Mathematical modelling of patient risks in a hospital environment, using multiple regression analysis

The aim of this research work was primarily to examine the relevance of patient parameters, ward structures, procedures and practices, in respect of the potential hazards of wound cross-infection and nasal colonisation with multiple resistant strains of Staphylococcus aureus, which it is thought might provide a useful indication of a patient's general susceptibility to wound infection. Information from a large cross-sectional survey involving 12,000 patients from some 41 hospitals and 375 wards was collected over a five-year period from 1967-72, and its validity checked before any subsequent analysis was carried out. Many environmental factors and procedures which had previously been thought (but never conclusively proved) to have an influence on wound infection or nasal colonisation rates, were assessed, and subsequently dismissed as not being significant, provided that the standard of the current range of practices and procedures is maintained and not allowed to deteriorate. Retrospective analysis revealed that the probability of wound infection was influenced by the patient's age, duration of pre-operative hospitalisation, sex, type of wound, presence and type of drain, number of patients in ward, and other special risk factors, whilst nasal colonisation was found to be influenced by the patient's age, total duration of hospitalisation, sex, antibiotics, proportion of occupied beds in the ward, average distance between bed centres and special risk factors. A multi-variate regression analysis technique was used to develop statistical models, consisting of variable patient and environmental factors which were found to have a significant influence on the risks pertaining to wound infection and nasal colonisation. A relationship between wound infection and nasal colonisation was then established and this led to the development of a more advanced model for predicting wound infections, taking advantage of the additional knowledge of the patient's state of nasal colonisation prior to operation.

Role of copper in reducing hospital environment contamination

The environment may act as a reservoir for pathogens that cause healthcare-associated infections (HCAIs). Approaches to reducing environmental microbial contamination in addition to cleaning are thus worthy of consideration. Copper is well recognised as having antimicrobial activity but this property has not been applied to the clinical setting. We explored its use in a novel cross-over study on an acute medical ward. A toilet seat, set of tap handles and a ward entrance door push plate each containing copper were sampled for the presence of micro-organisms and compared to equivalent standard, non-copper-containing items on the same ward. Items were sampled once weekly for 10 weeks at 07:00 and 17:00. After five weeks, the copper-containing and non-copper-containing items were interchanged. The total aerobic microbial counts per cm2 including the presence of ‘indicator micro-organisms’ were determined. Median numbers of microorganisms harboured by the copper-containing items were between 90% and 100% lower than their control equivalents at both 07:00 and 17:00. This reached statistical significance for each item with one exception. Based on the median total aerobic cfu counts from the study period, five out of ten control sample points and zero out of ten copper points failed proposed benchmark values of a total aerobic count of <5 cfu/cm2. All indicator micro-organisms were only isolated from control items with the exception of one item during one week. The use of copper-containing materials for surfaces in the hospital environment may therefore be a valuable adjunct for the prevention of HCAIs and requires further evaluation.

Needleless connectors:the way forward in the prevention of catheter-related infections?

Letter to the Editor

Infecções por enterobacteriaceae resistente aos carbapenêmicos em hospital de ensino: epidemiologia e caracterização molecular

Introduction: The production of KPC (Klebsiella pneumoniae carbapenemase) has become an important mechanism of carbapenem-resistance among Enterobacteriaceae strains. In Brazil, KPC is already widespread and its incidence has increased significantly, reducing treatment options. The “perfect storm” combination of the absence of new drug developmentand the emergence of multidrug-resistant strains resulted in the need for the use of older drugs, with greater toxicity, such as polymyxins. Aims: To determine the occurrence of carbapenemase-producing strains in carbapenem-resistant Enterobacteriaceae isolated from patients with nosocomial infection/colonization during September/2014 to August/2015, to determine the risk factors associated with 30-day- mortality and the impact of inappropriate therapy. Materials and Methods: We performed a case control study to assess the risk factors (comorbidities, invasive procedures and inappropriate antimicrobial therapy) associated with 30-day-mortality, considering the first episode of infection in 111 patients. The resistance genes blaKPC, blaIMP, blaVIM and blaNDM-1 were detected by polymerase chain reaction technique. Molecular typing of the strains involved in the outbreak was performed by pulsed field gel electrophoresis technique. The polymyxin resistance was confirmed by the microdilution broth method. Results: 188 episodes of carbapenem-resistant Enterobacteriaceae infections/colonizations were detected; of these, 122 strains were recovered from the hospital laboratory. The presence of blaKPC gene were confirmed in the majority (74.59%) of these isolates. It was not found the presence of blaIMP , blaVIM and blaNDM-1 genes. K. pneumoniae was the most frequent microorganism (77,13%), primarily responsible for urinary tract infections (21,38%) and infections from patients of the Intensive Care Unit (ICU) (61,38%). Multivariate statistical analysis showed as predictors independently associated with mortality: dialysis and bloodstream infection. The Kaplan-Meier curve showed a lower probability of survival in the group of patients receiving antibiotic therapy inappropriately. Antimicrobial use in adult ICU varied during the study period, but positive correlation between increased incidence of strains and the consumption was not observed. In May and July 2015, the occurrence rates of carbapenem-resistant Enterobacteriaceae KPC-producing per 1000 patient-days were higher than the control limit established, confirming two outbreaks, the first caused by colistin-susceptible KPC-producing K. pneumoniae isolates, with a polyclonal profile and the second by a dominant clone of colistin-resistant (≥ 32 μg/mL) KPC-producing K. pneumoniae. The cross transmission between patients became clear by the temporal and spatial relationships observed in the second outbreak, since some patients occupied the same bed, showing problems in hand hygiene adherence among healthcare workers and inadequate terminal disinfection of environment. The outbreak was contained when the ICU was closed to new admissions. Conclusions: The study showed an endemicity of K. pneumoniae KPC-producing in adult ICU, progressing to an epidemic monoclonal expansion, resulted by a very high antibiotic consumption of carbapenems and polymyxins and facilitated by failures in control measures the unit.

