Adriano Duse

Antimicrobial resistance in developing countries. Part I: recent trends and current status.

The global problem of antimicrobial resistance is particularly pressing in developing countries, where the infectious disease burden is high and cost constraints prevent the widespread application of newer, more expensive agents. Gastrointestinal, respiratory, sexually transmitted, and nosocomial infections are leading causes of disease and death in the developing world, and management of all these conditions has been critically compromised by the appearance and rapid spread of resistance. In this first part of the review, we have summarised the present state of resistance in these infections from the available data. Even though surveillance of resistance in many developing countries is suboptimal, the general picture is one of accelerating rates of resistance spurred by antimicrobial misuse and shortfalls in infection control and public health. Reservoirs for resistance may be present in healthy human and animal populations. Considerable economic and health burdens emanate from bacterial resistance, and research is needed to accurately quantify the problem and propose and evaluate practicable solutions. In part II, to be published next month, we will review potential containment strategies that could address this burgeoning problem.

Antimicrobial resistance in developing countries. Part II: strategies for containment.

The growing threat from resistant organisms calls for concerted action to prevent the emergence of new resistant strains and the spread of existing ones. Developing countries have experienced unfavourable trends in resistance-as detailed in part I, published last month--and implementation of many of the containment strategies recommended by WHO is complicated by universal, as well as developing country-specific, factors. The control of selective pressure for resistance could potentially be addressed through educational and other interventions for orthodox and unorthodox prescribers, distributors, and consumers of antimicrobials. At national levels, the implementation of drug use strategies--eg, combination therapy or cycling--may prove useful to lengthen the lifespan of existing and future agents. Programmes such as the Integrated Management of Childhood Illnesses (IMCI) and directly observed short-course therapy (DOTS) for tuberculosis are prescriber-focused and patient-focused, respectively, and have both been shown to positively influence factors that contribute to the selective pressure that affects resistance. The institution of interventions to prevent the transmission of infectious diseases could also lead to beneficial effects on the prevalence of resistance, as has vaccination against Haemophilus influenzae type B and Streptococcus pneumoniae. There has been an upsurge in the number of organisations and programmes that directly address issues of resistance, and collaboration could be one way to stem the dire trend. Additional factors such as unregulated drug availability, inadequate antimicrobial drug quality assurance, inadequate surveillance, and cultures of antimicrobial abuse must be addressed to permit a holistic strategy for resistance control.

Geographic variation in the frequency of isolation and fluconazole and voriconazole susceptibilities of Candida glabrata: an assessment from the ARTEMIS DISK Global Antifungal Surveillance Program

Geographic differences in frequency and azole resistance among Candida glabrata may impact empiric antifungal therapy choice. We examined geographic variation in isolation and azole susceptibility of C. glabrata. We examined 23 305 clinical isolates of C. glabrata during ARTEMIS DISK global surveillance. Susceptibility testing to fluconazole and voriconazole was assessed by disk diffusion, and the results were grouped by geographic location: North America (NA) (2470 isolates), Latin America (LA) (2039), Europe (EU) (12 439), Africa and the Middle East (AME) (728), and Asia-Pacific (AP) (5629). Overall, C. glabrata accounted for 11.6% of 201 653 isolates of Candida and varied as a proportion of all Candida isolated from 7.4% in LA to 21.1% in NA. Decreased susceptibility (S) to fluconazole was observed in all geographic regions and ranged from 62.8% in AME to 76.7% in LA. Variation in fluconazole susceptibility was observed within each region: AP (range, 50-100% S), AME (48-86.9%), EU (44.8-88%), LA (43-92%), and NA (74.5-91.6%). Voriconazole was more active than fluconazole (range, 82.3-84.2% S) with similar regional variation. Among 22 sentinel sites participating in ARTEMIS from 2001 through 2007 (84 140 total isolates, 8163 C. glabrata), the frequency of C. glabrata isolation increased in 14 sites and the frequency of fluconazole resistance (R) increased in 11 sites over the 7-year period of study. The sites with the highest cumulative rates of fluconazole R were in Poland (22% R), the Czech Republic (27% R), Venezuela (27% R), and Greece (33% R). C. glabrata was most often isolated from blood, normally sterile body fluids and urine. There is substantial geographic and institutional variation in both frequency of isolation and azole resistance among C. glabrata. Prompt species identification and fluconazole susceptibility testing are necessary to optimize therapy for invasive candidiasis.

