Performance of SARS COV-2 IgG Anti-N as an Independent Marker of Exposure to SARS COV-2 in an Unvaccinated West African Population

Determination of previous SARS-COV-2 infection is hampered by the absence of a standardized test. The marker used to assess previous exposure is IgG antibody to the nucleocapsid (IgG anti-N), although it is known to wane quickly from peripheral blood. The accuracies of seven antibody tests (virus neutralization test, IgG anti-N, IgG anti-spike [anti-S], IgG anti-receptor binding domain [anti-RBD], IgG anti-N + anti-RBD, IgG anti-N + anti-S, and IgG anti-S + anti-RBD), either singly or in combination, were evaluated on 502 cryopreserved serum samples collected before the COVID-19 vaccination rollout in Kumasi, Ghana. The accuracy of each index test was measured using a composite reference standard based on a combination of neutralization test and IgG anti-N antibody tests. According to the composite reference, 262 participants were previously exposed; the most sensitive test was the virus neutralization test, with 95.4% sensitivity (95% CI: 93.6-97.3), followed by 79.0% for IgG anti-N + anti-S (95% CI: 76.3-83.3). The most specific tests were virus neutralization and IgG anti-N, both with 100% specificity. Viral neutralization and IgG anti-N + anti-S were the overall most accurate tests, with specificity/sensitivity of 100/95.2% and 79.0/92.1%, respectively. Our findings indicate that IgG anti-N alone is an inadequate marker of prior exposure to SARS COV-2 in this population. Virus neutralization assay appears to be the most accurate assay in discerning prior infection. A combination of IgG anti-N and IgG anti-S is also accurate and suited for assessment of SARS COV-2 exposure in low-resource settings.

Limited emergence of resistance to integrase strand transfer inhibitors (INSTIs) in ART-experienced participants failing dolutegravir-based antiretroviral therapy: a cross-sectional analysis of a Northeast Nigerian cohort

BACKGROUND

Due to the high prevalence of resistance to NNRTI-based ART since 2018, consolidated recommendations from the WHO have indicated dolutegravir as the preferred drug of choice for HIV treatment globally. There is a paucity of resistance outcome data from HIV-1 non-B subtypes circulating across West Africa.

AIMS

We characterized the mutational profiles of persons living with HIV from a cross-sectional cohort in North-East Nigeria failing a dolutegravir-based ART regimen.

METHODS

WGS of plasma samples collected from 61 HIV-1-infected participants following virological failure of dolutegravir-based ART were sequenced using the Illumina platform. Sequencing was successfully completed for samples from 55 participants. Following quality control, 33 full genomes were analysed from participants with a median age of 40 years and median time on ART of 9 years. HIV-1 subtyping was performed using SNAPPy.

RESULTS

Most participants had mutational profiles reflective of exposure to previous first- and second-line ART regimens comprised NRTIs and NNRTIs. More than half of participants had one or more drug resistance-associated mutations (DRMs) affecting susceptibility to NRTIs (17/33; 52%) and NNRTIs (24/33; 73%). Almost a quarter of participants (8/33; 24.4%) had one or more DRMs affecting tenofovir susceptibility. Only one participant, infected with HIV-1 subtype G, had evidence of DRMs affecting dolutegravir susceptibility-this was characterized by the T66A, G118R, E138K and R263K mutations.

CONCLUSIONS

This study found a low prevalence of resistance to dolutegravir; the data are therefore supportive of the continual rollout of dolutegravir as the primary first-line regimen for ART-naive participants and the preferred switch to second-line ART across the region. However, population-level, longer-term data collection on dolutegravir outcomes are required to further guide implementation and policy action across the region.

Costs of HIV prevention services provided by community-based organizations to female sex workers in Nigeria

BACKGROUND

Nigeria has been consistently targeted in sub-Saharan Africa as an HIV-priority country. Its main mode of transmission is heterosexual, and consequently, a key population of interest is female sex workers (FSWs). While HIV prevention services are increasingly implemented by community-based organizations (CBOs) in Nigeria, there is a paucity of evidence on the implementation costs of these organizations. This study seeks to fill this gap by providing new evidence about service delivery unit cost for HIV education (HIVE), HIV counseling and testing (HCT), and sexually transmitted infection (STI) referral services.

METHODS

In a sample of 31 CBOs across Nigeria, we calculated the costs of HIV prevention services for FSWs taking a provider-based perspective. We collected 2016 fiscal year data on tablet computers during a central data training in Abuja, Nigeria, in August 2017. Data collection was part of a cluster-randomized trial examining the effects of management practices in CBOs on HIV prevention service delivery. Staff costs, recurrent inputs, utilities, and training costs were aggregated and allocated to each intervention to produce total cost calculations, and then divided by the number of FSWs served to produce unit costs. Where costs were shared across interventions, a weight proportional to intervention outputs was applied. All cost data were converted to US dollars using the mid-year 2016 exchange rate. We also explored the cost variation across the CBOs, particularly the roles of service scale, geographic location, and time.

RESULTS

The average annual number of services provided per CBO was 11,294 for HIVE, 3,326 for HCT, and 473 for STI referrals. The unit cost per FSW tested for HIV was 22 USD, the unit cost per FSW reached with HIV education services was 19 USD, and the unit cost per FSW reached by STI referrals was 3 USD. We found heterogeneity in total and unit costs across CBOs and geographic location. Results from the regression models show that total cost and service scale were positively correlated, while unit costs and scale were consistently negatively correlated; this indicates the presence of economies of scale. By increasing the annual number of services by 100 percent, the unit cost decreases by 50 percent for HIVE, 40 percent for HCT, and 10 percent for STI. There was also evidence that indicates that the level of service provision was not constant over time across the fiscal year. We also found unit costs and management to be negatively correlated, though results were not statistically significant.

CONCLUSIONS

Estimates for HCT services are relatively similar to previous studies. There is substantial variation in unit costs across facilities, and evidence of a negative relationship between unit costs and scale for all services. This is one of the few studies to measure HIV prevention service delivery costs to female sex workers through CBOs. Furthermore, this study also looked at the relationship between costs and management practices-the first of its kind to do so in Nigeria. Results can be leveraged to strategically plan for future service delivery across similar settings.

Effect of Nigeria Presidential Task Force on COVID-19 Pandemic, Nigeria

Nigeria had a confirmed case of COVID-19 on February 28, 2020. On March 17, 2020, the Nigerian Government inaugurated the Presidential Task Force (PTF) on COVID-19 to coordinate the country's multisectoral intergovernmental response. The PTF developed the National COVID-19 Multisectoral Pandemic Response Plan as the blueprint for implementing the response plans. The PTF provided funding, coordination, and governance for the public health response and executed resource mobilization and social welfare support, establishing the framework for containment measures and economic reopening. Despite the challenges of a weak healthcare infrastructure, staff shortages, logistic issues, commodity shortages, currency devaluation, and varying state government cooperation, high-level multisectoral PTF coordination contributed to minimizing the effects of the pandemic through early implementation of mitigation efforts, supported by a strong collaborative partnership with bilateral, multilateral, and private-sector organizations. We describe the lessons learned from the PTF COVID-19 for future multisectoral public health response.

