Study design and period
Unmatched case control study design was conducted in Guna-begemidir district from January 30-February 25/2018. The line list was filled and sent to the district health office by the trained health extension workers and medical officers from zonal health department, district health office and health center staffs during verification, identified by multisectoral scabies outbreak guideline using suspected case definition from September to November 2017.
Guna-begemidir district is one of the districts found in South Gondar Zone, located 35 km from Debretabor town, 137 km from the Regional town Bahirdar formed as a district on July 2017. The district has catchment area of 51373.2 hectare with altitude range of 1200-4220m above sea level. The district has weather condition of 17% tropical (kola), 46% subtropical (weynadega), 32% temperate (Dega) and 5% alpine (Wurch). The total population of the district was 100727 of which females constitute 50464 (50.1%). Districts that share boundaries with Guna-begemidir district are Lay Gayint at the North, Farta the South, Estie district at the East and Ebinat district at the West. Some of population have contacts with the surrounded district population through market and different ceremonies like weeding. The district has 19 Kebeles (collection of surrounded villages together), 04 Health Centers, 21 Health Posts, 79 health care providers, 79 other non-health staffs and 37 health extension workers (HEW).
All populations living in Guna-begemidir district
Populations living in the assessed six kebeles of Guna-begemidir district where cases selected randomly from 420 case identified in all kebeles of the district listed in the line list.
Sampling and sample size determination:
We calculated the sample size using Epi Info 7 for unmatched case control study with an assumption of 95% CI, 90% power, OR of 2, ratio of controls to cases 2:1 and taking 26.6% of controls shared close with ill person from studies done in Gondar town among Yekolo-temaries. The total calculated sample was 156 case and 312 controls. Cases were selected using simple random sampling technique from the registered of 420 cases in the line list document where identified by teams from zonal health department, district health office and health center staffs during verification, identified by Ethiopian interim guideline for multisectoral scabies outbreak guideline using suspected case definition. Controls were enrolled from the family of cases or villages where cases were enrolled without the history of scabies during the study period and if no control from family we select from neighboring villages.
Data collection methods
Data was collected from cases and controls by moving house to house of exposed villages from January 30-February 25/2018. Participants were interviewed using structured questionnaires and primary data was collected from respondents by the Public health officer investigator who had trained based on Ethiopian interim-guideline for multi-sectorial scabies outbreak emergency response by the clinician (internist doctors) from Debretabor hospital. Data of children who were unable to respond was taken from their mothers (care givers). A total of 156 cases and 312 controls were interviewed to assess their sociodemographic and other variables and exposure status.
Data entry and analysis
Data was entered by using SPSS version 22 and analyzed by MS excel 2013, SPSS version 22 and Arc Gis10.3. Descriptive analysis was performed for sociodemographic characteristics and other risk factors. We explained results as frequencies, proportions, rates, mean /median and standard deviations. Risk factors were identified statically by computing OR with 95% CI, by bivariate and multivariable logistic regression analysis. Variables having p value of less than 0.2 were entered to multivariable analysis to identify significant variables. Variables with p value less than 0.05 with corresponding 95% CI were considered as significantly associated in multivariable logistic regression.
Inclusion and Exclusion criteria
Cases: Any resident of Guna-begemidir district who had signs and symptoms of scabies using suspected case definition during identification of cases in the line list and during interview for verification of cases listed in the line list.
Controls: Any resident of Guna-begemidir district during the study living in the family or village of neighboring cases that did not develop signs and symptoms of scabies.
- Suspected case: A person with signs and symptoms consistent with scabies.
- Confirmed case: A person who has a skin scraping in which mites, mite eggs or mite feces have been identified by a trained health care professional.
Contact: A person without signs and symptoms of scabies who had direct contact (particularly prolonged, direct, skin-to-skin contact) with a suspected or confirmed case in the two months preceding the onset of scabies signs and symptoms in the case.
Infrequent changing of cloths: Those who wear same cloth for more than one week without washing and changing
General Knowledge about scabies – those who answered at least one transmission, one prevention mechanism and or one treatment of scabies.
Mild case – patients having less than 6 skin lesions
Moderate – patients having 6-10 lesions
Severe – patients having greater than 11 skin lesion and or has crusted scabies.
Attack rate – percentage of total new cases identified divided by risk population
Monthly income – classified based on quartile as in four classes as <84$, 84-152$, 153-210$ and >210$ using US$.
Prolonged contact – having daily contact with patients during their day to day activity; living together.
Putting of cloths together with patient cloths – if they usually put cloths together with patient cloths with one putting material like bag or other things.
The null hypothesis was stated as there is no association between socio
demographic variables, access to water, frequency of bathing, washing and changing cloths and other factors with counteracting scabies.