Epidemic Spread of Multidrug-Resistant Tuberculosis in Johannesburg, South Africa

ABSTRACT Numerous reports have documented isolated transmission events or clonal outbreaks of multidrug-resistant Mycobacterium tuberculosis strains, but knowledge of their epidemic spread remains limited. In this study, we evaluated drug resistance, strain diversity, and clustering rates in patients diagnosed with multidrug-resistant (MDR) tuberculosis (TB) at the National Health Laboratory Service (NHLS) Central TB Laboratory in Johannesburg, South Africa, between March 2004 and December 2007. Phenotypic drug susceptibility testing was done using the indirect proportion method, while each isolate was genotyped using a combination of spoligotyping and 12-MIRU typing (12-locus multiple interspersed repetitive unit typing). Isolates from 434 MDR-TB patients were evaluated, of which 238 (54.8%) were resistant to four first-line drugs (isoniazid, rifampin, ethambutol, and streptomycin). Spoligotyping identified 56 different strains and 28 clusters of variable size (2 to 71 cases per cluster) with a clustering rate of 87.1%. Ten clusters included 337 (77.6%) of all cases, with strains of the Beijing genotype being most prevalent (16.4%). Combined analysis of spoligotyping and 12-MIRU typing increased the discriminatory power (Hunter Gaston discriminatory index [HGDI] = 0.962) and reduced the clustering rate to 66.8%. Resolution of Beijing genotype strains was further enhanced with the 24-MIRU-VNTR (variable-number tandem repeat) typing method by identifying 15 subclusters and 19 unique strains from twelve 12-MIRU clusters. High levels of clustering among a variety of strains suggest a true epidemic spread of MDR-TB in the study setting, emphasizing the urgency of early diagnosis and effective treatment to reduce transmission within this community.

The Global Antibiotic Resistance Partnership (GARP)

Antimicrobial resistance (AMR) is an important public health concern shared by developed and developing countries. In developing countries the burden of infectious diseases is greater and exacerbated by limited access to, and availability and affordability of, antimicrobials required to treat infections caused by AMR organisms.

Guideline for the management of nosocomial infections in South Africa.

OBJECTIVEnTo write a guideline for the management and prevention of nosocomial infections in South Africa in view of the following: Nosocomial infections are a common and increasing problem globally, including South Africa. Widely varying standards of prevention and management of these important infections. Increasing and emerging antimicrobial resistance among commonly isolated pathogens. The significant economic burden of these infections on the health care system as well as their impact on patient morbidity and mortality. The main aims of the guideline are to provide recommendations for the initial choice of antimicrobial agents and the appropriate management of these infections encompassing the following conditions: (i) nosocomial pneumonia, health care-associated pneumonia and ventilator-associated pneumonia; (ii) nosocomial bloodstream infections; (iii) nosocomial intravascular infections; (iv) nosocomial urinary tract infections; (v) nosocomial intra-abdominal infections; and (vi) nosocomial surgical skin and soft-tissue infections.nnnEVIDENCEnWorking group of clinicians from relevant disciplines, following detailed literature review.nnnRECOMMENDATIONSnThese include details of the likely pathogens, an appropriate diagnostic approach, antibiotic treatment options and appropriate preventive strategies.nnnENDORSEMENTnThe guideline document was endorsed by the South African Thoracic Society, the Critical Care Society of Southern Africa and the Federation of Infectious Diseases Societies of Southern Africa.

Central Venous Catheterization: A Prospective, Randomized, Double-Blind Study

Central venous catheters (CVCs) are extensively used worldwide. Mechanical, infectious and thrombotic complications are well described with their use and may be associated with prolonged hospitalization, increased medical costs and mortality. CVCs account for an estimated 90% of all catheter-related bloodstream infections (CRBSI) and a host of risk factors for CVC-related infections have been documented. The duration of use of CVCs remains controversial and the length of time such devices can safely be left in place has not been fully and objectively addressed in the critically ill patient. Antimicrobial-impregnated catheters have been introduced in an attempt to limit catheter-related infection (CRI) and increase the time that CVCs can safely be left in situ. Recent meta-analyses concluded that antimicrobial-impregnated CVCs appear to be effective in reducing CRI. The authors conducted a prospective, randomized, double-blind study at Johannesburg Hospital over a 4-year period. The study entailed a comparison of standard triple-lumen versus antimicrobial impregnated CVCs on the rate of CRI. Our aim was to determine whether we could safely increase the duration of catheter insertion time from our standard practice of seven days to 14 days, to assess the influence of the antimicrobial impregnated catheter on the incidence of CRI, and to elucidate the epidemiology and risks of CRI. One hundred and eighteen critically ill patients were included in the study which spanned 34 951.5 catheter hours (3.99 catheter years). It was found that antimicrobial catheters did not provide any significant benefit over standard catheters, which the authors feel can safely be left in place for up to14 days with appropriate infection control measures. The most common source of CRI was the skin. The administration of parenteral nutrition and the site of catheter insertion (internal jugular vein vs subclavian vein) were not noted to be risk factors for CRI. There was no clinical evidence of thrombotic complication in either of the study groups. This study offers direction for the use of CVCs in critically ill patients and addresses many of the controversies that exist.

