Clinical Trial Details
— Status: Active, not recruiting
Administrative data
NCT number |
NCT04419766 |
Other study ID # |
REPELMALARIA |
Secondary ID |
|
Status |
Active, not recruiting |
Phase |
N/A
|
First received |
|
Last updated |
|
Start date |
April 28, 2021 |
Est. completion date |
December 30, 2024 |
Study information
Verified date |
December 2023 |
Source |
Universidade Nova de Lisboa |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
Mozambique contributes with 5% of global malaria cases, and despite control efforts the
Sofala province continues to experience a high burden of malaria. The resistance to
insecticides and changes in vector habits can compromise the use of common vector control
tools. The use of spatial repellents is thus an interesting alternative, as it does not exert
selective pressure on resistance genes or eliminate other insects with impact on
biodiversity. IR3535 is a non-toxic repellent and if used at community level can extend
protection to outdoor biting.
Hypothesis: Using the IR3535 repellent for indoor and outdoor spraying will reduce the
prevalence of malaria and reduce vector density and infection.
An experimental Before-After-Control-Intervention will be carried out with two groups: a)
Intervention (Tambai Q2 and Q6): with intra and extra-household spraying with IR3535 and b)
Control (Tambai Q3 and Q4): without spraying. Tambai is acommunity of Bebedo, Nhamatanda,
Sofala, Mozambique. The mosquito distribution, diversity, density and sporozoite rate will be
monitored indoors and outdoors in both communities for 2 years. The prevalence of malaria
will be determined in under five years old children at the beginning, the end of the 1st year
and at the end of the study. Additionally, cross-sectional studies with a mixed approach
assessing the community knowledge, attitudes and practices (KAP) will be carried out to
detect gaps that persist at the community level. Heads of households and health professionals
will be interviewed at the beginning of the study, the end of 1st year and at the end of the
study. The data will be analyzed using SPSS and R software packages. For matching situations
(before and after), the McNemar test will be used to ascertain statistical significance.
Generalized Linear Models (GLM) will be used to jointly analyze several explanatory
variables. Linear Mixed Models (LMM) and Generalized Estimation Equation (GEE) models will be
used to compare longitudinal data. The prevalence of malaria and entomological indices
relevant for transmission are expected to decrease with the intervention while community
knowledge on malaria and its control are expected to increase.
Description:
Study area and population
The study will be carried out in the communities of Tambai, locality of Bebedo, district of
Nhamatanda, Sofala province, Mozambique. The community is covered by the Mutondo Health
Center.
Study design
A prospective experimental Before-After-Control-Intervention test will be carried out with
two groups: a) Intervention (community of Tambai quarters 2 (Q2) and 6 (Q6)): with indoors
and outdoors spraying with IR3535 (3-(N-acetyl-N-butyl) aminopropionic acid ethyl ester) and
b) Control (community of Tambai quarters 3 (Q3) and 4 (Q4)): without spraying. This
longitudinal study will last for 2 years. Mosquitoes will be captured indoors and outdoors to
determine entomological indicators relevant to transmission. Mosquito breeding sites in the
communities will be mapped using "Participatory Mapping". The prevalence of malaria in
children under five will be determined in the control and in the intervention communities, at
the beginning, middle and end of study. A KAP survey on malaria to Tambai householders (Q2,
Q3, Q4; Q6) and health professionals and key community actors.
Population interventions and procedures
Initially, the Beira Operational Research Center (CIOB) and the Institute of Hygiene and
Tropical Medicine of the Nova University Lisbon (IHMT-NOVA), in collaboration with the
Mutondo health center, Provincial Directorate of Health of Sofala and the Directorate
district health district of Nhamatanda and the Gorongosa National Park, will present the
intervention in a participatory manner and explain the approach directed to the community in
order to guarantee its appropriation by the community from the beginning of the study. Before
conducting the study, communities will be informed, and the local structures will be briefed
in order for the community to understand the objectives of the study.
Surveys on community knowledge, attitudes and practices (KAP).
