SUMNIARYThe chemical disinfection of virus-contaminated non-porous inanimate surfaces was investigated using coxsackievirus B3, adenovirus type 5, parainfluenzavirus type 3 and coronavirus 229E as representatives of important nosocomial viral pathogens. A 10 ,ul amount of the test virus, suspended in either faeces or mucin, was placed onto each stainless steel disk (about 1 cm in diameter) and the inoculum allowed to dry for 1 h under ambient conditions. Sixteen disinfectant formulations were selected for this study based on the findings of an earlier investigation with a human rotavirus. After 1 min exposure to 20,u1 of the disinfectant, the virus from the disks was immediately eluted into tryptose phosphate broth and plaque assayed. Using an efficacy criterion of a 3 log10 or greater reduction in virus infectivity titre and irrespective of the virus suspending medium, only the following five disinfectants proved to be effective against all the four viruses tested: (1) 2 % glutaraldehyde normally used as an instrument soak, (2) a strongly alkaline mixture of 05 % sodium o-benzyl-p-chlorophenate and 0-6 % sodium lauryl sulphate, generally used as a domestic disinfectant cleaner for hard surfaces, (3) a 0 04 % solution of a quaternary ammonium compound containing 7 % hydrochloric acid, which is the basis of many toilet bowl cleaners. (4) chloramine T at a minimum free chlorine level of 3000 p.p.m. and (5) sodium hypochlorite at a minimum free chlorine concentration of 5000 p.p.m. Of those chemicals suitable for use as topical antiseptics, 70 % ethanol alone or products containing at least 70% ethanol were ineffective only against coxsackievirus B3. These results emphasize the care needed in selecting chemical disinfectants for routine use in infection control. INTROD)UCTIONOutbreaks of viral infections in institutional settings arc quite common andl it is not unusual for more than one virus to be circulating simultaneously within a given institution (Meissner et al. 1984; Payne, Grilli & Smith, 1984). The exact means of spread of viral agents in many such outbreaks still remain unclear, but, for many viral pathogens, multiple vehicles mav be involved. Evidence suggests that virus-contaminated surfaces may play a role (Pattison et al.

A number of viruses have been shown to be transmitted by the airborne route. It is the ability of these viruses to retain their infectivity for living hosts which play a key role in their aerial dissemination. Data generated by a number of workers on the airborne survival of viruses varies considerably because laboratory techniques have not been standardized. About 5 yr ago we started studies on the airborne survival of a number of animal and human viruses. This paper describes the methodology developed to study the aerobiology of these viruses. These methods should be useful in the aerobiological work of other viruses.

Rhinovirus-14, suspended in tryptose phosphate broth supplemented with uranine (physical tracer) and an antifoam, was aerosolized by use of a Collison nebulizer. The aerosols were held in a rotating drum with the relative humidity at either the low (30 +/- 5%), medium (50 +/- 5%), or high (80 +/- 5%) level at 20 +/- 1 degrees C. An all-glass impinger was used to recover the virus from the air in the drum, with the first air sample being collected after a 15-min period of aerosol stabilization. Subsequent air samples were withdrawn at 2, 4, 8, and 14 h after stabilization of the aerosol. At the low and medium relative humidity levels, the infectivity of the airborne virus was rapidly lost and less than 0.25% could be detected in the first air sample. At the high RH level, however, the airborne virus had a half-life of 13.7 +/- 1.91 h and nearly 30% of the input infectious virus could be detected in the drum air even after 24 h of aerosolization. These findings suggest that under certain environmental conditions, notably high relative humidity, air may act as a vehicle for the spread of rhinovirus infections.

To study the survival of human rhinovirus 14 on environmental surfaces, each stainless steel disk (1 cm in diameter) was contaminated with 10 microL (about 10(5) plaque-forming units) of the virus suspended in either 1 chi tryptose phosphate broth (TPB), 5 mg/mL of bovine mucin in normal saline, or undiluted human nasal discharge. The inoculum was dried in a laminar flow cabinet for 1 h under ambient conditions. The disks were then placed in a glass chamber (20 +/- 1 degree C) with the relative humidity at either low (20 +/- 5%), medium (50 +/- 5%), or high (80 +/- 5%) level. At appropriate intervals, the disk to be tested was placed in 1 mL of tryptose phosphate broth and the eluate titrated in A-5 HeLa cells. When the virus was suspended in either tryptose phosphate broth, mucin, or the nasal discharge and subjected to initial drying, there was a 3.0 +/- 1.0, 82.0 +/- 6.7, and 89.0 +/- 3.0% loss in virus infectivity, respectively. The half-life of the TPB-suspended virus was about 14 h at the high relative humidity as compared with less than 2 h at the other two relative humidity levels. The half-lives for the mucin-suspended virus at the high, medium, and low relative humidity were 1.42, 0.55, and 0.24 h, respectively; the corresponding values for the nasal discharge suspended virus being 0.17, 0.25, and 0.09 h.

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The coding-complete genome sequence of a coronavirus strain, SARS-CoV-2/human/BGD/G039392/2021, obtained from a symptomatic male patient with coronavirus disease 2019 (COVID-19) in Dhaka, Bangladesh, is reported. The strain G039392 is 99.9% identical to the UK variant B.1.1.7.

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Arsenic (As) toxicity and diabetes mellitus (DM) are emerging public health concerns worldwide. Although exposure to high levels of As has been associated with DM, whether there is also an association between low or moderate As exposure and DM remains unclear. We explored the dosedependent association between As exposure levels and hyperglycemia, with special consideration of the impact of demographic variables, in 641 subjects from rural Bangladesh. The total study participants were divided into three groups depending on their levels of exposure to As in drinking water (low, moderate and high exposure groups). Prevalence of hyperglycemia, including impaired glucose tolerance (IGT) and DM was significantly associated with the subjects' drinking water arsenic levels. Almost all exposure metrics (As levels in the subjects' drinking water, hair and nails) showed dose-dependent associations with the risk of hyperglycemia, IGT and DM.