)
	Magazine	118 (12.0)	868 (88.0)
	Radio	265 (26.9)	721 (73.1)
Total knowledge score	Low score (0–2)	282 (28.6)
	High score (3–6)	704 (71.4)

The univariate analyses shown in Table 3 revealed that five factors were significantly associated with mosquito knowledge score. Respondents aged 30–44 had the highest scores of knowledge of mosquitoes (n = 284, 79.1%). Male respondents (n = 401, 77.0%) had higher scores than female respondents. For marital status, the greater scores for knowledge of mosquitoes came from married respondents (n = 446, 75.7%). The average monthly income for Malaysia is RM 7,901. Respondents with monthly household incomes between RM 2,500 and RM 4,999, which are categorized in the lower income group, had the highest scores (n = 325, 79.7%).

Table 3.

Factors associated with knowledge of mosquitoes (n = 986)

				Univariate analysis			Multivariate analysis
				Total mosquito-related knowledge score			High score vs Low score
	Frequency (%)	Chi- square	df	Low score (0–2) (n = 282)	High score (3–6) (n = 704)	P-value	Odds Ratio (95% CI)c
Socio demographic factor
Age group (yrs)
18-29	433 (43.9)			153 (35.3)	280 (64.7)		Ref
30-44	359 (36.4)	20.120	2	75 (20.9)	284 (79.1)	P < 0.001	1.552 (1.005–2.396)*
45 and above	194 (19.7)			54 (27.8)	140 (72.2)		0.696 (0.402–1.204)
Gender
Male	521 (52.8)			120 (23.0)	401 (77.0)		1.664 (1.209–2.291)**
Female	465 (47.2)	16.771	1	162 (34.8)	303 (65.2)	P < 0.001	Ref
Marital status
Single	397 (40.3)	13.381	1	139 (35.0)	258 (65.0)	P < 0.001	Ref
Married/ Widowed/ Divorced	589 (59.7)			143 (24.3)	446 (75.7)		1.318 (0.863–2.013)
Ethnicity
Malay	839 (85.1)			224 (26.7)	615 (73.3)		3.220 (1.196–8.670)*
Indian	64 (6.5)	19.987	3	17 (26.6)	47 (73.4)	P < 0.001	3.083 (0.979–9.711)
Chinese	60 (6.1)			28 (46.7)	32 (53.3)		1.523 (0.495–4.684)
Others	23 (2.3)			13 (56.5)	10 (43.5)		Ref
Highest educational level
Secondary school and below	577 (58.5)	1.666	1	156 (27.0)	421 (73.0)	0.199
Tertiary	409 (41.5)			126 (30.8)	283 (69.2)
Average monthly household income (MYR)
Less than 2500	417 (42.3)			137 (32.9)	280 (67.1)		1.267 (0.825–1.945)
2500-4999	408 (41.4)	25.058	2	83 (20.3)	325 (79.7)	P < 0.001	2.153 (1.385–3.346)**
5000 and above	161 (16.3)			62 (38.5)	99 (61.5)		Ref
Type of house
Landed housea	701 (71.1)	1.742	1	192 (27.4)	509 (72.6)	0.187
High riseb	285 (28.9)			90 (31.6)	195 (68.4)

*P < 0.05, **P < 0.01, ***P < 0.001.

^aSingle house/Wooden house/Double storey/Bungalow.

^bFlat/Apartment/Condominium.

^cHosmer & Lemeshow test, chi-square: 10.193, P-value: 0.252.

Univariate analysis: Chi-square test.

Multivariate analysis: Logistic regression.

Ref: Reference Category.

