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Acute pesticide poisoning in England and Wales.

Between 1979 and 1983 less than 1% of admissions from acute poisoning in the UK were due to pesticides and fewer than 4% of admissions in those under 5 years were from this cause. Organochlorine, organophosphorus and carbamate insecticides account for only 10% of the total in both children and adults. Suspected pesticide poisoning was the cause of fewer than 0.3% of home accidents in those under 10 years of age and less than 4% of suspected poisonings documented by the Home Accident Surveillance System. Rodenticides were thought to be involved in 62% of these cases. Of children who presented to hospital 42% were admitted and 93% of these were discharged home within 2 days. In the UK, the morbidity from acute pesticide poisoning in children is low and the mortality is nil and there is therefore no evidence to support the view that paediatric pesticide intoxication is a significant clinical problem. Though no fatalities were recorded in children, pesticides were responsible for 1.3% of all deaths due to poisoning in the UK between 1979 and 1983. In adults admitted to hospital, the mortality from pesticide poisoning is approximately 12% and three quarters of these deaths are due to the deliberate ingestion of paraquat. The general term pesticide refers to a group of products that are used as insecticides, acaricides, fungicides, herbicides, rodenticides, and plant growth agents. Chemically, the group includes bipyridilium compounds, carbamates, chloralose, chlorates, coumarins, dinitro compounds, dithiocarbamates, fluoroacetates, organochlorine organophosphorus and organotin compounds, pentachlorophenol, phenoxyacetates, phosphine (as magnesium and aluminium phosphides), pyrethrins, pyrethroids and triazines.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

Illnesses associated with use of automatic insecticide dispenser units--selected states and United States, 1986-1999.

To control indoor flying insects, restaurants and other businesses commonly use pyrethrin and pyrethroid insecticides sprayed from automatic dispensing units. Usually placed near entrances, these units are designed to kill flying insects in food service or work areas. On May 18, 1999, the Florida Department of Health (FDH) was notified by the Florida Department of Business and Professional Regulation (DBPR) that during May 12-17, three persons developed pesticide-related illnesses associated with improperly placed automatic insecticide dispensers. After FDH conducted a follow-up investigation and notified CDC's National Institute for Occupational Safety and Health (NIOSH) of this event, surveillance data were reviewed to identify additional cases of pesticide-related illnesses associated with automatic insecticide dispensers. Data were provided by the Toxic Exposure Surveillance System (TESS), the California Department of Pesticide Regulation (CDPR), the Montana Department of Agriculture (MDA), the National Pesticide Telecommunications Network (NPTN), and the Washington State Department of Health (WSDH)*. This report describes cases, summarizes surveillance data for pesticide-related illnesses associated with automatic insecticide dispensers, and provides recommendations for safe dispenser use.

Adolescent↗

Chrysanthemum allergy. Pt. II: Experimental studies on the causative agents.

Experimental studies on allergic contact dermatitis due to Chrysanthemum indicum 1. (Chrysanthemum x-morifolium) (chrysanthemum of the florists) have indicated the following results: 1. In 5 patients with allergic contact dermatitis from chrysanthemum oil of turpentine and its sensitizing compounds gave no patch test responses. No relationship between contact allergy due to chrysanthemus and to turpentine oil could be determined. 2. The pyrethrins, constituents with insecticidal activity, derived from certain Chrysanthemum species and often suspected as the causative agents, play no role in chrysanthemum allergy. 3. Tests on sensitized guinea pigs (pirl bright white strain) with flowers of chrysanthemum as well as with the two sesquiterpene lactones parthenolide and alantolactone, derived from different Composite species, gave positive patch test reactions. The results showed that parthenolide produced stronger reactions than alantolactone. 4. By thin layer chromatography neither parthenolide, nor alantolactone or pyrethrosin could be detected in extracts of chrysanthemum flowers of the florists. But the investigations indicated that several other terpenic compounds are present, which gave positive color reactions to certain lactone reagents. Five of them showed strong positive patch test reactions in our patients as well as in sensitized guinea pigs. Further studies are required to identify these compounds.

