PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “INSECT BITES AND STINGS”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 577 records · Page 32Linked to original sources
PubMed1992

[Observation on malaria transmission intensity at a stone-pit of the mountain area in Baoan County, Guangdong Province].

Zhangshubu stone-pit in Baoan County is located in the mountain area. The workers' camps are 2-3 km away from the village. In a recent survey, in malaria peak season (June, July, August) An. anthropophagus accounted for 87.7% (1059/1207) of the total anopheline population and the average man-biting rate was 10.90, 24.88 and 8.71 respectively. The sporozoite positive rate, the human blood index and the daily survival rate were 0.54% (3/554), 1.0 and 0.803 respectively. The parasitaemia rate, the rate of gametocyte carriers, and the rate of persons with malaria history within 1-2 months were 45.5% (10/22), 13.6% (3/22) and 50.0% (11/22), respectively. On average, the entomological inoculation rate A, B and C calculated by three methods were 0.084, 0.665 and 0.215, respectively, indicating that the workers might get malaria infection if they stayed at the camp for 1.5-11.9 days. An analysis of the malaria onset time of the patients suggested that the time calculated from the inoculation rate A was closer to the real situation than those calculated from the inoculation rate B or C. The prevalence trend of malaria could be predicted through the monitoring of the entomological inoculation rate.

Animals↗
PubMed2003

[Study on the thresholds of malaria transmission by Anopheles anthropophagus in Hubei Province].

OBJECTIVE: To study the thresholds and potential of malaria transmission by Anopheles anthropophagus in Hubei Province and provide indicators for the disease surveillance, early warning, prevention and control in the locality. METHODS: From July to August 2001, field investigations on vectors and malaria situation were carried out in the village of Yanjiafan, Suizhou City, where the malaria incidence was high. The entomological investigations included the man-biting rate, the proportion of parous anophelines, the human blood index and the blood preference. The others included malaria incidence and parasite rate in human population, the intervals from episode to treatment of the cases, and collection of data on the mean temperature in the area. Based on the formula of basic reproductive rate, the critical man-biting rate was estimated. RESULTS: 92.6% (63/68) of An. anthropophagus were found to have human blood meals, it occupied 91.5% (97/106) of the mosquitoes in human dwellings, its human blood index and vectorial capacity were 12.5 times (0.50/0.04) and 6.5 times (0.9448/0.1449) higher than those of An. sinensis. The critical man-biting rate was 0.2823 and the adjusted man-biting rate was 3.5 times of its critical man-biting rate (0.9892/0.2823). The malaria incidence was 0.65% (12/1844) and the parasite rate in pupils was 0.51%(1/198). CONCLUSION: A reduction of the adjusted man-biting rate of An. anthropophagus by 71.5% is needed for interrupting malaria transmission by this vector in the study area.

Animals↗
PubMed2003

[Epidemiology of malaria in a village of Sudanese savannah area in Mali (Bancoumana). 2. Entomo-parasitological and clinical study ].

We carried out five cross sectional surveys between 1993 and 1994 to assess the epidemiology of malaria in the village of Bancoumana, located in the Sudanese savannah areas of Mali. Each survey included a collection of entomological, clinical, parasitological and immunological data. The study population involved 1600 children from six months to 9 years of age. The main vector was Anopheles gambiae s.l., man bite rate and entomological inoculation rate were maximum respectively in August (peak of the transmission season) and October (end of transmission season). Plasmodium. falciparum was the main parasite species observed. Spleen enlargement rate, parasite rate, gametocyte rate and parasite density varied significantly with age and season. The parasite rate, gametocyte rate and parasite density were significantly low in October 1994 compared with October 1993 while the entomologic parameter did not show any variation over the two years. This reduction of parasitologic index between 1993 and 1994 may be related to an increase of anti-malarial drug use in the population. Our results show that malaria is hyperendemic in the village of Bancoumana.

Animals↗
PubMed2003

[Ecoethology of vectors and transmission of malaria in the lowland rice growing region of Mandritsara, Madagascar ].