The multivariate analyses shown in Table 3 indicated that respondents aged 30–44 yrs old (OR = 1.552, 95% CI = 1.005–2.396) were more likely to have better knowledge of mosquitoes than those aged 18-29 years old. Specifically, male (OR = 1.664, 95% CI = 1.209-2.291) and Malay respondents (OR = 3.220, 95% CI = 1.196-8.670) had better knowledge than others. Respondents with a monthly income range of RM 2,500–RM 4,999 (OR = 2.153, 95% CI = 1.385–3.346) were more likely to have good knowledge than those with incomes RM 5,000 and above, suggesting that lower income group had better knowledge than higher income group.

Knowledge of Household Insecticides

Table 4 shows the descriptive findings on knowledge of household insecticides among the respondents. Advertisements (through nontelevision medium) were the main source of information for the choice of household insecticide among the respondents (n = 509, 51.6%), followed by health personnel (n = 415, 42.1%) and television (n = 391, 39.7%). The three most common forms of insecticides were aerosols (n = 838, 85.0%), coils (n = 660, 66.9%), and mat vaporizers (n = 385, 39.0%). Meanwhile, only 26.5% (n = 261) of the respondents were aware of active ingredients labelled on the package.

Table 4.

Knowledge of household insecticides (n = 986)

Knowledge of household insecticides		Frequency (%)
		Yes	No
Source of information on household insecticides	Health personnel	415 (42.1)	571 (57.9)
	School/ university	181 (18.4)	805 (81.6)
	Television	391 (39.7)	595 (68.3)
	Family & relatives	343 (34.8)	643 (65.2)
	Friends	336 (34.1)	650 (65.9)
	Newspaper	244 (24.7)	742 (75.3)
	Internet	353 (35.8)	633 (64.2)
	Poster	172 (17.4)	814 (82.6)
	Advertisement	509 (51.6)	477 (48.4)
	Retailer	202 (20.5)	784 (79.5)
	Radio	184 (18.7)	802 (81.3)
Form of insecticide use	Aerosol/ spray	838 (85.0)	148 (15.0)
	Mat vaporizer	385 (39.0)	601 (61.0)
	Coil	660 (66.9)	331 (326)
	Liquid vaporizer	359 (36.4)	627 (63.6)
	Larvicide (Abate)	495 (50.2)	491 (49.8)
	Repellent cream	139 (14.1)	847 (85.9)
Aware of active ingredient in the insecticide		261 (26.5)	725 (73.5)

Attitudes toward Household Insecticides

The descriptive analysis in Table 5 shows the attitudes of respondents toward household insecticides. More than 50% (n = 666, 67.5%) of the users of mosquito coils, 50.1% (n = 494) of users of mosquito mat vaporizers, and 52.1% (n = 514) of users of liquid vaporizers agreed that these products could be harmful to their own health. Meanwhile, 74.3% (n = 733) of the users of mosquito coils, 62.8% (n = 619) of the users of mosquito mat vaporizers, and 65.4% (n = 645) of the users of liquid vaporizers agreed that household insecticides could harm their children’s health. However, less than 50% of the respondents agreed that household insecticides could harm the environment. About 51% of the respondents had high attitude scores towards household insecticides.

Table 5.

Attitudes towards household insecticides (n = 986)

Attitudes towards household insecticides		Frequency (%)
		Yes	No
Harmful to my health	Mosquito coil	666 (67.5)	320 (32.5)
	Mat vaporizer	494 (50.1)	492 (49.9)
	Liquid vaporizer	514 (52.1)	472 (47.9)
Harmful to childrens health	Mosquito coil	733 (74.3)	253 (25.7)
	Mat vaporizer	619 (62.8)	367 (37.2)
	Liquid vaporizer	645 (65.4)	341 (34.6)
Harmful to the environment	Mosquito coil	493 (50.0)	494 (50.0)
	Mat vaporizer	421 (42.7)	565 (57.3)
	Liquid vaporizer	447 (45.3)	539 (54.7)
Total attitude score	Low score (0-5)	482 (48.9)
	High score (6-9)	504 (51.1)

Table 6 shows the association between the respondents’ knowledge of mosquitoes and their attitudes on household insecticides (P = 0.035). However, multivariate analysis demonstrated no association involving respondents’ attitudes toward household insecticide.

