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T P Subrahmanyan

Publications and source records attributed to T P Subrahmanyan.

12 recordsLinked to original sources
PubMed1984

Virological examination of drinking water: a Canadian collaborative study.

A collaborative virological survey of drinking water was initiated in three major Canadian urban areas, Montreal, Ottawa, and Toronto. In each selected area, three water purification plants were sampled monthly for up to 18 months. The total population served by all nine plants was about 1 500 000. Samples of raw (100 L) and treated (1000 L) water were examined by virus concentration procedures based on adsorption-elution. Sample concentrates were assayed for cytopathic viruses on BS-C-1 cells and the results were expressed as the most probable number of cytopathic units (MPNCU). Viruses were detected in 57% (0-15.35 MPNCU/L) of the raw water samples from Montreal, 37% (0-46.0 MPNCU/L) in Ottawa, and 33% (0-4.91 MPNCU/L) in Toronto. The majority of isolates were reoviruses, but picornaviruses were also found. All finished waters (177 samples) met bacteriological, turbidity, and residual chlorine standards and were free of detectable viruses.

Canada↗
PubMed1977

Persistence of enteroviruses in sewage sludge.

Sewage from residential areas often contains viruses pathogenic for man and significant amounts are probably associated with solids in sewage sludge. Information on the survival of viruses in sewage sludge is necessary in order to develop guidelines for recycling programmes that involve spreading the sludge on land. In the present study, a number of enteroviruses were added to sewage sludge and the artificially contaminated sludges were tested for viruses at intervals over a 12-week period. Most of the viruses survived for many weeks at room temperature. It is clear that sewage sludge destined for land application should be adequately treated for virus inactivation. In interpreting these results, it should be borne in mind that the survival of hepatitis A virus might be similar. Recent reports about the reappearance of poliomyelitis in regions with immunization programmes should also be taken into consideration.

Enterovirus↗
PubMed1973

Paralytic poliomyelitis in Ontario: laboratory studies of two recent cases.

Sporadic cases of paralytic poliomyelitis are being reported with increasing frequency, particularly in unvaccinated persons, in several countries in which the disease had been absent for several years following adequate initial vaccination programmes. In Ontario, two paralytic cases occurred in unvaccinated children after several disease-free years. Detailed studies of the strains of poliovirus type 1 isolated from these patients showed that they were not vaccine strains. Contact surveillance in one case showed that 21 originally unvaccinated contacts were also excreting virulent virus.

Adolescent↗