Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “INSECT CONTROL”

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 1,693 records · Page 94Linked to original sources

EPIFIL: the development of an age-structured model for describing the transmission dynamics and control of lymphatic filariasis.

Mathematical models of transmission dynamics of infectious diseases provide a useful tool for investigating the impact of community based control measures. Previously, we used a dynamic (constant force-of-infection) model for lymphatic filariasis to describe observed patterns of infection and disease in endemic communities. In this paper, we expand the model to examine the effects of control options against filariasis by incorporating the impact of age structure of the human community and by addressing explicitly the dynamics of parasite transmission from and to the vector population. This model is tested using data for Wuchereria bancrofti transmitted by Culex quinquefasciatus in Pondicherry, South India. The results show that chemotherapy has a larger short-term impact than vector control but that the effects of vector control can last beyond the treatment period. In addition we compare rates of recrudescence for drugs with different macrofilaricidal effects.

Adolescent↗

Repellency of synthetic and plant-derived preparations for Culicoides imicola.

The study was conducted to find a safer and longer lasting repellent for C.imicola than di-ethyl toluamide (DEET), to validate whether the current recommendations in Israel for application of repellents during an outbreak of disease caused by pathogens borne by Culicoides imicola are justified, and to test plant-derived preparations as potential replacements for the synthetic repellents. Seven repellents were compared by a method using treated netting across the entrance of a suction light trap. Those inferior to DEET were: oregano and Herbipet which showed a slight non-significant repellency for 2 h, Tri-Tec 14TM which showed significant (P < 0.05) repellency with respect to controls for 2 h and Stomoxin which showed significant (P < 0.05) repellency for 1 h. As the active ingredient of Stomoxin is permethrin, this indicates that recommendations to spray animals with this insecticide to prevent the spread of C.imicola-borne pathogens will not be useful. The repellents superior to DEET were: the plant-derived material Ag 1000 that repelled significantly (P < 0.05) with respect to controls for up to 4 h following a similar pattern to but somewhat more strongly than DEET, and pyrethroid-T which exerted significant (P < 0.05) repellency for 9 h. Pyrethroid-T proved to be the best repellent tested, and if sprayed nightly it might provide protection from C.imicola-borne pathogens.

Animals↗

Control of zoonotic visceral leishmaniasis: is it time to change strategies?

Zoonotic visceral leishmaniasis (ZVL) is an important emerging parasitic disease. This article reviews the recommended control methods for the disease and concludes that they have only been partially effective. The continued endemicity of ZVL, its recent appearance in urban areas of Latin America, and its increasing importance as an opportunistic infection among persons infected with human immunodeficiency virus indicate that present control methods for the disease are ineffective and that new control strategies are needed. Prevention of the disease in dogs appears to be the best approach for interrupting the domestic cycle of ZVL. The most feasible approach would seem to be a canine vaccine that protects dogs from developing parasitemia and from becoming peridomestic reservoirs of the parasite.

AIDS-Related Opportunistic Infections↗

Control of the transmission of Chagas' disease in Mambai, Goias, Brazil (1980-1988).

The results of entomologic surveillance conducted after Chagas' disease control in Mambai, Goias, Brazil are reported for the years 1985-1988, including a summary of results from 1980 to 1988. A progressive decrease in the incidence of Triatoma infestans in houses reached zero in 1988. The threat of secondary vector colonization and the continued need for vigilance are discussed.

Animals↗

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↗

Drastic reduction of populations of Simulium sirbanum (Diptera: Simuliidae) in central Sierra Leone after 5 years of larviciding operations by the Onchocerciasis Control Programme.

