The burden and epidemiology of community-acquired central nervous system infections: a multinational study

Risk assessment of central nervous system (CNS) infection patients is of key importance in predicting likely pathogens. However, data are lacking on the epidemiology globally. We performed a multicenter study to understand the burden of community-acquired CNS (CA-CNS) infections between 2012 and 2014. A total of 2583 patients with CA-CNS infections were included from 37 referral centers in 20 countries. Of these, 477 (18.5%) patients survived with sequelae and 227 (8.8%) died, and 1879 (72.7%) patients were discharged with complete cure. The most frequent infecting pathogens in this study were Streptococcus pneumoniae (n = 206, 8%) and Mycobacterium tuberculosis (n = 152, 5.9%). Varicella zoster virus and Listeria were other common pathogens in the elderly. Although staphylococci and Listeria resulted in frequent infections in immunocompromised patients, cryptococci were leading pathogens in human immunodeficiency virus (HIV)-positive individuals. Among the patients with any proven etiology, 96 (8.9%) patients presented with clinical features of a chronic CNS disease. Neurosyphilis, neurobrucellosis, neuroborreliosis, and CNS tuberculosis had a predilection to present chronic courses. Listeria monocytogenes, Staphylococcus aureus, M. tuberculosis, and S. pneumoniae were the most fatal forms, while sequelae were significantly higher for herpes simplex virus type 1 (p < 0.05 for all). Tackling the high burden of CNS infections globally can only be achieved with effective pneumococcal immunization and strategies to eliminate tuberculosis, and more must be done to improve diagnostic capacity.

Prevalence of hospital-associated infections can be decreased effectively in developing countries

BACKGROUND

Hospital-acquired infections (HAI) are an important public health problem worldwide. Little information is available from African countries, but published data show that the burden of HAI is greater in Africa than in developed countries. In 2002, the World Health Organization (WHO) published guidelines for preventing HAI.

AIM

To evaluate the impact of a hospital infection control programme on the prevalence of HAI among patients in a large Ugandan hospital.

METHODS

A one-day cross-sectional prevalence survey and a ward procedure survey were performed in Lacor Hospital in March 2010 using standardized questionnaires. All patients admitted to hospital not less than two days before the survey were eligible to participate in the prevalence survey. Modified WHO criteria for HAI were used. The ward procedure survey examined the procedures to prevent HAI. Several hospital infection control measures were subsequently implemented, in accordance with WHO infection control guidelines, starting in October 2010. The prevalence survey and ward procedure survey were repeated in October 2011.

FINDINGS

The prevalence of HAI was 34% in 2010 and 17% in 2011. The prevalence of infected patients reduced from 28% to 14%. The prevalence of HAI was lower in all age groups and for all types of HAI except urinary tract infections following the implementation of infection control activities.

CONCLUSION

This study showed that HAI is an important problem in this large African hospital, and that the prevalence of HAI can be reduced effectively following the adoption of basic infection control procedures.

Comparison of different techniques for detection of anti-HLA antibodies in sera from patients awaiting kidney transplantation

The aim of the present study was to compare different techniques of HLA antibody detection in patients waiting for a transplant. Two methods of HLA antibody screening were compared: the complement-dependent cytotoxicity (CDC) test and the enzyme-linked immunosorbent solubility assay (ELISA). Three different commercial kits for the latter assay were tested: the kits were produced by One Lambda (O.L.) and SANG STAT for prescreening and specificity determination, and GTI only for prescreening. Of the two techniques, only CDC can detect IgM. The study included 207 serum samples selected from 192 patients waiting for a first kidney transplant. The conclusions are that O.L. is more sensitive than CDC and the other ELISA kits and is much faster for analysing a serum (taking only a few hours), but costs about 16 times more than CDC and does not detect IgM antibodies, so can be used only in support of CDC.

