Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Rodent 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 109 records · Page 6Linked to original sources

Use of repellents and attractants in filariasis control.

The ways in which repellents and attractants could be used to interrupt the transmission of bancroftian filariasis, especially by Culex pipiens fatigans, are assessed. Dimethyl phthalate (DMP) is an effective repellent against C. p. fatigans. It is also very toxic to all larval stages of Wuchereria bancrofti. The median lethal time to microfilariae of a solution of about 0.2% in normal saline is about 10 minutes. Other stages are similarly sensitive. Contact with DMP in very thin films is almost immediately lethal. It is highly unlikely that infection could take place under ordinary conditions through skin treated with DMP for at least many hours afterwards. This toxicity made it impossible to evaluate repellency in vitro. An in vivo test of the effect of skin applications of DMP on microfilaria counts gave anomalous results. A schedule for filariasis control, involving education, garbage disposal, rodent control, sewage disposal, and mosquito control, is proposed, and the research needed to allow repellents and attractants to play a full role in such a schedule is delineated.

Animals↗

Hantavirus infections.

Hantaviruses are the causative agents of the zoonotic diseases known as haemorrhagic fever with renal syndrome (HFRS) in Europe and Asia, and hantavirus pulmonary syndrome (HPS) in the Americas. These pathogens are maintained in the wild by rodent reservoirs and are mainly transmitted via the aerosol route. The infection is chronic and apparently asymptomatic in host animals. Whilst HFRS is caused by Hantaan, Seoul, Dobrava and Puumala hantaviruses, HPS is associated with Sin Nombre-like viruses. Common clinical features of HFRS and HPS include fever, myalgia, thrombocytopenia, leukocytosis and a capillary leak syndrome associated with shock in most severe cases. Outbreaks of HFRS and HPS are generally observed during years with dense rodent populations resulting from favourable climatic and environmental conditions. Human activities, such as rodent trapping, farming, cleaning rodent-infested areas, construction work, camping and hunting, are also implicated in the occurrence of hantavirus disease. Prophylactic measures in endemic areas rely essentially on information campaigns and rodent control.

Americas↗

The black death past and present. 1. Plague in the 1980s.

This paper considers firstly the epidemiology of plague in the 1980s. The largest number of cases occurred in Tanzania. Most cases were in children and young adults; in the USA the male:female ratio was about 2:1. Plague had a seasonal distribution. Almost all cases arose from bites of infected rodent fleas, and Rattus spp. were the most important reservoir hosts. Virulence is linked with the presence of a 45 MDa plasmid. The predominant clinical form of plague is bubonic, followed by septicaemic, meningitic and pneumonic. For treatment, streptomycin is the antibiotic of choice, with tetracycline and chloramphenicol as alternatives. Treatment given on the first 1-2 d of illness is highly effective, and resistance is not a problem. Rodent control, insecticide application, and avoidance of contact with rodents and their fleas remain the prime means of control. Plague vaccine is not in general use.

Animals↗

A scheme for the placement of rodenticide baits for rat eradication on confinement livestock farms.

We investigated whether the allocation of rodenticide baiting points to specific structural elements would result in complete rat eradication on livestock farms, as opposed to assigning the baiting points only to places where there were obvious signs of rat activity. The goal was to establish an effective rodent-control program that is easy for untrained persons to conduct.Rat-control strategies were examined on 25 farms in Velen (Muensterland), Germany, where an average of 20% of trapped rats were resistant for bromadiolone according to a blood-clotting response (BCR) test. All farms were investigated for signs of rat activity prior to and after the control measure. Differences in the percentage level of farmer compliance in setting up the baiting points as prescribed were analysed for each type of baiting point and in total, and were compared between the group of farms which achieved complete rat eradication and those which did not. Farms achieving complete eradication had an average of 81% compliance with prescribed control plans, whereas a significantly lower compliance level of only 51% was recorded on farms that did not achieve eradication. A >/=75% level of implementation of the control plan always resulted in complete control success. The new method of bait-point allocation was incorporated into a self-explanatory computer program, which was verified to be effective during a rat-control campaign in the restricted area after an outbreak of classical swine fever near Soltau in northern Germany, in July 2001. This program, which is available on the Internet, enables the creation of individualised rat-control plans, including complete documentation of the control measure.

