Operational use of neem oil as an alternative anopheline larvicide. Part A: Laboratory and field efficacy.

We conducted a study to determine the laboratory and field efficacy of neem oil towards anopheline larvae. No difference in LC50 was observed between laboratory and field strains for temephos, chlorpyriphos-methyl/fenitrothion and neem oil. No difference in susceptibility was found after 3 months of application every 2 weeks. Water treated with a single application of traditional larvicides was free of larvae after 4 weeks; neem oil-treated water, however, was free after 2 weeks but not at 4 weeks. Application of chlorpyriphos-methyl/fenitrothion and neem oil every 2 weeks for 7 rounds resulted in dramatic reduction in larval density with no statistically significant differences. An adult survey after larviciding also showed no significant difference. The efficacy of crude neem oil appears to be below that of conventional larvicides.

Operational use of neem oil as an alternative anopheline larvicide. Part B: Environmental impact and toxicological potential.

This study was conducted to investigate the preliminary environmental and mammalian toxicology of neem oil, temephos and chlorpyriphos-methyl/fenitrothion. Culex pipiens, Daphnia magna and Gambusia affinis were used to study environmental impact. A high level of toxicity was observed, with slight differences between organisms. The emulsifiers individually also displayed toxicity towards the tested organisms. Up to 90 days daily oral crude neem oil treatment (5 g/kg body weight) of laboratory mice did not cause any significant changes in weekly body weight gain, nor in serum liver damage indicators, direct bilirubin or total bilirubin. Blood parameters of treated mice up to 90 days were not statistically different from those of control mice. Neem oil could be used as an environmentally friendly alternative to the traditional chemical anopheline larvicides.

Operational use of neem oil as an alternative anopheline larvicide. Part B: environmental impact and toxicological potential

This study was conducted to investigate the preliminary environmental and mammalian toxicology of neem oil, temephos and chlorpyriphos-methyl/fenitrothion. Culex pipiens, Daphnia magna and Gambusia affinis were used to study environmental impact. A high level of toxicity was observed, with slight differences between organisms. The emulsifiers individually also displayed toxicity towards the tested organisms. Up to 90 days daily oral crude neem oil treatment [5 g/kg body weight] of laboratory mice did not cause any significant changes in weekly body weight gain, nor in serum liver damage indicators, direct bilirubin or total bilirubin. Blood parameters of treated mice up to 90 days were not statistically different from those of control mice. Neem oil could be used as an environmentally friendly alternative to the traditional chemical anopheline larvicides

Operational use of neem oil as an alternative anopheline larvicide. Part A: laboratory and field efficacy

We conducted a study to determine the laboratory and field efficacy of neem oil towards anopheline larvae. No difference in LC50 was observed between laboratory and field strains for temephos, chlorpyriphos-methyl/fenitrothion and neem oil. No difference in susceptibility was found after 3 months of application every 2 weeks. Water treated with a single application of traditional larvicides was free of larvae after 4 weeks; neem oil-treated water, however, was free after 2 weeks but not at 4 weeks. Application of chlorpyriphos-methyl/fenitrothion and neem oil every 2 weeks for 7 rounds resulted in dramatic reduction in larval density with no statistically significant differences. An adult survey after larviciding also showed no significant difference. The efficacy of crude neem oil appears to be below that of conventional larvicides

Reassessment of some environmental conditions of Maawa el-Sayadeen squatter area.

Reassessment of some environmental conditions of Maawa El-Sayadeen squatter area was carried out during 2000. Due to unplanned urbanization, environmental sanitation has been ignored for several decades resulting in many health, social and economic problems. Maawa El-Sayadeen was chosen by West District officials for environmental and health upgrading in 1995, which depended mainly upon health education in addition to some engineering constructions. The environmental conditions and health status were reporded before 1995 and after 2000. The reassessment proved that, there was an increase in number of families use tap water inside the house by 29% compared with 1995 assessment. Moreover, number of families using water closets increased by 15%, also wastewater disposal throught public sewers increased by 34%. However, a decrease by 17% in dry areas surrounding the houses was recorded. Solid waste storage improved by 11% although solid waste collection sites decreased by 23%. It is concluded that, after Maawa El-Sayadeen area was exposed to a certain level of environmental upgrading, the environmental conditions of the area were some how better categorized, however, further training programs should be taken into account or stressed including increase of people awareness, and strong partnership should be developed with their non governmental organizations.

Study on rodents infestation in Alexandria and prevalence of Trichinella spiralis infection among them.

