Misuse, perceived risk, and safety issues of household insecticides: Qualitative findings from focus groups in Arequipa, Peru.

BACKGROUND: The current body of research on insecticide use in Peru deals primarily with application of insecticides offered through Ministry of Health-led campaigns against vector-borne disease. However, there is a gap in the literature regarding the individual use, choice and perceptions of insecticides which may influence uptake of public health-based vector control initiatives and contribute to the thousands of deaths annually from acute pesticide poisoning in Peru. METHODS: Residents (n = 49) of the Alto Selva Alegre and CC districts of peri-urban Arequipa participated in seven focus group discussions (FGD). Using a FGD guide, two facilitators led the discussion and conducted a role-playing activity. this activity, participants insecticides (represented by printed photos of insecticides available locally) and pretended to "sell" the insecticides to other participants, including describing their qualities as though they were advertising the insecticide. The exercise was designed to elicit perceptions of currently available insecticides. The focus groups also included questions about participants' preferences, use and experiences related to insecticides outside the context of this activity. Focus group content was transcribed, and qualitative data were analyzed with Atlas.ti and coded using an inductive process to generate major themes related to use and choice of insecticides, and perceived risks associated with insecticide use. RESULTS: The perceived risks associated with insecticides included both short- and long-term health impacts, and safety for children emerged as a priority. However, in some cases insecticides were reportedly applied in high-risk ways including application of insecticides directly to children and bedding. Some participants attempted to reduce the risk of insecticide use with informal, potentially ineffective personal protective equipment and by timing application when household members were away. Valued insecticide characteristics, such as strength and effectiveness, were often associated with negative characteristics such as odor and health impacts. "Agropecuarios" (agricultural supply stores) were considered a trusted source of information about insecticides and their health risks. CONCLUSIONS: It is crucial to characterize misuse and perceptions of health impacts and risks of insecticides at the local level, as well as to find common themes and patterns across populations to inform national and regional programs to prevent acute insecticide poisoning and increase community participation in insecticide-based vector control campaigns. We detected risky practices and beliefs about personal protective equipment, risk indicators, and safety levels that could inform such preventive campaigns, as well as trusted information sources such as agricultural stores for partnerships in disseminating information.

Efficacy of a low dose fipronil bait against blacklegged tick (Ixodes scapularis) larvae feeding on white-footed mice (Peromyscus leucopus) under laboratory conditions.

BACKGROUND: Lyme disease is the most prevalent vector-borne disease in the USA with cases continuing to increase. Current control measures have not been shown to be impactful, and therefore alternatives are needed. Treating pathogen reservoirs with low dose systemic acaricides in endemic areas may provide a useful tool for disrupting the cycle of the vector and pathogen. The purpose of this study was to determine the efficacy of a 0.005% fipronil bait, presented orally to white-footed mice, in controlling blacklegged tick larvae (larvae). METHODS: Sixty mice were assigned to 3 treatment groups and three untreated control groups. All individually housed mice in treatment groups were exposed to 0.005% fipronil bait for 48 hours. Larvae were manually applied to mice within feeding capsules at one of three timepoints: Day 1, Day 9 and Day 15 post-exposure. For 4-days post-tick attachment, replete larvae were collected from water moats underneath each cage and attached larvae were observed by microscopy. Plasma from 4 treated mice at Day-1, Day 13 and Day 19, and 4 control mice (n = 16) was collected to obtain fipronil plasma concentrations (CP). RESULTS: Fipronil bait did not appear to produce neophobia in mice, as the amount of bait eaten at 24- and 48-hours exposure did not differ significantly. The 48-hour fipronil bait exposure prevented 100% of larvae from feeding to repletion at Day 1, Day 9 and Day 15 post-treatment. Within the treatment groups, all larvae observable within the capsules expired and were prevented from detaching by Day 4. In contrast, within the control groups a total of 502 replete larvae were collected from moats and 348 larvae observable within the capsules successfully detached. CP averaged 948.9, 101.2 and 79.4 ng/ml for mice euthanized at Day 1, Day 9 and Day 15, respectively. No fipronil was detected in control mice. CONCLUSIONS: We provide early indication that low dose fipronil bait, orally presented to white-footed mice, can effectively control blacklegged tick larvae. Future research should modify the exposure duration and post-exposure tick attachment timepoints to simulate various field scenarios under which successful efficacy might be obtained. Low dose fipronil bait could provide a cost-effective, practical means of controlling blacklegged ticks and other arthropod vectors.

Better than DEET Repellent Compounds Derived from Coconut Oil.