Three KAP surveys will be carried out, at the start (baseline), at the end of the first year
and at the end of the second year. The study population will comprise all households from Q2,
Q3, Q4 and Q6 of Tambai. Household data will be collected using a questionnaire designed for
tablets, with Android system, through the ODK application. Interviews to the head of
household will take place at their homes or at a location proposed by them. The KAP about
malaria and the different aspects related to the acceptability of the use of repellents will
be complemented by focus groups and interviews to local key actors. The collection of the
data will be carried out based on two techniques: a) semi-structured interviews (Flick, 2006)
to health professionals at the Vinho Health Center (a Maternal and Child Health Nurse and a
preventive medicine professional), two activists and local leaders; b) focus groups (Flick,
2006) with matrons and practitioners of traditional medicine from the two communities under
study. All participants in this component of the study will be selected intentionally
(Hancock, Ockleford and Windridge, 2009). Participation will be made by signing the informed
consent.
Malaria prevalence
The malaria prevalence will be determined in children under 5 years of age in both locations
Tambai Q2 and Q6 (intervention) and Tambai Q3 and Q4 (control) at the beginning of the study,
at the beginning of the second year and at the end of the second year (end of the project).
Consent will be requested to the legal guardian. Capillary blood will be collected using a
sterile pipette and individual lancet from all children in the study aged 6-59 months of age
for: a) Rapid Diagnostic Test (RDT) for Plasmodium falciparum; b) blood drop smears and c)
filter paper for nucleic acids extraction (FTA Cards ThermoFisher). The samples will be
coded, and information about the coordinates of the associated household will be recorded.
The initial sample processing will be carried out at the laboratory of the Health Center of
Ponta Gea - Beira, and the molecular analyzes at IHMT-NOVA - Lisbon, as defined in the MTA.
Identification of Plasmodium will be done by PCR and genotyping by whole genome sequencing
(Ocholla et al. 2014). Children who are diagnosed with malaria by RDT during the study will
be referred to the Mutondo Health Center for treatment.
House Spraying with repellent
The spraying with IR3535 will start at the beginning of the study and will be performed
monthly during the first 3 months, bimonthly during the next 6 months and then quarterly
thereafter. The spraying will be carried out inside and outside the houses during the
morning. Spraying will only be carried out in intervention quarters, while there will be no
spraying in control quarters.
Entomology
For entomological study households will be randomly selected. In case of failure of satellite
imagery and geographical analysis (Wampler et al. 2013, Escamilla et al. 2014), a classic
approach based on household inventories in each community will be used manually. Using local
mapping and numbering, two lists of numbered households will be created. After a random
number generator (e.g., Random.org) will be used to randomly select the households from each
list (Wampler et al. 2013). Mosquitoes will be collected twice a month inside and outside the
houses at the selected households for 2 years in the intervention and the control quarters.
Inside each household, resting mosquitoes that fed the previous night will be collected using
a Prokopak aspirator. Outside the residences, CDC- light traps will be placed in the early
evening and collected at the following morning. The traps will be placed outdoors, in places
equidistant from the buildings (houses) that compose the household. The physiological state
of the mosquitoes will be determined, and the females classified as unfed, partially fed,
fed, semi-gravid or gravid (Detinova, 1962). Mosquito females will be identified
morphologically and confirmed by the PCR (Abilio et al. 2015). The density of mosquitoes
caught in the control and intervention communities will be estimated using Williams'
geometric mean. GEE and LMM will be explored to compare the two groups along time. The rate
of infection will be determined by detecting and quantifying sporozoites in mosquitoes. The
mosquitoes' heads and thorax will be removed and prepared to isolate DNA (Abilio et al.
2011). Sporozoites will be detected and quantified by quantitative PCR (qPCR) as described in
(Marie et al. 2013).
Breeding sites mapping
The mosquito breeding sites will be mapped using the "participatory mapping" approach (Dickin
et al. 2014). The method will be used to identify the spatial perceptions of malaria risk in
the community, based on the spatial identification of existing breeding sites. Interview
participants and focus groups will be invited to draw a map of the areas they associate with
breeding in communities and describe the important features of the map. These maps can then
be digitized on a geographic information system (GIS) to create a georeferenced map of
community knowledge.
