West Nile virus existence in humans and mosquitoes in Alexandria Governorate

West Nile virus [WNV] is a zoonotic mosquito-transmitted arbo-virus belonging to the genus flavivirus in the family Flaviviridae. The aim of the present study was to determine the role of WNV in human cases with fever of unknown etiology and to study the immune status to WNV among healthy humans. In addition, the prevalence of WNV in Culex mosquito vectors was estimated. The study included 210 patients [with undiagnosed acute febrile illness for more than 2 days; admitted to Alexandria Fever Hospital during a period of one year], 200 healthy humans [volunteer blood donors accepted for donation at Alexandria Regional Blood Bank] and 200 mosquito pools [from six administrative districts of Alexandria]. WNV antibodies of the 1gM and lgG types were detected in patients and healthy humans using enzyme linked immunosorbent assay [ELISA], respectively. WNV was detected in mosquito by virus isolation on Vero cell culture. WNV 1gM antibodies were detected in 56 [26.7%] patients, while WNV lgG antibodies were detected in 42 [21%] out of the 200 healthy humans. WNV was isolated from 27 [13.5%] out of the 200 mosquito pools. Patients in the age groups 20- and 40- had the highest percentages of WNV 1gM antibodies. The highest WNV gM antibodies positivity rates occurred in spring and in fall seasons. Male samples had significantly higher percentage of the IgG antibodies than female samples [25.6%Vs 13.3%]. Conclusion: WNV should not be overlooked in diagnosis of fevers as the main problem may be not due to the disease itself but the economic consequences from the hospitalization of indeclinable numbers of patients. WN disease can be difficult to monitor; almost unpredictable and appearing unexpectedly, this disease has to be surveyed and the viral circulation rapidly detected so that the sanitary authorities can take protective measures

Monitoring of housefly [Musca domestica] population abundance in Alexandria governorate and assessment of its susceptibility towards some commonly used insecticides

This study was conducted to monitor the housefly "Musca domestica" population abundance in different districts of Alexandria Governorate throughout one year from January to December 2002. Also, it determined the susceptibility of housefly against different currently used insecticides by Ministry of Health and Population [namely malathion and azamethiphos against adults and chlorpyriphos against larvae]. In addition, it evaluated the effect of a botanical compound; neem oil against both adults and larvae as an alternative insecticide. The data demonstrated that the highest housefly abundance was observed in El-Amreya and West Districts with mean grid count of 75.0 +/- 40.8 and 72.9 +/- 46.3, respectively. The lowest housefly abundance was observed in Borg El-Arab and East Districts with mean grid count of 37.7 +/- 19.7 and 39.5 +/- 28.1, respectively. The order of housefly population abundance in different districts of Alexandria Governorate was as follows: El-Amreya > West > El-Montaza > Middle > El-Gomrok> East> Borg El-Arab. Also, the abundance of housefly was greatly affected by temperature fluctuation where there were two peaks observed in Spring and Autumn while there were two depressions in Summer and Winter. There was a negative significant correlation between housefly abundance and both shadow and wind. As regards the susceptibility of housefly towards tested insecticides, the LD[50] of malathion against adult insect using topical application for laboratory strain was 0.0199 mg/fly while in case of field strain, it was 0.0363 mg/fly [1.824 times more than that of laboratory strain]. As regards azamethiphos using diet treatment, the LC50 for laboratory strain was 0.0281% while it was 0.0312% for field strain [1.11 times more than that of laboratory strain]. The EC50 of chloropyriphos using diet treatment against first instar larvae of field strain of housefly was 3.50 ppm. The most prominent toxic effect of neem oil emulsion was noticed in larval stage where EC[50] for laboratory strain was 1982.9 ppm, while it was 2045.3 ppm for field strain. Neem oil had no toxic effect on adult housefly by either topical application or diet treatment. In conclusion, the study reports no resistance of housefly against the tested compounds

Pediculicidal activity of certain plant essential oils against head lice pediculus humanus capitis

This paper reports the pediculicidal activity of certain monoterpenoids of plant essential oils compared to several anti-head lice formulations. It also reports the molecular features required for a chemical to kill head lice. Live adult Pediculus humanus capitus were collected from children living in the Qabary area, Alexandria, Egypt and used in in vitro bioassays. The data demonstrated that the commercial formulation, Quick [0.5% malathion] was the most potent formulation against head lice, while Para plus was the least potent. It was clear that the potency of the tested monoterpenoids was at least similar to Quick. The data also revealed that, monoterpenoid phenols and alcohols were more potent against head lice than monoterpenoid aldehydes, esters and acyclic monoterpenoids. One of the molecular features that is evidently important for monoterpenoid toxicity against head lice is the presence of electronegative group such as a hydroxyl group. In conclusion, this study reports an alternative chemical control that is safer, and more effective against head lice