To evaluate the determining factors of the malaria transmission in the northwest region of Madagascar, transversal studies were carried out through one year, from March 1997 to April 1998, in two villages located near Mandritsara, at less than 300 meters above sea level. The rice-growing region forms an intermediate zone between the central highlands with epidemic and instable malaria and the coastal zone with endemic and stable malaria. Mosquitoes were collected when landing on humans during the night and by pyrethrum spray catches as regards endophilic mosquitoes. Three vectors were identified: Anopheles arabiensis, An. gambiae and An. funestus. An. arabiensis and An. gambiae were exophagic and zoophilic. An. funestus was endo-exophagic and anthropophilic but this species shows also a zoophilic trophic deviation. In both villages, An. funestus is the main vector of human malaria. Malaria transmission was estimated to be around 50 and 70 infective bites/person/year in each village.

Altitude↗
PubMed2003

High seasonal variation in entomologic inoculation rates in Eritrea, a semi-arid region of unstable malaria in Africa.

Entomologic studies were conducted in eight villages to investigate the patterns of malaria transmission in different ecologic zones in Eritrea. Mosquito collections were conducted for 24 months between September 1999 and January 2002. The biting rates of Anopheles arabiensis were highly seasonal, with activity concentrated in the wet season between June and October in the highlands and western lowlands, and between December and March in the coastal region. The biting rates in the western lowlands were twice as high as in the western escarpment and 20 times higher than in the coastal region. Sporozoite rates were not significantly different among villages. The risk of infection ranged from zero on the coast to 70.6 infective bites per year in the western lowlands. The number of days it would take for an individual to receive an infective bite from an infected An. arabiensis was variable among villages (range = 2.8-203.1 days). The data revealed the presence of only one main malaria transmission period between July and October for the highlands and western lowlands. Peak inoculation rates were recorded in August and September (range = 0.29-43.6 infective bits/person/month) at all sites over the two-year period. The annual entomologic inoculation rates (EIRs) varied greatly depending on year. The EIR profiles indicated that the risk of exposure to infected mosquitoes is highly heterogeneous and seasonal, with high inoculation rates during the rainy season, and with little or no transmission during the dry season. This study demonstrates the need to generate spatial and temporal data on transmission intensity on smaller scales to guide targeted control of malaria operations in semi-arid regions. Furthermore, EIR estimates derived in the present study provide a means of quantifying levels of exposure to infected mosquitoes in different regions of the country and could be important for evaluating the efficacy of vector control measures, since Eritrea has made significant steps in reducing the burden of malaria based on the Roll Back Malaria initiative of the World Health Organization.

Animals↗
PubMed1992

Mosquito size and multiple transmission of avian malaria in the laboratory.

Probing mosquitoes salivate before ingesting blood, and malaria sporozoites are transmitted during this phase of feeding. Large and small Aedes aegypti infected with Plasmodium gallinaceum were allowed to probe briefly on a series of 3 naive chicks. Large mosquitoes were more infective overall, but there was no difference in the ability of either size class to infect the first host. Large mosquitoes were more likely than small mosquitoes to infect more than one host during serial feeding.

Aedes↗
PubMedDate not supplied

Picaridin: a new insect repellent.

Picaridin is a new insect repellent that is comparable in effect and less irritating than diethyl toluamide (deet). Its activity and effects are reviewed in this article.

Administration, Cutaneous↗
PubMed2004

Negative effect of antibodies against maxadilan on the fitness of the sand fly vector of American visceral leishmaniasis.

Lutzomyia longipalpis expresses a salivary protein called maxadilan (MAX) that functions to dilate vertebrate blood vessels and thereby to facilitate the sand fly's acquisition of blood. We hypothesized that antibodies specific for one of many MAX variants would inhibit vasodilatory function of that variant. In vitro and in vivo experiments showed that antibodies against a specific MAX variant decreased vasodilatory function. More specifically, antibodies against MAX blocked vasodilation of a constricted rabbit aorta. Additionally, a strain of Lu. longipalpis, with a nearly uniform MAX genotype, obtained a larger blood meal from naive BALB/c mice compared with mice that were either immunized with a homologous MAX genotype or sensitized to bites of flies from the same strain. Those flies taking blood from mice sensitized by sand fly bites also laid significantly fewer eggs than when they took blood from naive mice. These results have potential epidemiologic importance in light of the potential use of MAX in a vaccine or as part of a diagnostic test because they imply that a uniform MAX genotype is selected against by the vertebrate host immune response and that antigenic diversity is selected for.