Malaria cases in the community
During the study, cases of malaria in Tambai will be monitored through patients who visit the
Mutondo Health Center. Patients of all ages from the communities with suspected malaria will
be recruited. A questionnaire will be administered. A RDT, a thick drop and blood smear will
be performed, and a drop of blood collected for subsequent molecular diagnosis by PCR (as
described above). Enrolment and consent will be asked after the patients have received all
the care they need in the health unit. Written informed consent will be obtained from the
participants or their legal representatives for patients under 18 years old.
Study variables
The study variables can be divided into variables from the survey (questionnaire) and
semi-structured interviews. Variables can be grouped into the following categories:
- Socio-demographic variables: Age; Sex; Marital status; Profession; Education level;
Degree of kinship to the householder; Household size (nº of houses, area); Number of
rooms in the house; nº of people per division; Type of construction.
- Ownership and use of mosquito nets: Ownership of mosquito nets; Use of mosquito nets;
Mobility and activities of household members.
- Malaria knowledge, attitudes and practices: Malaria knowledge level; Malaria attitudes;
Mosquito control and bites; Ownership, conservation and use of mosquito nets; Knowledge
about repellents; After analyzing the questionnaire data, the variables are deduced;
Level of knowledge, attitude and practices about malaria (score categorized as: bad (>
50%), medium (50% -74%) and high (≥75%)).
Variables of the study will also be those resulting from the collection of biological
material (peripheral blood and mosquitoes):
- Malaria cases in children under five (RDT, optical microscopy and PCR);
- Malaria cases attending the Vinho Health Center;
- Mosquito density inside and outside homes; Percentage of infected mosquitoes;
Distribution of mosquito species inside and outside homes;
- Breeding site (participatory mapping)
Sample size for KAP
Approximately 126 householders will be surveyed (according to the National Institute of
Statistics of Moçambique (INE) report, 2017) corresponding to the total number of households
in the communities under study. The chosen locations are comprised of only 126 households,
therefore everyone contacted will be included to participate in order to guarantee a maximum
power for the study.
Prevalence of malaria in the intervention and control community
According to the INE report, 2017, the total number of the population in the two study areas
is 630 inhabitants. To calculate the number of children under 5 years of age, the total
population was multiplied by 17.5%, so the sample will consist of about 110 children. The
attempt to include all children aims to try to obtain a sample size that guarantees us the
highest possible power.
Sample size and statistical power for entomological indicators
Different scenarios and programs were explored to calculate the sample size. Initially, a
scenario corresponding to a sample size of 40 households (20 in each community) followed for
48 moments was considered as being feasible. The statistical power was calculated using the G
* Power v.3.2 program (Faul et al. 2007, 2009), with a correlation between measurements made
at different times 0.2; with effect of size f = 0.25; a type I error probability equal to
0.05. A statistical power of 91.1% was estimated. Conversely, for the same parameter values,
fixing the power at 95%, in the perspective of using ANOVA for repeated measurements, 24
aggregates were obtained in each community. However, if the assumptions of ANOVA for repeated
measurements fail, LMM or GEE models will be used, so it is important to have an idea of the
statistical power for these models. Using the Longpower package
(https://www.rdocumentation.org/packages/longpower/versions/1.0-19/topics/longpower-package)
of the R software, the power associated with the GEE and LMM models, for the previous
scenario (24 households), would not be satisfactory. Considering the possibility of missing
values (up to 20% in the last visit), a more realistic autoregressive correlation matrix for
measurements in each visit, several scenarios were explored in Longpower to guarantee at
least powers of 80%, for the various types of models. Thus, also keeping the budget and human
resources available, we have 40 households in each location (80 households in total), with a
single monthly visit to each household.
Data analysis
The data will be analyzed using SPSS version 25.0 and R package. Initially, descriptive
statistics and exploratory analysis will be performed. Parametric and non-parametric tests
will be used, either for independent samples (for example, comparing the two communities at a
given time), or for paired samples (comparing each community at the beginning, middle and end
of the study). The Chi-square or Fisher's test will be used to test the association between
qualitative variables or to compare proportions between independent groups. For paired
qualitative data, the McNemar test and Cochran's Q test (for binary data) will be applied.
