Prospective surveillance of varicella-zoster virus infections in an out-patient setting in Switzerland

Limited data are available on the clinical impact of varicella in the ambulatory setting. Our goal was to determine real-life data on the clinical outcomes, medical management, and resource utilization in patients with varicella in Switzerland, a country without a universal immunization program against varicella. A total of 236 patients (222 = 94% primarily healthy individuals) with a clinical diagnosis of varicella were recruited by pediatricians and general practitioners. Age range of patients was 0-47 years with a median of 5 years. The great majority of patients (179 = 76%) were

Hepatitis C and human immunodeficiency virus infections in injecting drug users in drug treatment centers in Vietnam

Background. Injecting drug users (IDUs) are at risk of infection with Hepatitis C Virus (HCV) and Human Immunodeficiency Virus (HIV). Independently, each of these viruses is a serious threat to health, with HIV ravaging the body’s immune system, and HCV causing cirrhosis, liver cancer and liver failure. Co-infection with HIV/HCV weakens the response to antiretroviral therapy in HIV patients. IDUs with HIV/HCV co-infection are at a 20 times higher risk of having liver-related morbidity and mortality than IDUs with HIV alone. In Vietnam, studies to ascertain the prevalence of HIV have found high rates, but little is known about their HCV status. ^ Purpose. To measure the prevalence of HCV and HIV infection and identify factors associated with these viruses among IDUs at drug treatment centers in northern Vietnam. ^ Methods. A cross-sectional study was conducted from November 2007 to February 2008 with 455 injecting drug users aged 18 to 39 years, admitted no more than two months earlier to one of four treatment centers in Northern Vietnam (Hatay Province) (response rate=95%). Participants, all of whom had completed detoxification and provided informed consent, completed a risk assessment questionnaire and had their blood drawn to test for the presence of antibody-HCV and antibody-HIV with enzyme immuno assays. Univariate and multivariable logistic regression models were utilized to explore the strength of association using HIV, HCV infections and HIV/HCV co-infection as outcomes and demographic characteristics, drug use and sexual behaviors as factors associated with these outcomes. Unadjusted and adjusted odds ratios and 95% confidence intervals were calculated. ^ Results. Among all IDU study participants, the prevalence of HCV alone was 76.9%, HIV alone was 19.8%. The prevalence of HIV/HCV co-infection was 92.2% of HIV-positive and 23.7% of HCV-positive respondents. No sexual risk behaviors for lifetime, six months or 30 days prior to admission were significantly associated with HCV or HIV infection among these IDUs. Only duration of injection drug use was independently associated with HCV and HIV infection, respectively. Longer duration was associated with higher prevalence. Nevertheless, while HCV infection among IDUs who reported being in their first year of injecting drugs were lower than longer time injectors, their rates were still substantial, 67.5%. ^ Compared with either HCV mono-infection or HIV/HCV non-infection, HIV/HCV co-infection was associated with the length of drug injection history but was not associated with sexual behaviors. Higher education was associated with a lower prevalence of HIV/HCV co-infection. When compared with HIV/HCV non-infection, current marriage was associated with a lower prevalence of HIV/HCV co-infection. ^ Conclusions. HCV was prevalent among IDUs from 18 to 39 years old at four drug treatment centers in northern Vietnam. Co-infection with HCV was predominant among HIV-positive IDUs. HCV and HIV co-infection were closely associated with the length of injection drug history. Further research regarding HCV/HIV co-infection should include non-injecting drug users to assess the magnitude of sexual risk behaviors on HIV and HCV infection. (At these treatment centers non-IDUs constituted 10-20% of the population.) High prevalence of HCV prevalence among IDUs, especially among HIV-infected IDUs, suggests that drug treatment centers serving IDUs should include not only HIV prevention education but they should also include the prevention of viral hepatitis. In addition, IDUs who are HIV-positive need to be tested for HCV to receive the best course of therapy and achieve the best response to HIV treatment. These data also suggest that because many IDUs get infected with HCV in the first year of their injection drug career, and because they also engaged in high risk sexual behaviors, outreach programs should focus on harm reduction, safer drug use and sexual practices to prevent infection among drug users who have not yet begun injecting drugs and to prevent further spread of HCV, HIV and co-infection. ^

Recent insights into the mucosal reactions associated with Giardia lamblia infections.