Table 6.

Factors associated with attitudes towards household insecticides (n = 986)

				Univariate analysis			Multivariate analysis
				Total attitudes towards insecticide usage score			High score vs Low score
	Frequency (%)	Chi- square	df	Low score (0-5) (n=482)	High score (6-9) (n=504)	p-value	Odds Ratio (95% CI)d
Socio demographic factor
Age group (years)
1–29	433 (43.9)			221 (51.0)	212 (49.0)
3–44	359 (36.4)	2.374	2	164 (45.7)	195 (54.3)	0.305
45 and above	194 (19.7)			97 (50.0)	97 (50.0)
Gender
Male	521 (52.8)			266 (51.1)	255 (48.9)	0.160
Female	465 (47.2)	2.084	1	216 (46.5)	249 (53.5)
Marital status
Single	397 (40.3)			203 (51.1)	194 (48.9)
Married/ Widowed/  Divorced	589 (59.7)	1.345	1	279 (47.4)	310 (52.6)	0.270
Ethnicity
Malay	839 (85.1)			407 (48.5)	432 (51.5)
Indian	64 (6.5)			35 (54.7)	29 (45.3)
Chinese	60 (6.1)	1.971	3	31 (51.7)	29 (48.3)	0.578
Others	23 (2.3)			9 (39.1)	14 (60.9)
Highest educational level
Secondary school and below	577 (58.5)	0.071	1	280 (48.5)	297 (51.5)	0.796
Tertiary	409 (41.5)			202 (49.4)	207 (50.6)
Average monthly household income (MYR)
Less than 2,500	417 (42.3)			210 (50.4)	207 (49.6)
2,500–4,999	408 (41.4)	0.934	2	198 (48.5)	210 (51.5)	0.627
5,000 and above	161 (16.3)			74 (46.0)	87 (54.0)
Type of house
Landed housea	701 (71.1)			335 (47.8)	366 (52.2)	0.292
High riseb	285 (28.9)	1.165	1	147 (51.6)	138 (48.4)
Mosquito-related knowledge
Total knowledge score
Low score (0–2)	282 (28.6)	4.560	1	153 (54.3)	129 (45.7)	0.035	Ref
High score (3–6)	704 (71.4)			329 (46.7)	375 (53.3)		1.325 (0.982–1.788)

*P < 0.05, **P < 0.01, ***P < 0.001.

^aSingle house/Wooden house/Double storey/Bungalow.

^bFlat/Apartment/Condominium.

^dHosmer & Lemeshow test, Chi- square: 7.961, P-value: 0.437.

Practices for Household Insecticides

Table 7 describes the information regarding respondents’ practices for household insecticide. Most respondents (n = 919, 93.2%) washed their hands after using the insecticides. The majority of respondents (n = 903, 91.6%) mentioned that they kept the products out of reach of children and pets. Most respondents (n = 884, 89.7%) also stated that they did not store insecticides with food and beverages. The data also showed that 88.4% (n = 872) of respondents did not use these products in the presence of a person with allergies. However, about 24.4% (n = 241) and 23.7% (n = 234) of respondents claimed to close the doors and windows and switch off the fans during the application of insecticide, respectively. Nearly 90% of respondents (n = 859, 87.1%) read the manufacturer’s instructions before use. Many (n = 769, 78.0%) declared that children had access to the insecticides. More than half the respondents (n = 672, 68.2%) stated that they applied insecticides where children sleep. Only 46.9% (n = 462) of the respondents applied insecticides in the corner of the room. Overall, approximately 59% of the respondents had high (good) practice scores on use of household insecticides.

Table 7.