The major vectors of the blinding form of human onchocerciasis in West Africa are two blackfly species, Simulium sirbanum and Simulium damnosum s.s. (Diptera: Simuliidae), identified at the adult stage as the 'savanna group' of the Simulium damnosum complex. In 1988, in the central part of Sierra Leone, the average daily biting rate (females/man/day) by savanna blackflies (mostly S. sirbanum) during the peak of the dry season (April-May) was 59.9, making up 69.1% of total captures on average. There was evidence of a strong long-range immigration of adult females of S. sirbanum through eastern Guinea in the dry season, with a reverse movement towards Guinea in the rainy season. Therefore, in 1989, the World Health Organization's Onchocerciasis Control Programme (OCP) extended its vector control operations from central West Africa to rivers of central and northern Sierra Leone, and to rivers of eastern Guinea. Four years of efficient larviciding drastically reduced adult populations of S. sirbanum in Sierra Leone. In the peak of the dry seasons of 1993 and 1994, the average biting rate by savanna blackflies in central Sierra Leone had dropped to 1.0, making up only 4.3% of total captures on average. Yearly biting rates by S. sirbanum in central Sierra Leone were therefore reduced to 2% of their pre-intervention levels. Based on larval samples, the S. sirbanum has been replaced by two forest species, S. leonense in the south and S. squamosum in the north. Since 1992, it has been possible to calculate accurate transmission rates for blinding onchocerciasis, based on DNA-probe identifications. From 1993, the risk of transmission has not only been reduced by vector control but also by mass distribution of ivermectin to rural communities. In terms of control strategy, the authors conclude that larviciding operations could be alleviated in central Sierra Leone without increasing the risk of blinding onchocerciasis transmission, as long as the migration of S. sirbanum through eastern Guinea and northern Sierra Leone is prevented.

Animals↗

[Current situation with chagas disease vector control in the Americas].

This article identifies and describes various epidemiological aspects in the natural transmission of Chagas disease in the Americas. It also examines the relative importance of the principal vector species in the disease's transmission and the control levels that are feasible in each instance. Estimations of the population at risk, number of infected cases, and number of chronic cases are presented. Prospects for control are discussed on the basis of past results to predict the expected results with introduced species like Triatoma infestans in the Southern Cone and Rhodnius prolixus in Central America and with the other autochthonous species in areas where they are found. Finally, the article discusses the role of other transmission mechanisms in the maintenance of endemic Chagas disease.

Americas↗

[New data on the control of African animal trypanosomiasis].

The glossina control turns towards cheaper, ecological, easier techniques: trapping, which the efficacy might be increased by odour attractants; synthetic pyrethrinoids (impregnated targets; dipping or application of "Pour-on" formulations on skin of cattle). Only one new trypanocide was set up during the last 25 years: Melarsamine, arsenical derivative, effective in camels, cattle, horses infected by Trypanozoon (3.5 mg/kg b. w. by IM or SC routes). The trypanotolerant cattle is characterized by a better control of parasitemia and anaemia, dominant gene A of hemoglobin and gene F of albumin, a better immune response and a smaller drop of hematocrit. Monoclonal antibodies are used to detect, in micro-ELISA plates, circulating somatic trypanosomal antigens of T. brucei (s. l.) and T. evansi (common antigens), T. congolense and T. vivax (species specific antigens).

Animals↗

Effects of plant protease inhibitors, oryzacystatin I and soybean Bowman-Birk inhibitor, on the aphid Macrosiphum euphorbiae (Homoptera, Aphididae) and its parasitoid Aphelinus abdominalis (Hymenoptera, Aphelinidae).

Transgenic plants expressing protease inhibitors (PIs) have emerged in recent years as an alternative strategy for pest control. Beneficial insects such as parasitoids may therefore be exposed to these entomotoxins either via the host or by direct exposure to the plant itself. With the objective of assessing the effects of PIs towards aphid parasitoids, bioassays using soybean Bowman-Birk inhibitor (SbBBI) or oryzacystatin I (OCI) on artificial diet were performed on Macrosiphum euphorbiae-Aphelinus abdominalis system. OCI significantly reduced nymphal survival of the potato aphid M. euphorbiae and prevented aphids from reproducing. This negative effect was much more pronounced than with other aphid species. On the contrary, SbBBI did not affect nymphal viability but significantly altered adult demographic parameters. Enzymatic inhibition assays showed that digestive proteolytic activity of larvae and adults of Aphelinus abdominalis predominantly relies on serine proteases and especially on chymotrypsin-like activity. Immunoassays suggested that OCI bound to aphid proteins and accumulated in aphid tissues, whereas SbBBI remained unbound in the gut. Bioassays using M. euphorbiae reared on artificial diets supplemented with both OCI and SbBBI showed a fitness impairment of Aphelinus abdominalis that developed on intoxicated aphids. However, only SbBBI was detected in parasitoid larvae, while no PI could be detected in adult parasitoids that emerged from PI-intoxicated aphids. The potential impact of PI-expressing plants on aphid parasitoids and their combined efficiency for aphid control are discussed.