Hematophagous arthropods are capable of transmitting human and animal pathogens worldwide. Vector-borne diseases account for 17% of all infectious diseases resulting in 700,000 human deaths annually. Repellents are a primary tool for reducing the impact of biting arthropods on humans and animals. N,N-Diethyl-meta-toluamide (DEET), the most effective and long-lasting repellent currently available commercially, has long been considered the gold standard in insect repellents, but with reported human health issues, particularly for infants and pregnant women. In the present study, we report fatty acids derived from coconut oil which are novel, inexpensive and highly efficacious repellant compounds. These coconut fatty acids are active against a broad array of blood-sucking arthropods including biting flies, ticks, bed bugs and mosquitoes. The medium-chain length fatty acids from C8:0 to C12:0 were found to exhibit the predominant repellent activity. In laboratory bioassays, these fatty acids repelled biting flies and bed bugs for two weeks after application, and ticks for one week. Repellency was stronger and with longer residual activity than that of DEET. In addition, repellency was also found against mosquitoes. An aqueous starch-based formulation containing natural coconut fatty acids was also prepared and shown to protect pastured cattle from biting flies up to 96-hours in the hot summer, which, to our knowledge, is the longest protection provided by a natural repellent product studied to date.

Repellence of essential oils and selected compounds against ticks-A systematic review.

Ticks act as vectors of a wide range of infectious agents, far encompassing any other group of bloodsucking arthropods worldwide. The prevention of tick-borne diseases is strictly linked to the successful management of tick vector populations. The employ of repellents can represent a worth solution to avoid tick bites. It is widely adopted to protect travellers and pets exposed to ticks during limited periods of the year. The use of natural products as active ingredients in eco-friendly repellent formulations is currently a prominent research area, due to the wide diversity and high effectiveness of a number of plant-borne compounds, with special reference to essential oils (EOs) extracted from medicinal and aromatic species. Here, we reviewed current knowledge available on EOs tested as repellents against tick species of veterinary importance. Furthermore, we analysed the effectiveness of pure compounds isolated from EOs as tick repellents and their potential implications for practical use in the öreal world". A quantitative analysis of literature available is this research field was provided, along with its impact (i.e., in terms of citations over time) on the scientific community of researchers in tick control science and natural product chemistry. In the final sections, future outlooks are highlighted. We discussed major challenges to stabilize the most effective EOs and pure molecules, explore the synergistic and antagonistic effects in blends of EOs and/or pure constituents, standardize currently adopted testing methods, and evaluate non-target risks of herbal repellents.

Mosquito repellents: An insight into the chronological perspectives and novel discoveries.

Mosquito being the major medically important arthropod vector; requires utmost attention to reduce the sufferings and economic consequences of those living in the endemic regions. This is only possible by minimising the human-mosquito contact by an absolute preventing measure. However, unfortunately, such absolute measures are yet to be developed despite enormous efforts and huge investments worldwide. In the absence of vaccines for number of mosquito-borne diseases, repellents could be an attractive option for both military personal and civilians to minimise the risk of contacting different mosquito-borne diseases. However, to achieve this golden goal, the detailed knowledge of a particular repellent is must, including its mode of repellency and other relevant informations. Here, in the present article, an effort has been made to convey the best and latest information on repellents in order to enhance the knowledge of scientific community. The review offers an overview on mosquito repellents, the novel discoveries, and areas in need of attention such as novel repellent formulations and their future prospective.

Chemical and Plant-Based Insect Repellents: Efficacy, Safety, and Toxicity.

Most emerging infectious diseases today are arthropod-borne and cannot be prevented by vaccinations. Because insect repellents offer important topical barriers of personal protection from arthropod-borne infectious diseases, the main objectives of this article were to describe the growing threats to public health from emerging arthropod-borne infectious diseases, to define the differences between insect repellents and insecticides, and to compare the efficacies and toxicities of chemical and plant-derived insect repellents. Internet search engines were queried with key words to identify scientific articles on the efficacy, safety, and toxicity of chemical and plant-derived topical insect repellants and insecticides to meet these objectives. Data sources reviewed included case reports; case series; observational, longitudinal, and surveillance studies; and entomological and toxicological studies. Descriptive analysis of the data sources identified the most effective application of insect repellents as a combination of topical chemical repellents, either N-diethyl-3-methylbenzamide (formerly N, N-diethyl-m-toluamide, or DEET) or picaridin, and permethrin-impregnated or other pyrethroid-impregnated clothing over topically treated skin. The insecticide-treated clothing would provide contact-level insecticidal effects and provide better, longer lasting protection against malaria-transmitting mosquitoes and ticks than topical DEET or picaridin alone. In special cases, where environmental exposures to disease-transmitting ticks, biting midges, sandflies, or blackflies are anticipated, topical insect repellents containing IR3535, picaridin, or oil of lemon eucalyptus (p-menthane-3, 8-diol or PMD) would offer better topical protection than topical DEET alone.