Practices with household insecticides (n = 986)

Practices		Frequency (%)
		Yes	No
Method of disposal of household insecticide:
Throw it into dustbin		751(76.2)	235 (23.8)
Throw it away		568 (57.6)	418 (42.4)
Wrap in separate container before disposing		505 (51.2)	481 (48.4)
Insecticide burning in the corner of the room		462 (46.9)	524 (53.1)
Insecticide repackaged after it has been opened		695 (70.5)	291 (29.5)
Doors and windows closed while insecticide is in use		241 (24.4)	745 (75.6)
Insecticide used where children sleep		672 (68.2)	314 (31.8)
Wash hands after using the insecticide		919 (93.2)	67 (6.8)
Children have access to the insecticide		769 (78.0)	217 (22)
Fans switched off while the insecticide is burning		234 (23.7)	752 (76.3)
Observation of manufacturer’s instructions before use		859 (87.1)	107 (12.9)
Does not store insecticide together with food and beverages		884 (89.7)	102 (10.3)
Kept out of reach of children and pets		903 (91.6)	83 (8.4)
Does not use in the presence of a person with allergies		872 (88.4)	114 (11.6)
Total practices score	Low score (1–7)	402 (40.8)
	High score (8–11)	584 (59.2)

The factors associated with the practice score for household insecticide use are shown in Table 8. More respondents aged 45 yrs and above had high (good) practice scores on household insecticide use (n = 145, 74.7%). Respondents who lived in houses with land (n = 439, 62.6%) also had higher practice scores. Respondents who had high scores on the knowledge of mosquitoes (n = 433, 61.5%) had significantly higher practice scores than others. Moreover, respondents who had high scores on attitudes to household insecticide use (n = 322, 63.9%) had significantly higher practice scores than others. Multivariate analysis showed that respondents with ages from 30 to 44 yrs (OR = 0.604, 95% CI = 0.435–0.839) were less likely to have high practice scores than those aged from 18 to 29 yrs. Respondents who had high scores on attitudes on household insecticide use (OR = 1.342, 95% CI=1.010–1.784) were more likely to have high practice scores on household insecticide use than others.

Table 8.

Factors associated with practices of household insecticides (n = 986)

				Univariate analysis			Multivariate analysis
				Total practices in using insecticide score			High score vs Low score
Sociodemographic	Frequency (%)	Chi- square	Df	Low score (1–7) (n = 402)	High score (8–11) (n = 584)	P -value	OR (95% CI)e
Age group (years)
18–29	433 (43.9)			176 (40.6)	257 (59.4)		Ref
30–44	359 (36.4)	30.161	2	177 (49.3)	182 (50.7)	P < 0.001	0.604 (0.435–0.839)**
45 and above	194 (19.7)			49 (25.3)	145 (74.7)		0.987 (0.629–1.550)
Gender
Male	521 (52.8)			207 (39.7)	314 (60.3)	0.516
Female	465 (47.2)	0.494	1	195 (41.9)	270 (58.1)
Marital status
Single	397 (40.3)	0.013	1	161 (40.6)	236 (59.4)	0.947
Married/ Widowed/ Divorced	589 (59.7)			241 (40.9)	348 (59.1)
Ethnicity
Malay	839 (85.1)			331 (39.5)	508 (60.5)
Indian	64 (6.5)			34 (53.1)	30 (46.9)	0.093
Chinese	60 (6.1)	6.412	3	29 (48.3)	31 (51.7)
Others	23 (2.3)			8 (34.8)	15 (65.2)
Highest educational level
Secondary school and below	577 (58.5)			224 (38.8)	353 (61.2)	0.148
Tertiary	409 (41.5)	2.189	1	178 (43.5)	231 (56.5)
Ave. monthly house. income (MYR)
Less than 2,500	417 (42.3)			165 (39.6)	252 (60.4)
2,500–4,999	408 (41.4)	2.763	2	178 (43.6)	230 (56.4)	0.251
5,000 and above	161 (16.3)			59 (36.6)	102 (63.4)
Type of house
Landed housea	701 (71.1)	11.580	1	262 (37.4)	439 (62.6)	0.001	1.072 (0.787–1.460)
High riseb	285 (28.9)			140 (49.1)	145 (50.9)		Ref
Mosquito-related knowledge
Total knowledge score
Low score (0-2)	282 (28.6)	5.283	1	131 (46.5)	151 (53.5)	0.026	Ref
High score (3-6)	704 (71.4)			271 (38.5)	433 (61.5)		1.140 (0.832–1.562)
Attitudes towards insecticide usage
Total attitudes score
Low score (0–5)	482	9.270	1	220 (45.6)	262 (54.4)	0.003	Ref
High score (6–9)	504			182 (36.1)	322 (63.9)		1.342 (1.010–1.784)*