For quantitative variables, the comparison of two independent groups will be performed using
the T-Student test, in case of compliance with the assumptions of normality and homogeneity
of variances, or alternatively the Mann-Whitney-Wilcoxon test. ANOVA or Kruskal-Wallis test
will be used for more than two groups. Signs, Wilcoxon and Friedman tests will be used to
compare two or more paired samples. If the sample sizes allow, generalized linear models can
be used to jointly analyze several explanatory variables for some events of interest (for
example, use of repellent). For the longitudinal comparison between the intervention and
control groups, as for entomological indices, Mixed Linear Models and Generalized Estimation
Equation Model or a Nonparametric Analysis of Longitudinal Data in Factorial Experiments
(nparLD) approach will be applied, using several packages of the R. software. The
(CONsolidated Standards of Reporting Trials) CONSORT2010 standards, an intention-to-treat
(IT) analysis will be used, and there may be a need to proceed previously with a treatment
for missing values. Differences and associations will be considered statistically significant
when p <0.05. In order to estimate the prevalence or other proportions of interest, 95%
confidence intervals will be obtained by Wald method or alternatively the Wilson or Jeffreys
methods.
The sporozoite rate (% of mosquitoes with sporozoites in the salivary glands) will be
compared between the control and intervention community and the percentage of reduction
determined. The temporal and spatial distribution of the different mosquito species and their
densities will be explored using ArcGIS 10 with Spatial Analysis and Statistical Tools) and
compared between the 2 locations (control x intervention).
In the qualitative component, after recording the interviews, their full transcription will
be carried out. Data processing and analysis will be manual, using the content analysis
technique.
Data management - Questionnaires
The Open Data Kit (ODK) will be used for data collection and its quality control. The
supervisor will review the interviews on a daily basis, before sending them to the secure
server located at the CIOB for storing. The server will be accessible only to the data
manager and the team of researchers. The transferred data does not include the names of
participants, only their codes. The data manager will clean and validate the data daily and
provide feedback to the field staff. All physical documents such as informed consents, data
collection forms and electronic devices (GPS and tablets) will be stored and only accessible
to the CIOB Principal Investigator. The paper documents will be kept for 5 years after the
study is completed and then destroyed.
Data Management - Prevalence and entomology
The data will be collected through a paper data collection form. Every day, each data
collector must enter all data in a database available on a computer and send it to the data
manager, after a careful revision by responsible of the team. After the data manager receives
the data, she/he can create a password protected folder to archive the data on a daily basis.
Quality control and monitoring - Training of staff
Study personnel will be properly trained by the study's research team. The field team will be
subdivided into three (3) groups:
- Collecting blood samples and administering the survey to householders and conducting
interviews with health professionals. The team will consist of 3 health technicians with
experience in research.
- Mosquitoes collection and breeding sites mapping. The team will consist of 2 entomology
technicians.
- Sprayers that will be spraying houses with repellent. The team will consist of 4 people.
The training will be focused on ethical aspects, selection of households, children aged 6-59
months, conducting interviews, blood sampling procedures, good clinical and laboratory
practices, mosquito collection, manipulation, identification, processing and storing,
breeding mapping and spraying techniques and safety.
Quality control and monitoring - Supervision of field work
The teams will have a field coordinator who will be responsible for monitoring the field work
and ensuring data quality. During the study, a team of supervisors will periodically visit
the field teams to ensure proper practices. The quality control (QC) of the data will start
in the pilot phase, with the identification and replacement of unclear terms and study
questions. The field coordinator will also continuously assess compliance with standard
operating procedures (SOP) and ethical principles.
Data quality and quality assurance
The baseline study will include a pilot that will be conducted during training in a community
that is not part of the study. The pilot will have the following objectives (i) to evaluate
and validate the contents of the data collection instruments, (ii) to ensure compliance with
the ethical aspects related to the study. The pilot will help to identify the difficulties
and omissions during the questionnaire. The pilot will analyze the fieldwork strategy, team
composition, staff responsibilities and time required to complete all activities.
