Low prevalence of meticillin-resistant Staphylococcus aureus carriage at hospital admission: implications for risk-factor-based vs universal screening

BACKGROUND

There is debate over the optimal policy for detecting meticillin-resistant Staphylococcus aureus (MRSA) colonization at hospital admission. The emergence of community-associated (CA)-MRSA may compromise targeted screening strategies based on risk factors for healthcare-associated (HA)-MRSA.

AIM

To determine the prevalence of MRSA colonization at admission, and the genotype and molecular epidemiology of the strains involved.

METHODS

A 12-month observational study was performed at a 1200-bed London tertiary referral hospital from 1 April 2008 to 1 March 2009. All available MRSA isolates were genotyped by spa and staphylococcal cassette chromosome mec (SCCmec) typing.

FINDINGS

The overall MRSA colonization rate was 2.0% of 28,892 admissions (range 6.6% in critical care to 0.8% in obstetrics/gynaecology/neonatology). The overall frequency of previously unknown carriage of MRSA on admission was 1.4%. Most colonizing strains were epidemic HA-MRSA-15 and -16. However, heterogeneous CA strains accounted for 18% of recovered isolates, including 37.5% of MRSA from accident and emergency and 23.1% of MRSA from surgery. The CA-MRSA strain types had significantly different epidemiological associations from the HA-MRSA strains, so risk factors used for the identification of HA-MRSA may not detect CA-MRSA reliably.

CONCLUSION

The low rate of HA-MRSA in the UK increases the relative proportion due to CA-MRSA, for which conventional risk-factor-based screening strategies may be less effective. Cost-benefit analyses of universal MRSA admission screening will need to take account of this new epidemiology.

Community-based multi-disease prevention campaigns for controlling human immunodeficiency virus-associated tuberculosis

Human immunodeficiency virus (HIV) infection increases the risk of tuberculosis (TB) 21-34 fold, and has fuelled the resurgence of TB in sub-Saharan Africa. The World Health Organization (WHO) recommends the Three I's for HIV/TB (infection control, intensified case finding [ICF] and isoniazid preventive therapy) and earlier initiation of antiretroviral therapy for preventing TB in persons with HIV. Current service delivery frameworks do not identify people early enough to maximally harness the preventive benefits of these interventions. Community-based campaigns were essential components of global efforts to control major public health threats such as polio, measles, guinea worm disease and smallpox. They were also successful in helping to control TB in resource-rich settings. There have been recent community-based efforts to identify persons who have TB and/or HIV. Multi-disease community-based frameworks have been rare. Based on findings from a WHO meta-analysis and a Cochrane review, integrating ICF into the recent multi-disease prevention campaign in Kenya may have had implications in controlling TB. Community-based multi-disease prevention campaigns represent a potentially powerful strategy to deliver prevention interventions, identify people with HIV and/or TB, and link those eligible to care and treatment.

Can theory be embedded in visual interventions to promote self-management? A proposed model and worked example

Nurses are increasingly involved in a range of strategies to encourage patient behaviours that improve self-management. If nurses are to be involved in, or indeed lead, the development of such interventions then processes that enhance the likelihood that they will lead to evidence that is both robust and usable in practice are required. Although behavioural interventions have been predominantly based on written text or the spoken word increasing numbers are now drawing on visual media to communicate their message, despite only a growing evidence base to support it. The use of such media in health interventions is likely to increase due to technological advances enabling easier and cheaper production, and an increasing social preference for visual forms of communication. However, the development of such media is often highly pragmatic and developed intuitively rather than with theory and evidence informing their content and form. Such a process may be at best inefficient and at worst potentially harmful. This paper performs two functions. Firstly, it discusses and argues why visual based interventions may be a powerful media for behaviour change; and secondly, it proposes a model, developed from the MRC Framework for the Development and Evaluation of Complex Interventions, to guide the creation of theory informed visual interventions. It employs a case study of the development of an intervention to motivate involvement in a lifestyle intervention among people with increased cardiovascular risk. In doing this we argue for a step-wise model which includes: (1) the identification of a theoretical basis and associated concepts; (2) the development of visual narrative to establish structure; (3) the visual rendering of narrative and concepts; and (4) the assessment of interpretation and impact among the intended patient group. We go on to discuss the theoretical and methodological limitations of the model.