4-Hydroxycoumarins↗

Biosecurity and minimal disease herds.

The minimal disease concept is a way of raising pigs so that some specific diseases are absent. Many bacteria and viruses can be transferred by pigs, air, or mechanical contact. To avoid contamination, the herd location should take into consideration disease transmission possibilities. Herd health status and source herd health status should be continuously monitored. To maintain herd health status, specific rules need to be followed for herd construction and establishment, compound perimeter, people movement, down time, animal transportation, feed use and delivery, vehicle movement, material, dead animal disposition, and rodent control. All new incoming animals should go through quarantine, and in some herds, safer methods such as AI, embryo transfer, MEW, or hysterectomy and fostering need to be used.

Animal Feed↗

Leptospira interrogans serovar icterohaemorrhagiae seropositivity and the reproductive performance of sows.

The reproductive performance of 28 sows seropositive to Leptospira interrogans serovar icterohaemorrhagiae was compared with that of 87 Leptospira sp. seronegative dams belonging to the same herd. Sows were sampled during 1988 to 1993. During this period the herd was not submitted to any kind of intervention (antibiotic therapy, immunoprophylaxis or rodent control). Relative risks (RR) of return to heat, mummified fetuses, stillbirth, and weak newborn piglets for infected sows were assessed and the differences in means of total piglets born per litter, piglets born alive, piglets effectively housed, weaned piglets, stillbirths, mummified fetuses, weak newborn piglets, weight at birth of the piglets effectively housed, weight at 21 days of life and weight at weaning were evaluated. Seropositive dams had a greater risk of having weak newborn piglets (RR = 1.67, 1.02 < or = CI 95% < or = 2.72) and also of having more weak newborn piglets per litter (P = 0.01). Other variables examined were not different (P > 0.05).

Aging↗

Seroprevalence of murine typhus and fièvre boutonneuse in certain human populations in Egypt.

A study was conducted between 1984 and 1987 to determine the prevalence of Rickettsia typhi and Rickettsia conorii infections among humans residing in the Nile Delta, Suez Canal area and Nile Valley of Egypt. Serum specimens were obtained from garbage and rodent control workers, other unclassified occupational workers, and from patients with fever of undetermined aetiology. All sera were assayed for IgA + IgM + IgG (IgAMG) antibody mixture and if positive, reassayed for specific IgM antibody to rickettsia by the indirect fluorescent antibody technique. R. typhi antibody was found in 19% (33/178) of the garbage collectors, whereas only 1% (2/178) had demonstrable antibody to R. conorii. Among those with other occupations, R. typhi antibody was detected in 0.7% (2/295) and none had R. conorii antibody. The antibody prevalence rate for R. typhi among patients with febrile illness ranged from 25 to 41%, and from 2 to 15% for R. conorii, at three different locations in Egypt. In addition, IgM antibody to R. typhi was demonstrated in some patients showing symptoms compatible with rickettsial disease and in some patients who seroconverted, indicating that R. typhi was the cause of illness among some of these patients. These findings support previous observations that R. typhi and R. conorii are the causes of human rickettsial disease in Egypt, and that humans are commonly infected with R. typhi.

Adult↗

Experiments on direct and secondary poisoning by fluoroacetamide (1081) in wildlife and domestic carnivores.

Fluoroacetamide (1081 or F.A.A) is used in Israel for field rodent control. Experiments on direct and secondary, short and long term poisoning caused by 1081 were carried out. Mongoose (Herpestes ichneumon), hyena (Hyaena hyaena), cats and dogs were susceptible. Barn owls (Tyto alba), buzzards (Buteo buteo) and black kites (Milvus m. migrans) were markedly resistant. Barn owls tolerated total direct poisoning ranging from 6.8 to 10.9, and a final dose ranging from 0.8 to 2.0 mg/kg. In secondary poisoning, total doses ranging from 1.7 to 7.1, and final doses ranging from 0.2 to 1.3 mg/kg were tolerated. Buzzards tolerated total direct poisoning ranging from 6 to 12.0, and final doses ranging from 0.7 to 1.3 mg/kg. In secondary poisoning, doses ranging from 0.8 to 10.3 and final doses ranging from 0.2 to 2.4 mg/kg were tolerated. One black kite tolerated a total direct dose of 6.1 and final dose of 0.7 mg/kg, another survived a total dose of 2.3 and final dose of 0.2 mg/kg in secondary poisoning. A small-scale secondary poisoning experiment on two Palestine vipers (Vipera palestinae), a Syrian black snake (Coluber jugularis) and two Montpellier snakes (Malpolon monspessulanus) indicated that these species were resistant to total doses ranging from 0.1 to 3.2 and final doses of 0.1 to 0.8 mg/kg.

