Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Insect Repellents”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 523 records · Page 29Linked to original sources

[Protection of travellers against biting arthropod vectors].

Several diseases are transmitted by hematophageous insect/arthropod and, except for yellow fever and Japanese B encephalitis, there are still no vaccines. Personal protection therefore remains the choice method for disease prevention and can usefully complete chemoprophylaxis if available (such as for malaria). Personal protection can be ensured by three main methods: avoiding risky areas; using repellents on skin and/or garments; using pyrethroids insecticide on garments (permethrin), mosquito nets (several Pyr. available) and any other materials (curtains etc.) including camping tents, plasting "UN sheeting" used in refugees camps etc. Repellent gave some protection for few hours (# 6 hours) and new formulations have been developed to extend their duration. Great care must be taken when using DEET which is not recommended for children and pregnant women. Coils and mats can be used but care must also be taken when using some coils available on local market and which can often be irritating and useless. Mosquito nets impregnated with an insecticide remains the choice method of protection against night-biting insects such as anopheles and is a good way of preventing malaria. Insecticide must be used according to safety measures clearly indicated (or which must be clearly indicated) by companies. All these measures are efficient and must be selected according to local conditions and human behaviour. Travelling is not "risky" but 3 points must be kept in mind: accurate advice must be sought before travelling; this advice must be followed while persuing a "normal life"; a physician must be consulted in case of any trouble during and after the trip.

Animals↗

Field efficacy of thermally expelled or live potted repellent plants against African malaria vectors in western Kenya.

OBJECTIVE: To estimate the effectiveness of live potted plants and thermal expulsion of plant materials in repelling African malaria vectors in traditional houses in western Kenya. METHODS: Ocimum americanum, Lantana camara and Lippia ukambensis were tested in live, intact potted form whereas leaves of Corymbia citriodora, leaves and seeds of O. kilimandscharicum and O. suave were tested by thermal expulsion from modified traditional stoves. A latin square design was applied for randomly assigning the treatment and control plants to experimental houses over different nights. RESULTS: All plant species showed significant repellency against Anopheles gambiae sensu lato Giles (Diptera: Culicidae) (81.5%An. arabiensis Patton and 18.5%An. gambiae sensu stricto Giles), the main vectors of malaria in Africa, with the highest repellency by C. citriodora (48.71%, P < 0.0001) followed by an equal level of repellency of O. kilimandscharicum and O. suave (44.54%, P = 0.001) during application of plant material by thermal expulsion. All three plant species also showed a residual effect against An. gambiae s.l. with 36-44% repellency post-application period (22.30-06.30 hours) after a period of thermal expulsion. Similarly, intact potted plants of O. americanum and L. camara repelled An. gambiae s.l. significantly (37.91%, P = 0.004; and 27.22%, P = 0.05, respectively). Thermal expulsion of leaves and seeds of O. kilimandscharicum significantly repelled An. funestus Giles, although none of the potted plants repelled this species. CONCLUSION: Both methods of application may offer cost-effective alternatives as additional means of household protection, and a useful complement to bed nets, particularly for the early part of the evening before bedtime.

Animals↗

Mosquito repellency of the seeds of celery (Apium graveolens L.).

When the mosquito repellencies of four fractions of Apium graveolens seeds (one hexane, two dichloromethane and one methanolic) were investigated in the laboratory, all four were found to offer human volunteers some protection against female, adult Aedes aegypti. The hexane fraction, however, was found to exhibit the highest repellency in the laboratory, with median effective doses (ED50) and ED95 of 0.41 and 2.93 mg/cm2 skin, respectively. Only this fraction, which was also found to provide protection against mosquito bites for 3.5 h when applied, in the laboratory, at a concentration of 250 mg/ml, was then investigated for its repellency in the field and its stability. In storage, it was found to retain its repellency for at least 2 months, although significant reductions in its repellency were observed (in terms of shortened complete-protection times) after 3 months, whatever the temperature of storage (-20 degrees C, 4 degrees C, or room temperature). When applied to the skin of volunteers under field conditions, the hexane fraction showed strong repellent activity against a wide range of mosquito species belonging to various genera (Ae. gardnerii, Ae. lineatopennis, Armigeres subalbatus, Culex tritaeniorhynchus, Cx. vishnui group, Cx. quinquefasciatus and Mansonia uniformis). It appeared not to cause dermal irritation or any other adverse effect, either during 6 months of use or in the following 3 months of follow-up. Mosquito repellents based on extracts of Ap. graveolens seeds could be developed commercially, as an effective personal-protection measure against mosquito bites and the diseases caused by mosquito-borne pathogens.