Animals↗

Description of a computer model of forest onchocerciasis transmission and its application to field scenarios of vector control and chemotherapy.

This paper describes a computer simulation model for onchocerciasis (SIMON). Using epidemiological and entomological data from a specific hyperendemic village in the forest area of Sierra Leone, the model is used to examine the effect of vector and chemotherapeutic control strategies, both separately and in combination, as well as the risk to an uninfected population caused by immigrant, infected Simulium damnosum and humans. The model suggests that, in this village, the human population of about 420 requires an average annual input of about 200 mature fecund, female Onchocerca volvulus per year to maintain a skin-snip prevalence of just under 70%. SIMON also predicts that 99% effective vector control would lead to eradication of all adult worms in 18 years, and that abandoning control before 14 years could lead to recrudescence. Chemotherapy with ivermectin at six-month intervals reaching 90% of eligible persons (effective 66%) might take 29 years to achieve eradication because of continuing transmission, particularly in the early years, but it would probably be possible to abandon treatments after 18 years because the residual worm population would no longer be self-sustaining. Combined ivermectin and vector control, both at reduced levels, could be as effective as 99% vector control. Immigrant infected flies are likely to pose a greater threat to an uninfected human population than small numbers of infected persons. The model suggests that, at levels of infection undetectable by skin-snip, the parasite could linger in the human population for 30 or more years sustained by sporadic transmission.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

[The antimalaria campaign in Italy between control and eradication: the Sardinian experiment].

The aim of this paper is to examine historically the alternative between control and eradication of the infectious diseases, starting with the idea of eradication itself, a result of the Pasteurian revolution. The eradication of malaria in Italy is taken as a case study. Through an extensive use of the archival sources, the alternative between control and eradication is analysed for the first years of the Sardinian Project, directed by the Rockefeller Foundation, that resulted in the eradication of malaria in Sardinia. This program is compared with the different program, grounded in the Italian malariological tradition, that in the same years carried out the eradication of malaria in the rest of Italy.

Animals↗

[Strategy of sleeping sickness control in the Peoples' Republic of Congo: research and perspectives].

The authors review the different strategies applied nowadays in the Popular Republic of Congo to eradicate sleeping sickness. They underline the problems encountered on the field as well as researches carried out to solve them. Recent progress at both levels of screening and trapping opened interesting prospects. Success of the Congo in its fight against sleeping sickness depends now mainly on means made available to apply on a large scale these new methods.

Congo↗

Results of the National Cooperative Inner-City Asthma Study (NCICAS) environmental intervention to reduce cockroach allergen exposure in inner-city homes.

BACKGROUND: Cockroach allergen is important in asthma. Practical methods to reduce exposure are needed. OBJECTIVE: We sought to evaluate the effectiveness of house cleaning and professional extermination on lowering cockroach antigen levels in inner-city dwellings. METHODS: As part of the National Cooperative Inner-City Asthma Study intervention, 265 of 331 families with asthmatic children who had positive skin test responses to cockroach allergen consented to a professional home extermination with 2 applications of a cockroach insecticide (Abamectin, Avert) combined with directed education on cockroach allergen removal. On a random subset of 48 homes undergoing cockroach extermination in the intervention group, Bla g 1 was measured in settled dust from the kitchen, bedroom, and TV/living room. The first sample was collected 1 week before extermination, with additional samples after the exterminations at approximately 2, 6, and 12 months after the first sample. Self-reported problems with cockroaches were collected at baseline and after 12 months of follow-up in both the intervention and control group. RESULTS: The geometric mean kitchen level of Bla g 1 decreased at 2 months (33.6 U/g) relative to preextermination levels (68.7 U/g, P <.05). The percent of kitchens with over 8 U/g of Bla g 1 followed a similar pattern, but only the decrease from preextermination to 6-month levels was significant (86.8% vs 64.3%, P <.05). By the 12-month visit, the allergen burden had returned to or exceeded baseline levels. Except for an increase in the bedroom at 2 months (8.9 U/g vs 11.1 U/g, P <.05), no other significant change was seen. Only about 50% of the families followed the cleaning instructions; no greater effect was found in these homes. Self-reported problems with cockroaches showed no difference between the intervention and control group after 1 year of follow-up. CONCLUSIONS: Despite a significant, but short-lived, decrease the cockroach allergen burden remained well above levels previously found to be clinically significant.

Allergens↗

Managing animal trypanosomosis in Africa: issues and options.