Amides↗

Recent trends in public health.

Environmental sanitation is experiencing a reawakening with concerted drives at control of water and atmospheric pollution, mosquito and rodent control, and improvement in restaurant sanitation. Communicable disease control efforts are being intensified. With prolongation of life, chronic diseases are assuming increasing importance as public health problems. Maintenance of standards of hospitals and provision for more adequate hospital facilities are also receiving attention. Mental health and chronic alcoholism are being considered as a public health problem. With all these new trends emphasizing prevention of disease, increasing teamwork between physicians in private practice and in public health practice is being manifested. Preventive medicine and public health are now a recognized specialty in medicine.

Communicable Disease Control↗

Haemorrhagic fever with renal syndrome: memorandum from a WHO meeting.

Haemorrhagic fever with renal syndrome (HFRS) is a public health problem throughout most of the European and Asian land mass. Although predominantly associated with rural areas, it is now being recognized as an urban problem in some countries, and also presents a particular hazard to laboratory staff who use rodents for biomedical research. In wild rodents (rats, mice and voles) the infection is asymptomatic. Human infection with the HFRS agent(s) is sporadic, but under special circumstances epidemics occur; the infection may be completely silent, or associated with mild or severe disease. Severe cases are usually seen in the Far East. The epidemiological features of the disease vary from country to country and depend upon a variety of factors, the elucidation of which requires a multidisciplinary approach. The recently discovered Hantaan virus is the etiologic agent of HFRS in Asia. It is now possible to detect Hantaan virus antigen by immunofluorescence using either infected mouse lung or infected human cells as substrate. Prevention measures to date have concentrated on rodent control; the role played by the ectoparasites of rodents, if any, has still to be elucidated. Antigens have been detected in rodents captured in HFRS-endemic areas in China, Finland, Japan, Sweden, and the Soviet Union. None of these have been cultured as yet, but preliminary results with the Puumala agent detected in Finland indicate a relationship with the Hantaan virus. Sera collected from Scandinavian patients react to a high titre with both Puumala and Hantaan agents, whereas sera collected from patients in East Asia have much higher titres against the homologous antigen. Surveillance is very important and further research on the virus is needed, especially to identify the virus in the West and to determine strain differences.

Adolescent↗

Heterogeneic autoantibody against neurofilament protein in the sera of animals with experimental kuru and Creutzfeldt-Jakob disease and natural scrapie infection.

Heterogeneic autoantibodies against axonal neurofilament proteins of mature mouse neurons grown in vitro were detected by the indirect immunofluorescence technique in 12.7% (9 of 71) of the sera from nonhuman primates infected with kuru, in 14.5% (17 of 117) and 4% (1 of 25), respectively, of the sera from nonhuman primates and laboratory rodents infected with Creutzfeldt-Jakob disease, and in 35% (7 of 20) of the sera from sheep naturally infected with scrapie. Autoantibody titers ranged from 1:16 to 1:512 in Creutzfeldt-Jakob disease-infected animals, 1:32 to 1:512 in kuru-infected animals, and 1:64 to 1:1,024 in sheep with natural scrapie. The sera from 11 monkeys and 17 hamsters infected with scrapie and from 19 chimpanzees inoculated with brain tissues from humans with other neurological diseases did not contain autoantibodies. Of the 41 chimpanzees with Creutzfeldt-Jakob disease, 6 had autoantibodies against neurofilament proteins before experimental inoculation, whereas 6 others developed autoantibodies after inoculation, 4 developed autoantibodies during the asymptomatic phase, and 2 developed autoantibodies during the terminal clinical phase. Of the 48 chimpanzees with kuru, 2 had autoantibodies before inoculation, 6 developed autoantibodies after inoculation, 3 developed autoantibodies during the asymptomatic phase, and 3 developed autoantibodies during the terminal clinical phase. Among the normal nonhuman primate controls, 4.6% (9 of 195) had autoantibodies. In contrast, no autoantibodies were detected in 49 control rodents and 13 control sheep. The increased incidence of autoantibodies against neurofilament proteins in animals with kuru, Creutzfeldt-Jakob disease, and scrapie constitutes the first evidence of an immunological reaction in this group of atypical infections caused by unconventional viruses and suggests that neurofilaments may be involved in pathogenesis.

