Study area and period
A cross-sectional survey was conducted in December 2012 on prevalence and risk factors of louse- borne relapsing fever in high risk populations in Bahir Dar city.
Bahir Dar city is situated on the Southern shore of Lake Tana, the source of the Blue Nile (or Abay), in what was previously the Gojjam province. The city is located approximately 578 km North-West of Addis Ababa, having a latitude and longitude of 11°36′N 37°23′E11.6°N and an elevation of 1,840 meters above sea level. Based on the 2007 Census conducted by the Central Statistical Agency of Ethiopia, this city has a total population of 221,991, an increase of 130.90% over the population recorded in the 1994 census, of whom 108,456 are men and 113,535 women [10].
Study participants were high risk populations who were randomly selected and volunteered to participate in the survey. In this survey, the sample size was determined by considering that the prevalence of louse- borne relapsing fever in high risk populations was assumed to be 50%. Moreover, marginal error of 5% and 95% confidence interval (CI) with non response rates of 10% of the sample size was included. Using single proportion formula, 415 study participants were determined. The final study participants were sampled from each high risk populations, proportional to their number. Therefore, 234, 99 and 82 participants were included from prisoners, yekolotemaries and street children respectively.
However, 8 prisoners did not respond hence, survey questionnaire was completed in case of 407 participants to assess their knowledge and risk factors. Blood was taken from the tip of the left ring finger of the participants by laboratory technicians and thick blood film was prepared from each participant and stained with 3% Giemsa for 30 min. The slides were examined under 100 X objective using oil immersion. Finally, the result was reported as positive or negative using light microscopy to determine the prevalence of louse-borne relapsing fever [2].
Data analysis
The quantitative data was checked for completeness, coded and fed in to SPSS version 16 and descriptive statistics (frequency, percentage, mean and standard deviation) were used primarily to summarize and describe the data to make it more graspable. For analytical statistic, p < 0.05 was considered statistically significant for association between variables.
A standardized questionnaire was developed and designed to address socio-demographic characteristics and risk factors of louse- borne relapsing fever and the following operational definitions were used.
Yekolotemaries
Are students who are from rural family of Ethiopia dedicated to learn in the Ethiopian Orthodox Church to become priests. They are grouped in low socio economic status; their livelihood is based on lobbing of foods like Ethiopian local foods from house to house. They live in mud houses and their hygienic condition is poor because they believe that being hygienic could reduce their learning capacities.
High risk populations
Are people who live in over-crowded high risk sites like prisons, military camps, yekolotemaries learning areas, street children sleeping areas etc. and are susceptible to the disease.
Knowledge
The knowledge that the respondent have regarding the prevention of louse- borne relapsing fever.
High levels of knowledge
Study participants who had 7–9 scores out of 9 questions about prevention of LBRF.
Moderate level
Study participants who had 4–6 scores out of 9 questions about prevention of LBRF.
Low level
Study participants who had 0–3 scores out of 9 questions about prevention of LBRF.
Ethical consideration
Ethical clearance was obtained from Bahir Dar University, College of Medicine and Health Sciences and Regional health Bureau. The study participants were informed about the study in their language, including the purpose of the study. For those who were illiterate, the informed consent was read. Only those study participants who agreed and signed the informed consent were included. Finally, individuals’ positive for Borrelia recurrentis were treated accordingly with appropriate drugs.