SARS-COV-2 antibody responses to AZD1222 vaccination in West Africa

Real-world data on vaccine-elicited neutralising antibody responses for two-dose AZD1222 in African populations are limited. We assessed baseline SARS-CoV-2 seroprevalence and levels of protective neutralizing antibodies prior to vaccination rollout using binding antibodies analysis coupled with pseudotyped virus neutralisation assays in two cohorts from West Africa: Nigerian healthcare workers (n = 140) and a Ghanaian community cohort (n = 527) pre and post vaccination. We found 44 and 28% of pre-vaccination participants showed IgG anti-N positivity, increasing to 59 and 39% respectively with anti-receptor binding domain (RBD) IgG-specific antibodies. Previous IgG anti-N positivity significantly increased post two-dose neutralizing antibody titres in both populations. Serological evidence of breakthrough infection was observed in 8/49 (16%). Neutralising antibodies were observed to wane in both populations, especially in anti-N negative participants with an observed waning rate of 20% highlighting the need for a combination of additional markers to characterise previous infection. We conclude that AZD1222 is immunogenic in two independent West African cohorts with high background seroprevalence and incidence of breakthrough infection in 2021. Waning titres post second dose indicates the need for booster dosing after AZD1222 in the African setting despite hybrid immunity from previous infection.

Introducing biomarkers for invasive fungal disease in haemato-oncology patients: a single-centre experience

Hypothesis/Gap Statement. The impacts of increased biomarker testing on antifungal prescribing have not yet been fully examined in a real-life setting.Objectives. Biomarkers for invasive fungal disease (IFD) have been shown to reduce antifungal prescriptions in neutropaenic haemato-oncology patients. Our study aimed to assess the real-life impacts of introducing a novel biomarker-based pathway, incorporating serum galactomannan and Aspergillus PCR, for pyrexial haemato-oncology admissions.Methods. Patients with neutropaenic fever were identified prospectively after introduction of the new pathway from 2013-2015. A historical group of neutropaenic patients who had blood cultures taken from 2009-2012 was generated for comparison. Clinical details, including demographics, underlying diagnosis, investigations, radiology and antimicrobial treatment were obtained.Results. Prospective data from 308 patients were compared to retrospective data from 302 patients. The proportion of patients prescribed an antifungal medication was unchanged by the pathway (P=0.79), but the pattern was different, with more patients receiving targeted antifungals (P=0.04). A negative serum galactomannan test was not sufficient evidence to withhold therapy, with 17.2% of these episodes felt to have possible or probable IFD using the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) criteria. There was no difference in 30-day mortality (P=0.21) or 1-year mortality (P=0.57) following introduction of the pathway.Conclusions. Biomarkers can be used safely as part of a multidisciplinary approach to the diagnosis of IFD in neutropaenic haemato-oncology patients. Whilst they do not necessarily result in antifungal therapy being withheld, they can allow more confident diagnosis of IFD and more specific antifungal therapy in selected cases.

Population health outcomes in Nigeria compared with other west African countries, 1998-2019: a systematic analysis for the Global Burden of Disease Study

BACKGROUND

Population-level health and mortality data are crucial for evidence-informed policy but scarce in Nigeria. To fill this gap, we undertook a comprehensive assessment of the burden of disease in Nigeria and compared outcomes to other west African countries.

METHODS

In this systematic analysis, using data and results of the Global Burden of Diseases, Injuries, and Risk Factors Study 2019, we analysed patterns of mortality, years of life lost (YLLs), years lived with disability (YLDs), life expectancy, healthy life expectancy (HALE), and health system coverage for Nigeria and 15 other west African countries by gender in 1998 and 2019. Estimates of all-age and age-standardised disability-adjusted life-years for 369 diseases and injuries and 87 risk factors are presented for Nigeria. Health expenditure per person and gross domestic product were extracted from the World Bank repository.

FINDINGS

Between 1998 and 2019, life expectancy and HALE increased in Nigeria by 18% to 64·3 years (95% uncertainty interval [UI] 62·2-66·6), mortality reduced for all age groups for both male and female individuals, and health expenditure per person increased from the 11th to third highest in west Africa by 2018 (US$18·6 in 2001 to $83·75 in 2018). Nonetheless, relative outcomes remained poor; Nigeria ranked sixth in west Africa for age-standardised mortality, seventh for HALE, tenth for YLLs, 12th for health system coverage, and 14th for YLDs in 2019. Malaria (5176·3 YLLs per 100 000 people, 95% UI 2464·0-9591·1) and neonatal disorders (4818·8 YLLs per 100 000, 3865·9-6064·2) were the leading causes of YLLs in Nigeria in 2019. Nigeria had the fourth-highest under-five mortality rate for male individuals (2491·8 deaths per 100 000, 95% UI 1986·1-3140·1) and female individuals (2117·7 deaths per 100 000, 1756·7-2569·1), but among the lowest mortality for men older than 55 years. There was evidence of a growing non-communicable disease burden facing older Nigerians.

INTERPRETATION

Health outcomes remain poor in Nigeria despite higher expenditure since 2001. Better outcomes in countries with equivalent or lower health expenditure suggest health system strengthening and targeted intervention to address unsafe water sources, poor sanitation, malnutrition, and exposure to air pollution could substantially improve population health.

FUNDING

The Bill & Melinda Gates Foundation.

Development of a Quality Assurance Score for the Nigeria AIDS Indicator and Impact Survey (NAIIS) Database: Validation Study

BACKGROUND

In 2018, Nigeria implemented the world's largest HIV survey, the Nigeria AIDS Indicator and Impact Survey (NAIIS), with the overarching goal of obtaining more reliable metrics regarding the national scope of HIV epidemic control in Nigeria.

OBJECTIVE

This study aimed to (1) describe the processes involved in the development of a new database evaluation tool (Database Quality Assurance Score [dQAS]) and (2) assess the application of the dQAS in the evaluation and validation of the NAIIS database.

METHODS

The dQAS tool was created using an online, electronic Delphi (e-Delphi) methodology with the assistance of expert review panelists. Thematic categories were developed to form superordinate categories that grouped themes together. Subordinate categories were then created that decomposed themes for more specificity. A validation score using dQAS was employed to assess the technical performance of the NAIIS database.

RESULTS

The finalized dQAS tool was composed of 34 items, with a total score of 81. The tool had 2 sections: validation item section, which contains 5 subsections, and quality assessment score section, with a score of "1" for "Yes" to indicate that the performance measure item was present and "0" for "No" to indicate that the measure was absent. There were also additional scaling scores ranging from "0" to a maximum of "4" depending on the measure. The NAIIS database achieved 78 out of the maximum total score of 81, yielding an overall technical performance score of 96.3%, which placed it in the highest category denoted as "Exceptional."

