|Year : 2016 | Volume
| Issue : 2 | Page : 111-117
Effectiveness of transfluthrin-coated inflammable-fumes insecticide-paper (Rambo™) in the prevention of malaria in Kano, Nigeria
Muhammad Hamza1, Musa Muhammed Bello2, Mahmoud Yakub Ma'aruf2, Abdulsalam Yayo Manu3, Abduljalal Ado4, Yasmine Dalhatu5, Abdulhadi Ahmad Abubakar5, Isa Abubakar Sadeeq2, Zubairu Iliyasu2, Muhammad Musa Borodo1, Sadiq Sulaiman Wali1, Abdulrazaq Garba Habib1
1 Department of Internal Medicine, Bayero University, Kano, PMB 3011, Nigeria
2 Department of Community Medicine, Bayero University, Kano, PMB 3011, Nigeria
3 Department of Medical Microbiology and Parasitology, Bayero University, Kano, PMB 3011, Nigeria
4 Department of Science, Kano State Polytechnic, Kano State, Nigeria
5 Gongoni Nigeria Unlimited, Kano State, Nigeria
|Date of Submission||30-Jan-2016|
|Date of Acceptance||24-May-2016|
|Date of Web Publication||21-Jun-2016|
Dr. Muhammad Hamza
Department of Medicine, Aminu Kano Teaching Hospital, Bayero University, PMB 3452, Kano State
Background: A 15-month community-based randomized controlled trial was conducted with the aim of assessing the effectiveness of transfluthrin-coated inflammable-fumes insecticide-paper (TCIP) (Rambo™) on indoor mosquitoes and malaria. Methods: The study was conducted in two communities, Panshekara and Danbare, Kano, Nigeria, randomly selected as intervention and control, respectively. One hundred and fifty Households (HH) were systematically selected in each of the two and their doors and windows were "netted" with mesh-wire. In the intervention community, there were "netted-alone" and "netted+TCIP" administered HHDs. Participants were allowed to the use of insecticide-treated mosquito nets. An additional 20 HHDs were randomly selected within the two communities as internal controls and were neither "netted" nor administered TCIP. Fever, blood-film microscopy for malaria parasite, hematocrit, and entomological indices (indoor mosquito collection and determination of species at breeding sites) were conducted quarterly. Pyrethrum spray collection technique was used to collect adult mosquitos monthly from rooms in both communities. Main malaria vector species were identified using molecular techniques such as polymerase chain reaction. ELISA was used to identify circumsporozoite protein (CSP) of Plasmodium falciparum. Results: A total 2565 persons were studied in Panshekara (1208) and Danbare (1357). There was a declining trend in malaria through 4 quarters in Panshekara compared to baseline (χ2 -trend, P = 0.02) and slight reduction in proportion with anemia. In Panshekara, a total of 1592 Culex species were collected, out of which 911 (57.2%) were from the internal control, 440 (27.6%) were from the screened "netted," and 241 (15.1%) from "netted+TCIP" treated HHDs. Three hundred and ninety-six Anopheline malaria vectors were collected, out of which 339, 27, and 30 were from the control, "netted," and "netted+TCIP" treated sites, respectively. In comparison to the baseline prenetting phase, wire netting alone provided 51% protection against the nuisance of culicine mosquitoes, whereas netting plus TCIP provided 73% protection against Culicine mosquitoes. The main malaria vector species were Anopheles gambiae s. s and Anopheles arabiensis, but Anopheles funestus could not be analyzed further. CSP of P. falciparum was seen in all the 3 vector species. Conclusions: Very slight reduction in malaria and anemia was observed. Protection conferred by TCIP was modest against Culex spp., but small against the malaria vectors. TCIP complimented netting with Trial number-ATMR2010050002022487 (Pan-African-Clinical-Trial-Group).
