Antibiotic-resistant pathogens born in hospitals may enter the wider environment through the facilities’ sewers, although the magnitude of the danger remains unclear. A team from the Federal University of Saõ Paulo in Brazil analyzed wastewater from their medical center, finding that 21 of 130 Gram-negative bacterial isolates contained the antibiotic resistance KPC (Klebsiella pneumoniae carbapenemase) gene. These included two classes of generally benign environmental bacteria not previously known to harbor the gene.

In a similar study, another group based at the University of Limoges, France, found a host of resistance elements in the local university hospital’s sewage. Both studies were reported at the 2011 Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC).

The Limoges researchers went a step further and examined wastewater from elsewhere in the community, including the main input to the city’s sewage treatment plant, where the hospital’s effluents were combined with the rest of the city’s. The analysis showed that bacteria carrying antibiotic resistance genes were much less common in general urban effluents prior to treatment.

That is a surprising result, since another recent audit here in the UK has demonstrated far more liberal antibiotic prescribing in the community than in hospital practice.

Antibiotic resistant bacterial and other nasty pathogens, both bacteria and virus, will frequently arise in clinical wastes and in any general run-off from those wastes (though any run-off must be contained and should be prevented). In general, we direct our attention to the bloodborne virus agents of Hepatitis B, Hepatitis C and HIV. However, many other pathogens may arise and cause infections in those who are exposed by any direct or indirect route.

As always, the avoidance of procedures generating splashes or other aerial dispersion, careful PPE selection and use, and exemplary standards of personal hygiene supported by the provision of carefully sited hand wash facilities, vehicle-mounted facilities, hand wipes and, perhaps as a last resort, of hand rubs are the key to prevention.