Insecticide-treated clothes for the control of vector-borne diseases: a review on effectiveness and safety.

Insecticide-treated clothing has been used for many years by the military and in recreational activities as personal protection against bites from a variety of arthropods including ticks, chigger mites, sandflies and mosquitoes. Permethrin is the most commonly used active ingredient, but others, including bifenthrin, deltamethrin, cyfluthrin, DEET (N,N-diethyl-3-methylbenz-amide) and KBR3023, have also been trialled. Treatment is usually carried out by home or factory dipping. However, new microencapsulation technologies which may prolong the activity of insecticides on clothing are now available and may help to overcome the inevitable reduction in efficacy over time that occurs as a result of washing, ultraviolet light exposure, and the normal wear and tear of the fabric. The aim of this article is to review the evidence base for the use of insecticide-treated clothing for protection against bites from arthropods and its effect on arthropod-borne pathogen transmission. Although some studies do demonstrate protection against pathogen transmission, there are surprisingly few, and the level of protection provided varies according to the disease and the type of study conducted. For example, insecticide-treated clothing has been reported to give between 0% and 75% protection against malaria and between 0% and 79% protection against leishmaniasis. Studies vary in the type of treatment used, the age group of participants, the geographical location of the study, and the pathogen transmission potential. This makes it difficult to compare and assess intervention trials. Overall, there is substantial evidence that insecticide-treated clothing can provide protection against arthropod bites. Bite protection evidence suggests that insecticide-treated clothing may be useful in the prevention of pathogen transmission, but further investigations are required to accurately demonstrate transmission reduction.

Repellency of cassia bark, eucalyptus, and star anise oils and their major constituents to Leptotrombidium pallidum (Acari: Trombiculidae).

Leptotrombidium pallidum (Nagoya, Miyagawa, Mitamura & Tamiya) is a primary vector of Orientia tsutsugamushi (Hyashi), the causative agent of scrub typhus. An assessment is made of the repellency to L. pallidum larvae (chiggers) of cassia bark, eucalyptus, and star anise oils and major constituents (E)-cinnamaldehyde, 1,8-cineole, and (E)-anethole of the corresponding oils. Results were compared with those of conventional repellents DEET (N,N-diethyl-3-methylbenzamide), IR3535 [(ethyl 3-[acetyl(butyl)amino]propanoate)], and permethrin. Based on the median repellent concentration (RC50) values, (E)-cinnamaldehyde, (E)-anethole, cassia bark oil, and star anise oil (RC50, 0.95-1.52 mg/cm2) exhibited significantly more potent repellency than DEET (3.85 mg/cm2). (E)-cinnamaldehyde, (E)-anethole, cassiabark oil, 1,8-cineole, and star anise oil were approximately 43, 16, 11, 8, and 4 times more effective than IR3535 (CC5, 6.51%) as judged by the median climbing distance-disturbing concentration (CC50) values. The median residual duration time of repellency (RT50) was significantly more pronounced in DEET (RT50, 323 min) than in all essential oils and constituents (108-167 min). In the light of global efforts to reduce the level of highly toxic synthetic repellents, the three essential oils and their major constituents described merit further study as potential biorepellents for the control of L. pallidum populations.

[Prevention with repellent in children]. / Prévention par insectifuge chez l'enfant.

Use of topical insect repellent is an important component in prophylaxis of arthropod bite vector borne diseases. Topical insect repellent are used in a three part management regimen, along with impregnated clothing and mosquito netting. Parental training for efficacious and secure use of repellents for their children is essential part of a successful strategy to combat Lyme borreliosis, dengue fever, Chikungunya, West Nile virus infection and malaria, amongst children, according to local epidemiological risks. Rational repellent prescription for a child must take into account age, active substance concentration, topical substance tolerance, nature and surface of the skin to protect, number of daily applications, and the length of use in a benefit-risk ratio assessment perspective. The 4 currently repellents recommended by Whopes (Who) for their long lasting efficacy and patient tolerance are: 1) Citriodiol (PMD), 2) DEET, 3) Icaridine (KB3023), and 4) IR3535. In field trials the minimum required concentration of each four of these agents to be effective for 3 hours against most arthropods is 20% (in cream, roll-on or spray vehicle). Described side effects of these agents are mild, being limited to local irritative dermatitis and allergy. The risk of severe side effects has been related to DEET misused and neurotoxicity. The international recommendations concerning utilization of topical repellent amongst children for prophylaxis of arthropod borne diseases is concerning short term usage (several weeks). But the use of repellent is sub chronic or chronic amongst the majority of children living in subtropical regions where these vector borne diseases are endemic. And toxicity of topical repellent when used sub-chronically and chronically is not well studied in pediatric age groups. Taking into account these considerations, the current recommendations of the French Group of Tropical Paediatrics are to teach the parents of children who live in arthropod vector disease endemic regions to use topical insect repellent on their children with the recommended age related frequency in the following way: the use of topical repellent in infants above 6 months, once daily. Only in exceptional circumstances of severe arthropod exposure risk, their brief use in nursing infants as young as 2 months is acceptable, however with never more than 1 application daily. From ages 1 to 12 years, 2 applications daily may be safely used; 3 applications daily after 12 years old through adulthood.