Keywords: Malaria, prevention, transfluthrin
|How to cite this article:|
Hamza M, Bello MM, Ma'aruf MY, Manu AY, Ado A, Dalhatu Y, Abubakar AA, Sadeeq IA, Iliyasu Z, Borodo MM, Wali SS, Habib AG. Effectiveness of transfluthrin-coated inflammable-fumes insecticide-paper (Rambo™) in the prevention of malaria in Kano, Nigeria. Sub-Saharan Afr J Med 2016;3:111-7
|How to cite this URL:|
Hamza M, Bello MM, Ma'aruf MY, Manu AY, Ado A, Dalhatu Y, Abubakar AA, Sadeeq IA, Iliyasu Z, Borodo MM, Wali SS, Habib AG. Effectiveness of transfluthrin-coated inflammable-fumes insecticide-paper (Rambo™) in the prevention of malaria in Kano, Nigeria. Sub-Saharan Afr J Med [serial online] 2016 [cited 2021 Jun 16];3:111-7. Available from: https://www.ssajm.org/text.asp?2016/3/2/111/184379
| Introduction|| |
Among the estimated 3.3 billion people at risk of malaria globally, in 2006, an estimated 247 million cases and about a million deaths, mostly among children <5 years of age, were reported.  In Nigeria, which has the largest population at risk in Africa, malaria is still a major public health problem, as there is stable transmission throughout the country, and to make matters worse, coverage of key Roll Back Malaria interventions also remains unacceptably low.  The Nigerian 2014 National Guidelines and Strategies for Malaria Prevention and Control confirmed that long-lasting insecticidal nets, intermittent preventive treatment, and appropriate case management through prompt diagnosis and effective treatment with recommended drugs as strategies of control and prevention are in place.  However, even though vector control using insecticides is in common use in the country, this practice is not recognized by the National Policy and Strategy.  This could possibly be due to the fact that only few studies, such as the Garki project,  exist in Nigeria on the efficacy of mosquito repellents in the form of sprays and smoke. The Garki project was the most comprehensive study on the effect of residual spraying campaign ever attempted in the Sudan savannah of West Africa. Subsequent studies  mainly concentrated on investigating insecticide-treated nets. This justified carrying out a study aimed at determining the effectiveness of a commonly used insecticide, i.e., paper mosquito repellent containing transfluthrin (Rambo ® ) in preventing malaria among two rural communities in Kumbotso local government area, Kano State, Nigeria.
The active agent in the mosquito repellent is transfluthrin, which is a fast-acting pyrethroid with low persistency and high selectivity. It has an excellent knockdown action against mosquitoes and does not have residual effect.  The World Health Organization has classified transfluthrin as an insecticide that is unlikely to present acute hazard in normal use.  Entomological research has found that mosquitoes are highly susceptible to transfluthrin with the mean mortality rate when used in portable blowers at a distance of 10 cm from mosquito cages ranging from 95 to 100%.  A reduction by 72-96% in landing-biting rates of mosquitoes has been reported when the usage of mosquito coils (the most preferred product used by the poor in Thailand) were studied.  The efficacy of transfluthrin was found to be higher when used in vegetable oil.
Transfluthrin (0.5%) in vegetable oil when heated provides >90% protection, which is comparatively much higher than other synthetic pyrethroids such as d-allethrin (0.25%) and mosquito repellents containing dichlorodiphenyltrichloroethane (DDT).  However, transfluthrin is not without its shortcomings, it has been shown to cause mutation on the epithelial cells of the nasal mucosa, therefore possibly have a genotoxic effect. 
The aim of the study was to determine the efficacy of the mosquito repellent (Rambo ® ) in the protection against malaria and to compare the effectiveness of two products. According to our hypothesis, there is a significantly lower cases of clinical fevers, spleen rate, malaria parasitemia, and higher hematocrit levels among individuals who consistently use the insecticide mosquito repellent containing transfluthrin (Rambo ® ) compared to those who do not.
| Methods|| |
A randomized trial was carried out in two villages of Kumbotso local government area (LGA) of Kano State, Nigeria. Kumbotso is one of the 44 LGAs of Kano State, Nigeria, which according to the 2006 National Population Census, has a population of 295,979 consisting of 149,447 males and 146,532 females.  Panshekara village is one of the major settlements in Kumbotso LGA and is geographically located within latitude from 11°51΄N to 11°53΄N and longitude from 8°27΄E to 8°29΄E. Danbare village is a settlement similar to Panshekara. It is located within latitude from 11°12΄N to 11°28΄N and longitude from 8°27΄E to 8°28΄E. Malaria is endemic in both communities. Transmission of malaria is all-year round, but an increase is seen during the months of May to September, which corresponds to the rainy season when breeding sites for Anopheles increase.
This study was a household randomized controlled trial that took place over a 12-month period. However, 2 months after commencement of the trial, a trial modification was done following trial review meetings; it was observed that the two study communities were not exactly similar, with Panshekara being more cosmopolitan and residents possibly having higher socioeconomic status. Therefore, the protocol was slightly modified to include internal control in both the intervention and control communities. This was to enable specific analysis for each of the communities.
Each house (and household) in the two villages was assigned a unique number. The minimum sample size required was calculated using a simple sample size formula for binary outcomes. 
assuming ά =0.05, power = 0.90, and equal sample size in the two groups.
n = the sample size in each of the groups.
P1 = event rate in the treatment group (not in the formula, but implied when R and P2 are estimated).
P2 = event rate in the control group.
R = risk ratio (P1/P2 ).