Adolescent↗

Laboratory and field evaluations of a repellent soap containing diethyl toluamide (DEET) and permethrin against phlebotomine sand flies (Diptera: Psychodidae) in Valle del Cauca, Colombia.

The repellency and insecticidal efficacy of Nopikex, a soap formulation containing 20% diethyl toluamide and 0.5% permethrin, was evaluated against a laboratory colony of phlebotomine sand flies (Lutzomyia longipalpis). The repellency of Nopikex soap was also compared with that of a placebo soap against another species (Lu. youngi) in a forest near Tulua, Valle del Cauca, Colombia. In laboratory trials of the soap, no reduction in repellency was seen 4 hr after application, but within 8 hr, repellency decreased significantly to 67.0% of the initial value (P < 0.05) based on calculations of the coefficient of protection (CP). Under field conditions, the soap gave up to 100% protection immediately after application, but within 4 hours its CP value had decreased to a median value of only 44.3%. The placebo soap was also found to be somewhat repellent when compared with no treatment, giving a median CP value of 67.7 immediately after application. No significant mortality was seen in sand flies within 24 hr of exposure to the soap in the laboratory, even in those that had fed on protected volunteers.

Animals↗

Repellency of volatile oils from Moschosma polystachyum and Solanum xanthocarpum against filarial vector Culex quinquefasciatus say.

Volatile oils extracted by steam distillation from leaves of two plant species Moschosma polystachyum and Solanum xanthocarpum were evaluated in mosquito cages for their topical repellency effects against filarial vector Culex quinquefasciatus. The oil from M. polystachyum was tested at four different concentrations ranging from 1 to 4%. The 4% concentration gave 332.2 minutes protection whereas control gave only 4.4 minutes protection against mosquito bites. However, the volatile oil of S.xanthocarpum was tested from 2 to 8% concentration. The 8% concentration gave 311.4 minutes protection whereas control gave only 4.4 minutes protection against mosquito bites. The results suggest that the volatile oils of these two plant species were effective as repellents and gave more than 300 minutes of (>5 hour) protection against the bite of Cx. quinquefasciatus bite. Both volatile oils did not cause dermal irritation when applied to human skin. No adverse effects on human volunteers were observed after application. Therefore, both volatile oils can be applied as an effective personal protection measure against mosquito bites.

Animals↗

Repellency of live potted plants against Anopheles gambiae from human baits in semi-field experimental huts.

The repellency of potted plants against the malaria vector Anopheles gambiae sensu stricto Giles was quantified in experimental huts under semi-field conditions inside a screen-walled greenhouse. Ocimum americanum Linnaeus (Labiatae), Lantana camara L. (Verbenaceae), and Lippia uckambensis Spreng (Verbenaceae) repelled at an average of 39.7% (95% confidence interval [CI] = 29.6-48.4%), 32.4% (95% CI = 19.7-43.1%), and 33.3% (95% CI = 21.5-43.3%) of the mosquitoes, respectively (P < 0.0001 for all treatments). This was determined by logistic regression, allowing for variations associated with different bait hosts, sampling huts, and replicate test nights. In contrast, Ocimum kilimandscharicum Guerke (Labiatae), Ocimum suave Willd. (Labiatae), Corymbia citriodora Hook (Myrtaceae), Azadirachta indica A. Juss (Meliaceae), Tagetes minuta L. (Asteraceae), and Hyptis suaveolens Poit. (Lamiaceae) did not significantly repel mosquitoes. The combination of O. americanum with either L. camara or L. uckambensis repelled 31.6% (95% CI = 19.7-41.7%) and 45.2% (95% CI = 34.7-54.0%) of the mosquitoes, respectively (P < 0.0001 for both treatments). This study is the first to show that live intact plants can reduce domestic exposure to malaria vector mosquitoes. As such, they may represent a new, sustainable and readily applicable malaria vector control tool for incorporation into integrated vector management programs.