CONCLUSIONS

This study showed the feasibility of remote internet-based collaboration for the development of dQAS-a tool to assess the validity of a locally created database infrastructure for a resource-limited setting. Using dQAS, the NAIIS database was found to be valid, reliable, and a valuable source of data for future population-based, HIV-related studies.

Lessons from co-production of evidence and policy in Nigeria's COVID-19 response

In February 2020, Nigeria faced a potentially catastrophic COVID-19 outbreak due to multiple introductions, high population density in urban slums, prevalence of other infectious diseases and poor health infrastructure. As in other countries, Nigerian policymakers had to make rapid and consequential decisions with limited understanding of transmission dynamics and the efficacy of available control measures. We present an account of the Nigerian COVID-19 response based on co-production of evidence between political decision-makers, health policymakers and academics from Nigerian and foreign institutions, an approach that allowed a multidisciplinary group to collaborate on issues arising in real time. Key aspects of the process were the central role of policymakers in determining priority areas and the coordination of multiple, sometime conflicting inputs from stakeholders to write briefing papers and inform effective national decision making. However, the co-production approach met with some challenges, including limited transparency, bureaucratic obstacles and an overly epidemiological focus on numbers of cases and deaths, arguably to the detriment of addressing social and economic effects of response measures. Larger systemic obstacles included a complex multitiered health system, fragmented decision-making structures and limited funding for implementation. Going forward, Nigeria should strengthen the integration of the national response within existing health decision bodies and implement strategies to mitigate the social and economic impact, particularly on the poorest Nigerians. The co-production of evidence examining the broader public health impact, with synthesis by multidisciplinary teams, is essential to meeting the social and public health challenges posed by the COVID-19 pandemic in Nigeria and other countries.

Evaluating the use of a 22-pathogen TaqMan array card for rapid diagnosis of respiratory pathogens in intensive care

Introduction. Pneumonia is highly prevalent in intensive care units (ICUs), with high associated mortality. Empirical treatment prioritizes breadth of coverage while awaiting laboratory diagnosis, often at the expense of antimicrobial stewardship. Microarrays use multiple parallel polymerase chain reactions to enable a rapid syndromic approach to laboratory diagnosis.Aim. To evaluate the clinical and laboratory implications of introducing a bespoke 22-pathogen TaqMan Array Card (TAC) for rapid pathogen detection in deep respiratory samples from adult ICUs.Methodology. TAC results from all ICU patients prospectively tested over a 9-month period at Cambridge's Clinical Microbiology and Public Health Laboratory were compared to those of corresponding conventional microbiological assays (culture-, PCR- or serology-based) in terms of result agreement and time-to-result availability. Clinical impact was assessed by retrospective review of medical records.Results. Seventy-one patients were included [45 (63 %) male, median age 59). Overall result agreement was 94 %, with TAC detecting more pathogens than conventional methods. TAC detected Streptococcus pneumoniae more readily than culture (7 vs 0 cases; P=0.02). TAC did not detect Aspergillus spp. in eight culture- or galactomannan-positive cases. The median turnaround time (1 day) was significantly shorter than that of bacterial/fungal culture, Pneumocystis jirovecii PCR and galactomannan testing (each 3 days; P<0.001), atypical bacteria serology (13 days; P<0.001) and Mycobacterium tuberculosis culture (46 days; P<0.001). Earlier result availability prompted discontinuation of unnecessary antimicrobials in 15/71 (21 %) cases, but had no bearing on patient isolation/deisolation.Conclusion. TAC provided greater overall yield of pathogen detection and faster turnaround times, permitting earlier discontinuation of unnecessary antimicrobials.

Verification of HIV Self-Testing Use and Results: A Global Systematic Review

HIV self-testing (HIVST) allows individuals to interpret and report their own test results, thus decentralizing testing. Yet, this decentralization can make it difficult to verify self-testing results, which is important for linkage to care and surveillance. The aim of this systematic review is to summarize methods for verifying HIVST use and results. We followed guidance from the Cochrane Handbook 5.1 on systematic reviews. We searched four journal databases (PubMed, Embase, Scopus, and Cochrane Library), one clinical trials database (ClinicalTrials.gov), two conference abstract databases (International AIDS Society and Conference on Retroviruses and Opportunistic Infections) and one gray literature database (OpenGrey). We included studies that verified opening of kits or test results. Two researchers independently screened articles and extracted data regarding HIVST location, method of verification, who performed verification, proportion of results verified, and primary or secondary kit distribution. The search yielded 3853 unique citations, of which 40 contained information on HIVST verification and were included. Among these 40 studies, 13 were in high-income countries, 16 were in middle-income countries, and 11 were in low-income countries. Seventeen studies included key populations and two focused on youth. Three methods verified results: supervision by a health provider, returning used test kits, and electronic transmission of photographs. One method verified opening of kits using Bluetooth sensors. Although HIVST has increased worldwide, strategies to verify self-testing results remain limited. These findings suggest a need for additional innovative strategies for verifying HIVST use and results and linkage of self-testing results to surveillance and care systems.

Missed opportunities for early infant diagnosis of HIV in rural North-Central Nigeria: A cascade analysis from the INSPIRE MoMent study

Background

Early identification of HIV-infected infants for treatment is critical for survival. Efficient uptake of early infant diagnosis (EID) requires timely presentation of HIV-exposed infants, same-day sample collection, and prompt release of results. The MoMent (Mother Mentor) Nigeria study investigated the impact of structured peer support on EID presentation and maternal retention. This cascade analysis highlights missed opportunities for EID and infant treatment initiation during the study.

Methods

HIV-infected pregnant women and their infants were recruited at 20 rural Primary Healthcare Centers. Routine infant HIV DNA PCR testing was performed at centralized laboratories using dried blood spot (DBS) samples ideally collected by age two months. EID outcomes data were abstracted from study case report forms and facility registers. Descriptive statistics summarized gaps and missed opportunities in the EID cascade.

Results

Out of 497 women enrolled, delivery data was available for 445 (90.8%), to whom 415 of 455 (91.2%) infants were live-born. Out of 408 live-born infants with available data, 341 (83.6%) presented for DBS sampling at least once. Only 75.4% (257/341) were sampled, with 81.7% (210/257) sampled at first presentation. Only 199/257 (77.4%) sampled infants had results available up to 28 months post-collection. Two (1.0%) of the 199 infants tested HIV-positive; one infant died before treatment initiation and the other was lost to follow-up.

Conclusions

While nearly 85% of infants presented for sampling, there were multiple missed opportunities, largely due to health system and not necessarily patient-level failures. These included infants presenting without being sampled, presenting multiple times before samples were collected, and getting sampled but results not forthcoming. Finally, neither of the two HIV-positive infants were linked to treatment within the follow-up period, which may have led to the death of one. To facilitate patient compliance and HIV-free infant survival, quality improvement approaches should be optimized for EID commodity availability, consistent DBS sample collection, efficient processing/result release, and prompt infant treatment initiation.