P5-19-05: Age-Related Changes in the Pharmacokinetics (pK), Response, and Toxicity of Weekly nab-Paclitaxel in Patients with Metastatic Breast Cancer (MBC)

Background: Although cancer is a disease of aging, few studies have evaluated the association between patient age and the pK or pharmacodynamics (pD) of cancer therapeutics. The goals of this study were 1) to evaluate the age-related changes in the pK and pD of weekly nab-paclitaxel in patients with MBC; 2) to determine response rate; and 3) to explore the relationship of age with pK and pD parameters (i.e., dose reductions, dose delays and grade ≥ 3 toxicities). Patients and Methods: Forty patients with MBC, receiving 1st or 2nd line chemotherapy, entered an IRB approved protocol to evaluate the age-related changes in the pK of weekly nab-paclitaxel administered at 100 mg/m2 IV for 3 weeks followed by a 1-week break. Patients were accrued from 4 age strata <50, 50–60, 60–70, and >70 years of age. Blood samples were collected for pK analysis with the first dose of nab-paclitaxel. Response was assessed every 2 cycles. Toxicity was graded using the NCI Common Toxicity Criteria for Adverse Events (v 3.0) and was adjudicated as attributable to nab-paclitaxel if it was possibly, probably, or definitely related. Linear regression analysis was used to examine the strength of the relationship between patient age and natural logarithm of 24 hour area under the curve (AUC). Two-sided two-sample t-tests were used to assess if there was a difference in mean age based on the presence of pD variables (i.e., dose reductions, dose delays and grade ≥ 3 toxicities). The significance level was set to 0.05.

Results: Of the 40 patients who entered the study, 39 (98%) were evaluable with a mean age of 60 (SD=13.4; min=30; max=81). Patients were accrued in the following age cohorts: <50 (n= 10; 26%), 50–60 (n= 5; 13%), 60–70 (n= 15; 38%), and >70 (n= 9; 23%) years of age. The median number of courses completed was 4 (min=1, max=21). The response rate was: 0% (n=0) CR, 31% (n=12) PR, 38% (n=15) SD. Grade 3 toxicity was experienced by 26% (n=10). We observed 8% (n=3) grade 3 hematological toxicities [neutrophils (n=1; 3%), leukocytes (n=2; 5%)] and 18% (n=7) grade 3 non-hematological toxicities [nausea and hypophosphatemia (n=1; 3%), diarrhea and infection without neutropenia (n=1; 3%), fatigue (n=2; 5%), hyponatremia (n=1; 3%), and infections without neutropenia (n=2; 5%)]. There were no cases of grade 4 or 5 toxicity. Grade 2 sensory neuropathy was experienced by 8% (n=3; no cases in the 70+ age cohort). Dose reductions or course delays were experienced by 62% (n=24) and 21% (n=8), respectively. There was a borderline significant positive association between age and natural logarithm of total nab-paclitaxel 24 hour AUC (coef=.01; se=.006; p=0.055; n=36). There were no differences in the mean ages based on the presence of grade 3 or higher toxicity (p =0.75), need for dose reductions (p=0.48), or need for dose delays (p=0.61).

Discussion: There is a borderline statistically significant relationship between age and 24 hour AUC but no differences in mean age based on pD variables (i.e., dose reductions, dose delays and grade ≥ 3 toxicities) were identified. The treatment is well-tolerated across all age groups.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-19-05.

Pregnancy outcomes in adolescents in the UK and Ireland growing up with HIV

OBJECTIVES

Adolescents with HIV infection acquired perinatally or in early childhood are becoming sexually active, but little is known about fertility and pregnancy outcomes. Multicentre data on pregnancy outcomes in this population are described here.

METHODS

A retrospective case note review of pregnant women with perinatal/early acquired HIV infection, conceiving before 1 September 2009 and attending participating centres in the UK and Ireland, was carried out.

RESULTS

Among 252 women with perinatal/early acquired infection aged 12 years and older under follow-up in 21 centres, 42 pregnancies were reported in 30 women (19 women with a single pregnancy, 10 women with two pregnancies, and one woman with three pregnancies). Fifteen women (50%) had previous AIDS-defining diagnoses. The median age at first reported pregnancy was 18 years (range 14-22 years). Of the 42 pregnancies, 34 (81%) were reportedly unplanned, 31 (74%) involved regular partners, and in 21 (50%) of the 42 pregnancies the partners were reported to be unaware of maternal HIV status. Fifteen of the 42 pregnancies (36%) were electively terminated, six of the 42 (14%) resulted in first-trimester miscarriages and 21 of the 42 (50%) resulted in live births. Maternal viral load was detectable close to delivery in seven of 21 pregnancies (33%). Four infants required neonatal intensive care, three of whom were delivered preterm. One infant is HIV infected, there are ongoing concerns about the development of three of 21 infants (14%), and two of 21 (10%) have been fostered.