The calculation was based on the incidence of malaria, i.e., 30% in the control group, P2 = 0.30,  with the assumption that the clinically important difference to detect is a 70% reduction in transmission following the use of Rambo ® paper insecticide repellent, R = 0.30.  Using the formula, a minimum sample size of 70 was required in each of the study groups. The study used Panshekara as intervention community and Dambare as control community. In both communities, a detailed mapping and house numbering exercise were conducted initially. Each of the one hundred and fifty houses was randomly selected in both intervention and control communities, using a computer-generated random number table. The selected houses had their doors and windows mesh-wire netted. The intervention community was given Rambo ® mosquito paper to use on a monthly basis, whereas the control community was left to use standard (whatever) preventive measures they were using before the commencement of the trial, they were also given toilet soap as placebo. However, episodes of malaria obtained from clinical and laboratory results in both intervention and control communities were treated with standard antimalarial agents.
Households rather than individuals were used because it was logistically easier and more acceptable to administer the intervention at household level, and by that, the risk of different treatments being shared within households, which would very much affect the trial, was averted.
Before the commencement of the study, there were intensive advocacy, communication, and social mobilization. Information about the trial was made available to influential community leaders such as the Chairman of Kumbotso, LGA, the district head, religious leaders, village and ward heads. A meeting was organized in each ward with household heads where the aim of the trial was communicated to them and their questions were answered. A postadvocacy meeting took place to assess the level of acceptability. Throughout the duration of the study, there was continued advocacy.
Both study groups (villages) had their doors and windows wire-netted; health education sessions were given to the participants on how to appropriately use Rambo ® paper mosquito insecticide; study participants were provided with Rambo ® paper mosquito insecticide and a repellent pomade preparation (containing KBR) (KIK OFF) for outdoor use, especially among children. Participants in the control group were left to use whatever preventive measures they were using before the commencement of the trial. They were also requested not to use any form of anti-malarial chemoprophylaxis during the study period.
Four community health extension workers, two each from the two communities were recruited and trained for the trial. They were tasked with the responsibility of monitoring the utilization of Rambo ® paper insecticide repellent at 2-week interval. They also actively participated in data collection at baseline and at 3-month interval throughout the duration of the study. A laboratory technician and scientist were employed at intervals to collect and analyze the blood samples.
A questionnaire was used to collect the demographic details, clinical history, and physical examination findings of the study participants. A blood film was done to all participants to establish a baseline. Each participant was given a month's supply of Rambo ® or placebo and was visited for every 2 weeks to monitor the usage. A serial blood film for malarial parasite was done on all the participants quarterly for the duration of the trial. Those participants found to have malaria were treated with an antimalarial (Coartem ® ). The sponsors of the study ensured the availability of Coartem ® at the primary health care or comprehensive health center during the study. The sponsor's designee (a pharmacist) served as a monitor for drug distribution during the study. The outcomes were evaluated periodically at 0, 3, 6, 9, and at 12 months. Baseline data were collected in April, the 1 st and 2 nd data were collected in July and October 2010, while the 3 rd and 4 th data were collected in January and April of the following year, respectively. The outcomes were documented fever episodes, spleen rates, packed cell volume (PCV) (hematocrit), malarial parasitemia, and the use of Coartem ® by the study participants.
Adequate information on the trial was provided to all the participants in the study. The information was given in the language best understood by each participant. It was made explicitly clear to the study participants that taking part in the trial was voluntary and they had the right to withdraw at any time, without giving any reason and without any consequences. A signed or thumb-printed informed consent was obtained from each participant and only those who voluntarily consented were recruited into the study. An ethical clearance was obtained from the Research Ethics Committee of Aminu Kano Teaching Hospital (AKTH) and permission was sought from the Ministry of Health, Kano State, Nigeria, before the commencement of the trial. A member of AKTH research and Ethics Committee was responsible for monitoring, throughout the trial.
The design of the trial is to show that there are fewer cases of clinical fevers, spleen rate, and malarial parasitemia, but higher hematocrit level among participants who consistently use Rambo ® . This will be able to show the effectiveness of transfluthrin in the prevention of malaria. Blood-film screening for malaria was started a month from the beginning of the trial (more than the assumed 3 weeks incubation period of Plasmodium sp.). The intention-to-treat approach, in which comparison of outcomes among all those originally allocated one treatment with all those allocated the other treatment, was used in the analysis. Frequencies, mean, median, and interquartile range were used to describe patients' baseline characteristics and outcomes in each groups. Chi-square, Students t-test, and Mann-Whitney U-tests were used to compare categorical and continuous variables as appropriate. SPSS version 14 software was used for data analysis.
| Results|| |
The 15-month study recorded a response rate of 89.2% (1,079) and 88.7% (1,208) in the intervention and control communities, respectively. This gives attrition rates of 10.8% (130) and 11.3% (154) in the intervention and control communities, respectively, from baseline to the end of the study as accounted for in the flow charts below. However, these attrition rates were not found to be statistically significant in both communities.