New strategies for the control of arthropod vectors of disease in dogs and cats.

Arthropod-borne diseases (ABDs) in cats and dogs have a major impact on animal health and welfare and, in many cases, also on human health. Many ABDs are expected to increase in prevalence as a result of changing social habits, habitat modifications, introductions of exotic vectors and climate change. Control has, historically, focused on the use of insecticides and chemotherapy. We review alternative, emerging approaches to ABDs that currently offer promise, particularly modelling and molecular techniques and the development of novel vaccines that target molecules produced by arthropods during the bloodmeal. We argue that there is an urgent need to establish effective surveillance systems for most ABDs across various countries in order to facilitate a detailed risk analysis, which should include evaluation of potential spread to new areas and the possible introduction of new exotic species or disease agents. This will require clear and exhaustive knowledge on the distribution of ABDs in different areas, understanding of the diagnostic limitations pertaining to ABDs and standardization of techniques among reference laboratories in different countries. Continuous monitoring of insecticide resistance and the development of management strategies to minimize its onset are also essential. Ultimately, it is probable that approaches which attempt to reduce vector abundance or treat hosts with chemotherapy alone are unlikely to be effective in the long term. More suitable approaches may include greater use of a range of mutually compatible options in integrated management programmes.

Assay of fipronil efficacy to prevent canine monocytic ehrlichiosis in endemic areas.

Our objective was to evaluate the efficacy of fipronil for the prevention of Ehrlichia canis transmission to dogs by Rhipicephalus sanguineus in two endemic areas situated in Africa (Dakar and Djibouti). We carried out controlled trials in kennels for 1 year on 248 dogs, mainly police dogs and military working dogs. Eight groups were studied in a multi-centre study. Fifty five fipronil treated dogs were located in two separated kennels (G3, 37 dogs in Djibouti and G8, 18 dogs in Dakar). G1 (66 dogs) and G2 (60 dogs) were untreated control groups located in Djibouti, whereas G4 (32 dogs), G5 (13 dogs), G6 (18 dogs) and G7 (4 dogs) were the control groups located in Dakar. The epidemiological status of each group is known. G1 and G2 dogs were not kept in kennels, whereas G3, G4, G5, G6, G7, G8 dogs were housed in equivalent kennels. Tick infestation, clinical status and Ehrlichia seroprevalence were assessed during 1 year (duration of the study). Dog treated with fipronil showed neither canine monocytic ehrlichiosis (CME) nor tick infestations. In all groups of untreated control animals, R. sanguineus tick infestations were frequent, particularly in kennels (G5, G6 and G7) as well as morbidity and mortality due to CME. E. canis infection rates were low for fipronil treated animals: 2.7% (1/37) for G3 and 5.5% (1/18) for G8 group. Among control animals, seroprevalence was maximum (100%) in dogs kept in kennels (G5, G6 and G7 groups) and high among native dogs in Djibouti (G1 group): 69.7% (46/66) and in Dakar (G4 group): 50% (16/32). Dogs belonging to expatriate citizens (G2 group) were less likely to be infected: 21.7% (13/60). The comparison of serological results among French army dogs and French citizen dogs that were introduced in Djibouti for an average of 10 months shows a statistically significant (P<0.001) difference. Among fipronil treated animals (G3 group), 2 dogs out of 55 seroconverted (3.6%) compared to 13 out of 60 dogs (21.7%) in the control G2 group. The results of our study indicate the preventative efficacy of a fipronil monthly treatment to avoid CME in endemic areas. Epidemiological data concerning animals that live in the same endemic areas are an example of the serious consequences (in terms of mortality and morbidity) that are related to the absence of efficient methods for tick-control. In order to protect dogs that are in transit in endemic areas against tick-transmitted diseases, the use of an adapted acaricide product is recommended.

[Proposal for a testing protocol of insecticides against the copepod crustacean Mesocyclops aspericornis Daday 1906]. / Proposition de protocole de test insecticide vis-à-vis du crustacé copépode Mesocyclops aspericornis Daday 1906.

A method to determine the susceptibility of Mesocyclops aspericornis to insecticides is proposed. Tests were carried out by placing adults females in 100 ml of insecticide solution at 3 temperatures (20 degrees C, 25 degrees C, 30 degrees C). Mortality was scored 24 h after treatment. The results show a low variability of the insecticide effectiveness at these temperatures.