*P < 0.05, **P < 0.01, ***P < 0.001.

^aSingle house/Wooden house/Double storey/Bungalow.

^bFlat/Apartment/Condominium.

^eHosmer & Lemeshow test, Chi- square:12.836, P-value: 0.118.

Relationships Between KAP Domains

Table 9 indicates that there were positive and significant correlations between knowledge and attitudes (r = 0.157, P = 0.001), and between attitudes and practices (r = 0.184, P = 0.001). Overall, the high knowledge score (OR: 1.140, 95% CI: 0.832–1.562) was not significantly associated with the respondent’s good practice. However, the age group between 30 and 44 years old (OR: 0.604, 95% CI: 0.435–0.839) and high attitude score (OR: 1.342, 95% CI: 1.010–1.784) was significantly associated with good practices.

Table 9.

Correlation between knowledge, attitudes and practices on household insecticides

Relationship	r	P-value
Knowledge vs attitudes	0.157	0.001*
Attitudes vs practices	0.184	0.001*
Knowledge vs practices	0.042	0.193

*P < 0.001

Discussion

Overview of Principal Findings for Knowledge, Attitudes, and Practices

We conducted a survey to assess the level of knowledge, attitudes, and practices related to household insecticide products in selected dengue hotspots in Selangor. To the best of our knowledge, this is the first study to provide a detailed description of household insecticide product use in a dengue-endemic setting. Overall, the participants had good mosquito knowledge, good attitudes toward household insecticides, and good practices of household insecticide product use. However, the greater mosquito knowledge score was not a predictor of good practices. In contrast, the attitude needs to be emphasized since good attitudes will allow respondents to reflect their knowledge through the practices (Arham et al. 2018).

Knowledge of Mosquitoes

In the present study, television was the most popular source of mosquito knowledge. Likewise, previous studies also reported media as a major source in the spread of dengue knowledge (Karimah Hanim et al. 2017, Zaini et al. 2019). However, friends and relatives were the primary sources of dengue fever knowledge in a study conducted in Laos (Jeelani et al. 2015). Another study in Thailand discovered that health professionals were the main source of knowledge on dengue fever (Brusich et al. 2015).

The current study indicated that most respondents had good knowledge on mosquitoes, particularly that they could answer that Aedes has black and white markings on the legs. However, this finding was differed by other studies elsewhere (Paz-Soldan et al. 2015, Rahman et al. 2021). Furthermore, most respondents also knew that Aedes prefers to breed in clean water, probably because many breeding sites, such as discarded tires and stagnant water, were noticeable in residences where mosquitoes have been an annoyance for a long time (Rozendaal 1997, Kamel et al. 2017, Karimah Hanim et al. 2017).

Only a few were aware that Aedes bites during the daytime, suggesting a possible confusion with Culex, the night-time biting mosquito. Nevertheless, it is important to point out that Aedes mosquitoes also feed in the dark (Chen et al. 2014, 2017), approximately two hours after sunrise and several hours before sunset, and exhibit indoor-resting behavior, particularly in isolated stationary areas (Meena 2020). The young people surveyed in this study may work long hours and return home after sunset, which was the time when they were bitten. As a result, their responses could indicate the container breeding Aedes in Selangor may be adapting to host work-rest behaviors.