Clinical Features and Patient Management of Lujo Hemorrhagic Fever

Background In 2008 a nosocomial outbreak of five cases of viral hemorrhagic fever due to a novel arenavirus, Lujo virus, occurred in Johannesburg, South Africa. Lujo virus is only the second pathogenic arenavirus, after Lassa virus, to be recognized in Africa and the first in over 40 years. Because of the remote, resource-poor, and often politically unstable regions where Lassa fever and other viral hemorrhagic fevers typically occur, there have been few opportunities to undertake in-depth study of their clinical manifestations, transmission dynamics, pathogenesis, or response to treatment options typically available in industrialized countries. Methods and Findings We describe the clinical features of five cases of Lujo hemorrhagic fever and summarize their clinical management, as well as providing additional epidemiologic detail regarding the 2008 outbreak. Illness typically began with the abrupt onset of fever, malaise, headache, and myalgias followed successively by sore throat, chest pain, gastrointestinal symptoms, rash, minor hemorrhage, subconjunctival injection, and neck and facial swelling over the first week of illness. No major hemorrhage was noted. Neurological signs were sometimes seen in the late stages. Shock and multi-organ system failure, often with evidence of disseminated intravascular coagulopathy, ensued in the second week, with death in four of the five cases. Distinctive treatment components of the one surviving patient included rapid commencement of the antiviral drug ribavirin and administration of HMG-CoA reductase inhibitors (statins), N-acetylcysteine, and recombinant factor VIIa. Conclusions Lujo virus causes a clinical syndrome remarkably similar to Lassa fever. Considering the high case-fatality and significant logistical impediments to controlled treatment efficacy trials for viral hemorrhagic fever, it is both logical and ethical to explore the use of the various compounds used in the treatment of the surviving case reported here in future outbreaks. Clinical observations should be systematically recorded to facilitate objective evaluation of treatment efficacy. Due to the risk of secondary transmission, viral hemorrhagic fever precautions should be implemented for all cases of Lujo virus infection, with specialized precautions to protect against aerosols when performing enhanced-risk procedures such as endotracheal intubation.

Treatment outcomes of multidrug-resistant tuberculosis patients in Gauteng, South Africa

PurposeMultidrug-resistant tuberculosis (MDR-TB) is associated with lengthy treatment, expensive and potentially toxic regimens, and high rates of treatment failure and death. This study describes the outcomes of 351 MDR-TB patients who started treatment between 2004 and 2007 at the provincial MDR-TB referral hospital in Johannesburg, South Africa, and investigates risk factors associated with death.MethodsThe study involved the assessment of factors associated with treatment outcomes using a retrospective review of patient records, drug-susceptibility data and spoligotyping of isolates.ResultsTreatment success (completion/cure) was recorded in 158 (48.8xa0%) patients, while 65 (20xa0%) died, 93 (28.7xa0%) defaulted, 8 (2.5xa0%) failed treatment, 11(3.1xa0%) were transferred out to other health facilities and 16 (4.6xa0%) had no recorded final outcome. The proportion of successful treatment increased significantly over time. Univariable and multivariable analysis (Pxa0=xa00.05) identified the year of MDR-TB diagnosis and spoligotype-defined families as factors associated with treatment outcome. No associations were found between treatment outcome and human immunodeficiency virus (HIV) status, previous TB and additional MDR resistance to streptomycin or ethambutol. Molecular typing of the strains revealed a diverse group of spoligotypes, with Beijing, LAM4 and H3 making up the largest groups.ConclusionsThis is the first published study to investigate treatment outcomes at this facility and to find a link between genotype and treatment outcome, suggesting that genotype determination could potentially serve as a prognostic factor.

Antimicrobial susceptibility patterns of selected invasive pathogens from public sector hospitals in South Africa, 2007

Retrospective antibiotic surveillance data of selected invasive pathogens isolated from blood and cerebrospinal fluid at public sector hospitals in South Africa in 2007 are presented. Antimicrobial susceptibilities were determined according to the 2007 Clinical and Laboratory Standards Institute criteria. Klebsiella pneumoniae remains a highly resistant pathogen, with approximately half of all strains producing extended-spectrum beta-lactamases. All laboratories reported considerable resistance among Acinetobacter spp. Approximately 50-60% of Staphylococcus aureus isolates from blood were resistant to cloxacillin. Among Streptococcus pneumoniae isolates from blood and cerebrospinal fluid, resistance to penicillin ranged from 0% to 6% at most laboratories and 16-42% of isolates were classified with intermediate resistance to penicillin. Resistance to ceftriaxone in S. pneumoniae was rare.