Modelling the survival of Listeria monocytogenes strains in soft lactic cheese following acid and salt stress exposures

This study evaluated the survival responses of Listeria monocytogenes strains (individually and mixed) in a soft lactic cheese following acid and salt stress exposures. The Weibull and log-linear with tail models were used to predict the survival responses of the pathogen in the cheese stored at 4°C for 15 days. Both models showed a good prediction accuracy for stressed L. monocytogenes cells (Af = 1·00) and higher prediction errors (Af = 1·12-1·14) for nonstressed cells. The inactivation rates (δ (d) and k_max (d^-1 )) were significantly lower (P < 0·05) for cells subjected to stress exposure indicating the enhanced tolerance to food stress. However, while enhanced tolerance appeared to be the main effect of stress pre-exposure, in one susceptible strain (69), stress exposure led to higher rates of inactivation. When introduced into the food as mixed strains, one strain out-lived others and remained as the sole survivor. Such strains that perhaps have a predilection for the food environment can provide more cautious estimates of kinetic parameters for predicting L. monocytogenes responses in foods especially if their stress-hardened tolerant cells are used. SIGNIFICANCE AND IMPACT OF THE STUDY: The ability to predict the growth and survival of Listeria monocytogenes in contaminated RTE foods is essential for listeriosis risk assessment. The results of this study provided valuable information on the kinetic parameters of survival of some L. monocytogenes strains found within the South African food environment. In addition to showing differences in the survival responses among strains, the study also showed the importance of the pre-contamination state of the cells in influencing survival kinetics.

Adaptation and implementation of local maternity dashboards in a Zimbabwean hospital to drive clinical improvement

PROBLEM

The Commission on Information and Accountability for Women's and Children's Health of the World Health Organization (WHO) reported that national health outcome data were often of questionable quality and "not timely enough for practical use by health planners and administrators". Delayed reporting of poor-quality data limits the ability of front-line staff to identify problems rapidly and make improvements.

APPROACH

Clinical "dashboards" based on locally available data offer a way of providing accurate and timely information. A dashboard is a simple computerized tool that presents a health facility's clinical data graphically using a traffic-light coding system to alert front-line staff about changes in the frequency of clinical outcomes. It provides rapid feedback on local outcomes in an accessible form and enables problems to be detected early. Until now, dashboards have been used only in high-resource settings.

LOCAL SETTING

An overview maternity dashboard and a maternal mortality dashboard were designed for, and introduced at, a public hospital in Zimbabwe. A midwife at the hospital was trained to collect and input data monthly.

RELEVANT CHANGES

Implementation of the maternity dashboards was feasible and 28 months of clinical outcome data were summarized using common computer software. Presentation of these data to staff led to the rapid identification of adverse trends in outcomes and to suggestions for actions to improve health-care quality.

LESSONS LEARNT

Implementation of maternity dashboards was feasible in a low-resource setting and resulted in actions that improved health-care quality locally. Active participation of hospital management and midwifery staff was crucial to their success.

Anti-tuberculosis treatment outcomes in HIV-infected adults exposed to isoniazid preventive therapy in Botswana

SETTING

Eight public health clinics in Gaborone and Francistown, Botswana.

OBJECTIVES

To describe the characteristics and outcomes of incident tuberculosis (TB) cases in human immunodeficiency virus (HIV) infected adults exposed to isoniazid preventive therapy (IPT) with access to antiretroviral and anti-tuberculosis treatment.

DESIGN

In 1995 HIV-infected adults, TB disease was excluded before commencing IPT. During and after receipt of 6 or 36 months of IPT, symptomatic participants were evaluated using chest radiographs, sputum microscopy, cultures and drug susceptibility testing (DST). Incident TB cases received ≥6 months of anti-tuberculosis treatment.

RESULTS

Seventy-five incident TB cases were identified among 619 symptomatic participants. The median duration of IPT in these cases was 6 months (range 1-35), and the median time to initiation of anti-tuberculosis treatment was 12 months after IPT cessation. Antiretroviral therapy (ART) was initiated before anti-tuberculosis treatment in 37 cases. Culture was positive in 43/58 (74%) TB cultures. DST was available for 38 cases, of which six (16%) were resistant to isoniazid (INH); 67/75 (89%) cases, including four with INH-monoresistant TB, completed anti-tuberculosis treatment or were cured.

CONCLUSIONS

With prompt initiation of anti-tuberculosis treatment and access to ART, excellent outcomes were achieved in a public health setting in HIV-infected adults who developed TB disease.

A simple tool to measure patient perceptions of operative birth

OBJECTIVE

To assess the feasibility and validity of a maternal satisfaction measurement tool, the SaFE study Patient Perception Score (PPS), after operative delivery.