Furthermore, less than half the respondents stated that Culex has a brown body, while only a few of the respondents knew that Culex bites during the night. This finding agreed with previous studies, which indicated low levels of knowledge on the active time of Culex (Soe et al. 2018). In this study, more than half the respondents correctly responded that Culex breeds in drains or polluted water, which parallels the findings of previous studies elsewhere (Rozendaal 1997, Kudom et al. 2015, Patrick et al. 2018).

The present study revealed an association of mosquito knowledge with respondents’ age, but this finding differed from Jeelani et al. (2015). In this study, individuals aged below 30 years had low scores on knowledge of mosquitoes, as similarly reported by Zaini et al. (2019). The lack of knowledge in younger people could be explained by the shorter times they spend watching television, which is the primary source of information on dengue prevention (Lugova and Wallis 2017), as well as the prevention programs, which did not reach them (Benthem et al. 2002). Therefore, the Malaysian government should focus more on other social media to reach this age group. It is also important to highlight that the low knowledge levels of mosquito-borne diseases such as filariasis and Japanese encephalitis were related to the low exposure to health education regarding mosquitoes.

Moreover, gender had an association with knowledge on mosquitoes. However, this finding was inconsistent with the study by Karunamoorthi and Hailu (2014), which reported that gender was not a significant factor in respondents’ knowledge. In this study, male respondents attained more knowledge regarding mosquitoes than females. This is probably related to their responsibility to protect themselves and their families from mosquito bites and disease (Alobuia et al. 2015). Nevertheless, Hamid et al. (2021) found that females were more likely to have good knowledge on mosquitoes. Despite these discrepancies, the buyer of the household insecticide products is the key person who holds the responsibility and is likely to have taken the time to educate himself/herself on this proficiency.

The present study also revealed that those of Malay ethnicity scored significantly higher on mosquito knowledge. However, Alhoot et al. (2017) found that dengue knowledge was substantially higher among Chinese, Indian, and other ethnic groups than in Malays. By contrast, Leong (2014) found a significant relationship between Malay ethnicity and better dengue KAPs in a rural population. People living in rural areas have a traditional lifestyle, so they are more likely to spend considerable time in and around their houses engaging in the removal of mosquito breeding sites; however, the present study focused on individuals primarily in urban and suburban settings.

Households with incomes less than RM 5,000, most of whom lived in suburban areas, were more likely than others to know about mosquitoes. The conditions of suburban areas offer ideal breeding grounds for mosquitoes, making an increased adherence to dengue prevention activities particularly important. In comparison, mosquitoes might be less noticeable in higher-income neighborhoods, so residents could develop a false sense of security and thus fail to take preventative measures against mosquitoes (Alobuia et al. 2015). Therefore, efforts to educate and deliver messages need to be more targeted depending on the different economic income groups, such as the higher-income earners in urban areas who typically spent most of their time working away from home.

Knowledge of Household Insecticides

This study found numerous sources of information about household insecticides. Most respondents acquired knowledge on the use of insecticides through mass media, friends, and family, which differed from a study of health professionals (Malhotra and Kaur 2014). Therefore, these sources can influence respondents’ knowledge of safe insecticide handling.

The dengue control program in Malaysia has been promoting household responsibility in eradicating mosquito breeding sites. This includes treating essential water-holding containers with larvicides, cleaning water containers weekly, and house inspection for Aedes mosquitoes breeding (Ong 2016). Despite local governments promoting the use of the Abate larvicide to eliminate mosquito larvae, only half the respondents used it. This could be because the public had insufficient knowledge on the use of larvicide together with the poor instructions provided. In comparison, the studies of Al-Dubai et al. (2013) and Wong et al. (2015), found that more than half of the respondents reported the use of Abate. In view of the lack of knowledge on concerning Abate larvicide, the government should educate the public on the use of this insecticide in Aedes’ breeding grounds such as toilet pumps, flowerpots, and ornamental ponds. The public should also be informed that this larvicide would be distributed during house-to-house inspection and communal work or be provided for free from their local district health office. Additionally, the instructions should include a demonstration of the proper measurement and placement in potential mosquito breeding areas, and an explanation of the product’s safety properties. However, a few studies indicated that respondents did not like to use water containing Temephos, as it might pose a health risk (George et al. 2015, Legorreta-Soberanis et al. 2017).