Leave no one behind: response to new evidence and guidelines for the management of cryptococcal meningitis in low-income and middle-income countries

In 2018, WHO issued guidelines for the diagnosis, prevention, and management of HIV-related cryptococcal disease. Two strategies are recommended to reduce the high mortality associated with HIV-related cryptococcal meningitis in low-income and middle-income countries (LMICs): optimised combination therapies for confirmed meningitis cases and cryptococcal antigen screening programmes for ambulatory people living with HIV who access care. WHO's preferred therapy for the treatment of HIV-related cryptococcal meningitis in LMICs is 1 week of amphotericin B plus flucytosine, and the alternative therapy is 2 weeks of fluconazole plus flucytosine. In the ACTA trial, 1-week (short course) amphotericin B plus flucytosine resulted in a 10-week mortality of 24% (95% CI -16 to 32) and 2 weeks of fluconazole and flucytosine resulted in a 10-week mortality of 35% (95% CI -29 to 41). However, with widely used fluconazole monotherapy, mortality because of HIV-related cryptococcal meningitis is approximately 70% in many African LMIC settings. Therefore, the potential to transform the management of HIV-related cryptococcal meningitis in resource-limited settings is substantial. Sustainable access to essential medicines, including flucytosine and amphotericin B, in LMICs is paramount and the focus of this Personal View.

The role of management on costs and efficiency in HIV prevention interventions for female sex workers in Nigeria: a cluster-randomized control trial

Background

While the world has made much global progress toward the reduction of new HIV infections, HIV continues to be an important public health problem. In the face of constantly constrained resources, donors and grantees alike must seek to optimize resources and deliver HIV services as efficiently as possible. While there is evidence that management practices can affect efficiency, this has yet to be rigorously tested in the context of HIV service delivery.

Methods

The present protocol describes the design of a cluster-randomized control trial to estimate the effect of management practices on efficiency. Specifically, we will evaluate the impact of an intervention focused on improving management practices among community-based organizations (CBOs), on the costs of HIV prevention services for female sex workers (FSW) in Nigeria. To design the intervention, we used a qualitative, design thinking-informed methodology that allowed us to understand management in its organizational context better and to develop a user-centered solution. After designing the suite of management tools, we randomly assigned 16 CBOs to the intervention group, and 15 CBOs to the control group. The intervention consisted of a comprehensive management training and a management “toolkit” to support better planning and organization of their work and better communication between CBOs and community volunteers. Both treatment and control groups received training to record data on efficiency—inputs used, and outputs produced. Both groups will be prospectively followed through to the end of the study, at which point we will compare the average unit cost per FSW served between the two groups using a quasi-experimental “difference-in-differences” (DiD) strategy. This approach identifies the effect of the intervention by examining differences between treatment and control groups, before and after the intervention thus accounting for time-constant differences between groups. Despite the rigorous randomization procedure, the small sample size and diversity in the country may still cause unobservable characteristics linked to efficiency to unbalanced between treatment and control groups at baseline. In anticipation of this possibility, using the quasi-experimental DiD approach allows any baseline differences to be “differenced out” when measuring the effect.

Discussion

This study design will uniquely add to the literature around management practices by building rigorous evidence on the relationship between management skills and practices and service delivery efficiency. We expect that management will positively affect efficiency. This study will produce valuable evidence that we will disseminate to key stakeholders, including those integral to the Nigerian HIV response.

Trial registration This trial has been registered in Clinical Trials (NCT03371914). Registered 13 December 2018

Electronic supplementary material

The online version of this article (10.1186/s12962-018-0107-x) contains supplementary material, which is available to authorized users.

Genomic survey of Clostridium difficile reservoirs in the East of England implicates environmental contamination of wastewater treatment plants by clinical lineages

There is growing evidence that patients with Clostridiumdifficile-associated diarrhoea often acquire their infecting strain before hospital admission. Wastewater is known to be a potential source of surface water that is contaminated with C. difficile spores. Here, we describe a study that used genome sequencing to compare C. difficile isolated from multiple wastewater treatment plants across the East of England and from patients with clinical disease at a major hospital in the same region. We confirmed that C. difficile from 65 patients were highly diverse and that most cases were not linked to other active cases in the hospital. In total, 186 C. difficile isolates were isolated from effluent water obtained from 18 municipal treatment plants at the point of release into the environment. Whole genome comparisons of clinical and environmental isolates demonstrated highly related populations, and confirmed extensive release of toxigenic C. difficile into surface waters. An analysis based on multilocus sequence types (STs) identified 19 distinct STs in the clinical collection and 38 STs in the wastewater collection, with 13 of 44 STs common to both clinical and wastewater collections. Furthermore, we identified five pairs of highly similar isolates (≤2 SNPs different in the core genome) in clinical and wastewater collections. Strategies to control community acquisition should consider the need for bacterial control of treated wastewater.

Staphylococcus aureus urinary tract bacteriuria: single-institutional antibiotic susceptibility trends over a decade

Objectives: Methicillin resistant Staphylococcus aureus (MRSA) is a troublesome pathogen which is difficult for clinicians to treat. The purpose of this surveillance program is to assess the prevalence of MRSA urinary tract infections and determine risk factors for methicillin resistance in adults amongst urinary isolates of SA and to describe the antibiotic susceptibilities to guide empirical therapy.Methods: From 2005 through to 2014, we retrospectively reviewed urine cultures recorded in a laboratory database at a university hospital in Cambridge, UK. Susceptibility testing was performed by BSAC (British Society of Antimicrobial Chemotherapy) disc diffusion testing and reported for fluoroquinolones, gentamicin, nitrofurantoin, linezolid, trimethoprim and vancomycin. Samples were denoted “MRSA” if they were resistant to oxacillin or cefoxitin.Results: In total, 690 cultures were positive for SA, of which 293 (42.5%) were methicillin resistant. The number of SA bacteriuria decreased from around 100 per year to 40 per year. The proportion demonstrating methicillin resistance decreased from around 60% to around 20%. Both methicillin-sensitive Staphylococcus aureus (MSSA) and MRSA isolates were susceptible to vancomycin and nitrofurantoin. MRSA isolates demonstrated some increased resistance to trimethoprim and gentamicin and greatly increased resistance to fluoroquinolones. Urinary catheterization and increasing age were risk factors for methicillin resistance.Conclusion: The incidence of SA and MRSA bacteriuria decreased during the study period. A high degree of resistance to fluoroquinolones was observed in MRSA compared to MSSA. Analysis of antibiotic susceptibility profiles suggests nitrofurantoin and trimethoprim may be useful in treating uncomplicated MSSA and MRSA urinary tract infections without concurrent bacteremia.