Potential Cost-effectiveness of Early Identification of Hospital-acquired Infection in Critically Ill Patients.

RATIONALE: Limitations in methods for the rapid diagnosis of hospital-acquired infections often delay initiation of effective antimicrobial therapy. New diagnostic approaches offer potential clinical and cost-related improvements in the management of these infections. OBJECTIVES: We developed a decision modeling framework to assess the potential cost-effectiveness of a rapid biomarker assay to identify hospital-acquired infection in high-risk patients earlier than standard diagnostic testing. METHODS: The framework includes parameters representing rates of infection, rates of delayed appropriate therapy, and impact of delayed therapy on mortality, along with assumptions about diagnostic test characteristics and their impact on delayed therapy and length of stay. Parameter estimates were based on contemporary, published studies and supplemented with data from a four-site, observational, clinical study. Extensive sensitivity analyses were performed. The base-case analysis assumed 17.6% of ventilated patients and 11.2% of nonventilated patients develop hospital-acquired infection and that 28.7% of patients with hospital-acquired infection experience delays in appropriate antibiotic therapy with standard care. We assumed this percentage decreased by 50% (to 14.4%) among patients with true-positive results and increased by 50% (to 43.1%) among patients with false-negative results using a hypothetical biomarker assay. Cost of testing was set at $110/d. MEASUREMENTS AND MAIN RESULTS: In the base-case analysis, among ventilated patients, daily diagnostic testing starting on admission reduced inpatient mortality from 12.3 to 11.9% and increased mean costs by $1,640 per patient, resulting in an incremental cost-effectiveness ratio of $21,389 per life-year saved. Among nonventilated patients, inpatient mortality decreased from 7.3 to 7.1% and costs increased by $1,381 with diagnostic testing. The resulting incremental cost-effectiveness ratio was $42,325 per life-year saved. Threshold analyses revealed the probabilities of developing hospital-acquired infection in ventilated and nonventilated patients could be as low as 8.4 and 9.8%, respectively, to maintain incremental cost-effectiveness ratios less than $50,000 per life-year saved. CONCLUSIONS: Development and use of serial diagnostic testing that reduces the proportion of patients with delays in appropriate antibiotic therapy for hospital-acquired infections could reduce inpatient mortality. The model presented here offers a cost-effectiveness framework for future test development.

Infecções Retrofaríngeas e Laterofaríngeas em Crianças: A Experiência de um Hospital Pediátrico Durante a Última Década