The most common household insecticides respondents in this study used were aerosol sprays followed by mosquito coils and mat vaporizers. These findings were consistent with previous studies elsewhere (Mulla et al. 2001, Babu et al. 2007). The respondents’ knowledge of insecticides enabled them to identify potential exposure routes such as ingestion, inhalation, and skin absorption, and it encouraged them to participate in safe behavior practices and to follow the prescribed instructions for daily domestic use (Peterson et al. 2006, Hamid et al. 2021). The extent of people’s knowledge of insecticides can influence their willingness to employ safer handling practices such as wearing a mask or gloves (Brusich et al. 2015, Paz-Soldan et al. 2015, Laksham et al. 2016).

Attitudes towards Household Insecticides

More than half the respondents stated that household insecticides might be harmful to their health and their children’s health. Heydari et al. (2017), who reported that most people believed that insecticides were harmful to humans and considered them toxic and dangerous, reached a similar conclusion. High awareness of the harmful effects of insecticides among the respondents could have come from their experience of self-reporting medical problems. The awareness of the respondents was also an integral part of developing a good attitude towards insecticides (Hamid et al. 2021), and it was usually correlated with the literacy levels of the respondents, since literacy may allow them to acquire the necessary knowledge about insecticides (Shuaib et al. 2010). In addition, Hamid et al. (2021) highlighted that an individual with an adequate level of literacy can comprehend the color code and label of an insecticide product, ensuring a positive attitude towards insecticides.

The behavioral and biological factors of a person’s age may pose a greater risk of household insecticide exposure, especially in young children or the elderly (English et al. 2019). Actions such as putting the hand into the mouth, as well as poor hand hygiene among children, make them susceptible to accidental exposure to household insecticides (Wu et al. 2011, Vesin et al. 2013, Li et al. 2016). Surprisingly, this study did not find any factors associated with the attitudes on the use of household insecticides. However, several studies illustrated that the respondents’ willingness to use household insecticide products varied with educational level (Rahman et al. 2021) and family income (Alhoot et al. 2017). This result can be explained by the fact that educational background and experience can positively influence attitudes towards insecticides (Ghani et al. 2019). Furthermore, attitudes might be influenced by the information and experience passed from a relative, neighbor, or the community and eventually lead to respondents’ awareness based on recommendations and facts from previous users (Abdul Alif et al. 2019, Jambari et al. 2020).

Practices with Household Insecticides

The practices for household insecticides in the present study indicated that the respondents used safe protecting behaviors regarding health risks associated with the household insecticide application. Most of the respondents read the manufacturer’s instructions before using the insecticide. This indicated better behavior on the part of Malaysian respondents than in a study in Uganda, in which approximately half the respondents did not read the manufacturer’s product label (Nalwanga and Ssempebwa 2011). This may account for respondents’ ability to read and recognize the presence of toxicity symbols as well as the expiration date. It is essential that instructions are written in a language that is readable and understandable on the label, as this translates into good practice when applying insecticide [Department of Agriculture Malaysia (DOA) 2005].

Moreover, almost all the respondents did not store insecticides with food and beverages. This indicated their concern over the risk of food contamination as a safety precaution measure (Harirar Bhawan 2014). Indeed, if stored together, the household insecticide pyrethrin could contaminate food and water, which can eventually pose an accidental poisoning risk to the family members in a particular household (Akhtar et al. 2012, Legorreta-Soberanis et al. 2017). It is also important to note that inhalation is a major pathway of insecticide exposure, as it is distributed into the environment during domestic use (Pauluhn and Ozaki 2015, Saillenfait et al. 2015, Islam et al. 2020). This study found that most respondents used good and safe practices with household insecticide products and were well versed in the exposure risk to domestic insecticides.