Animals↗

Laboratory evaluation of face paint repellent formulation using human volunteers under three climatic regimens.

A new combination of repellent with camouflage face paint was evaluated on volunteers against the mosquitoes Aedes aegypti (L.) and Anopheles stephensi (Liston) in an environmental chamber under three climatic regimens: tropical open, tropical forested, and hot dry environments. The duration of protection varied significantly among different climates. The camouflage face paint with diethylmethylbenzamide (deet) provided 95% protection from mosquitoes for 4 h, except under tropical open climate, where it provided only 2 h protection.

Aedes↗

Longitudinal evaluation of repellent activity of Ocimum gratissimum (Labiatae) volatile oil against Simulium damnosum.

To determine the repellent activity of Ocimum gratissimum volatile oil against Simulium damnosum (blackflies), a 12 month (January-December 2003) field study was conducted in three onchocerciasis endemic communities (Idomido, Obio camp, and Ikot Adaha) in Ini Local Government Area of Akwa Ibom State, Nigeria. The result revealed that topical application of 20% (v/v) concentration of the oil with liquid paraffin as a base, reduced the biting rate of S. damnosum by 90.2, 81.6, and 79.7%, in Idomido, Obiocamp, and Ikot Adaha respectively. The oil gave protection against the bite of S. damnosum for at least 3 h. A total of 710 adults S. damnosum were caught by individuals treated with Ocimum oil, as against 4296 caught by the control group. When the flies caught by the treated individuals were dissected none of them was infected with microfilariae of Onchocerca volvulus. Human-vector contact and onchocerciasis transmission could be reduced by the topical application of the volatile oil during the peak biting periods of the vector

Analysis of Variance↗

Control of West Nile virus, Rhode Island, 2003.

Thanks largely to systematic larviciding by the State's 39 municipalities, and aided by the public's destruction of "backyard" mosquito habitats and adoption of personal protective measures (clothing, repellant), Rhode Island minimized the potential human burden of WNV during the 2003 mosquito season (six serious WNV cases, one death, and no reports of WNV-tainted blood donations). The potential burden of WNV on domestic animals was also reduced through immunization. Nonetheless, the State's first WNV death reminds us of the danger this disease poses for the very young, for elders, and for people of all ages who are immune-compromised. Similarly, the widespread location of birds positive for WNV signifies the ubiquity of risk. All mosquitoes must be avoided. Based on its experience with WNV control over the past few years, the State will continue and enhance its surveillance and control efforts in 2004. Once again, systematic larviciding by municipalities and continuing public education through multiple channels will form the backbone of control, supported by active surveillance for the virus in the wild, in domestic animals, and in humans. For the latter effort, the vigilance of the health care community is of signal importance to the protection of the public. Every human case is investigated thoroughly, to establish as accurately as possible the time and place of exposure. DEM and HEALTH use this information to assess potential weaknesses in WNV control efforts, and to take corrective action, as necessary. Health care providers also play an essential role in public education, reminding patients (all patients, but especially the very young, elders, and the immune-compromised) to avoid mosquito bites. Discussing the avoidance of mosquito bites with patients who engage in regular outdoor activity is especially important. School physicians and the medical directors of nursing homes are well-positioned to keep mosquito control and avoidance on the agenda of their respective institutions. Together, we can control the burden of this disease among domestic animals and humans, if we continue to pursue mosquito control and personal protection aggressively. If we don't, the potential for tragedy is tremendous, as evidenced by the recent experience of other regions of the country.

Animals↗