Lourdes Matas

Role of immunosuppression in the evolution of Legionnaires' disease.

The clinical course of legionella pneumonia in immunosuppressed patients is uncertain. This study was undertaken to determine the clinical evolution of legionellosis on the basis of the immune state and to establish the variables associated with death directly related to legionellosis. The study included 78 patients: 28 with chronic disease who had received immunosuppressive treatment (group 1), 24 with chronic disease without immunosuppressive treatment (group 2), and 26 controls. Inclusion criteria were the occurrence of nosocomially acquired pneumonia, Legionella pneumophila infection, and erythromycin therapy that was initiated within 72 hours following diagnosis. Respiratory and extrarespiratory complications were observed more frequently in groups 1 and 2. Bilateral radiological involvement was most frequent in group 1, and recurrence of legionella pneumonia was observed exclusively in group 1. None of these variables achieved statistical significance. The global mortality of the series was 11.5% (17.9%, 12.5%, and 3.8% in groups 1, 2, and 3, respectively). Variables statistically related to mortality were acute renal failure, shock, and need for mechanical ventilation. Although many of the variables analyzed lacked statistical significance, a trend was seen between complications and basal immunosuppression, as previously suggested.

Contribution of Immunological and Virological Factors to Extremely Severe Primary HIV Type 1 Infection

BACKGROUND During acute human immunodeficiency virus (HIV) infection, high viral loads and the induction of host immune responses typically coincide with the onset of clinical symptoms. However, clinically severe presentations during acute HIV type 1 (HIV-1) infection, including AIDS-defining symptoms, are unusual. METHODS Virus isolates were tested for clade, drug susceptibility, coreceptor use, and growth rate in 2 case reports of sexual transmission of HIV-1 infection. Human leukocyte antigen (HLA) genotype was determined, and HIV-1-specific cytotoxic T lymphocyte responses to an overlapping peptide set spanning the entire HIV clade A and clade B proteome were assayed. RESULTS The viruses isolated in the 2 unrelated case reports of severe primary HIV-1 infection showed R5/X4 dual-mixed tropism, belonged to clade B and CRF02-AG, and were highly replicative in peripheral blood mononuclear cell culture. Impaired humoral responses were paralleled by a profound absence of HIV-1-specific cytotoxic T lymphocyte responses to the entire viral proteome in the 2 case reports. In 1 case report for which the virus source was available, there was a remarkable HLA similarity between the 2 patients involved in the transmission event, because 3 of 4 HLA-A and HLA-B alleles had matched HLA supertype for both patients. CONCLUSIONS The data suggest that concurrence of viral and host factors contributes to the clinical severity of primary HIV-1 infection and that patients infected with highly replicative, dual-tropic viruses are more prone to develop AIDS-defining symptoms during acute infection if they are unable to mount humoral and cellular HIV-1-specific immune responses. The presence of concordant HLA supertypes might facilitate the preferential transmission of HLA-adapted viral variants, further accelerating disease progression.

Clinical usefulness of total hepatitis C virus core antigen quantification to monitor the response to treatment with peginterferon alpha-2a plus ribavirin*.

Summary.  Early virological response may predict outcome following treatment with peginterferon alpha‐2a and ribavirin in patients chronically infected with hepatitis C virus (HCV). As total HCV core antigen may constitute an alternative direct marker to HCV RNA for assessing the levels of viraemia in such patients, we evaluated the correlation between HCV core antigen and HCV RNA, and whether HCV core antigen at baseline, 4 and 12 weeks after treatment could predict sustained virological response (SVR) to combined therapy, in comparison with HCV RNA.