Adjuvants, Immunologic↗

Efficacy of Australian quarantine procedures against the mosquito Aedes aegypti.

Methods employed by Australian quarantine officers to control Aedes mosquitoes in containers were tested against all stages of Aedes aegypti. Saltwater emersion killed all larvae but not pupae or eggs that were briefly exposed. Swimming pool chlorine, methyl bromide fumigation, and permethrin (2% active ingredient) spray provided 100% mortality of eggs, larvae, and pupae. Aerosol sprays incorporating synthetic pyrethrins are practical and also provide effective control of adults.

Aedes↗

Recognition and management of acute pesticide poisoning.

Most poisonings from pesticides do not have a specific antidote, making decontamination the most important intervention. For maximal benefit to the patient, skin, eye, and gastric decontamination should be undertaken while specifics of the poisoning are being determined. As in most illnesses and injuries, the history of the poisoning is of great importance and will determine specific needs for decontamination and therapy, if any exist. Protection of health care workers during the decontamination process is important and frequently overlooked. Skin decontamination is primarily accomplished with large volumes of water, soap, and shampoo. Gastric decontamination by lavage is indicated if ingestion of the poisoning has occurred within 60 minutes of patient presentation. Activated charcoal, combined with a cathartic, is also indicated in most poisonings presenting within 60 minutes of ingestion. With large volume ingestion poisonings, activated charcoal may be used after 60 minutes, but little data exist to support this practice. Syrup of ipecac is no longer recommended for routine use. The cholinergic syndrome "all faucets on" characterizes poisoning by organophosphates and carbamates. Organochlorine insecticides (lindane and other treatments for scabies and lice) can produce seizures with excessive use or use on large areas of nonintact skin. Non-dipyridyl herbicides, biocides (including pyrethrins, pyrethroids, and Bacillus thuringiensis) rarely produce anything other than mild skin, eye, and/or gastrointestinal irritation on topical exposure or ingestion.

Acute Disease↗

American Academy of Pediatrics guidelines for the prevention and treatment of head lice infestation.

The American Academy of Pediatrics (AAP) established diagnosis and treatment guidelines for pediculosis in 2002. Ideally, diagnosis should be based on the observation of a live louse. The presence of nits is also used by many people to positively diagnose an infestation, although a nit located farther from the scalp than 1 cm is unlikely to be viable. Other material on the scalp may be mistaken for nits, leading to misdiagnosis. Because lice are not associated with serious medical problems, the primary consideration of the AAP regarding treatment is the safety of pediculicides and other products used to treat head lice. From a pediatrician's perspective, no significant risk is acceptable. Over-the-counter (OTC) pyrethroid products (pyrethrin and permethrin) are commonly used by parents to treat their children and are generally considered safe for most people. Pyrethroids are not completely ovicidal, however, so a second application is required. Misuse and overuse of these products have contributed to the development of resistance. Prescription products include permethrin 5%, lindane, and malathion 0.5%. Resistance to permethrin 5% and lindane has been documented. In addition, lindane is associated with serious adverse events and should be used with caution only in a select population. Malathion 0.5% is about 98% ovicidal, and no resistance has been reported. Malathion is highly effective, but AAP guidelines note that the product is flammable and serious adverse effects can occur with ingestion. Very few cases of ingestion have occurred, and no reported cases of flammability, but children being treated with malathion should be carefully supervised, and this pediculicide should not be used unless treatment with OTC products has failed. AAP guidelines also state that no-nit policies in schools are detrimental, causing lost time in the classroom, inappropriate allocation of the school nurse's time for lice screening, and a response to infestations that is out of proportion to their medical significance. Accurate diagnosis, safe treatment options, and a common-sense approach to managing infestations in schools are recommended.

Animals↗

Effects of onboard insecticide use on airline flight attendants.