Animals↗

Motility and infectivity of Plasmodium berghei sporozoites expressing avian Plasmodium gallinaceum circumsporozoite protein.

Avian and rodent malaria sporozoites selectively invade different vertebrate cell types, namely macrophages and hepatocytes, and develop in distantly related vector species. To investigate the role of the circumsporozoite (CS) protein in determining parasite survival in different vector species and vertebrate host cell types, we replaced the endogenous CS protein gene of the rodent malaria parasite Plasmodium berghei with that of the avian parasite P. gallinaceum and control rodent parasite P. yoelii. In anopheline mosquitoes, P. berghei parasites carrying P. gallinaceum and rodent parasite P. yoelii CS protein gene developed into oocysts and sporozoites. Plasmodium gallinaceum CS expressing transgenic sporozoites, although motile, failed to invade mosquito salivary glands and to infect mice, which suggests that motility alone is not sufficient for invasion. Notably, a percentage of infected Anopheles stephensi mosquitoes showed melanotic encapsulation of late stage oocysts. This was not observed in control infections or in A. gambiae infections. These findings shed new light on the role of the CS protein in the interaction of the parasite with both the mosquito vector and the rodent host.

Animals↗

Aberrant crypts, putative precancerous lesions, in the study of the role of diet in the aetiology of colon cancer.

Progress in the field of diet and colon cancer would be greatly enhanced by the development of a methodology which allowed for the identification and quantification of the early precursor lesions of colon cancer. Recently we described a method (Bird, 1987) consisting of staining the fixed, unsectioned colon with methylene blue for viewing the mucosal surface with the aid of a light microscope. With this methodology we observed early focal lesions in the colons of rodents which had been treated with a colon carcinogen but no lesions in the colons of control rodents. We termed these lesions aberrant crypts (AC). Based on our preliminary observations we hypothesized that AC represent precursor lesions of colon cancer. The findings from our subsequent studies (summarized in this paper) support this contention. We therefore suggest that evaluation of the characteristics of AC will further our understanding of the carcinogenic process as it occurs in the rodent colon and will provide a basis for the investigation of the role of diet in the aetiology of the disease.

Animals↗

Maintenance of thyroid hormone production during exercise-induced weight loss.

Calorie restriction reduces thyroxine (T4) and 3,5,3'-triiodothyronine (T3) production, but the effects of exercise-induced weight loss on thyroid hormone metabolism in rodents are unclear. We studied the effects of chronic exercise on T4 and T3 metabolism comparing exercising (exercise) rats pair fed to sedentary (control) rodents and to weight-matched underfed sedentary animals (underfed; caloric intake 75% of ad libitum-fed controls). The exercise group utilized voluntary running wheels (28 days), and thyroid hormone metabolism was assessed using a three-compartment kinetics model. The exercise and underfed groups were equivalent in weight, but protein mass was greater in the exercise vs. underfed groups (30.4 +/- 0.5 vs. 27.9 +/- 0.5 g; P less than 0.05). During exercise, the T4 plasma clearance rate (PCR) was decreased (-39.2%; P less than 0.01) and the T4 concentration in serum was increased (48.6%; P less than 0.01), resulting in an unchanged T4 plasma appearance rate (PAR) vs. the control group. The decrease in T4 PCR in the exercise group was associated with a lower transport rate of T4 out of the slow pool (P less than 0.01). In the underfed group there was a reduction in both T4 serum concentration and PAR (-36%; P less than 0.01) compared with the control group, which was associated with a decrease in the volume of distribution (-25%; P less than 0.01). T3 PAR decreased 38.7% (P less than 0.01) during underfeeding but only 16.9% (P = not significant) during exercise vs. the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Echinococcus multilocularis: secondary poisoning of fox population during a vole outbreak reduces environmental contamination in a high endemicity area.

