Exposure to blood borne pathogens poses a serious risk to healthcare workers (HCWs). This study was undertaken to investigate knowledge, attitudes and practices among HCWs towards blood borne pathogens. We carried out a cross sectional KAP (Knowledge, Attitudes and Practice) study, using self-administered questionnaire. The study population consisted of 127(23.6%) physicians, and 410 (76.4%) nurses and laboratory technicians. Factor analysis and conditional multiple logistic regression were used in statistical analysis. We found that the knowledge of the epidemiological characteristics of blood-borne infection, the risk of acquisition and available preventative measures among HCWs is insufficient. Doctors were more knowledgeable about the transmissibility of blood borne pathogens regarding sexual transmission after percutaneous exposure (odds ratio) OR=2.71; 95% (confidence interval) CI=1.51–4.84, OR=2.45; 95% CI=1.21–4.96), respectively. Nurses reported professional exposure to patient’s blood more often than doctors (OR=0.90; 95% CI=0.84–0.96). Negative attitudes towards HIV positive patients were also noted. Less than half of HCWs used appropriate barriers (gloves, mask, and glasses) to protect them regularly. The compulsory preventive measures implied by the results of this study are continuous education, immunization against Hepatitis B, implementing Standard Precautions, as well as the development of written guidelines on the prevention of blood-borne infections.

The remarkable differences that have been detected by metagenomics in the genomes of strains of the same bacterial species are difficult to reconcile with the widely accepted paradigm that periodic selection within bacterial populations will regularly purge genomic diversity by clonal replacement. We have found that many of the genes that differ between strains affect regions that are potential phage recognition targets. We therefore propose the constant-diversity dynamics model, in which the diversity of prokaryotic populations is preserved by phage predation. We provide supporting evidence for this model from metagenomics, mathematical analysis and computer simulations. Periodic selection and phage predation dynamics are not mutually exclusive; we compare their predictions to shed light on the ecological circumstances under which each type of dynamics could predominate.