The 3-day rule for stool cultures: should all patients with haematological malignancies be excluded?

OBJECTIVES: The '3-day rule' for stool culture ordering suggests that only selected inpatients with nosocomial diarrhoea should have stool cultures for enteropathogenic bacteria (EPBs). Patients with haematological malignancies are not included in this group. We have analysed the ordering of stool cultures at Laikon Hospital to investigate whether all patients with haematological malignancies should be excluded from the 3-day rule. METHODS: We have retrospectively analysed all inpatient stool specimens sent to the microbiology laboratory for enteropathogenic bacteria culture at Laikon Hospital, Athens, Greece, between January 1, 2014 and December 31, 2014. We classified stool cultures sent after the third day as 'appropriate', 'excluded' with standard rule, 'excluded' with haematological malignancies, and 'inappropriate'. RESULTS: During the study period, 1101/1593 inpatient stool cultures (69.1%) had been ordered after the third day of hospitalization. The total yield for inpatient EPB stool cultures was 0.7% (11/1593). The yield for 'appropriate' cultures was significantly higher than the yield of all 'excluded' specimens (3.7% (3/81) versus 0.3% (2/585), p 0.018) and to 'inappropriate' orders (3.7% (3/81) versus 0.0% (0/485), p 0.0028). There was no difference in the yield between specimens 'excluded' with the standard rule and 'excluded' with haematological malignancies. CONCLUSIONS: In our hospital, the yield of stool cultures from patients with haematological malignancies is similar to that of patients 'excluded' from the standard 3-day rule. If patients with haematological malignancies were not excluded from the rule, we would reduce the inpatient stool cultures by 13.6% (217/1593) at the cost of missing one positive stool culture.

Effective control of an acute gastroenteritis outbreak due to norovirus infection in a hospital ward in Athens, Greece, April 2011.

In April 2011, an acute gastroenteritis outbreak due to norovirus infection occurred in a hospital ward in Athens, Greece, affecting 28 people: 16 staff members, 10 inpatients and two relatives of symptomatic inpatients. The attack rate among the patients and staff was 16.4% (10/61) and 31.4% (16/51), respectively. The outbreak lasted eight days and the clinical symptoms were mild. Effective infection control measures prevented the spread of the virus to other hospital wards.

Prospective use of RFLP analysis on amplified Cryptococcus neoformans URA5 gene sequences for rapid identification of varieties and serotypes in clinical samples.

Clinical isolates of Cryptococcus neoformans, whole blood, cerebrospinal fluid, bronchoalveolar lavage fluid from patients with positive cryptococcal antigen latex-agglutination test, and spiked clinical material from healthy individuals, were tested by polymerase chain reaction (PCR) with primers amplifying C. neoformans URA5 gene sequences. To test compatibility of different DNA extraction protocols with the PCR-restriction fragment length polymorphism (RFLP) assay, a commercial DNA extraction kit (XTRAX; Gull Laboratories, UT, USA) was used alongside with the hexadecyltrimethylammonium bromide (CTAB) method on spiked biological fluids. Both methods extracted DNA from spiked clinical samples containing C. neoformans (8 +/- 2 cells ml(-1)) and generated amplification products suitable for restriction enzyme analysis. Alu I digestion differentiated the two varieties of C. neoformans. Three distinct RFLP patterns were obtained upon restriction with MspI corresponding to serotypes A, AD and B, C and D. URA5 PCR followed by RFLP analysis, coupled with a sensitive in-house or commercially available DNA extraction method from clinical samples, could be successfully incorporated into rapid routine diagnostic strategies. It could also provide an expeditious tool for epidemiology-based population genetics studies.