Flight attendants (FAs) exposed to insecticide spray in an aircraft were compared with unexposed subjects for neurobehavioral function, pulmonary function, mood states, and symptoms. The 33 symptomatic FAs were self-selected, and 5 had retired for disability. Testing procedures included balance, reaction time, color discrimination, visual fields, grip strength, verbal recall, problem solving, attention and discrimination functions, and long-term memory functions. Measurements were expressed as a percentage of their predicted values (derived from unexposed controls), and the author compared the means of the percentage predicted values by analysis of variance. Symptom frequencies and Profile of Mood States (POMS) scores were assessed. FAs were significantly more impaired than controls with respect to balance with eyes closed, grip strength, and color discrimination. Nearly half had 3 or more abnormal neurobehavioral functions, after adjustment was made for age, sex, and education level. Neither elevated POMS scores nor frequencies of average symptoms correlated with their numbers of abnormal measurements. Occupational exposure to synthetic pyrethrin insecticides on airliners was associated with neurobehavioral impairment and disability retirement.

Adult↗

[The control of storage mites in the mycological laboratory].

Mycological cultures in the laboratory are threatened by storage mites who feed on fungi and cause contamination by transferring bacteria and fungi from culture to culture. To eliminate mites from fungal cultures without damage to the fungi themselves several chemical and physical procedures were tested. The following substances were added to Sabouraud glucose (2%) agar at concentrations of 0.1 and 1.0%: gamma benzene hexachloride (lindane), N-ethyl-o-crotonyltoluide, pyrethrins, dieldrin N,N-diethyl-m-toluamide, benzyl benzoate, and--as popular household remedies--Eau de Cologne, neutral soap and garlic. The media were inoculated with 4 dermatophytes (T. rubrum, T. mentagrophytes, M. gypseum and E. floccosum). Two to three weeks later the fully grown cultures were contaminated with mites and their eggs. In other test series, mite infested cultures were exposed to heat (40 degrees C and 60 degrees C) or cold from -12 degrees C to -28 degrees C over different periods of time. Finally, the protective value of sealing culture dishes with adhesive tape was investigated. The most useful method to control mite infestation in fungal cultures seemed to be exposure to heat over a short time.

Animals↗

Sexually transmitted parasitic diseases.

Sexual activity is the primary method of transmission for several important parasitic diseases and has resulted in a significant prevalence of enteric parasitic infection among male homosexuals. The majority of parasitic sexually transmitted diseases involve protozoan pathogens; however, nematode and arthropod illnesses are also included in this group. Trichomoniasis, caused by Trichomonas vaginalis, is the most common parasitic STD. Infection with this organism typically results in the signs and symptoms of vaginitis. Trichomoniasis can be diagnosed in the office setting by performing a microscopic evaluation of infected vaginal secretions and can be successfully treated with metronidazole. Both pediculosis pubis, caused by the crab louse Pthirus pubis, and scabies, caused by the itch mite Sarcoptes scabiei, present with severe pruritus. A papular or vesicular rash and linear burrows seen in the finger webs and genital area are characteristic of scabies. Pediculosis pubis is diagnosed by observing adult lice or their nits in areas that bear coarse hair. The diagnosis of scabies is confirmed by scraping suspicious burrows and viewing the mite or its byproducts under the microscope. Lindane, 1% used in treating scabies, is also very effective for treating pediculosis pubis. Synthetic pyrethrins, also applied as a cream or lotion, are less toxic alternatives for the treatment of either condition. Oral-anal and oral-genital sexual practices predispose male homosexuals to infection with many enteric pathogens, including parasitic protozoans and helminths. The most common of these parasitic infections are amebiasis, caused by Entamoeba histolytica, and giardiasis caused by Giardia lamblia. Both entities may cause acute or chronic diarrhea, as well as other abdominal symptoms. Most gay men with amebiasis are asymptomatic, and invasive disease in this group is extremely rare. Both amebiasis and giardiasis can be diagnosed on the basis of microscopic examination of stool specimens, although duodenal aspiration is occasionally necessary to confirm a diagnosis of giardiasis. Multiple treatment regimens exist for amebiasis. Iodoquinol is a good choice for asymptomatic cyst carriers, whereas the combination of metronidazole plus iodoquinol is used for symptomatic patients. Quinacrine and metronidazole are both efficacious in the treatment of giardiasis.