The sociodemographic characteristics of the respondents were shown in [Table 1]. The respondents were comparable with respect to sex, age, and average household income.
|Table 1: Sociodemographic characteristics of study participants in intervention (Panshekara) and control (Dambare) communities |
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The baseline individual and household practices regarding malaria prevention as well as clinical and laboratory parameters were shown in [Table 2]. The two communities were comparable in most of the parameters, except the presence of sicklers, recent history of malaria, and use of insecticides such as mosquito coils and aerosol. These parameters where all more in the intervention community compared to the control community. However, the control community had more cases of malaria parasites on microscopy.
|Table 2: Individual and household practices regarding malaria prevention, clinical and laboratory parameters (at baseline) |
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There was a constant reduction in the number of clinical cases of malaria over the period of the study, which shows a statistically significant change, however all other parameters did not change significantly. The changes in clinical and laboratory parameters of the study participants over the period of the study were shown in Flow Chart and [Table 3].
|Table 3: Changes in clinical and laboratory parameters of study participants over the period of the study |
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| Discussion|| |
The results of the 15-month study show encouraging findings in relation to the effectiveness of the Rambo ® paper insecticide repellant in reducing both the malarial episodes and transmission. There was no statistically significant difference between the mean age of intervention and control community when compared by age group (P = 0.23). Male to Female ratio was not statistically different between the two communities (P = 0.37). Intervention community had higher average household income/year, though not statistically significant (P = 0.47).
In both communities, chloroquine was the most common antimalarial used to treat malaria in intervention (59.9%) and control (63.0%) communities. The control community has twice the number of pregnant women (14.3%) compared to the intervention group (7.7%). There were also surprisingly more malaria episodes in the intervention group (73%) compared to 27% at baseline; this might be associated with more breeding sites of mosquitoes at intervention community compared to that of the control and probably because the baseline data were collected during dry season, a season characterized by reduced malarial episodes and transmission, especially in rural areas.
When asked about which methods of malaria prevention were used, both intervention and control communities used different insecticides, but the intervention community uses more Rambo ® products (paper, coil, and spray), i.e., 16.5% compared to control community, i.e., 2.5%, possibly due to the level of education and household income, both of which are higher in intervention community as obtained during the baseline data collection. However, the amount of money spent on malaria treatment per week at baseline is similar (10-100 Naira) for both control (96.7%) and intervention groups (94.2%) (P = 0.91).
Three months after commencement of the study, there was a reduction in the malaria episodes in the intervention community to 53%, perhaps due to the use of the Rambo ® paper insecticide repellant and a slight increase in the control community, i.e., 47%.
The result of the second, third, fourth, and fifth data collected after 3, 6, 9, and 12 months, respectively, shows slightly different findings. The episodes of malaria attack in the control community remained similar with baseline (P = 0.71), at the control community while there was a reduction in the episodes of malaria in the intervention community (P = 0.001). The amount of money spent for malaria treatment and prevention at control community also is not significantly different with baseline.
The result of thick blood film for malaria parasite remained apparently the same for both control (P = 0.17) and intervention communities (P = 0.56) between baseline and subsequent follow-ups. This may probably be explained by the presence of low-level parasitemia among individuals in malaria-endemic communities.
Although both intervention and control communities have some degree of mild-to-moderate anemia (PCV of 18-30%) at baseline, there was a slight reduction in the percentage of those with same degree of anemia at subsequent data collections in the intervention community (P = 0.04) compared to the control community (P = 0.17).
| Conclusions|| |
There appears to be a slight reduction in clinical malaria as evidenced by the reduction in parameters assessed from baseline to subsequent data collections. Furthermore, the Rambo ® mosquito paper insecticide appears to be effective in the protection against malaria and is consistent with studies conducted in other parts of the world.
Limitations and Challenges
The limitations in this study are lack of internal control at the initial phase of the project which led to slight protocol modification. There was a loss of some subjects during the period of the survey either due to traveling or transfer from place of work. Although this is not statistically significant as is <10%, it would not affect the outcome. We were unable to examine spleen among older children, especially females due to cultural and religious barriers. Furthermore, the study fails to control for factors that are likely to influence the susceptibility of the participants to malaria.
We would like to acknowledge the efforts of Malaria Care Foundation which is the sponsor of this clinical study. We would also like to acknowledge the support given to us by Gongoni Nigeria Limited.
Financial Support and Sponsorship
Malaria Care Foundation, Kano, Nigeria.
Conflicts of Interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]