Introdução: Apresentando-se muitas vezes de forma insidiosa e mascarando-se por tratamentos efectuados previamente, as infecções retro e laterofaríngeas são um desafio diagnóstico. São pouco frequentes na era antibiótica moderna, mas têm capacidade para causarem complicações potencialmente fatais. Material e métodos: Estudo retrospectivo dos casos e análise de dados relativos à epidemiologia, etiologia, apresentação clínica, diagnóstico, tratamento e complicações, de crianças diagnosticadas com infecções retro e laterofaríngeas, no nosso hospital pediátrico, desde Janeiro 2001 a Janeiro 2012. Resultados: Foram incluídas no estudo 23 crianças, com idades compreendidas entre os 3 meses e os 8 anos, com uma média de idades de 47 meses (4 anos). Treze (57%) apresentavam infecções retrofaríngeas, 2 (9%) infecções laterofaríngeas e 8 (35%) ambas. A incidência de casos foi maior no ano de 2010 (4 casos). Doze (52%) eram do sexo masculino e 11 (48%) do sexo feminino. A odinofagia (57%), a cervicalgia (26%) e a recusa alimentar (22%) foram as queixas mais comuns à apresentação. A febre (87%), o torcicolo e a rigidez cervical (65%), a tumefacção cervical (52%) e a prostração (35%) foram os achados físicos mais frequentes. Todos (100%) os doentes receberam antibioticoterapia endovenosa. O tratamento médico sem drenagem foi inicialmente proposto para 15 (65%) crianças. A falência no tratamento médico, requerendo cirurgia, ocorreu em 5 (33%) delas. Num dos casos, foi necessário efectuar uma nova drenagem cirúrgica. O tratamento cirúrgico foi inicialmente proposto para 8 (35%) crianças, tendo sido efectuado durante as primeiras 24 horas. Este tratamento não teve falência em nenhum (0%) dos casos, não tendo sido necessária a realização de uma segunda cirurgia. No entanto, numa das crianças, por aparecimento de um novo abcesso noutra localização, houve necessidade de se proceder à sua drenagem. Duas (9%) crianças tiveram complicações: mediastinite, trombose da veia jugular e síndrome de Claude Bernard Horner. Conclusões: Os sintomas na apresentação das infecções retro e laterofaríngeas na população pediátrica são variados, requerendo o seu diagnóstico um elevado índice de suspeição. O tratamento correcto e atempado é fundamental para um prognóstico favorável. O tratamento ideal nos doentes sem obstrução iminente da via aérea é controverso e objecto de debate, particularmente a escolha entre tratamento médico ou cirúrgico como primeira linha. Torna-se portanto, essencial, maior investigação nesta área, de forma a optimizar resultados.

Microbiological assessment of indoor air quality at different hospital sites

Poor hospital indoor air quality (IAQ) may lead to hospital-acquired infections, sick hospital syndrome and various occupational hazards. Air-control measures are crucial for reducing dissemination of airborne biological particles in hospitals. The objective of this study was to perform a survey of bioaerosol quality in different sites in a Portuguese Hospital, namely the operating theater (OT), the emergency service (ES) and the surgical ward (SW). Aerobic mesophilic bacterial counts (BCs) and fungal load (FL) were assessed by impaction directly onto tryptic soy agar and malt extract agar supplemented with antibiotic chloramphenicol (0.05%) plates, respectively using a MAS-100 air sampler. The ES revealed the highest airborne microbial concentrations (BC range 240-736 CFU/m(3) CFU/m(3); FL range 27-933 CFU/m(3)), exceeding, at several sampling sites, conformity criteria defined in national legislation [6]. Bacterial concentrations in the SW (BC range 99-495 CFU/m(3)) and the OT (BC range 12-170 CFU/m(3)) were under recommended criteria. While fungal levels were below 1 CFU/m(3) in the OT, in the SW (range 1-32 CFU/m(3)), there existed a site with fungal indoor concentrations higher than those detected outdoors. Airborne Gram-positive cocci were the most frequent phenotype (88%) detected from the measured bacterial population in all indoor environments. Staphylococcus (51%) and Micrococcus (37%) were dominant among the bacterial genera identified in the present study. Concerning indoor fungal characterization, the prevalent genera were Penicillium (41%) and Aspergillus (24%). Regular monitoring is essential for assessing air control efficiency and for detecting irregular introduction of airborne particles via clothing of visitors and medical staff or carriage by personal and medical materials. Furthermore, microbiological survey data should be used to clearly define specific air quality guidelines for controlled environments in hospital settings.

Infecções cervicais profundas, casuística do serviço de otorrinolaringologia do Hospital Prof. Doutor Fernando Fonseca

As infecções cervicais profundas constituem um verdadeiro desafio clínico, permanecendo na actualidade um problema relevante de saúde. Objectivo: Análise estatística dos internamentos com diagnóstico de celulite/abcesso cervical no Serviço de Otorrinolaringologia do Hospital Prof. Doutor Fernando Fonseca. Material e métodos: Avaliação de processos clínicos referentes a internamentos com o diagnóstico de entrada de celulite/ abcesso cervical, entre 2001-2011. Resultados: Neste período foram internados 80 doentes com média de idade de 44 anos. As infecções odontogénicas foram responsáveis por 83,3% das etiologias detectadas. O tempo médio de internamento foi de 8,72 dias. 94% dos doentes foram medicados com antibioterapia de acção dupla e em 22,5% recorreu-se à drenagem cervical. Conclusão: Ainda hoje as infecções cervicais profundas constituem casos de gravidade acrescida, com índice de mortalidade elevado. A infecção odontogénica constitui a sua principal etiologia. A instituição de antibioterapia endovenosa precoce e eventual drenagem cirúrgica são fundamentais no tratamento desta condição.

