Subject selection criteria
Selection criteria for study areas included having a long period of malaria transmission, the prominent role of larviciding in vector control measures, easy access to the field, and willingness of health authorities to use the self-assessment method in larviciding operations. Chabahar was selected as the target district for the present study. Chabahar is located in the south of Sistan and Baluchistan province (south-east Iran) and it is one of the most malarious areas in the country with a more than nine-month transmission season (February to May and July to November).
Among all eight eligible rural health centres (RHC) in Chabahar, Kanmbel Soliman was selected randomly as the study region. Kanmbel Soliman is located in the north of Chabahar district. The 30 villages covered by Kanmbel Soliman RHC have a total population of 5,887 and 1,124 households . Anopheles stephensi and Anopheles culicifacies have been reported as the main vectors in the study areas .
Design of the study
The study is an action research with a before-and-after approach. It is a triangulation study, combining qualitative study, focus group discussions (FGDs), and quantitative studies; the second part of the study is a quasi-experimental study.
Data collection methods, instruments used, measurements
Data were gathered by well-qualified data collectors. Validated questionnaires were used to gather expert opinion in order to design the required toolkits. Data regarding effectiveness of larviciding operations and effects of intervention were also collected (using specifically developed toolkits that included questionnaires and recording forms) by direct interviews with related personnel, the review of official documents and field observation.
The study was carried out following three main steps:
assessment of the effectiveness of larviciding operations in the study areas before intervention as baseline;
design and establishment of a system for self-assessment of larviciding operations (intervention); and,
determination of the effectiveness of applying self-assessment of larviciding operations in the study areas after intervention.
Development of toolkits
As a primary phase to facilitate and standardize study procedures two toolkits were developed to determine the effectiveness of larviciding operations (DELT) and for the self-assessment of larviciding operation (SALT). The method for development of the toolkits was as follows:
After investigating similar studies in the other parts of the world [23, 27–30] and reviewing available documents on successful monitoring and evaluation of vector control measures that focus on larviciding, questionnaires were devised to collect expert opinions. The questionnaires included a list of related matters, concepts and questions to be used for data collection on DELT and SALT.
Meetings and teleconferences were held between 30 experts and academic staff from international, national, provincial and district levels. After which a final draft of the toolkits was designed using the valuable comments obtained from the above-mentioned specialists in the field of management, monitoring and evaluation of vector-borne diseases. The toolkits and questionnaires were pre-tested in the field and the final versions were developed for this survey.
Assessment the effectiveness of current larviciding operations in study areas (before intervention)
Using DELT, the effectiveness of larviciding operations before intervention were measured during field visits to 30 villages in Kanmbel Soliman's RHC by the research team acting as external evaluators. Two indicators: “percentage of missed breeding habitats” and “percentage of cleaned breeding habitats among randomly selected breeding sites” were measured as impact indicators of larviciding operations as baseline. The first indicator generally shows the coverage and the second indicator denotes the quality of larviciding operation. Same indicators were measured for determining effectiveness of applying self-assessment of larviciding operation after intervention. In addition, some pertinent processes and output indicators were measured to obtain a clear picture of larviciding operations.
Percentage of missed breeding habitats
Each village in the study area was searched for open water bodies to determine the percentage of missed breeding habitats (all open bodies of water were taken as potential breeding sites). To locate potential breeding sites, the search was led by malaria experts with a good knowledge of the area. All possible breeding places within houses and other buildings, as well as open spaces within a range of 1.6 km (the average flight radius of local vectors) of human habitation in all 30 target villages, were carefully investigated.
During the external evaluation process all detected breeding habitats were checked by the larviciding operator that they had been registered on the relevant registration sheet and the number of missed breeding habitats (i e, not registered habitats) was determined. the calculation of missed breeding habitats was divided by the total number of detected breeding sites.
