Study area, design and period
This cross-sectional, community-based study was conducted among food handlers working in food service establishments in Medebay Zana district Towns from January 2019 to February 2019. Medebay Zana district is about 1040kms from Addis Ababa. In the district, there were a total of 277 restaurants and hotels, 44 snack bars and 52 food bakeries. These establishments can accommodate a total of 1850 people. In total, in the hotels, restaurants and snack bars found in the district, there are 1050 food handlers.
All food handlers who were working in Medebay Zana district Towns were the source population; randomly selected (see the sampling technique) food handlers formed the study population. Food handlers who were under treatment or those who finished treatment for parasitic infection within two weeks prior to the study were excluded.
Sample size and sampling technique
The sample size was determined using the following assumptions (level of confidence of the population is taken to be 95% and Zα/2=1.96). A 5% margin of error (d=0.05) and the prevalence of intestinal parasites among food handlers were based on a previously conducted study in Ethiopia, Tigray Mekelle Town at 49.3 % . Based on these assumptions, the actual sample size for the study is computed using one sample population proportion formula as indicated below.
n = (Zα/2)2 P (1-P)/d2
Then, the sample size was, n ≈ 384+10% contingency=422. The total sample size was proportionally allocated according to the number of food handlers working in hotels, snack bars, and bakeries; a systematic random sampling technique was then employed to select the allocated number of study participants from the sampling frame.
Data collection tools
Interviewers administered structured questionnaires were used to collect the data. The content of the questionnaire included socio-demographic characteristics, educational status, economic status, individual behavioral factors, and house characteristics as well as environmental related conditions.
Fecal specimens were obtained from the selected food handlers and transported to the laboratory-based on the standard operating procedures for the collection and transportation of fecal specimens. In the laboratory, the stool was immediately examined by wet mount technique for motile parasites, helminth eggs, cysts, and oocysts of intestinal protozoa followed by Kato-Katz and formol ether concentration technique .
Dependent variable: Intestinal parasites status
Independent variable: Socio demographic variables, such as age, sex, monthly income, educational level, service year; Individual factors, such as proper personal hygiene practice, using fresh vegetable salads and meat, use of sanitizer and disinfectants, environmental sanitation, contact with water source, contact with an animal, eating raw meat and vegetables; Economic factors, such as quality of housing, isolation from work environment when sick, lack of supply of safe water, lack of access to toilet facility, lack of medical check screening
Data quality assurance
To assure the data quality, the data collection instrument was pretested in nearby towns. Data collectors were trained before the actual data collection period by experts from Tigray Health and Research Institute. Furthermore, the collected data were reviewed and checked for completeness each day. Laboratory investigations were done as per the standard operating procedures for specimen collection, transportation, and analysis of fecal specimen.
After checking for completeness, data were coded, cleaned, and entered into SPSS version 21.0 for analysis. Binary logistic regression was used to determine the possible associations between the independent variables and an outcome variable. Those factors with a p-value of 0.2 and below during the bivariate logistic regression analysis were considered for multivariate logistic regression to control the confounders. Finally, statistically significant was declared at p-value <0.05 with a 95% confidence interval.