DESIGN

Cross-sectional survey.

SETTING

A large maternity unit in England.

SAMPLE

150 women who had had an operative birth.

METHODS

We recruited women within 24 hours of birth and quantified their satisfaction with two questionnaires: PPS, and the Mackey Childbirth Satisfaction Rating Scale (CSRS; modified).

MAIN OUTCOME MEASURES

Participation rate to determine feasibility; Cronbach's alpha as measure of internal consistency; PPS satisfaction scores for groups of accoucheurs of different seniority to assess construct validity; correlation coefficient of PPS scores with total scores from the CSRS questionnaire to establish criterion validity.

RESULTS

Participation rate approached 85%. We observed high scores for most births except a few outliers. Internal consistency of the PPS was high (Cronbach's alpha=0.83). Total PPS scores correlated strongly with total CSRS scores (Spearman's r=0.64, P<0.001).

CONCLUSIONS

The PPS is a simple and valid tool for patient-centred assessments. High scores were observed for most births but there were a small minority of accoucheurs who consistently scored poorly and these data could be used during appraisal and training.

Retrospective cohort study of diagnosis-delivery interval with umbilical cord prolapse: the effect of team training

OBJECTIVE

To determine whether the introduction of multi-professional simulation training was associated with improvements in the management of cord prolapse, in particular, the diagnosis-delivery interval (DDI).

DESIGN

Retrospective cohort study.

SETTING

Large tertiary maternity unit within a University Hospital in the United Kingdom.

SAMPLE

All cases of cord prolapse with informative case record: 34 pre-training, 28 post-training.

METHODS

Review of hospital notes and software system entries; comparison of quality of management for umbilical cord prolapse pre-training (1993-99) and post-training (2001-07).

MAIN OUTCOME MEASURES

Diagnosis-delivery interval; proportion of caesarean section (CS) in whom actions were taken to reduce cord compression; type of anaesthesia for CS births; rate of low (<7) 5-minute Apgar scores; rate of admission to neonatal intensive care unit (NICU) (if birthweight >2500 g).

RESULTS

After training, there was a statistically significant reduction in median DDI from 25 to 14.5 minutes (P < 0.001). Post-training, there was also a statistically significant increase in the proportion of CS where recommended actions had been performed (from 34.78 to 82.35%, P = 0.003). There was a nonsignificant increase in the use of spinal anaesthesia for CS, from 8.70 to 17.65%, and a nonsignificant reduction in the rate of low Apgar scores from 6.45 to 0% and in the rate of admission to NICU from 38.46 to 22.22%.

CONCLUSIONS

The introduction of annual training, in accordance with national recommendations, was associated with improved management of cord prolapse. Future studies could assess whether this improved management translates into better outcomes for babies and their mothers.

A randomised controlled trial of a new handheld vacuum extraction device

OBJECTIVE

To evaluate the effectiveness of a new handheld vacuum delivery device.

DESIGN

Randomised controlled trial.

SETTING

Southmead Hospital, Bristol, UK.

POPULATION

One hundred and ninety-four women requiring delivery with vacuum extraction.

METHODS

Women were recruited into the study while still in early labour. If during delivery, vacuum extraction was indicated they were then randomly allocated to either a new handheld vacuum device, the Kiwi Omnicup, or to a 'standard' vacuum cup selected by the obstetrician. The 'standard group' consisted of the silastic (66/98, 67%) or the metal cups (32/98, 33%). Study data were recorded at completion of the delivery and at 24-48 hours. An additional brief symptom questionnaire was completed by the mother at 10 days postnatally. Statistical analyses were done on an 'intention-to-treat' basis.

MAIN OUTCOME MEASURES

The primary outcome was the successful completion of delivery with the allocated instrument. Secondary outcomes were substantial fetal scalp trauma and substantial maternal trauma.

RESULTS

The Omnicup was associated with a significantly higher failure rate than the standard cup [34%vs 21%, odds ratio (OR) = 1.9 (1.01-3.6)]. This difference persisted after adjusting for confounding factors [adjusted OR = 2.25 (1.01-5.0)] and resulted in significantly more forceps deliveries in the Kiwi Omnicup group [22%vs 10%, unadjusted OR = 2.5 (1.1-5.5)]. The caesarean section rates were similar in both groups [9.4%vs 8.2%, OR = 1.2 (0.4-3.2)]. Rates of substantial scalp trauma and maternal trauma were similar in both groups. However, there were more cases of jaundice in the standard cup group [2.3%vs 12.0%, unadjusted OR = 0.18 (0.04-0.82) and adjusted OR = 0.10 (0.01-0.88)].

CONCLUSIONS

The Omnicup is not as successful at achieving a vaginal delivery as the combination of the currently used vacuum cups.