The Changing Epidemiology of Invasive Fungal Infections

Invasive fungal infections (IFI) are an emerging problem worldwide with invasive candidiasis and candidemia responsible for the majority of cases. This is predominantly driven by the widespread adoption of aggressive immunosuppressive therapy among certain patient populations (e.g., chemotherapy, transplants) and the increasing use of invasive devices such as central venous catheters (CVCs). The use of new immune modifying drugs has also opened up an entirely new spectrum of patients at risk of IFIs. While the epidemiology of candida infections has changed in the last decade, with a gradual shift from C. albicans to non-albicans candida (NAC) strains which may be less susceptible to azoles, these changes vary between hospitals and regions depending on the type of population risk factors and antifungal use. In certain parts of the world, the incidence of IFI is strongly linked to the prevalence of other disease conditions and the ecological niche for the organism; for instance cryptococcal and pneumocystis infections are particularly common in areas with a high prevalence of HIV disease. Poorly controlled diabetes is a major risk factor for invasive mould infections. Environmental factors and trauma also play a unique role in the epidemiology of mould infections, with well-described hospital outbreaks linked to the use of contaminated instruments and devices. Blastomycosis is associated with occupational exposure (e.g., forest rangers) and recreational activities (e.g., camping and fishing).The true burden of IFI is probably an underestimate because of the absence of reliable diagnostics and lack of universal application. For example, the sensitivity of most blood culture systems for detecting candida is typically 50 %. The advent of new technology including molecular techniques such as 18S ribosomal RNA PCR and genome sequencing is leading to an improved understanding of the epidemiology of the less common mould and dimorphic fungal infections. Molecular techniques are also providing a platform for improved diagnosis and management of IFI.Many factors affect mortality in IFI, not least the underlying medical condition, choice of therapy, and the ability to achieve early source control. For instance, mortality due to pneumocystis pneumonia in HIV-seronegative individuals is now higher than in seropositive patients. Of significant concern is the progressive increase in resistance to azoles and echinocandins among candida isolates, which appears to worsen the already significant mortality associated with invasive candidiasis. Mortality with mould infections approaches 50 % in most studies and varies depending on the site, underlying disease and the use of antifungal agents such as echinocandins and voriconazole. Nevertheless, mortality for most IFIs has generally fallen with advances in medical technology, improved care of CVCs, improved diagnostics, and more effective preemptive therapy and prophylaxis.

Patient and public understanding and knowledge of antimicrobial resistance and stewardship in a UK hospital: should public campaigns change focus?

BACKGROUND

The rising global tide of antimicrobial resistance is a well-described phenomenon. Employing effective and innovative antimicrobial stewardship strategies is an essential approach to combat this public health threat. Education of the public and patients is paramount to enable the success of such strategies.

METHODS

A panel of hospital multidisciplinary healthcare professionals was set up and a short quiz containing true/false statements around antimicrobial stewardship and resistance was designed and piloted. An educational leaflet with the correct replies and supporting information was also produced and disseminated. Participants were recruited on a single day (18 November 2015) from the hospital outpatient clinics and the hospital outpatient pharmacy waiting room.

RESULTS

One hundred and forty-five completed quizzes were returned, providing a total of 1450 answers. Overall, 934 of 1450 (64%) statements were scored correctly whilst 481 (33%) were scored incorrectly; 35 (3%) statements were left unscored. We speculate that these results may demonstrate that respondents understood the statements, as only a small proportion of statements were left unanswered. The question dealing with the definition of antimicrobial resistance and the question dealing with the definition of antimicrobial stewardship obtained the most incorrect replies (85% and 72%, respectively). However, a specific factual recall question regarding only one microorganism (MRSA) received the most correct responses (99%).

CONCLUSIONS

We describe a simple, innovative method of engagement with patients and the general public to help educate and disseminate important public health messages around antimicrobial resistance and stewardship. We also identified the need for public health campaigns to address the knowledge gaps found around this topic.

Candida growth in urine cultures: a contemporary analysis of species and antifungal susceptibility profiles

BACKGROUND

Recent publications suggest the distribution of Candida species causing candiduria may vary geographically, which has implications for the continued efficacy of antifungal therapy and emerging resistance.

AIM

To investigate the incidence of Candiduria at a university hospital in the UK. Further, to assess the distribution of species and the accompanying antifungal susceptibility profile, in order to monitor the clinical utility of current antifungal treatment guidelines for candiduria so that patients receive the best possible outcomes from the most up to date care.

DESIGN

Retrospective audit.

METHODS

From 1st January 2005 to 31st October 2014, we retrospectively reviewed 37 538 positive urine cultures recorded in a computerized laboratory results database. Identification and susceptibility testing was performed using the VITEK® 2 fungal susceptibility card (bioMérieux, Marcy d'Etoile, France).

RESULTS

In total, 96 cultures were positive for Candida species, of which 69 (72%) were C.albicans, which translates to a prevalence of 2.6 per 1000 positive urine cultures. Candiduria was more common in younger patients, males and catheterized females. We report 94 and 73% of isolates of C.albicans and other non-C.albicans Candida species were susceptible to fluconazole. All isolates were susceptible to amphotericin B.

CONCLUSIONS

Our results add weight to the evidence supporting current European and North American guidelines recommending fluconazole or amphotericin B for treatment of candiduria, if antifungal treatment is clinically indicated.

Vancomycin resistant enterococci in urine cultures: Antibiotic susceptibility trends over a decade at a tertiary hospital in the United Kingdom

Purpose

Enterococci are a common cause of urinary tract infection and vancomycin-resistant strains are more difficult to treat. The purpose of this surveillance program was to assess the prevalence of and determine the risk factors for vancomycin resistance in adults among urinary isolates of Enterococcus sp. and to detail the antibiotic susceptibility profile, which can be used to guide empirical treatment.

Materials and Methods

From 2005 to 2014 we retrospectively reviewed 5,528 positive Enterococcus sp. urine cultures recorded in a computerized laboratory results database at a tertiary teaching hospital in Cambridge, United Kingdom.

Results

Of these cultures, 542 (9.8%) were vancomycin resistant. No longitudinal trend was observed in the proportion of vancomycin-resistant strains over the course of the study. We observed emerging resistance to nitrofurantoin with rates climbing from near zero to 40%. Ampicillin resistance fluctuated between 50% and 90%. Low resistance was observed for linezolid and quinupristin/dalfopristin. Female sex and inpatient status were identified as risk factors for vancomycin resistance.

Conclusions

The incidence of vancomycin resistance among urinary isolates was stable over the last decade. Although resistance to nitrofurantoin has increased, it still serves as an appropriate first choice in uncomplicated urinary tract infection caused by vancomycin-resistant Enterococcus sp.

Pseudomonas aeruginosa meningitis/ventriculitis in a UK tertiary referral hospital

BACKGROUND

Pseudomonas aeruginosa is a rare cause of meningitis and ventriculitis but is generally associated with significant morbidity and mortality.

AIM

We sought to determine the epidemiology, risk factors and outcome of meningitis and ventriculitis due to P. aeruginosa at our institution in order to inform preventive strategies and treatment guidelines.