The field coordinator will do the quality control of the inquiries made before they are sent
to the CIOB and in addition to the quality control done by the field coordinator, the main
investigators will also do the supervision to guarantee the quality of the data.
Storage of Data
The data will be stored at the CIOB. Study documents and data collection instruments,
including informed consent in physical format, that will be placed in file folders and kept
locked, with restricted access to researchers. All documents related to the research will be
filed according to the rules of the legislation and will be kept at CIOB for a period of 5
years.
Storage of Biological samples
Part of the blood and mosquito sample will be processed in the laboratory of IHMT-NOVA,
Portugal, for that purpose a material transfer agreement (MTA) has been signed between CIOB
and IHMT-NOVA, Portugal. Part of the blood sample will be kept in the CIOB for future
analysis in the scope of PhDs and/or Master programs, explicitly referring to the present
project. The samples will be kept in a freezer at CIOB at -80 ° C, for 5 years after the end
of the study. Biological samples that will not be used for further analysis will be destroyed
at the end of the analysis within the study.
Ethical review
This study protocol has been submitted for ethical approval to the Institutional Committee on
Bioethics for Health of the National Institute of Health (CIBS-INS) and to the National
Committee on Bioethics for Health (CNBS) - Clearance Ref. 63/CNBS/20 and Addendum Ref.
11/CNBS/21. The study will be carried out in accordance with the rules of "good clinical
practice (GCP)", "good clinical and laboratory practice (GCLP)" and all applicable regulatory
requirements, such as the Declaration of Helsinki 2013, at its 64th General Assembly.
Informed consent
The consent from the heads of households, parents or legal representatives of the children
and health professionals selected for the study will be obtained by trained interviewers.
They will be fluent in the local languages (Sena and Ndau) or accompanied by an interpreter
during the request for informed consent and interviews. All participants will be informed
about the objectives of the study, procedures to be performed during the study and potential
associated inconveniences, as well as the possibility of leaving the study even after signing
the informed consent without any implications for them.
The participant will have the right to privacy during the moment of the interview, it will be
held in a place where the participant feels comfortable, explaining that all the information
provided by him will be confidential, authorization for audio recording of the interview will
be specifically requested. Permission from the householder will be ask, for the collection of
a finger prick blood sample from the children in the household aged 6-59 months. If the
child's legal representative is different from the head of household, informed consent will
also be administered to her/him. If the child's parent/legal guardian is under 18, informed
consent will be administered to authorize the child to participate.
Authorizations for periodic visits throughout the study will be requested while explaining
the importance of the procedures for:
- spraying of their homes (indoor and outdoor) with mosquito repellent (monthly). Only in
Tambai Q2 and Q6;
- collection of mosquitoes from the interior and exterior of their houses (twice a month)
in two localities.
The inquirers and each participant will sign 2 copies of the informed consent form, in which
one copy will remain with the participant and the other will remain with the inquirer for
later filing in the study folder. The contact of the principal investigator of the study is
an integral part of the document. The informed consent form will serve as proof that the
participant accepted to be part of the study by their own free will. In order to guarantee
confidentiality, each participant will be assigned an identification code for the
questionnaire. Each questionnaire made will have a code corresponding to consent.
Participation risks
The risks of participation are minimal, but in the event that a participant feels
uncomfortable during the interview with any question, they can ask to pass the question on.
During the blood sample collection, there may be same risk of bleeding or inflammation from
the collection site. To minimize that adequate material will be provided to collect capillary
blood (sterilized lancets and disposable gloves) through health professionals trained for
that specific activity. Regarding the spraying of houses with repellent, participants will be
informed about potential rare adverse effects. If someone in the residence, where the
spraying was carried out, has any reaction, which is suspected to be associated with the
product, the spraying will be interrupted in that residence and the individual referred to
the health service.
Benefits of participation
Frequently, after carrying out interviews, an increase of knowledge in the communities is
noted. This is due to the fact that often those who apply the questionnaire can alert to best
practices, which can contribute to improvements in the health of the community. One of the
benefits will be knowing whether or not you have malaria, plus children diagnosed with
malaria will be able to benefit from treatment.