Transfer rates of enteric microorganisms in recycled water during machine clothes washing.

Approximately 15% of overall Australian household water usage is in the laundry; hence, a significant reduction in household drinking water demand could be achieved if potable-quality water used for clothes washing is replaced with recycled water. To investigate the microbiological safety of using recycled water in washing machines, bacteriophages MS-2 and PRD-1, Escherichia coli, and Cryptosporidium parvum oocysts were used in a series of experiments to investigate the transfer efficiency of enteric microorganisms from washing machine water to objects including hands, environmental surfaces, air, and fabric swatches. By determining the transference efficiency, it is possible to estimate the numbers of microorganisms that the user will be exposed to if recycled water with various levels of residual microorganisms is used in washing machines. Results, expressed as transfer rates to a given surface area per object, showed that the mean transfer efficiency of E. coli, bacteriophages MS-2 and PRD-1, and C. parvum oocysts from seeded water to fabric swatches ranged from 0.001% to 0.090%. Greatest exposure to microorganisms occurred through direct contact of hands with seeded water and via hand contact with contaminated fabric swatches. No microorganisms were detected in the air samples during the washing machine spin cycle, and transfer rates of bacteriophages from water to environmental surfaces were 100-fold less than from water directly to hands. Findings from this study provide relevant information that can be used to refine regulations governing recycled water and to allay public concerns about the use of recycled water.

Effectiveness of house dust mite acaricide tri-n-butyl tin maleate on carpets, fabrics and mattress foam: a standardization of methodology.

The aim of this study was to determine the effectiveness of the acaricide tri-n-butyl tin maleate, industrially applied to samples of carpets, mattress foam, and fabrics used for furniture upholstery, soft toys and shoe uppers. Approximately 100 adult house dust mites of the species Dermatophagoides pteronyssinus were inoculated into a Petri dish containing the sample (a piece of carpet, mattress foam, or fabric), treated with the acaricide, randomly collected. Mite-maintenance culture medium was added on top of each sample. After one, two, three, seven and 30 days of incubation at 25 degrees C and 75% relative humidity, each dish was examined using a 40X stereoscopic microscope (40X). One hundred percent acaricide effectiveness was obtained in treated materials by the end of the 30th-day postinoculation period, under optimal conditions for mite maintenance.

Effectiveness of house dust mite acaricide tri-n-butyl tin maleate on carpets, fabrics and mattress foam: a standardization of methodology

O objetivo do presente estudo foi verificar a eficácia do acaricida maleato de estanho tri-n-butílico, aplicado industrialmente em amostras de carpetes, tecidos de revestimentos de móveis e de calçados, assim como de espumas de colchão. Aproximadamente 100 ácaros adultos da espécie Dermatophagoides pteronyssinus foram inoculados em placa de Petri contendo a amostra (pedaço de colchão, tecido ou carpete), tratada com o produto acaricida, coletados aleatoriamente. Foi acrescentado sobre a amostra, meio de cultivo para a manutenção dos ácaros. Cada placa foi examinada após 1, 2, 3, 7 e 30 dias de incubação a 25 ºC e 75% de U.R.A. (umidade relativa do ar), sob microscópio estereoscópico com 40X de aumento. O acaricida maleato de estanho tri-n-butílico apresentou 100% de eficácia acaricida após 30 dias da aplicação, em condições ótimas para a manutenção dos ácaros.

Eliminating Dermatophagoides farinae spp. (Acari: Pyroglyphidae) and their allergens through high temperature treatment of textiles.

House dust mite allergens cause allergy and asthma in sensitized individuals. The allergens they produce are known to resist decay under natural household conditions and are thought to accumulate until removed. We sought to evaluate the effects of high temperature (96 degrees C) generated by a hard surface cleaner on live mite populations of American house dust mites, Dermatophagoides farinae Hughes and their allergens in carpet and mattresses. Statistically significant (P < 0.05) mite mortality (100%) was observed in response to treatment in both textile surfaces. Similar effects were observed on Der f1 fecal allergen. Allergen reductions in carpet with two or five pass treatment regimes were 61.4 and 100%, respectively. These results demonstrate the potential of employing a hard surface steam cleaner as a novel method to eliminate house dust mite populations and their allergens in a residential setting and appeal particularly promising as an environmental control strategy.

Body louse remains found in textiles excavated at Masada, Israel.

A leg of the body louse, Pediculus humanus humanus L. (Phthiraptera: Pediculidae), was found in a storeroom at Masada build during the reign of King Herod the Great. The unearthed culture material clearly indicates that the room was occupied by the rebels during the first Jewish revolt against the Romans (AD 66-73/4). The context of the textiles associated with the louse and their nature suggest a rebel origin. An exuvium of a leg of the third nymphal stage of body louse was found. The first three parts of the leg (tarsus, including the tarsal claw, tibia and femur) were preserved entirely, while the fourth segment of the leg, the trochanter, was only partially conserved. The comparison of the tarsus of this specimen with the legs of present day third instar nymphs of body and head lice revealed that the leg found within the archaeological debris belongs to a body louse.