METHODS

Retrospective study of all patients with a positive cerebrospinal fluid (CSF) culture admitted to a tertiary care hospital over 18 years. Clinical details, demographic, microbiological and antibiotic data were obtained from laboratory and medical records.

RESULTS

Twenty-four episodes occurred in 21 patients over 18 years. Pyrexia (75%), fluctuating mental status (50%) and headache (41%) were the most frequent presenting symptoms. Nineteen of the 21 patients had previously undergone a neurosurgical procedure and seven had extra-ventricular devices in situ. Twelve (57%) patients had P. aeruginosa isolated from another site prior to their episode. Most (89%) CSF samples demonstrated a neutrophilia; the CSF protein, when measured, was raised in all cases. Gram-negative bacilli were visible on CSF microscopy in only three isolates. There were relatively low rates of resistance to most antimicrobials tested and combination treatment of intravenous with intrathecal antibiotics was often used. No patients died within 28 days.

CONCLUSION

Pseudomonas aeruginosa meningitis and ventriculitis are predominantly nosocomial and related to prior neurosurgery. It can be difficult to diagnose as CSF Gram-film and meningism are insensitive markers. Appropriate empirical treatment, neurosurgical prophylaxis and surveillance can aid in managing this infection.

Bacteremia in children: epidemiology, clinical diagnosis and antibiotic treatment

The diagnosis of bacteremia in children is important and it can be clinically challenging to recognize the signs and symptoms. The reported rates of bacteremia are higher in young children but with the increasing vaccine coverage, there has been a decrease in bacteremia due to the three vaccine preventable bacteria (Streptococcus pneumoniae, Haemophilus influenzae group b and Neisseria meningitidis). Notably, there have been increases in healthcare-associated bacteremias with a rise in Staphylococcus aureus and Gram negative bacteremias. This review provides a brief overview of the clinical diagnosis of bacteremia in children, focusing on the epidemiology, clinical characteristics, risk factors, antibiotic treatment, outcomes and preventative measures to reduce the incidence of bacteremia and improve morbidity and mortality.

Impact of routine bedside infectious disease consultation on clinical management and outcome of Staphylococcus aureus bacteraemia in adults

Staphylococcus aureus bacteraemia (SAB) is a common, serious infection that is associated with high rates of morbidity and mortality. Evidence suggests that infectious disease consultation (IDC) improves clinical management in patients with SAB. We examined whether the introduction of a routine bedside IDC service for adults with SAB improved clinical management and outcomes compared to telephone consultation. We conducted an observational cohort study of 571 adults with SAB at a teaching hospital in the United Kingdom between July 2006 and December 2012. A telephone consultation was provided on the day of positive blood culture in all cases, but an additional bedside IDC was provided after November 2009 (routine IDC group). Compared to patients in the pre-IDC group, those in the routine IDC group were more likely to have a removable focus of infection identified, echocardiography performed and follow-up blood cultures performed. They also received longer courses of antimicrobial therapy, were more likely to receive combination antimicrobial therapy and were more likely to have SAB recorded in the hospital discharge summary. There was a trend towards lower mortality at 30 days in the routine IDC group compared to the pre-IDC group (12% vs. 22%, p 0.07). Our findings suggest that routine bedside IDC should become the standard of care for adults with SAB.

Screening urine samples for the absence of urinary tract infection using the sediMAX automated microscopy analyser

Urinalysis culminates in a workload skew within the clinical microbiology laboratory. Routine processing involves screening via manual microscopy or biochemical dipstick measurement, followed by culture for each sample. Despite this, as many as 80% of specimens are reported as negative; thus, there is vast wastage of resources and time, as well as delayed turnaround time of results as numerous negative cultures fulfil their required incubation time. Automation provides the potential for streamlining sample screening by efficiently (>30% sample exclusion) and reliably [negative predictive value (NPV) ≥ 95%] ruling out those likely to be negative, whilst also reducing resource usage and hands-on time. The present study explored this idea by using the sediMAX automated microscopy urinalysis platform. We prospectively collected and processed 1411 non-selected samples directly after routine laboratory processing. The results from this study showed multiple optimum cut-off values for microscopy. However, although optimum cut-off values permitted rule-out of 40.1% of specimens, an associated 87.5% NPV was lower than the acceptable limit of 95%. Sensitivity and specificity of leukocytes and bacteria in determining urinary tract infection was assessed by receiver operator characteristic curves with area under the curve values found to be 0.697 [95% confidence interval (CI): 0.665-0.729] and 0.587 (95% CI: 0.551-0.623), respectively. We suggested that the sediMAX was not suitable for use as a rule-out screen prior to culture and further validation work must be carried out before routine use of the analyser.

Introduction of an antifungal stewardship programme targeting high-cost antifungals at a tertiary hospital in Cambridge, England

BACKGROUND

Antifungal stewardship aims to promote the optimal use of antifungals through the careful selection of agents based on patient profile, target organism, toxicity, costs and the likelihood of emergence and spread of resistance.

METHODS

We report on an observational prospective 12 month study conducted by an antifungal stewardship team targeting the use of echinocandins (caspofungin and micafungin), voriconazole and liposomal amphotericin B in a tertiary referral hospital in the UK.

RESULTS

One-hundred-and-seventy-three patients were reviewed on 294 occasions. Clinical advice was given and implemented during review of 45 (88.2%) of micafungin prescriptions, 70 (78.7%) of those receiving voriconazole, 78 (62.4%) of those receiving liposomal amphotericin B and 3 (27.3%) of those receiving caspofungin. Except for voriconazole, nearly half of all treatments reviewed were stopped or changed. This study found that a crude cost saving of ∼£180 000 in antifungal drugs was generated compared with the previous year.

CONCLUSIONS

Using a multidisciplinary team, antifungal stewardship can achieve significant improvements in patient management and it may reduce costs.

Impact of infectious diseases consultation on the management of Staphylococcus aureus bacteraemia in children

OBJECTIVES

Infectious diseases consultation (IDC) in adults with Staphylococcus aureus bacteraemia (SAB) has been shown to improve management and outcome. The aim of this study was to evaluate the impact of IDC on the management of SAB in children.

STUDY DESIGN

Observational cohort study of children with SAB.

SETTING

Cambridge University Hospitals National Health Service (NHS) Foundation Trust, a large acute NHS Trust in the UK.

PARTICIPANTS

All children with SAB admitted to the Cambridge University Hospitals NHS Foundation Trust between 16 July 2006 and 31 December 2012.

METHODS

Children with SAB between 2006 and 31 October 2009 were managed by routine clinical care (pre-IDC group) and data were collected retrospectively by case notes review. An IDC service for SAB was introduced in November 2009. All children with SAB were reviewed regularly and data were collected prospectively (IDC group) until 31 December 2012. Baseline characteristics, quality metrics and outcome were compared between the pre-IDC group and IDC group.