This paper describes the role of fox population level on Echinococcus multilocularis infection in foxes in a highly endemic area in eastern France. Fox population level was monitored by spotlight survey at Le Souillot from 1989 to 2000, and from 1992 to 2000 at Chemin, a control site located in a low endemic area. The infection level of the fox population was estimated at Le Souillot from winter 1995 to winter 1999 using a coproantigen ELISA performed on faeces collected in the field. Population biomass of intermediate hosts (Microtus arvalis and Arvicola terrestris) was monitored using index methods from 1995 to 1999. At Le Souillot, a significant decline in the fox population level was recorded after spring 1997 (P<0.001), and the population level remained low until 2000. The decline occurred when 31% of the grassland area was treated with bromadiolone, an anticoagulant used at a large scale for the control of A. terrestris population outbreaks. No decline of population was recorded at Chemin, where bromadiolone was not used for rodent control. Significant differences among ELISA OD distributions in fox faeces were recorded for the five winters under study at Le Souillot (P=0.0004). The median of ELISA OD distribution was 0.209 and 0.207 before the population decline (winter 1995 and 1996, respectively), significantly increased to 0.306 just after the decline (winter 1997), and then significantly decreased to 0.099 and 0.104 afterwards (winter 1998 and 1999, respectively). Therefore, the decrease in infection level occurred during winter 1998, 1 year after the population decline, when the intermediate host biomass in the field was at its highest. These results suggest a complex dependence between the fox population level and E. multilocularis infection in a high endemicity area. Alternative ways to control fox population as a way to reduce E. multilocularis transmission in a given area are discussed.

4-Hydroxycoumarins↗

Effects of aging on resistance to Trichinella spiralis infection in rodents exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin.

Immune function, including resistance to infection, decreases as humans and rodents age. We have shown that preinfection exposure of young (9-11 weeks) mice or rats to TCDD decreased resistance to Trichinella spiralis (Ts) infection, expressed as delayed onset or completion of parasite elimination and as increased muscle burdens of larvae. It has also been shown that aged mice express lower constitutive levels of resistance to Ts infection, compared to young adult animals. This study tested the hypothesis that the age-related decrease in constitutive levels of resistance to Ts infection exacerbates the decreased resistance to infection that follows TCDD exposure. This hypothesis addresses the concern that TCDD may pose a greater threat to the elderly than to the population at large. Animals were given a single oral dose of 1, 10, or 30 microg TCDD/kg, 7 days before infection. Eleven days later, young (approximately 10 weeks) control rodents had eliminated a greater proportion of the original parasite burden from the intestine than aged control animals. Nevertheless, parasite elimination was decreased by TCDD exposure only in young rodents. The effect of TCDD exposure on numbers of encysted larvae was evaluated only in rats. Increased larvae burdens occurred in young rats at 30 microg TCDD/kg and at 10 or 30 microg TCDD/kg in aged rats. Parasite-specific splenocyte and lymph node cell proliferation was suppressed following dioxin exposure in young mice; cells from aged mice were markedly less responsive to stimulation, yet less sensitive to TCDD exposure. The response to parasite antigens was not affected in aged rats exposed to TCDD, although elevated mitogen-driven B-cell proliferation was observed. These results indicate that age-related constitutive immunosuppression did not exacerbate TCDD-induced suppression of T-cell mediated adult parasite expulsion; rather, advanced age provided some degree of protection. On the other hand, a lower dose of TCDD was required in aged rats to suppress the combined humoral and cellular responses that limit the burden of encysted larvae, compared to young rats. These model-dependent results preclude acceptance or rejection of the tested hypothesis.

Aging↗