Dialysate Calcium Loss Using a Calcium Free Dialysate

Using a dialysate that contained no calcium, we studied the amount of calcium lost and the clearances of urea, creatinine, phosphate and calcium in fifteen different dialyzers at blood flow/min (QB) of 200 and 300. Five of these dialyzers, covering the functional range of the fifteen, were also tested at QB of 100, 150 and 400. The collection period was divided into the first twenty minutes and the remaining 220 minutes. Clearance was calculated using the initial twenty minutes and for all dialyzers the creatinine, phosphate and calcium clearances were linearly related to the measured urea clearnce, r = 0.946, 0.810 and 0.808 respectively. Calcium recovered in the dialysate varied, depending on the dialyzer and QB, however the amount found plateaued at QB 200 and did not increase further, unlike creatinine, phosphate and urea. Total dialysate calcium loss for a four-hour dialysis averaged 49.9 mmol (range 42.2 -63) or almost 2g of elemental calcium for QB of 200 ml/min and 48.9 mmol (range 31.1 -65.5) or 1.95 g of elemental calcium for a QB of 300 ml/min. Decreasing the calcium infusion replacement rate did not decrease the calcium dialysate loss in equal amounts as the blood to dialysate gradient falls leading to a smaller than expected dialysate loss. Measured urea clearance in these fifteen dialyzers was approximately 20% less than specified by the manufacturer and almost 30% less for creatinine and phosphate. This difference is probably due to in vivo measurements with blood whereas most of the specifications are obtained using saline in vitro. The data given provide a basis for calcium replacement when using a calcium free dialysis and a variety of dialyzers and blood flow rates.

The occurrence of Salmonella spp. in duck eggs on sale at retail or from catering in England

Since 2010, human salmonellosis outbreaks in the UK have been detected as associated with the consumption of duck eggs. Little data are available on the rate of occurrence of Salmonella in duck eggs. The aim of this study was to investigate the occurrence of Salmonella spp. in duck eggs on sale and from catering in England during 2011, particularly those from small-scale production. All samples were collected independently of human salmonellosis outbreak investigations. Composite samples of 6-10 eggs (shells and contents were examined separately) were examined for the presence of Salmonella spp. using the ISO 6579:2002 method. Salmonella spp. was recovered from two of 145 samples (1·4%). In one sample, Salmonella Typhimurium DT 8 was isolated from the shells while Salm. Typhimurium DT 8 and Salm. Typhimurium DT30 were isolated from the contents. Salmonella Typhimurium DT8 was isolated from the egg shells only in the second contaminated sample. This study provides baseline data for risk assessors, regulators and the food industry and may be helpful in communicating risks associated with the consumption of this product as well as evaluating risk management options to control food safety including vaccination of ducks.

SIGNIFICANCE AND IMPACT OF THE STUDY

Human salmonellosis outbreaks in England and Northern Ireland due to Salmonella enterica serovar Typhimurium definitive phage type (DT) 8 have been identified as associated with the consumption of duck eggs since 2010. This study has shown that Salmonella spp. was detected in 1·4% of ducks egg samples providing baseline data for risk assessors, regulators and the food industry. This may be helpful in communicating risks associated with the consumption of this product as well as evaluating risk management options to control food safety including vaccination of ducks.

An assessment of the microbiological safety of fresh whole-leaf herbs from retail premises in the United Kingdom with a focus on Salmonella spp

AIMS

Fresh herbs have been associated with a number of outbreaks in recent years, in the United Kingdom and elsewhere. A study of fresh herbs was carried out to assess their microbiological safety in relation to Salmonella contamination and levels of Escherichia coli.

METHODS AND RESULTS

Between January and March 2014, 774 samples of ready-to-eat, fresh, whole-leaf herbs were collected from retail premises in the United Kingdom. Overall, Salmonella was detected in nine samples (1·2%). Of these, five were curry leaves. Other herbs contaminated with Salmonella were basil (two samples), walleria (1) and coriander (1). Escherichia coli was detected in 13% of samples, with 11% containing unsatisfactory levels (≥10(2) g(-1)).

CONCLUSIONS

Whilst 88% of samples in this study were of an acceptable microbiological quality, the presence of Salmonella and/or elevated E. coli levels in 12% is a cause for concern. Curry leaves, in particular, had significantly higher rates of contamination with both Salmonella and E. coli than other herbs.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study highlights the potential public health risk associated with the consumption of certain ready-to-eat fresh herbs, and the need for good hygiene practices and effective decontamination procedures during the growth, harvesting and subsequent handling of these products.

Laboratory identification of donor-derived coxsackievirus b3 transmission

Unexpected donor-to-recipient infectious disease transmission is an important, albeit rare, complication of solid organ transplantation. Greater work and understanding about the epidemiology of these donor-derived transmissions is continually required to further mitigate this risk. Herein we present the first reported case of proven donor-derived transmission of coxsackievirus serogroup-3, an enterovirus, following solid organ transplant. Swift and effective communication between the organ donation agency, treating physicians, laboratory testing and notification ensured a coordinated approach. The resulting clinical syndromes in the organ recipients were mild. This case highlights the requirement for ongoing surveillance over a broad range of infecting pathogens that may present as a donor-derived infection.