This paper discusses past and present approaches to managing tsetse-transmitted animal trypanosomosis in Africa and describes the three main weaknesses of these approaches, i.e., inappropriate objectives, inadequate links between research and policy-making and a lack of recognition that trypanosomosis should be high up on the social science research agenda. Making progress in managing trypanosomosis has been difficult and the authors argue that the weaknesses of the approaches must be corrected if Africa is to benefit from the few advances made so far, and for the continent to make further sustained efforts to combat the disease. The authors explain that this can be achieved by replacing the current widespread preoccupation among researchers and policymakers with controlling (or eradicating) trypanosomosis with a focus on managing (or coping with) the disease. In addition, ways of achieving greater coherence between research and policy-making must be explored. Finally, the social science issues raised by the question of which practical steps need to be taken to manage trypanosomosis in Africa should be placed at the forefront of research efforts.

Africa↗

Importance of migrants infected with Onchocerca volvulus in west African river valleys protected by 14 to 15 years of Simulium control.

A study was done to determine the importance of human migration from non-controlled endemic onchocerciasis foci to the river valleys that have been protected for the past 14 to 15 years by the vector control operations of the Onchocerciasis Control Programme in West Africa. The aim of the study was to assess the contribution of migrants to the prevalence and intensity of infection in villages from 5 major river valleys and their potential role in causing relapse of transmission once the vector is allowed to return. In Burkina Faso the migrant population varied from 0.0% to 18.1% of the village population, and averaged 4.9%. Migrants accounted only for 0.6% of the population in Ghanaian and Ivorian villages along the Black Volta river. The prevalence of infection was significantly higher in migrants (8.2%) than in non migrants (1.1%) in the surveyed villages in Burkina Faso, and 1.5% of migrants had infections with more than 16 microfilariae per snip as against 0.2% of non migrants. Nearly all infected migrants came from the south of the Côte d'Ivoire. The study shows that human migration has caused the importation of Onchocerca volvulus from non-controlled areas. However, the epidemiological importance of this phenomenon is limited because of the very small number of infected migrants per village while two-third of the infected migrants are believed to be infected with the less pathogenic forest strain of the parasite. Because migration patterns changes geographically and over time similar studies will be continued on a regular basis.

Animals↗

Research on the control of bluetongue in livestock by vector suppression.

From 1979-83, research has been conducted along the South Platte River drainage system northeast of Denver, CO, to develop and evaluate techniques of wide-area vector suppression for the control of bluetongue (BT) disease in ruminant livestock. Water management and chemical treatment at larval development sites have resulted in a decrease in the activity of Culicoides variipennis (Coquillett) in the 100 km2 treatment area, and there is some correlation between levels of vector activity (as reflected by light trap catches) and the levels of BT in livestock as measured by serologic and virologic evaluations.

Animals↗

Laboratory evaluation of five pesticides for control of Leptotrombidium fletcheri (Acari: Trombiculidae).

Five pesticides were evaluated against laboratory colonies of Leptotrombidium fletcheri (Womersly and Heaslip) by the Pasteur pipet technique. The pesticides were dieldrin (LC50 = 3.6 ppm, LC99 = 18.2 ppm), bromopropylate (LC50 = 9.2 ppm, LC99 = 239.6 ppm), dicofol (LC50 = 27.8 ppm, LC99 = 118.1 ppm), fenthion (LC50 = 15.4 ppm, LC99 = 29.7 ppm), and malathion (LC50 = 84.7 ppm, LC99 = 313.9 ppm). Dieldrin was the most toxic. Dicofol was recommended for further evaluation in field trials.

Animals↗

[Epidemiology of malaria in French Guiana].

A malaria investigation in the 1970-1986 period in French Guiana shows an increased plasmodium index (4.6%) when compared with the data of the 1970-1979 decade (2.7%), an incidence rate of 8.6 per 1,000 inhabitants (against 6.4 previously) and always a high frequency of P. falciparum (85%). The principal vector, A. darlingi, still remains sensitive to DDT but the authors recommend an updating of the anti-vectorial program control. A longitudinal serologic survey, on the school children during two years, shows the epidemiologic value of an immunological index. Its permits to precise the annual dynamic of malaria transmission and to distinguish in French Guiana three areas: a forest area with apparently permanent transmission, an hypo-endemic area with episodic transmission and a sporadic transmission area.

Animals↗