RESULTS

There were 66 episodes of SAB in 63 children-28 patients (30 episodes) in the pre-IDC group, and 35 patients (36 episodes) in the IDC group. The median age was 3.4 years (IQR 0.2-10.7 years). Patients in the IDC group were more likely to have echocardiography performed, a removable focus of infection identified and to receive a longer course of intravenous antimicrobial therapy. There were no differences in total duration of antibiotic therapy, duration of hospital admission or outcome at 30 or 90 days following onset of SAB.

CONCLUSIONS

IDC resulted in improvements in the investigation and management of SAB in children.

Utility of a novel multiplex TaqMan PCR assay for metallo-β-lactamase genes plus other TaqMan assays in detecting genes encoding serine carbapenemases and clinically significant extended-spectrum β-lactamases

Prompt detection of infections caused by Enterobacteriaceae that produce therapeutically important β-lactamases [metallo-β-lactamases (MBLs), serine carbapenemases, acquired AmpC and CTX-M extended-spectrum β-lactamases (ESBLs)] is crucial for infection prevention and control and surveillance purposes, and, more contentiously, also for effective patient management. A novel TaqMan PCR assay was developed to detect genes encoding IMP, VIM, NDM, SPM, SIM and GIM MBLs. Published PCR assays for acquired genes encoding CTX-M ESBLs and AmpC β-lactamases were updated and adapted to the TaqMan format, respectively. A published TaqMan assay for serine carbapenemase genes was used. Assay specificity was tested using a panel of 59 isolates with known acquired genes from the four different β-lactamase groupings. The four TaqMan assays correctly identified the most clinically relevant acquired β-lactamase genes in the panel of 59 resistant Enterobacteriaceae, which included 3 VIM-, 7 NDM- and 12 IMP-producers. Consecutive, non-duplicate isolates of Enterobacteriaceae from 965 urinary and 343 blood cultures during 2010 were then screened for β-lactamase genes using these TaqMan assays. Amongst the urinary and blood culture isolates tested, 69 CTX-M-producers and 21 acquired AmpC β-lactamase-producers were identified; the CTX-M rate amongst blood culture isolates (9.3%) broadly reflects the UK national average. During the study period, one Klebsiella pneumoniae isolate producing an NDM carbapenemase was identified from a wound sample. The assays developed and/or used will enable the future surveillance and the rapid detection and appropriate early treatment of infections caused by Gram-negative bacteria producing clinically important β-lactamases, including carbapenemases.

Gram negative bacteraemia – are they preventable and what will E. coli surveillance add?

The Department of Health in England introduced mandatory reporting of Escherichia coli bacteraemia in June 2011. We sought to determine the preventability of Gram negative bacteraemias and the efficacy of using E. coli bacteraemia as a surveillance tool. A six-month prospective study evaluated the preventability of Gram negative bacteraemias. Two investigators independently classified bacteraemias as preventable or not preventable. There were 141 bacteraemias (122 episodes) in 118 patients in the study period. E. coli was the most frequently isolated organism. Thirty five episodes (28.7%) were community onset, 24 (19.7%) hospital onset and 63 (51.6%) were healthcare-associated. Three bacteraemias (2.5%) were thought to be probably preventable and 21(17.2%) were thought to be possibly preventable. Factors associated with preventability by multivariable analysis included presence of a urinary catheter or central venous catheter and dependent functional state. A significant number of Gram negative bacteraemias were thought to be preventable, especially in patients with urinary catheters and central venous catheters. Surveillance of E. coli bacteraemias is an insensitive and non-specific method for identifying preventable Gram negative bacteraemias. We propose that targeted surveillance of patients with urinary catheters and central venous catheters in situ could help reduce infections.

Campylobacter gastroenteritis associated with Sweet's syndrome

Sweet's syndrome or acute febrile neutrophilic dermatosis has been associated with underlying infection, malignancy, inflammatory disease and certain medications. The infection agents associated with this include Streptococcus species, Yersinia species, Chlamydia species, Salmonella species and Helicobacter pylori. We report a case of Sweet's syndrome in a 73-year-old woman following a 2 week course of severe gastroenteritis caused by Campylobacter species. Histological examination of skin lesions showed marked inflammatory infiltrate throughout the dermis, composed of neutrophils and histiocytes. The patient was successfully treated with topical and systemic steroids. To date, this is the first case of Sweet's syndrome to be reported linked to Campylobacter species to our knowledge.

An audit of acute bacterial meningitis in a large teaching hospital 2005-10

BACKGROUND

Acute bacterial meningitis (ABM) is a rare disease associated with severe neurological sequelae and death. Clinical features on admission may be subtle and thus delay recognition. Previous studies have shown association between early administration of antibiotics and favourable outcomes.

AIM

To examine the presenting clinical features of patients aged >15 years with ABM admitted to a University teaching hospital. To audit investigations and treatment including lumbar puncture (LP), computed tomography (CT) and antibiotics against British Infection Association guidelines.

DESIGN

Retrospective observational audit.

METHODS

Hospital records were reviewed for presenting clinical features and timing of CT scan, LP and antibiotics.

RESULTS

Records of 39 patients with ABM were reviewed. The classical triad of fever, neck stiffness and altered mental state was present on admission in only 21% of cases. LP was contraindicated in 69% of cases. Immediate LP was carried out in only 17% of those who had no contraindication. Antibiotics were administered after a median of 79 min (interquartile range 24-213 min); 65% were given within 3 h after arrival. Eighty-five percent of patients had antibiotics in accordance with local guidelines.

CONCLUSION

In patients with ABM, the classical clinical features are uncommon on arrival to hospital and frequently evolve following admission. The majority of patients have contraindications to immediate LP. Efforts should be made to facilitate immediate LP performed in the Emergency Department when there are no contraindications. Earlier administration of antibiotics in cases of suspected ABM and close review following admission is recommended.

Clostridium difficile in children: colonisation and disease

Clostridium difficile is the commonest cause of hospital acquired diarrhoea in adults and is associated with significant mortality and morbidity. The clinical significance of C. difficile in children, however, is less certain. In this article we discuss colonisation and infection and describe C. difficile in childhood in terms of risk factors, epidemiology and management.

Outcome for Gram-negative bacteraemia when following restrictive empirical antibiotic guidelines

INTRODUCTION

Restrictions in prescribing broad spectrum antimicrobials have been part of a strategy to reduce Clostridium difficile cases in the UK in recent years. However, there has been little work on assessing the safety of alternative antimicrobial agents.

METHODS

We performed an uncontrolled prospective observational survey over a 1-year period to determine the effectiveness and safety of a new antimicrobial stewardship programme in a district hospital in the UK.

