Study design
This is a descriptive, exploratory mixed cross-sectional study. It was conducted in the general population from the municipalities of two endemic plague districts in Madagascar’s central highlands: Ambositra and Tsiroanomandidy. To assess KAPs towards plague of the general population, a quantitative survey was conducted. In addition to the KAP quantitative survey, a qualitative study on health professionals' perceptions on plague was performed.
Study sites
The selection of studied sites was based on the number of plague cases reported between 2006 and 2015 in the database of the Central Laboratory for Plague (CLP) which is hosted by Institut Pasteur de Madagascar (IPM) in Antananarivo, Madagascar. From this database, two sites in the central highlands were selected for the KAP survey (figure 1): (i) Tsiroanomandidy district, in the mid-west of Madagascar which is located 215 km northwest of Antananarivo. This district possesses 17 municipalities and is an active focus with altitudes ranging from 800 to 1,500 metres. Human plague cases were reported annually in this district and it recorded an average of 40 cases per year with peaks during the selected period. (ii) The Ambositra district, on the southern axis of Madagascar, is located 255 km south of Antananarivo, Ambositra and has 23 municipalities. It is another active plague focus where altitudes range from 700 to 1,000 meters. Between 2000 and 2010, it was one of the districts with the highest incidence of human plague in Madagascar. Between the selected periods some years without human plague cases were recorded. On average, 10 cases per year were reported between 2006 and 2015 in this district.
Distribution of plague cases in the 2 study districts
The above information was taken into account to determine the sites to be investigated.
The CLP database contains all suspected, probable and confirmed cases of human plague reported in Madagascar's health facilities. As a first step, a mapping of plague cases distribution by year at different administrative scales (district, municipality) was performed. To classify municipalities for investigation, we used information from the plague database including a person’s address, clinical forms of plague (bubonic, pulmonary or septicemic plague), category of cases and the health facility of the reported case.
The municipalities were classified according to the presence or absence of cases of plague. Moreover, suspected and confirmed were taken into account in this study. Based on WHO recommendations in 2006, suspected or probable cases were defined as clinically suspected cases with positive rapid diagnostic tests or positive molecular biology, and culture negative or not done. A confirmed clinical case was defined as suspected case with a positive rapid diagnosis test or positive molecular biology and positive culture (25, 26). The municipalities to be surveyed were randomly selected, according to the category of the municipality. Depending on the presence or absence of cases per municipality, municipalities were classified into two categories: (i) municipalities with presence of cases (i.e. reported at least one case of plague during the selected period); (ii) municipalities without cases (i.e. no case recorded during the selected period). Among the 17 municipalities in the district of Tsiroanomandidy, only one municipality did not report any cases of plague between 2006 and 2015. A total of 18 out of 23 municipalities reported cases of plague in Ambositra district during the study period.
Sampling size calculation
The margin of error and confidence interval were 5 % and 95 %, respectively. The minimum required sample size was estimated at 548 individuals for the two study districts with an estimated response rate of 70%.
Sampling method
The questionnaires were pre-tested in another endemic district. Adjustments and improvements were performed after this test phase. The data from the pre-test survey were not included in the final analysis. The surveys were conducted between June and August 2017. A two-steps selection process was performed at the municipality and fokontany level (the smallest administrative unit in Madagascar). Municipalities were randomly selected from the two districts. The municipalities to be investigated were randomly selected for each district, according to the category of municipality (municipality with presence of plague case during study period /municipality without case during same period). Then, we randomly selected a fokontany per each municipality category for field investigation. Concerning Ambositra, 7 municipalities were investigated including 5 municipalities with cases during the study period and 2 municipalities without case during study period, among which 11 fokontany were visited. In the case of Tsiroanomandidy, a total of 10 fokontany were visited. These fokontany are part of 7 municipalities including 6 municipalities with cases and 1 municipality without cases. Around 30 people per site were randomly selected and planned to survey. With two consenting persons per household, we estimated 20 households to be visited per fokontany. Households were randomly selected to obtain up to thirty investigated individuals. Household members were listed and the questionnaire was administered to a maximum of two participants of the household. The participants were randomly selected if the households presented more than two members. Criteria for selecting the subjects were as follows: individuals, aged 15 years or over at the time of the survey, who agreed to participate in the study and signed the informed consent form. If household members were absent or unwilling to participate to study, another household was randomly selected.