Validation of COBAS Taqman CT for the detection of Chlamydia trachomatis in vulvo-vaginal swabs

BACKGROUND

Vulvo-vaginal swabs (VVSs) are not validated for use by the manufacturers of two widely used nucleic acid amplification tests (NAAT) for the detection of Chlamydia trachomatis. However, there is evidence that this type of swab is suitable for diagnosis.

OBJECTIVE

To validate the Cobas Taqman CT assay for the detection of C trachomatis in VVS.

METHOD

Women aged 18-24 years attending a genitourinary medicine clinic were invited to take part in the study. Participants provided a self-taken VVS and the results obtained with these samples were compared with those obtained with an endocervical swab collected by a healthcare worker. A total of 267 women took part.

RESULTS

255/267 (96%; 95% CI 92 to 98%) sets of samples gave concordant results. 12/267 (4.5%) VVSs were invalid/inhibitory and so no result was available for these samples. This compared with 2/267 (0.7%) for endocervical swabs.

CONCLUSION

VVS are suitable samples for detecting C trachomatis.

Surveillance of respiratory virus infections in adult hospital admissions using rapid methods

Both influenza and respiratory syncytial virus (RSV) cause epidemics of respiratory illness of variable severity during the winter season. Influenza in particular has been blamed for hospital winter bed pressures, although it is thought that RSV may also play a role. Human metapneumovirus (hMPV) is a new respiratory virus reported to be important in children; only a limited number of studies are available for adult populations. We aimed to determine initially the burden of virologically confirmed infections, i.e. influenza, RSV and hMPV using polymerase chain reaction (PCR) technology and, in addition, to assess the feasibility of this approach as a surveillance tool for these respiratory viruses. Adult patients admitted to hospital in the previous 24 hours with onset of acute respiratory symptoms in the last 14 days were asked to participate. Informed written consent was obtained and nose and throat swabs taken. Multiplex PCR for influenza A (H1N1 and H3N2), influenza B and RSV A and B were carried out together with a separate PCR for hMPV. A total of 219 patients in 2001-2002 and 216 in 2002-2003 were tested and the combined results for both seasons were: 8 positive for influenza A/H1N1, 14 for influenza A/H3N2, 2 for influenza B, 14 for RSV A and 6 for RSV B. Most patients (261/435) were >65 years and most positives (30/44) were found within this age group. A number of patients aged >65 years who were positive for influenza (12/15) reported having had vaccine. In total, 373 samples were tested for hMPV and 20 were found positive across all age groups except the 45-54 years age group. As influenza activity was low during the study period the impact of infection on admissions could not be assessed. Nevertheless the viruses studied accounted for 15% of hospital admissions for respiratory infection. Most patients were aged >65 years, as expected. In the two years studied RSV and hMPV were each responsible for as many hospitalized cases of respiratory infection as influenza. Influenza infection must be considered even in those who give a history of vaccination. The molecular methods used in this study showed that surveillance of these respiratory viruses can be conducted and may help in the management of patients.

HIV and hepatitis C coinfection within the CAESAR study

The declining incidence of AIDS-related opportunistic diseases among people with HIV infection has shifted the focus of clinical management to prevention and treatment of comorbidities such as chronic liver disease. The increased risk of hepatitis C virus (HCV)-related advanced liver disease in people with HIV infection makes early HCV diagnosis a priority. To assess HCV prevalence and predictors of HIV/HCV coinfection, we have conducted a retrospective analysis of people enrolled in the CAESAR (Canada, Australia, Europe, South Africa) study, a multinational randomized placebo-controlled study of the addition of lamivudine to background antiretroviral therapy. The impact of HCV on HIV disease progression was also examined. Anti-HCV antibody testing on 1649 CAESAR study participants demonstrated a HIV/HCV coinfection prevalence of 16.1%, which varied from 1.9% in South Africa to 48.6% in Italy. The strongest predictor of HIV/HCV coinfection was HIV exposure category (P<0.0001), with odds ratios (ORs) compared to homosexual as follows: injecting drug use (IDU), 365 [95% confidence interval (CI): 179-742]; transfusion or blood products, 32.2 (95% CI: 15.2-67.6); homosexual and IDU, 22.9 (95% CI: 8.5-62.1). The prevalence of HIV/HCV was low (3.7%) among homosexual men without reported IDU. Other predictors of HIV/HCV coinfection were alanine aminotransferase (ALT), country of residence, ethnicity and stage of HIV disease. A history of IDU or ALT > or =40 U/L at baseline had a positive predictive value (PPV) of 35%, negative predictive value (NPV) of 96%, sensitivity of 82% and specificity of 71% for HIV/HCV coinfection. HIV disease progression was similar in HIV monoinfected and HIV/HCV coinfected patients. People with HIV and a history of IDU or elevated liver function tests should be targeted for HCV testing. The low prevalence of HIV/HCV coinfection among homosexual men without a history of IDU suggests low efficiency of sexual HCV transmission.