RESULTS

In total, 227 Gram-negative bacteraemias (203 episodes) occurred in the study period. Guidelines were adequate in 194 of 203 (95%) episodes and 163 episodes (80.2%) received adequate therapy. Patients in the inadequate therapy group had >2-fold increased likelihood of death [odds ratio (OR) = 2.63, 95% confidence interval (CI) = 1.09-6.34] within 30 days and >6-fold increased risk of death (OR = 6.40, 95% CI = 2.22-18.45) within 1 week when compared to patients in the adequate therapy group. Failure to administer gentamicin was the principal reason for not following the guidelines (18 episodes). Eight of these 18 episodes were susceptible to cefuroxime and two of these patients died.

DISCUSSION

Adherence to the guidelines was associated with a correct empirical antibiotic choice and reduced mortality. This study also demonstrates the importance of adopting guidelines based on local susceptibility patterns.

Bacteraemia and subsequent vertebral osteomyelitis: a retrospective review of 125 patients

BACKGROUND

Vertebral osteomyelitis (VO) is associated with considerable morbidity and its incidence seems to be increasing. Haematogenous spread is an important aetiological factor.

AIM

The objective was to describe a series of patients with VO and to search for a relationship between preceding bacteraemia and subsequent VO with the same pathogen.

DESIGN AND METHODS

A retrospective study of all treated cases of VO in a tertiary hospital over a 10-year period.

RESULTS

There were 129 cases of VO (involving 125 patients) that received antimicrobial treatment. Eighty-three (66%) were male and the mean age was 59.5 years (range 1 month to 87 years). The vertebral level involved was lumbar in 66 (53%) cases and thoracic in 35 (28%) cases. Seventy-four cases (59%) had a microbiologically confirmed aetiology. The diagnostic yield from procedures was 46 and 36% from blood culture and bone biopsy, respectively. Staphylococcus aureus was the most common pathogen [38 of 74 (51%) cases]. Nine of 38 (24%) cases of Staphylococcus aureus VO had a preceding bacteraemia with the same pathogen in the previous year.

CONCLUSION

Staphylococcus aureus is an important pathogen causing bacteraemia with the ability to cause metastatic complications including VO. The high proportion of cases developing VO following a documented bacteraemia, sometimes many months previously, reinforce the importance of adequate aggressive treatment for bacteraemia. VO must be considered in all patients presenting with back pain up to a year after bacteraemia. Previous bacteraemias with relevant pathogens can help guide antibiotic treatment at presentation of VO and if biopsy cannot be obtained.

Spondylodiscitis: update on diagnosis and management

Spondylodiscitis, a term encompassing vertebral osteomyelitis, spondylitis and discitis, is the main manifestation of haematogenous osteomyelitis in patients aged over 50 years. Staphylococcus aureus is the predominant pathogen, accounting for about half of non-tuberculous cases. Diagnosis is difficult and often delayed or missed due to the rarity of the disease and the high frequency of low back pain in the general population. In this review of the published literature, we found no randomized trials on treatment and studies were too heterogeneous to allow comparison. Improvements in surgical and radiological techniques and the discovery of antimicrobial therapy have transformed the outlook for patients with this condition, but morbidity remains significant. Randomized trials are needed to assess optimal treatment duration, route of administration, and the role of combination therapy and newer agents.

A review of mortality due to Clostridium difficile infection

SUMMARY

In this review we examine published literature to ascertain mortality in relation to Clostridium difficile infection (CDI) and the factors associated with mortality. In the 27 studies that had sufficient data, there were 10975 cases of CDI with great heterogeneity in the methods for reporting mortality. We calculated the overall associated mortality to be at least 5.99% within 3 months of diagnosis. The most important finding is that higher mortality is associated with advanced age, being 13.5% in patients over 80 years. Studies performed after 2000 had a significantly higher mortality than those before this date. We propose minimum standards for reporting mortality in future studies.

Role of interferon-gamma release assays in healthcare workers

The advent of interferon-gamma release assays (IGRAs) provides new options for detection of latent tuberculosis infection (LTBI). This is particularly relevant to healthcare workers (HCWs), who are at higher risk of infection, but who have often also been vaccinated. In this article, we discuss the role of IGRAs for the diagnosis of LTBI in various healthcare settings. A search was performed for studies that reported data on IGRAs in HCWs in the last 18 years. Twenty-two studies met the inclusion criteria. IGRAs showed poor agreement with the tuberculin skin test (TST), except in countries with high incidences of tuberculosis (TB), but generally correlated better with markers of exposure to TB including during contact investigation. The T-SPOT.TB assay has not been adequately assessed in HCWs; the few studies available showed enhanced specificity of T-SPOT.TB when compared to TST. This review confirms the utility of IGRAs as important tools in the prevention and control of tuberculosis in healthcare settings.

Detection of Mycobacterium avium subspecies paratuberculosis from patients with Crohn's disease using nucleic acid-based techniques: a systematic review and meta-analysis

This study is a systematic review and meta-analysis of studies using nucleic acid-based techniques to detect Mycobacterium avium paratuberculosis (MAP) in patients with Crohn's disease (CD) compared with controls. Database searches were conducted and risk difference estimates were calculated using meta-analysis. Fifty-eight studies were reviewed, 47 of which were included in the analysis. The pooled estimate of risk difference from all studies was 0.23 (95% confidence interval [CI], 0.14-0.32) using a random effects model. Similarly, MAP was detected more frequently from patients with CD compared with those with ulcerative colitis (risk difference 0.19, 95% CI, 0.10-0.28). Year of study, assay type, and inclusion of children explained some but not all of the observed heterogeneity. The data confirms the observation that MAP is detected more frequently among CD patients compared with controls. However, the pathogenic role of this bacterium in the gut remains uncertain. Our analysis demonstrates that there is an association between MAP and CD, across many sites, by many investigators, and controlling for a number of factors; however, this association remains controversial and inconclusive. Future studies should determine whether there is a pathogenic role.

A case of Mycoplasma hominis septic arthritis postpartum

A 17-year-old woman presented 1-week post caesarean section with septic arthritis which was unresponsive to first-line empirical antimicrobial therapy. Cultures of the hip aspirate revealed Mycoplasma hominis as the causative organism. M. hominis-associated septic arthritis is extremely rare in the absence of underlying joint abnormalities or immunosuppression. Strikingly four of the 26 cases reported have been pregnancy-associated.

Reversible parkinsonism in a patient with progressive multifocal leucoencephalopathy

A case of pathologically confirmed progressive multifocal leucoencephalopathy presenting with unilateral parkinsonism and cognitive decline that significantly improved over a 12-month period without any treatment is described. The patient had a background of chronic lymphocytic leukaemia, but had been in complete remission for 4 years at the time of diagnosis. This case is highly unusual not only in terms of the mode of clinical presentation in an apparently immunocompetent patient but also in that the patient spontaneously improved without any intervention. Progressive multifocal leucoencephalopathy should therefore be considered in the differential diagnosis of movement disorders developing in patients with a history of lymphoproliferative disease, even if they are in remission. Furthermore, such cases may not always require treatment, as the patient's immune system may overcome the viral disease process with spontaneous resolution of their neurological disorder.