Amebiasis↗

Scabies.

Scabies is a mite infestation caused by Sarcoptes scabiei. Varieties of this organism can produce disease on 40 different species of animal, including humans. The organisms mature, burrow, and lay eggs. The newly hatched larvae mature and mate on the skin, causing itching and excoriated papules on humans, and mange, with crusts and oozing, on hair-bearing animals. Treatment with the gamma isomer of hexachlorobenzene or with pyrethrins is effective. Care must be taken that all infected or exposed individuals are treated. The role of fomites in the transmission of the disease is not clear. Most cases seem to be transmitted by close personal contact.

Animals↗

Pesticide exposures and other agricultural risk factors for leukemia among men in Iowa and Minnesota.

Mortality surveys and death certificate studies have suggested an association between leukemia and farming. To investigate whether exposure to carcinogens in an agricultural setting is related to risk of leukemia, the authors conducted a population-based case-control interview study of 578 white men with leukemia and 1245 controls living in Iowa and Minnesota. Consistent with recent mortality studies, there were slight, but significant, elevations in risk for all leukemia [odds ratio (OR) 1.2] and chronic lymphocytic leukemia (OR 1.4) for farmers compared to nonfarmers. There were no significant associations with leukemia for exposure to specific fungicides, herbicides (including 2,4-D and 2,4,5-T), or crop insecticides. However, significantly elevated risks for leukemia of greater than or equal to 2.0 were seen for exposure to specific animal insecticides including the organophosphates crotoxyphos (OR 11.1), dichlorvos (OR 2.0), and famphur (OR 2.2) and the natural product pyrethrins (OR 3.7) and the chlorinated hydrocarbon methoxychlor (OR 2.2). There were also smaller, but significant, risks associated with exposure to nicotine (OR 1.6) and DDT (OR 1.3). This finding of elevated risks for insecticides used on animals deserves further evaluation.

Agricultural Workers' Diseases↗

Comparative efficacy of treatments for pediculosis capitis infestations.

Ovicidal activity and killing times were evaluated for six pediculicides, using viable eggs and recently fed head lice from infested children. Lice were continuously exposed to the products until death, and elapsed time was recorded. Eggs were immersed for ten minutes, rinsed, and dried. Four synergized pyrethrin products (RID, R&C Shampoo, A-200 Pyrinate Shampoo, A-200 Pyrinate Liquid) killed all lice in ten to 23 minutes, and 23% to 32% of treated eggs hatched; 0.5% malathion lotion (Prioderm Lotion) killed lice within five minutes and was highly ovicidal, with only 5% of eggs hatching. One percent lindane shampoo (Kwell Shampoo) was the slowest-acting pediculicide, requiring approximately three hours to kill all lice; 30% of the eggs hatched after treatment. The in vitro results for RID, Prioderm Lotion, and K well Shampoo were validated by clinical trials.

Child↗

The locus of inhibition of NADH oxidation by benzothiadiazoles in beef heart submitochondrial particles.