The respondents in this study also showed concern over allergies in the use of household insecticides, as most of them would not use insecticides in the presence of people with allergies. Domestic insecticide use may cause deposition of toxins into indoor dust, which could accumulate into a greater concentration (Wu et al. 2011, English et al. 2019) and subsequently contribute to the insecticide inhalation exposure threat. On practices, participants 30–44 years old were 39% less likely to have high practices scores. Members of this age group may be occupied with work and not have enough time to keep their houses and surroundings clean or to take preventive or protective measures to control vectors and mosquito infestation. This study contrasted with a previous study that found the best practice scores among retired people (Sulistyawati et al. 2019), and one that found that skilled workers were less likely to practice dengue prevention than unemployed people (Wong et al. 2015). Respondents with high attitude scores also tended to have high practice scores. This indicates that those with better attitudes were more likely to take precautionary measures to prevent infection.

Relationship between Knowledge of Mosquitoes, Attitudes, and Practices Involving Household Insecticides

This study revealed a positive correlation between knowledge of mosquitoes and attitudes on household insecticide use, as reported in other studies elsewhere (Jambari et al. 2020, Selvarajoo et al. 2020). However, this study showed that there was no correlation between the knowledge and practices of the respondents. This finding was consistent with previous similar studies (Nur Ain et al. 2017, Ajibola et al. 2018, Kumaran et al. 2018). The correlation between knowledge and attitudes represents the simple basic requirement of the respondents, which may mediate into logical thinking to employ a safe approach to insecticide handling (Morgan et al. 2011).

In the present study, attitude scores on the use of household insecticides seemed to have influenced practices. The finding was similar to another study, which claimed there was an association between the attitude and practice of respondents on safe handling of insecticides (Abdullah et al. 2013, Aung et al. 2016). However, others found no association between these variables (Ajibola et al. 2018, Leong 2014). The attitudes and practices might be influenced by the information and experience from relatives, neighbors, or the community, which might lead to practices based on recommendations from previous users (Aung et al. 2016). Thus, respondents’ attitudes and practices in this study were positively influenced by various sources; however, the variables were not prominently explored, and they need further study to determine their exposure risk.

In relation to the current study, it should be noted that there is a need for government and the MOH to find ways of providing and improving access to educational materials and programs across the country. This should provide communities with the opportunity to understand the risks of vector-borne diseases and prevention practices that can reduce or prevent their transmission. This knowledge should also emphasize the time and frequency of use, as well as the locations and storage of household insecticides. Knowing how to use insecticides in the home is essential for consumer safety and efficacy of vector control.

This study offers valuable perspectives and information that may direct public health officials and nongovernment entities in preparing, developing, and launching dengue prevention and control programs. The public’s understanding of insecticides is critical in encouraging safer household insecticide usage when navigating their home vector control routine. The use of mass media as a medium for disseminating critical information about household insecticide use should be encouraged. Moreover, unique traditional community collective activities, which are commonly practiced in rural villages, could also be promoted in urban communities.

This study can be recommended as a reference for public health authorities in developing effective interventions to reduce the risk of insecticide exposure in the public, especially in urban areas. These will assist the public in making better decisions and taking the necessary steps toward daily domestic insecticide use to protect their health and well-being. A better understanding of household insecticides would result in a better attitude on household insecticide use. Continuous health education through community engagement, in collaboration with health workers, will help to raise awareness about dengue prevention initiatives and promote positive attitudes and safe practices for the use of household insecticide products.

Acknowledgments

This study was supported by the Higher Institution Centre of Excellence (HICoE) program (MO002-2019) and Universiti Malaya research grant (RP021D-16SUS).