Animals↗
PubMedDate not supplied

Bioecology of An. philippinensis in Andaman group of islands.

Studies on bioecology of An. philippinensis a vector of malaria was carried out in eight islands of the Andaman group. It was found that An. philippinensis preferred to rest and bite outdoors. Maximum biting was observed during 1800 to 2100 hrs on both cattle and human bait. The maximum breeding of An. philippinensis was recorded in slow moving stream followed by ponds with vegetation. The breeding sites infested with Chara and Spirogyra algae were most favourable whereas, with Lemna and Oscillatoria were unfavourable for the proliferation of this species. The breeding association of An. philippinensis was found with other seven anopheline species in different breeding habitats.

Animals↗
PubMedDate not supplied

Evaluation of botanicals as repellents against mosquitoes.

Repellent properties of three plant extracts--essential oil (steam distillate) of Zanthoxylum limonella (fruits), Citrus aurantifolia (leaf) and petroleum ether extract of Z. limonella (fruits) were evaluated as repellent against Aedes (S.) albopictus mosquitoes in mustard (Dhara) and coconut (Parachute) oil base under laboratory conditions. Three concentrations--10, 20 and 30% of the repellents were evaluated. Repellents in mustard oil afforded longer protection time against the bites of Aedes (S.) albopictus mosquitoes than those in coconut oil. At 30% concentration, 296-304 min protection time was achieved by the test repellents in mustard oil base while repellents in coconut oil exhibited 223.5-245 min protection time at the same concentration. Oil of Z. limonella gave the highest protection time against the bites of Aedes (S.) albopictus mosquitoes at all the concentrations than other herbal repellents tested both in mustard and coconut oil.

Aedes↗
PubMedDate not supplied

Causes and effective management of insect bites in the UK.

Insects play an important role in maintaining the world's ecosystem (Zhu and Stiller, 2002) but many of them feed on other animals. Humans are relatively hairless and provide an easy target, especially when partly clothed (Cohn, 2003). Biting insects common to the UK include midges, gnats, mosquitoes, flies, fleas, lice, mites, ticks, and bedbugs (Fig 1).

Animals↗
PubMed2004

Seasonal abundance, vector behavior, and malaria parasite transmission in Eritrea.

Entomological studies were conducted over a 24-month period in 8 villages to establish the behavior patterns, seasonal densities, and variation in entomological inoculation rates (EIRs) of Anopheles arabiensis, the main vector of malaria in Eritrea. A total of 5,683 anopheline mosquitoes were collected through indoor sampling (1,613), human-landing catches (2,711), and outdoor pit shelters (1,359). Overall, An. arabiensis was the predominant species at all of the study sites, with its population density increasing during the rainy season. Peak indoor-resting densities was observed during September and October. Human landing indices for An. arabiensis averaged 1.9 and 3.8 per person per night in October and September, respectively. Peak biting and landing rates occurred between 2000-2200 h and 0100-0300 h. Of the total number of bites, 44.7% occurred between 1800 and 2300 h, and at least 56.5% of the total bites occurred outdoors, indicating that the species was partially exophagic. The fed to gravid ratio for An. arabiensis in indoor-resting collections was 2:1, indicating some degree of exophily. The sporozoite rates (SRs) for An. arabiensis ranged from 0.54% in the Anseba zone to 1.3% in the Gash-Barka zone. One mosquito each of An. d'thali (SR = 0.45%) and An. cinereus (SR = 2.13%) was found to be positive. Of the total positive An. arabiensis (n = 64), 18.2% came from human-landing collections outdoors. Blood-meal analysis by enzyme-linked immunosorbent assay for An. arabiensis indicated that this species was partially zoophilic with a human to bovine ratio of 2:1 being recorded. The EIR profiles indicated that malaria transmission is highly seasonal, increasing during the wet season and declining drastically during the dry season. On average, the greatest risk of infection occurs in Hiletsidi, in the Gash-Barka zone (6.5 infective bites per month). The exophilic behavior and early evening biting of An. arabiensis present obstacles for control with treated bed-nets and indoor residual spraying within the context of integrated malaria control, and call for greater focus on strategies such as larval control.