Percentage of cleaned breeding habitats among randomly selected breeding sites
To measure this indicator in villages covered by the study, on average 25% of the total breeding habitats of each village was randomly selected (minimum three, maximum six) and screened for larvae and pupae using a dipper. The assessment was conducted during the transmission season when breeding places were expected to be covered by routine larviciding operations. The number of cleaned breeding habitats was divided by the total number of randomly selected breeding sites to calculate this indicator.
Method for measuring larvae density in potential breeding sites
The presence of larvae and their density was determined by dipping. From every randomly selected, potential breeding site, up to 10 dips were taken using a standard white 350 ml dipper. A slow-release formulation of Bacillus thuringiensis (Bioflash™ granule 10%) was used as the larviciding agent. Based on the product quality control protocol, breeding habitats where no Anopheles pupae were recorded by dipping were considered as a cleared site.
Development of a system for self-assessment of larviciding operation
A system for self-assessment of the operation was designed using lessons learned from other countries and the points of view of local experts and health authorities regarding standard larviciding operations. The system included a toolkit (SALT) and relevant procedures.
Intervention (establishment of a system for self-assessment of larviciding operations in the target areas)
The research team briefed target groups who were involved in larviciding operations in the study areas regarding the system for self-assessment of larviciding operations and the method of using SALT. Their role and responsibilities, and procedures for the establishment of self-assessment of larviciding operations, were identified by the main investigators. The system had been established in collaboration with local authorities and staff. The researchers advised and supervised local authorities to facilitate implementation of the system. No direct intervention in the procedure of conducting self-assessment of larviciding operations was made by the research team in order to avoid the possibility of any bias in the results.
Using SALT toolkit, self-assessment by the involved staff in larviciding operations was carried out on a quarterly basis. Staff were asked to use the results of their self-assessment to determine areas in need of enhancement and to take necessary action towards the improvement of larviciding operations. Study subjects recorded the results of their self-assessment on the designed forms.
Determining effectiveness of larviciding operation in the study areas after self-assessment (after intervention)
The effectiveness of applying self-assessment of larviciding operations (after intervention) was measured through field visits to the 30 villages of Kanmbel Soliman's RHC by determining two impact indicators of larviciding operations including “percentage of missed breeding habitats” and “percentage of cleaned breeding habitats among randomly selected breeding sites”. This step was carried out by the research team acting as external evaluators, without giving prior notice to the staff involved in the intervention, exactly one week after the third round of self-assessment. . The method of measuring the indicators was exactly the same as that used in the preceding stage. It was evident that randomly selected breeding habitats for determining cleaned breeding sites were not the same as at the “before” stage. In addition, as in the previous stage (before intervention) the process and output indicators of larviciding operations were measured by the research team to find how larviciding operations worked compared to the previous stage (before intervention) which was considered as the baseline. Therefore, the quantity and quality of changes in the various areas of larviciding operations following the intervention were determined.
Determining validity of results of self-assessment
To measure validity of the received data from the self-assessment process, the recorded self-assessment reports by staff in the first round, including process and output indicators, were collected by the research team and compared with the results of the first round of the external assessment. In addition, the results of the third round of self-assessment were compared with the results of external assessment that was conducted after intervention. Noting the short period (one week) between the third round of self-assessment and external assessment after intervention, the results were not affected by the time lag between the two evaluations.
Data management and analysis plan
All indices’ scores were transformed to a scale of 100 and correlation coefficient and Mann Whitney test were used to analyse the data.
Timeline of the study
Assessing the effectiveness of larviciding operations in the study areas before intervention was conducted from September to October 2010. The system for self-assessment of larviciding operations was established from October 2010 to September 2011. Assessment effectiveness of larviciding operations in the study areas (after intervention) was conducted from September to October 2011.
This study was approved by the Research Ethics Committee of Zahedan University Medical Sciences, Iran. The aims of the project were discussed with all district health authorities and their written or verbal informed consent to cooperate was received. The names of staff pertinent to assessment were kept strictly confidential and were not used in the presentation of the results.