Rodents were monthly collected from the six districts of Alexandria all year round using live traps. The 1025 collected rodents were divided according to species, gender, age, and weight El-Amryia and El-Montaza were the most infested districts, while West, East, Middle and El-Gomrok Districts were the lowest infested ones. Rallus norvegicus was the highest abundant species in the city (41.9%) followed by R. rattus (37.2%), then Mus musculus (20.9%). There was no difference in abundance of rodents during summer compared with winter. Meanwhile, males represented 57.6% of the total collected rodents. Most of the collected rodents were < or = 2 months old (63.8%) or light weighed (61.6%) however, number of caught rodents became less and less as age or weight increased. Concerning El-Amryia and El-Montaza Districts where abattoirs are located, number of collected rodents from and around the abattoirs represented 70.4% of the total collected rodents compared with 29.6% collected from and around the houses of the same districts. The total prevalence of T. spiralis infection among collected rodents using digestion technique was 13.3%. El-Amryia, El-Montaza, West and El-Gomrok Districts were, in order, the only infected districts. Neither gender nor season of collection has influence on the prevalence of infection. The present study proved the role of abattoirs in the prevalence of T. spiralis infection. However, high prevalence of T. spiralis infection was detected among higher age or higher body weight groups of rodents. Sensitivity of the digestion diagnostic technique is proved compared with compressorium diagnostic technique. Nevertheless, diaphragm was the most sensitive site for detection of light infection in all studied rodents followed by thigh then tongue; expressed as number of larvae per gram tissue.

Parasitological profile of the surveyed population for malaria in an endemic area in Faiyoum Governorate, Egypt.

Egypt represents the only focus in the Mediterranean region where Plasmodium falciparum transmission still occurs. A longitudinal parasitological study has been implemented (September 1995 to December 1996) in Faiyoum, Egypt. A total of 9065 blood slides for malaria parasites were taken from all people in the study area as mass blood examination (MBE); those attending the malaria unit as passive case detection (PCD) as well as from neighborhood of the detected cases (NOD). They were stained by Giemsa stain and examined under standard conditions for positivity, parasite species and parasite density. Our results show that MBE detected 61.5% of malaria cases while 23.1% and 15.4% of the confirmed cases were detected through PCD and NOD respectively. The overall parasite rate was 5.7/1000 examined population. P. falciparum was the most predominant species (96.1%), followed by P. vivax (3.9%). The epidemiological factors causing the persistence of malaria transmission in the study area are discussed.

Bionomics of the anopheline vectors in an endemic area in Fayoum Governorate, Egypt.

A one-year longitudinal entomological study was carried out at Kafr Fazara village, Sinnuris District, Faiyoum Governorate from January to December 1996. The results revealed that three species of anophelines were found. A. sergenti was the most prevalent species followed by A. multicolor and the least prevalent one was A. pharoensis. The influence of climatic conditions on anopheline abundance was also studied. The mean monthly temperature has a significant effect on larvae abundance, while no significant correlation was found concerning relative humidity or wind speed for both larvae and adult anophelines. The transmission season of P. falciparum in Faiyoum Governorate extended to more than eight months a year which could explain the persistence of malaria up there. The bionomics of the recorded vectors were discussed.

Influence of different means of washing and processing on removing of Actellic residue from spinach and eggplant and its in-vivo action on mice hepatic biochemical targets.

This study was carried out to investigate the effect of different washing solutions on the removal of Actellic residue from fresh and processed vegetables, namely; spinach and eggplant. Also, to identify the effect of Actellic residue on the health status of mice when fed these contaminated vegetables. The amount of insecticide residue detected using GLC indicated that, tap water, sodium hydroxide solution and potassium permanganate solution gave high percent removal. However, processing did not remove more than 45% except for grilling of eggplant which removed 88.17%. Meanwhile, changes in some hepatic biological parameters were well recognized in the groups of mice fed contaminated- unwashed either processed or unprocessed vegetables.

Molecular mechanism for the inhibition of acetylcholinesterase enzyme by organophosphorothionates.

The different mechanisms, whereby EPN and malathion inhibit the action of cholinesterase on acetylcholine, are described. Partially purified brain enzyme was used for the kinetic studies. The approach of the theory of Krupka and Laidler was followed. The ratio of [S]I opt/[S]opt = 1 + Ki [I] to the first power was found with malathion but to the square root of (1 + Ki [I]) 1/2 with EPN. The intercept on the slope axis of plots of slopes of (1/V not equal to [I]) against the reciprocal of substrate concentrations showed a non-zero value in the case of EPN and a zero value in the case of malathion. Accordingly, and based on the above theory, it seems that malathion acts as a competitive inhibitor of cholinesterase while EPN seems to be a mixed type inhibitor.

Identity of rat kidney and urine alkaline phosphatase actions and relation to the effect of nitrofuranfuradroxyl.

The activities of alkaline phosphatases of kidney and urine appear similar and identical in action. Both are magnesium-dependent and inhibited by higher concentrations of 2-glycerophosphate. A band of similar mobility is obtained on electrophoresis of kidney and urine enzymes. In vitro magnesium competitively inhibits their activities when the ratio of Mg-+2 ions/2-glycerophosphate is above a definite level. Their activities are not affected by exogenous zinc and follow the Michaelis-Menten equation only when attention is given to the ratio of Mg-+2 ions/substrate. Nitrofuranfuradroxyl is a mixed type inhibitor showing a second-order rate of reaction with kidney and urine phosphatases.