CONCLUSIONS

Despite access to ongoing sexual health and contraceptive services, unplanned pregnancies are occurring in young women growing up with HIV. Pregnancy care and prevention of onward transmission require complex case management for this emerging population.

Inhibition of hepatitis B virus and human immunodeficiency virus (HIV-1) replication by Warscewiczia coccinea (Vahl) Kl. (Rubiaceae) ethanol extract

The primary objective of this study was to search for natural products capable of inhibiting hepatitis B virus (HBV) replication. The research design, methods and procedures included testing hydro-alcoholic extracts (n = 66) of 31 species from the Venezuelan Amazonian rain forest on the cell line HepG2 2.2.15, which constitutively produces HBV. The main outcomes and results were as follows: the species Euterpe precatoria, Jacaranda copaia, Jacaranda obtusifolia, Senna silvestris, Warscewiczia coccinea and Vochysia glaberrima exerted some degree of inhibition on HBV replication. The leaves of W. coccinea showed a significant antiviral activity: 80% inhibition with 100 µg mL⁻¹ of extract. This extract also exerted inhibition on covalently closed circular deoxyribonucleic acid (cccDNA) production and on HIV-1 replication in MT4 cells (more than 90% inhibition with 50 µg mL⁻¹ of extract). Initial fractionation using organic solvents of increasing polarity and water showed that the ethanol fraction was responsible for most of the antiviral inhibitory activities of both the viruses. It was concluded that Warscewiczia coccinea extract showed inhibition of HBV and HIV-1 replication. Bioassay-guided purification of this fraction may allow the isolation of an antiviral compound with inhibitory activity against both viruses.

Protease inhibitor-containing antiretroviral treatment and tuberculosis: can rifabutin fill the breach?

OBJECTIVE

To assess how to best manage co-administration of rifabutin (RFB) and human immunodeficiency virus 1 (HIV-1) protease inhibitor (PI) containing antiretroviral treatment (ART). Recommended for initial anti-tuberculosis treatment, rifampicin (RMP) lowers PI concentrations below therapeutic levels, posing significant challenges for ART. As RFB has little effect on PI concentrations, it could be an alternative to RMP.

METHODS

A review of the scientific literature on the safety and efficacy of RFB for adult tuberculosis (TB) treatment was conducted, focusing on ART-TB co-therapy. A cost comparison was performed between treatment regimens, and estimates of the burden of TB disease in patients on ART were used to model RFB demand in low- and middle-income countries (LMICs).

RESULTS

Eleven clinical studies were identified, comprising 1543 TB patients treated with RFB; 980 (64%) were living with HIV. RFB was as safe and effective as RMP, including in 313 patients receiving co-administered ART (unboosted PIs included indinavir, nelfinavir or saquinavir; a minority received ritonavir [RTV] boosted amprenavir or saquinavir). The total cost for 6 months of all HIV and TB treatment containing RTV-boosted lopinavir (LPV) and RFB is US$410, compared to US$455 if RMP is used with LPV super-boosted with RTV. Our model suggests that demand for RFB in LMICs could be between 10,000 and 18,000 courses by 2012.

CONCLUSION

RFB is effective and safe in combination with the PIs studied, cost-saving for co-therapy with currently recommended boosted PIs, and may have a pivotal role in the roll-out of ART. Further research into a daily dose of RFB to simplify dosing regimens and developing fixed-dose combinations can enhance the public sector roll-out of ART.

Validation of a high-sensitivity assay for C-reactive protein in human saliva

This study aimed to validate a high-sensitivity assay for C-reactive protein (CRP) in saliva as an alternative medium to study inflammation in large epidemiological cohorts and young people. We measured CRP in saliva and serum in 61 (29.5% males) healthy adult volunteers. We found a moderate-to-strong association between CRP measured in saliva and in serum (r=.72, p<.001). In agreement with the non-steroidal structure and the high molecular weight of CRP, we observed a low saliva-to-serum CRP ratio (1:1633.64). Furthermore, a dichotomous index of salivary CRP, equivalent to a clinically relevant serum CRP cut-off (3mg/l), was associated to known correlates of systemic inflammation (IL-6, BMI and smoking). Finally, we showed that CRP in saliva is stable at room temperature up to 8h after collection. Our study provides initial evidence suggesting that non-invasive assessment of CRP in saliva allows valid prediction of serum CRP. Salivary CRP may thus facilitate and promote research exploring the correlates of low-grade inflammation in epidemiological studies and makes it feasible to expand psychoneuroimmunology research to pediatric populations.