Data collection
The questionnaire was based on the WHO KAP methodology on tuberculosis (27) and adapted to the Malagasy context. The questionnaire was administered in Malagasy native language and was designed to measure the following constructs: (i) general information, ii) population’s knowledge on plague, iii) attitudes adopted in case of illness iv) general practices in case of care-seeking.
The general information section contained all the personal information and socio-demographic characteristics of the interviewed individuals. The section on the knowledge about plague contained 14 questions including the number of known types of plague, known forms of plague, symptoms of the plague, contagious nature of the plague, mode of transmission of the plague, lethal nature of the plague, duration after which the plague can be fatal after the first symptoms appear, existence of a treatment against the plague, treatments of the plague, place of access to care and treatment. The attitudes in case of illness section contained 5 questions. General practices in case of care-seeking presented 6 questions.
Qualitative study on the perception of plague among health actors
A qualitative study on health professionals' perceptions of plague was performed. The study was conducted on the basis of individual interviews and focus group with health professionals of all ages, genders and functions. Among previous municipalities, two facilities per district were selected for the qualitative study. Facilities were selected from municipalities investigated during KAP study depending on availability of medical staff for interviews. One focus group and three individual interviews were conducted. A pre-established interview template was used for both types of interviews. The framework had three main components: a knowledge component of health professionals on plague (symptoms, clinical forms, transmission mode, treatment, etc.), a component on their perception about communities’ attitudes in case of plague occurrence, and a component on their perception on population practices in the case of plague occurrence. After participants’ consent, focus groups and individual interviews were recorded using a dictaphone and were then transcribed and translated.
Data analysis
KAP scoring
KAP scores were assigned to respondents by individual scores based on the literature and adapted to the plague items. Scores were assigned based on the proportion of correct answers provided by respondents to the total possible correct answers (6, 28, 11, 18, 15, 16). The KAP questionnaire had 3 components for a total of 39 (100%) possible points, 24 points for the knowledge component (61% of possible correct answers), 12 points for the attitude component (30% of possible correct answers) [see additional files], 3 points for the practices component (7% of possible correct answers). The combined KAP scores (combined knowledge, attitudes and practices) were classified in three categories according to the scores obtained by respondent: low KAP (< Mean - 1SD), average KAP (Mean ± 1SD) and good KAP (> Mean ± 1SD) (9, 12).
Statistical analyses
Descriptive analyses were used to summarize the characteristics of the respondents and their KAP scores on plague. Two types of variables were cross-referenced with KAP score for the bivariate analyses: (i) socio-spatial characteristics: age, sex, level of education, telephone ownership, district of residence; (ii) characteristics related to history of plague and/or epidemiological status of the investigated localities : contact with a former plague case, municipality category (presence/absence of plague cases).
A backward stepwise ordinal logistic regression was performed to determine the relationships between KAP scores, demographic features, epidemiological characteristics, and socio-spatial determinants. All variable with a p-value ≤ 0.2 were includes in the initial statistical model. However, other variables with a p>0.2 value that could influence KAP level were included in the final model. All statistical analyses were performed using Stata 13.0 © statistical software. The statistical significance level was set at p< 0.05.
Qualitative analysis
A manually thematic method was used for analyzing the data collected from individual interviews and focus group. Information were categorized, coded by component categories, and analyzed using manually process.
Ethical considerations
The study received the approval from the Ethics Committee board of the Malagasy Ministry of Public Health (n#50 MINSANP/CE of 27 April 2016). All surveys were systematically preceded by an information session on the process and purpose of the study. All participants signed an informed consent form. For individuals less than 18 years who had agreed to participate in the study, the guardian or a parent gave the consent and signed the informed consent form. Each participant was allowed to decline or to leave the study at any time.