MICA and MICB microsatellite alleles in HLA extended haplotypes

The present study is a contribution to the definition of the linkage disequilibrium relationship of MICA and MICB with adjacent loci and to the characterization of extended HLA haplotypes. These issues are of importance for the identification of disease associations and for a better definition of donor-recipient compatibility in bone-marrow grafts through the typing of haplospecific markers. The distribution of the five alleles of MICA and the 13 alleles of MICB microsatellites, located, respectively, in MICA transmembrane exon 5 and in MICB intron 1, was examined in 133 healthy Italian individuals previously typed for HLA class I, class II and complement loci and for the TNFa microsatellite. The MICB microsatellite was also analysed in 49 HTCLs for which MICA typing was already available. Very strong linkage disequilibria with HLA-B and TNFa were detected in the Italian population for both MICA and MICB microsatellite alleles, in spite of the high mutability rate of the larger MICB alleles. Some strong associations were also detected between MICB and DRB1. The strongest associations (P < 0.001, D' > 0.7) were those of MICA-A4 with HLA-B18, B27 and TNFa1, MICA-A5 with HLA-B35, B61 and B62, MICA-A5.1 with HLA-B7, B8, B13, B63 and MICB-CA24, MICA-A6 with HLA-B51, MICA-A9 with HLA-B39, B57 and TNFa2, MICB-CA14 with HLA-B14, B27 and TNFa1, MICB-CA15 with HLA-B52, TNFa4 and TNFa13, MICB-CA17 with HLA-B7 and TNFa11, MICB-CA18 with HLA-B13 and TNFa7, MICB-CA22 with HLA-B57, and MICB-CA24 with HLA-B8 and TNFa2. From pairwise associations in the random panel and results for the homozygous cell lines it was possible to deduce the MICA and MICB microsatellite alleles present in many of the well-known Caucasoid extended haplotypes.

Cytotoxic T lymphocyte precursor frequency as a predictor of acute graft-versus-host disease in bone marrow transplantation from HLA-identical siblings

The measurement of precursor frequencies of donor anti-recipient cytotoxic T lymphocytes (CTL-p) has been shown to predict the incidence and the severity of acute graft-versus-host disease (aGVHD) in unrelated donor bone marrow transplantation (BMT). In HLA-identical sibling BMT, where aGVHD is most likely caused by minor histocompatibility antigen mismatches, this assay did not appear to be sensitive enough to provide similar predictive information. In this study, the CTL-p frequencies and the incidence and severity of aGVHD in 51 onco-hematological patients transplanted from HLA-identical siblings were compared. Sibling donors were selected on the basis of HLA identity using serological typing for HLA-A, B, C antigens, whereas HLA-DRB was tested by molecular analysis. Sibling identity was also confirmed by DNA heteroduplex analyses. Fifteen out of 21 (71%) patients with high precursor frequency (>1:100 x 10(3)) and 12 out of 30 (40%) with low precursor frequency (<1:100 x 10(3)) experienced clinically significant (II-IV) aGVHD. A significant correlation (P = 0.04) between CTL-p frequency and severe aGVHD was demonstrated. Moreover there was a positive trend for a high frequency response according to an increasing grade of aGVHD, which was statistically significant (P = 0.04). In our experience the CTL-p assay is a helpful predictive test for aGVHD in HLA-identical sibling BMT, indicating high risk patients possibly requiring additional prophylaxis.

Waiting list for kidney transplant. Some patients wait too long

The selection of a kidney graft recipient should be made not only taking into account biological and clinical parameters, for assuring the maximum possible clinical success; the ethical objective to allow every patient equal opportunity of receiving a transplant should also be pursued. In every waiting list of transplant candidates a proportion of patients remains in the list for a particularly long time. The present analysis aimed to find out the factors associated with a prolonged waiting time, in order to allow the implementation of patient selection criteria able to balance unfavourable factors. The analysis of the waiting list of our kidney transplant centre allowed to observe that blood group 0, anti-HLA immunisation, presence of rare HLA antigens and, at a lesser extent, HLA homozygosity are associated with a longer waiting time for a kidney transplant.

HLA class II gene frequencies in Italy

The frequency of HLA alleles at HLA-DR and DQ loci, and that of the related HLA-D specificities, were estimated in the Italian population. 109 healthy unrelated subjects, born in several Italian regions and living in the district of Torino, were studied. DNA typing was achieved by the restriction fragment length polymorphism (RFLP) analysis of HLA-DR beta, DQ alpha and beta genes, hybridizing specific probes with TaqI digested DNAs. The present study allowed to define in more detail the HLA class II polymorphisms in the Italian population.