Outcomes of a general hospital-based Home Parenteral Nutrition (HPN) program: report of our experience from a 26-year period

Background: Home parenteral nutrition (HPN) was introduced in Spain in the late 1980s. Our hospital was a pioneering medical centre in this field. Aim: Analyze outcomes of our HPN program. Methods: Retrospective study of patients receiving HPN between 1986-2012. Study variables are expressed as frequency, mean ± SD (range), median [interquartile range]. Parametrics, non-parametrics test and survival analysis (p < 0.05) were applied. Results: 91 patients (55 females and 36 males, mean age: 50.6 ± 5 yrs.) who received HPN for an accrual period of 55,470 days (median: 211 days [range: 63-573]) were included. The most prevalent underlying condition was cancer (49.5%), with the commonest HPN indication being short bowel syndrome (41.1%). The most frequently used catheter type was the tunneled catheter (70.7%). The complication rate was 3.58/1,000 HPN days (2.68, infection; 0.07, occlusion; 0.07 thrombosis; and 0.59, metabolic complications). Complications were consistently associated with both the underlying condition and HPN length. Infections were most frequent within the first 1,000 days of HPN. Liver disease incidence was related to HPN duration. HPN could be discontinued in 42.3% of patients. Ten-year survival rate was 42%, and varied across the underlying conditions. Conclusions: In the present series, the commonest reason for HPN was cancer. Our complication rate is in keeping with that reported in the literature. The overall survival rate was 42%, and varied across the underlying conditions.

Middle East respiratory syndrome coronavirus (MERS-CoV) infections in two returning travellers in the Netherlands, May 2014

Two patients, returning to the Netherlands from pilgrimage in Medina and Mecca, Kingdom of Saudi Arabia, were diagnosed with Middle East respiratory syndrome coronavirus (MERS-CoV) infection in May 2014. The source and mode of transmission have not yet been determined. Hospital-acquired infection and community-acquired infection are both possible.

PCR-Internal Transcribed Spacer (ITS) genes sequencing and phylogenetic analysis of clinical and environmental Aspergillus species associated with HIV-TB co infected patients in a hospital in Abeokuta, southwestern Nigeria.

Background: Aspergillosis has been identified as one of the hospital acquired infections but the contribution of water and inhouse air as possible sources of Aspergillus infection in immunocompromised individuals like HIV-TB patients have not been studied in any hospital setting in Nigeria. Objective: To identify and investigate genetic relationship between clinical and environmental Aspergillus species associated with HIV-TB co infected patients. Methods: DNA extraction, purification, amplification and sequencing of Internal Transcribed Spacer (ITS) genes were performed using standard protocols. Similarity search using BLAST on NCBI was used for species identification and MEGA 5.0 was used for phylogenetic analysis. Results: Analyses of sequenced ITS genes of selected fourteen (14) Aspergillus isolates identified in the GenBank database revealed Aspergillus niger (28.57%), Aspergillus tubingensis (7.14%), Aspergillus flavus (7.14%) and Aspergillus fumigatus (57.14%). Aspergillus in sputum of HIV patients were Aspergillus niger, A. fumigatus, A. tubingensis and A. flavus. Also, A. niger and A. fumigatus were identified from water and open-air. Phylogenetic analysis of sequences yielded genetic relatedness between clinical and environmental isolates. Conclusion: Water and air in health care settings in Nigeria are important sources of Aspergillus sp. for HIV-TB patients.

Characteristics and management of Enterobacteriaceae harboring IMP-4 or IMP-8 carbapenemase in a tertiary hospital.

Background: The emergence of Enterobacteriaceae harboring IMP-4 or IMP-8 carbapenemases is rare. We report an occurrence of Enterobacteriaceae harboring IMP-4 or IMP-8 carbapenemases in a Chinese tertiary care hospital from November 2010 to December 2012. Methods: The clinical characteristics of 30 patients were described. The genetic relationship of isolates was determined by pulsed-field gel electrophoresis (PFGE). Carbapenemases were detected by modified Hodge test (MHT) and polymerase chain reactions (PCRs). Amplicons were sequenced and blasted to determine the genotype. Results: Most infected patients were from intensive care unit and had complex and serious underlying illnesses requiring mechanical ventilation. PFGE revealed that Klebsiella pneumoniae showed two major PFGE types. Two Klebsiella oxytoca had an indistinguishable PFGE pattern, while four Enterobacter cloacae were different strains. The sequencing studies showed Enterobacteriaceae harboring IMP-4 or IMP-8 carbapenemase in the 23 infected patients. The majority of patients had infections with the carbapenemase-producing Enterobacteriaceae (CPE) strain, most were successfully treated with a range of antibiotics and discharged. Conclusion: It is important to maintain a high index of suspicion to screen for carbapenemase-producing Enterobacteriaceae strains. Rapid identification of these strains and implementation of stringent procedures are the key to prevent major outbreaks in a hospital setting. Keywords:

Factors influencing the recommendation of the Human Papillomavirus vaccine by South African doctors working in a tertiary hospital.

Background: In South Africa, HPV vaccination programme has been incorporated recently in the school health system. Since doctors are the most trusted people regarding health issues in general, their knowledge and attitudes regarding HPV infections and vaccination are very important for HPV vaccine program nationally. Objective: The objective of this study was to investigate factors contributing to recommendation of HPV vaccines to the patients. Methods: This was a quantitative cross-sectional study conducted among 320 doctors, using a self-administered anonymous questionnaire. Results: All the doctors were aware of HPV and knew that HPV is transmitted sexually. Their overall level of knowledge regarding HPV infections and HPV vaccine was poor. But the majority intended to prescribe the vaccine to their patients. It was found that doctors who knew that HPV 6 and 11 are responsible for >90% of anogenital warts, their patients would comply with the counselling regarding HPV vaccination, and received sufficient information about HPV vaccination were 5.68, 4.91 and 4.46 times respectively more likely to recommend HPV vaccination to their patients, compared to their counterparts (p<0.05). Conclusion: There was a knowledge gap regarding HPV infection and HPV vaccine among the doctors.

Cerebro-meningeal infections in HIV-infected patients: a study of 116 cases in Libreville, Gabon.

Background: Cerebro-meningeal pathology is common in human immunodeficiency virus (HIV) infection and the aetiology is often difficult to ascertain with certainty. Objective: To describe the major suspected and identified causes of meningeal or encephalitic syndromes in HIV infection in Libreville, Gabon. Methods: A descriptive study using clinical records of patients hospitalised in the Department of Medicine in the Military Hospital of Libreville (Gabon) between January 2006 and May 2010. Clinical features were evaluated using multivariable logistic regression to evaluate association with the outcome of a clinical improvement or death. Results: The most frequent neurological symptoms were reduced level of consciousness (54.3%), headache (55.2%), motor deficit (38.7%), and convulsions (36.2%). Cerebral toxoplasmosis represented 64.7% of diagnoses, followed by cryptococcal neuromeningitis in 12.9% of cases. Tuberculoma was diagnosed in 4 cases and lymphoma in 2 cases. In 9.5% of cases, no aetiology was determined. Toxoplasmosis treatment led to clinical improvement in 69.3% of cases with suspected cerebral toxoplasmosis. Overall mortality was 39.7%. Conclusion: The diagnosis of neurological conditions in HIV positive patients is difficult, particularly in a low-resource setting. A trial of treatment for toxoplasmosis should be initiated first line with all signs of neurological pathology in a patient infected with HIV.

Sero-prevalence and associated factors of Helicobacter pylori infection among adult patients with dyspepsia attending the gastroenterology unit in a tertiary hospital in Mwanza, Tanzania.

Background: Prevalence of H. pylori infection varies greatly between populations in different countries. This study was conducted to determine the magnitude of H.pylori among adult patients with dyspepsia attending the gastroenterology unit at Bugando medical centre. Methods: A cross sectional study involving 202 dyspeptic patients was conducted between June and July 2014. A Standardized data collection tool was used to collect socio-demographic characteristics. H.pylori antibodies were detected using rapid immunochromatographic tests according to manufacturer’s instructions. Results: The median age of study population was 42 (IQR: 33-54). Females 105 (51.9%) formed majority of the population studied. Of 202 participants; 119 (58.9%) were from rural areas. Seroprevalence of H.pylori infection was found to be 79/202 (39.1%, 95% CI: 32.3 -45.7). As the age increased the risk of having H.pylori infection also increased (OR: 1.02 95% CI: 1-1.04, P=0.02). On multivariate logistic regression analysis untreated drinking water was found to predict H.pylori seropositivity (OR: 2.33, CI: 1.09-4.96, p=0.028). Conclusion: The seroprevalence of H.pylori among dyspeptic patients is high in this setting. Therefore the community in Mwanza should be educated on the use of safe drinking water in order to minimize H. pylori infections.