6-Chloro-1,2,3-benzothiadiazole (6-Cl-BTD) is an effective inhibitor of NADH oxidase (site I) but not of succinate oxidase in beef heart submitochondrial particles. For NADH oxidase activity maximal inhibition (80-85%) was achieved at 0.75mM 6-Cl-BTD. A similar level of inhibition was also observed (half maximal inhibitory concentration 0.5mM) towards NADH-duroquinone reductase; NADH-juglone reductase was slightly inhibited (23%) at 0.5mM 6-Cl-BTD while NADH-ferricyanide reductase was unaffected. The data suggest that 6-Cl-BTD interacts with an electron transport site on the oxygen side of NADH dehydrogenase and inhibitory studies with 6-Cl-BTD and rotenone indicate that it might correspond with one of the two sites affected by rotenone. The substituted 1,2,3-benzothiadiazoles (BTDs) are perhaps best known for their activity as inhibitors of cytochrome P-450-mediated mixed-function oxidation (MFO). In vitro, the BTDs are potent inhibitors of MFO activities in microsomes from mammalian liver and insect tissues and they have been demonstrated to inhibit aminopyrine metabolism in perfused rat liver. In vivo, they reportedly prolong hexobarbital sleeping time in mice, inhibit the irreversible binding of labeled trichloro-ethylene to microsomal protein and effectively enhance the toxicity (synergize) of pyrethrin, organophosphorus-containing and carbamate insecticides to insects.

Animals↗

A general noninteractive multiple toxicity model including probit, logit, and Weibull transformations.

A multiple toxicity model for the quantal response of organisms is constructed based on an existing bivariate theory. The main assumption is that the tolerances follow a multivariate normal distribution function. However, any monotone tolerance distribution can be applied by mapping the integration region in the n-dimensional space of transforms on the n-dimensional space of normal equivalent deviates. General requirements to noninteractive bivariate tolerance distributions are discussed, and it is shown that bivariate logit and Weibull distributions, constructed according to the mapping procedure, meet these criteria. The univariate Weibull dose-response model is given a novel interpretation in terms of reactions between toxicant molecules and a hypothetical key receptor of the organism. The application of the multiple toxicity model is demonstrated using literature data for the action of gamma-benzene hexachloride and pyrethrins on flour beetles (Tribolium castaneum). Nonnormal tolerance distributions are needed when the mortality data include extreme response probabilities.

Analysis of Variance↗

The relationship between the structure and the activity of pyrethroids.

There is considerable scope for developing new non-persistent insecticides with little hazard for man and mammals by modifying the structures of the natural pyrethrins. New compounds already synthesized are more effective against some insect species than are the natural compounds, are even less hazardous to mammals, and do not need synergists to supplement their insecticidal action. Other examples show considerable insect species specificity. These compounds may help to control insect vectors when other insecticides are no longer effective because resistance has developed or because their residues can no longer be tolerated.

Animals↗

Trombiculosis in a cat.

Trombiculosis (dermatitis caused by trombiculid mites) in a Domestic Shorthair cat was characterized by diffuse thickening and crusting of the skin of the abdomen and limbs and by multiple papules on the face, ears, and sides of the trunk. Skin biopsy revealed acanthosis and hyperkeratosis involving the epidermis and hair follicles, mites in epidermal tunnels, and edema of the dermis, with infiltration of eosinophils and mast cells. Mites from skin scrapings were identified as Walchia americana. The cat was treated systemically with a broad-spectrum antibiotic and topically with a carbaryl and pyrethrin powder preparation. The lesions were resolved within 2 months.

Animals↗

Second survey of insecticid-resistance in body-lice, 1958-63.

Between 1953 and 1956 the World Health Organization carried out a global survey of the susceptibility of body-lice to insecticides. A second survey was organized in 1958; this paper summarizes the results of susceptibility tests done in 22 countries over the period 1958-63.Resistance to DDT has been found in a number of countries. The LC(100) for resistant body-lice has been found to be over 5% DDT, the LC(100) for hybrids to be between 1% and 5% DDT; and the LC(50) for susceptible genotypes has been estimated to be less than 0.04% DDT.Body-lice continue to be susceptible to gamma-HCH and pyrethrins in most countries, although they show increased tolerance to gamma-HCH in Egypt. Their susceptibility to malathion in various localities in Egypt has been assessed, and the LC(50) found to range from 0.02% to 0.032%.

Insecticide Resistance↗