Epidemiology of rotavirus in greater Cairo

Rotaviruses are a major cause of gastroenteritis in children worldwide. This study was carried out to determine the incidence of rotavirus infection among children and the genotypes circulating in Greater Cairo. During May 2006 to April 2008 one hundred and sixty eight wastewater samples and five hundreds and sixty seven stool specimens from children with acute diarrhea were examined using RT-PCR and multiplex nested PCR for genotyping. Prevalence of rotavirus reached 162/567 [28.6%] and 10/48 [20.8%] in fecal specimens and raw wastewater samples, respectively. A marked occurrence of rotaviruses appeared during autumn and winter [from Sept. to Feb.]. In stool samples, the G-P type combination were G1P[4] 14.8%, G1P[6] 9.9%, G3P[4/ ] 9.9% and G3P[6] 8, 6%, while in wastewater samples G1P[4] 20.6%, and G3P[4] 5.9% were only detected. The efficiency of Zenin wastewater treatment plant [WWTP] to remove infectious rotavirus was higher than El Gabal El Asfar [WWTP] as the former uses a final chlorination step. The time needed for complete removal of the rotavirus infectious units and its genome was 15 and 30 mm, respectively when exposed to UV Lamp[Vilber-Lour mat T-15c] 9W and a virus concentration of 2x 106 CC-RT-PCR units/ml, The chlorine dose 15 mg for 30 mm is sufficient to remove the infectious units of rotavirus at 2x106 CC-RT-PCR units /ml, while the same dose for 45 mm is needed for complete removal of the rotavirus genome. The antiviral activity of a pigenin 7-o-glucoside [extracted from Chrysanthemum coronarium] against rotavirus was 60%

Microbiological assessment of sludge treatment at the 6[th] October wastewater treatment plant, Giza, Egypt

This study was carried out to assess the sludge treatment processes applied at the 6[th] October wastewater treatment plant [WWTP], Giza, Egypt. The applied processes included aerobic digestion followed by gravity thickening, filter-pressing and drying beds [in emergency cases]. Bacteriological, virological and parasitological evaluation was carried out. Results showed that aerobic digestion removed two log units of total and faecal coliforms and one log unit of Escherichia coli [E. coli] and feacal streptococci. The removal percentages of coliphage and enteroviruses after aerobic digestion were 97.0 and 58.3%, resectively. The salmonellae disappeared from sludge after aerobic digestion. Qualitative and quantitative decrease in helminth ova [Ascaris, Trichuris, Trichostrongylus, Taenia and Hymenoleois] was observed after aerobic digestion and thickening stages. An average decreae of 4 log units for total and faecal coliforms, 3 log units for each of faecal streptococci and coliphage and 2 log units for E. coli through sludge treatment process was observed. Enteroviruses, helminth ova and enteric protozoa were completely eliminated from sludge after 6 months in drying beds. The loads of faecal coliform, E coli, faecal streptococci and coliphage in the dried sludge were 6.5 x 10[2], 1.6 x10[2], 4.5 x 10[2], 4.56 x 10[2] cfu and 8.5 x 10[1] pfu/g, respectively. Microbiological quality of the final treated sludge complied with the regulations of Untied States Environmental Protection Agency

Enteroviruses in sewage: comparison od different technologies for waste water treatment and reuse

Seven wastewater treatment plants were twice sampled to compare their different technologies for the removal of enteroviruses. These technologies are extended aeration, oxidation ditch, stabilization pond, aerated stabilization pond, submerged fixed film reactor, trickling filter and trickling filter followed by activated sludge in El-Serw, El-Rahamna, El-Adliya, Daqahla, El-Barashiya, Sohag and El-Fayoum wastewater treatment plants, respectively. Virus counts of raw sewage ranged between 2.7x10[3] and 20x10[3] PFU/L and for treated effluents was between 0 and 6x10[3]. The percentage of virus removal was varied where trickling filter and tickling filter followed by activated sludge reduced virus counts by 95.7 and 99.9, respectively. Extended aeration removed 64.2%, oxidation ditch 66.5%, stabilization pond 44.9%, aerated stabilization pond 13.34%, and submerged fixed film reactor removed 53.4%. The neutralization test revealed five types of enteroviruses, Poliovirus types 1, 2 and 3 and Coxsackievirus types B[4] and B[5]. The isolated polioviruses were vaccine strains. From the frequency distribution of the detected viruses, poliovirus type 2 was the most dominant