Surveillance of methicillin-resistant Staphylococcus aureus (MRSA) in acute care hospitals. Results of the VINCat Program (2008-2010)

Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of healthcare-related infection. Surveillance and prevention of MRSA is a priority in infection control programs. The aim of this study was to describe rates and trends of MRSA colonization or infection in 40 hospitals participating in the VINCat Program from 2008 to 2010. The study included all patients treated in acute care areas of participating hospitals. Hospitals were stratified into 3 groups based on size. The following annual indicators were reported: Methicillin-resistance rate, incidence density of new cases of MRSA and incidence density of MRSA bacteremia. Between 2008 and 2010, the yearly mean rate of resistance to methicillin remained stable for the study period (24%-25%), while the mean incidence of new cases of MRSA decreased from 0.65 to 0.54 cases per 1000 patient-days (p=NS) and the mean incidence of MRSA bacteremia decreased from 0.06 to 0.05 cases per 1,000 patient-days (p=NS). The implementation of a MRSA surveillance system in hospitals that participated in the VINCat Program provides information on the situation of each institution and facilitated interhospital comparisons in order to establish appropriate preventive measures.

Prevalence of and Risk Factors for Methicillin-Resistant Staphylococcus aureus Carriage at Hospital Admission

To determine the prevalence of and risk factors for methicillin-resistant Staphylococcus aureus (MRSA) carriage at the time of admission to our hospital, we screened the medical records of 1,128 patients for demographic and clinical data. The antimicrobial resistance pattern and genotype of MRSA isolates were studied. The prevalence of MRSA carriage at hospital admission was 1.4%. Older patients and patients previously admitted to healthcare centers were the most likely to have MRSA carriage at admission.

Epidemiology of surgical site infections after total hip and knee joint replacement during 2007-2009, a report from the VINCat Program

The VINCat Program is a system for epidemiological surveillance of healthcare-related infections in which the majority of Catalan hospitals participate. It has a specific module for surgical site infections (SSI) surveillance. Primary hip and knee arthroplasties are basic indicators of the program due to their high frequency and the important morbidity of SSI of these sites. Results are presented for surgical site infection (SSI) surveillance of primary hip and knee arthroplasties for the first three years of the VINCat Program. The program requires SSI surveillance to be performed in a standardized, prospective and continuous manner by an infection control team from the centers. With primary arthroplasties, as with all procedures involving implants, the surveillance is maintained for 1 year after the intervention. The VINCat Program uses the SSI definitions of the Centers for Disease Control (CDC) and patients are stratified by surgical risk, following the classification of the National Healthcare Safety Network (NHSN). During the period 2007-2009, 51 Catalan hospitals participated in the SSI surveillance of prosthetic orthopedic surgery. The overall SSI rate in the interventions for total primary hip prosthesis (7,804 procedures) was 3.0% (IC 95%: 2.6-3.4) and for total primary knee prosthesis (16,781 procedures) was 3.3% (IC95%: 3.0-3.6). During the period 2007-2009, the overall SSI rates for total primary hip and knee arthroplasty were higher than those published by some surveillance systems in our environment. There were significant differences in the infection rates by procedure and in those adjusted by risk among the different hospitals.

Recursos diagnósticos para las infecciones de transmisión sexual en los laboratorios de Cataluña (España)

OBJECTIVE With the aim of describing both the capacity and organization of the laboratories in Catalonia to diagnose sexually transmitted infections, a cross-sectional study was performed between November 2005 and March 2006, which included 140 laboratories. RESULTS Ninety-eight laboratories performed some STI tests, 45 received more than 50 vaginal swabs per month, 42 diagnosed Chlamydia trachomatis, but only six used polymerase chain reaction techniques. None diagnosed venereal lymphogranuloma. Eighty were able to detect Neisseria gonorrhoeae, 76 by means of culture and 63 analyzed its antibiotic resistance. A total of 23, 22, 22 and 14 laboratories received more than 500 blood samples for hepatitis B, hepatitis C, HIV and syphilis, respectively. Non-treponemic and treponemic tests were available in 84 and 52 laboratories, respectively. CONCLUSIONS In Catalonia, most STIs can be diagnosed but new technologies need to be introduced. Moreover, the efficiency of biological sample circuits should be improved.