Animals↗
PubMed2004

Does anything beat DEET?

In comparison trials, DEET is more effective than any other insect repellent. Despite some reports of serious adverse events, when comparing the thousands of other reports of exposure and millions of past users, DEET has a good safety record. The appropriate and safest concentration to use on children remains unclear, however. Due to potential absorption through the skin, prudence would dictate that the lowest effective concentration for the time period of exposure be used. Because research has shown that solvents with less skin permeation may be used as an alternative to the ethanol used in some commercial DEET preparations, manufacturers could develop products that are less likely to be absorbed. Pediatricians should be familiar with the duration of action of various formulations of DEET and the efficacy (and in some cases lack of efficacy) of other products in order to advise patients on safe but effective methods of insect control.

Animals↗
PubMed2004

Comparative efficacy of IR3535 and deet as repellents against adult Aedes aegypti and Culex quinquefasciatus.

Arm-in-cage laboratory evaluations of 2 proprietary formulations of the mosquito repellents IR3535 and N,N-diethyl-3-methylbenzamide (deet; aqueous cream, hydroalcoholic spray) were made with 10 and 20% concentrations of each repellent. Also, 4 commercially available products containing IR3535 (Expedition insect repellent 20.07% active ingredient [AI], Bug Guard Plus with SPF30 sunscreen 7.5% AI, Bug Guard Plus with SPF15 sunscreen 7.5% AI, and Bug Guard Plus 7.5% AI) were tested. All comparisons were made on an equal formulation or concentration basis. Eight volunteers tested all formulations or products 3 times against laboratory-reared, Aedes aegypti and Culex quinquefasciatus mosquitoes (6-10 days old). Products were applied to a forearm at the rate of 0.002 g/cm2. The other forearm was not treated and served as a control. Elapsed time to 1st and 2nd consecutive bite was recorded. Mean protection time (i.e., time to 1st bite) with proprietary formulations of IR3535 were comparable to those of deet, with 20% concentrations providing greater protection against Ae. aegypti (3 h) and Cx. quinquefasciatus (6 h). Mean protection time for commercial products containing IR3535 ranged from nearly 90 to 170 min for Ae. aegypti and 3.5 to 6.5 h for Cx. quinquefasciatus. Mean time to the 2nd bite was similar to time to 1st bite for each mosquito species, product, and formulation.

Aedes↗
PubMedDate not supplied

[Nocturnal biting activity of mosquitoes (Diptera, Culicidae) in Volgograd and its environs].

The nocturnal biting activity of mosquitoes was investigated by a Berezansev's bell and bird traps as baits in August 2003. Among 7 man-attacking species, C. modestus, C. pipiens, and Coq. richiardii were most abundant. C. pipens showed two peaks of biting activity at night while both C. modestus and Coq. richiardii displayed one peak of this activity. Bird traps attracted the mosquitoes C. pipiens and C. modestus. The results are discussed in terms of the possible involvement of the above species in the transmission of WNF virus in Volgograd and its environs.

Animals↗
PubMedDate not supplied

[Synanthropic fleas (Siphonaptera) biting people in Moscow and control of their size].

The species composition of fleas attacking man in Moscow, the time course of changes in their size, and the efficiency of disinfecting measures against them have been studied. The basement premises are the commonest habitat of fleas. The absolute predominant species in these biotopes are Cetenocephalides felis (Boushe) whose feeders are dogs, synanthropic rodents, and humans, other than cats. Micropopulations of the fleas have been existed in some structures for more than 5 years (a follow-up period). A mathematical analysis of the factors that influence the efficiency of disinfestation has established that the most influential factors were the factors associated with the poor state of basement premises (the presence of a substrate for the breeding and shelter of fleas, the possibility of homeless animals and rodents, the feeders of fleas, to penetrate there) that reduce the residual effect of insecticides. Out of 15 applied insecticides, those based on chlorpyrifos, cypermethrin, and fenvalerate showed the highest efficacy. The combined use of liquid and powered insecticides is most effective in disinfestation. The treatments made in the periods when the number of fleas is small in the basements (April-May and August-September) provide the most prolonged residual effect.

Animals↗