Giardia lamblia is an intestinal protozoan parasite infecting humans and various other mammalian hosts. The most important clinical signs of giardiasis are diarrhoea and malabsorption. Giardia lamblia is able to undergo continuous antigenic variation of its major surface antigen, named VSP (variant surface protein). While intestinal antibodies, and more specifically anti-VSP IgA antibodies, were proven to be involved in modulating antigenic variation of the parasite the participation of the local antibody response in control of the parasite infection is still controversial. Conversely, previous studies based on experimental infections in mice showed that cellular immune mechanisms are essential for elimination of the parasite from its intestinal habitat. Furthermore, recent data indicated that inflammatory mast cells have a potential to directly, or indirectly, interfere in duodenal growth of G. lamblia trophozoites. However, this finding was challenged by other reports, which did not find a correlation between intestinal inflammation and resistance to infection. Since intestinal infiltration of inflammatory cells and/or CD8+T-cells were demonstrated to coincide with villus-shortening and crypt hyperplasia immunological reactions were considered to be a potential factor of pathogenesis in giardiasis. The contribution of physiological factors to pathogenesis was essentially assessed in vitro by co-cultivation of G. lamblia trophozoites with epithelial cell lines. By using this in vitro model, molecular (through surface lectins) and mechanical (through ventral disk) adhesion of trophozoites to the epithelium was shown to be crucial for increased epithelial permeability. This phenomenon as well as other Giardia-induced intestinal abnormalities such as loss of intestinal brush border surface area, villus flattening, inhibition of disaccharidase activities, and eventually also overgrowth of the enteric bacterial flora seem to be involved in the pathophysiology of giardiasis. However, it remains to be elucidated whether at least part of these pathological effects are causatively linked to the clinical manifestation of the disease.

Dually Active HIV/HBV Antiretrovirals Protect Against Incident Hepatitis B Infections: Potential for Prophylaxis.

BACKGROUND  Hepatitis-B virus (HBV) has a detrimental effect on HIV natural course, and HBV vaccination is less effective in the HIV infected. We examine the protective effect of dually active antiretroviral therapy (DAART) for HIV/HBV (Tenofovir/Lamivudine/Emtricitabine) in a large cohort encompassing heterosexuals, men-who-have-sex-with-men (MSM), and intravenous drug users (IDU), who are HIV-infected yet susceptible to HBV, with comprehensive follow-up data about risky behavior and immunological profile. METHODS  We defined an incident HBV infection as the presence of any of HBV serological markers (HBsAg/AntiHBc/HBV-DNA) following a negative baseline AntiHBc test. Patients with positive AntiHBs were excluded. Cox proportional hazard models were utilized, with an incident case of HBV infection as the outcome variable. RESULTS  We analyzed 1,716 eligible patients from the Swiss HIV Cohort Study with 177 incident HBV cases. DAART was negatively associated with incident HBV infection (hazard ratio 0.4, 95%CI 0.2-0.6). This protective association was robust to adjustment (0.3, 0.2-0.5) for condomless sex, √CD4 count, drug use, and patients' demographics. Condomless sex (1.9,1.4-2.6), belonging to MSM (2.7,1.7-4.2) or IDU (3.8,2.4-6.1) were all associated with higher HBV hazard. CONCLUSIONS  Our study suggests that DAART, independently of CD4 count and risky behavior, has a potentially strong public health impact including pre-exposure prophylaxis of HBV co-infection.

High prevalence of herpes simplex virus (HSV)- type 2 co-infection among HIV-positive women in Ukraine, but no increased HIV mother-to-child transmission risk.

BACKGROUND Over 3500 HIV-positive women give birth annually in Ukraine, a setting with high prevalence of sexually transmitted infections. Herpes simplex virus Type 2 (HSV-2) co-infection may increase HIV mother-to-child transmission (MTCT) risk. We explored factors associated with HSV-2 seropositivity among HIV-positive women in Ukraine, and its impact on HIV MTCT. METHODS Data on 1513 HIV-positive women enrolled in the Ukraine European Collaborative Study from 2007 to 2012 were analysed. Poisson and logistic regression models respectively were fit to investigate factors associated with HSV-2 seropositivity and HIV MTCT. RESULTS Median maternal age was 27 years (IQR 24-31), 53% (796/1513) had been diagnosed with HIV during their most recent pregnancy and 20% had a history of injecting drugs. Median antenatal CD4 count was 430 cells/mm(3) (IQR 290-580). Ninety-six percent had received antiretroviral therapy antenatally. HSV-2 seroprevalence was 68% (1026/1513). In adjusted analyses, factors associated with HSV-2 antibodies were history of pregnancy termination (APR 1.30 (95% CI 1.18-1.43) for ≥ 2 vs. 0), having an HIV-positive partner (APR 1.15 (95% CI 1.05-1.26) vs partner's HIV status unknown) and HCV seropositivity (APR 1.23 (95 % CI 1.13-1.35)). The overall HIV MTCT rate was 2.80% (95% CI 1.98-3.84); no increased HIV MTCT risk was detected among HSV-2 seropositive women after adjusting for known risk factors (AOR 1.43 (95% CI 0.54-3.77). CONCLUSION No increased risk of HIV MTCT was detected among the 68% of HIV-positive women with antibodies to HSV-2, in this population with an overall HIV MTCT rate of 2.8%. Markers of ongoing sexual risk among HIV-positive HSV-2 seronegative women indicate the importance of interventions to prevent primary HSV-2 infection during pregnancy in this high-risk group.

Contemporaneous fluctuations in T cell responses to persistent herpes virus infections

The classical paradigm for T cell dynamics suggests that the resolution of a primary acute virus infection is followed by the generation of a long-lived pool of memory T cells that is thought to be highly stable. Very limited alteration in this repertoire is expected until the immune system is re-challenged by reactivation of latent viruses or by cross-reactive pathogens. Contradicting this view, we show here that the T cell repertoire specific for two different latent herpes viruses in the peripheral blood displayed significant contemporaneous co-fluctuations of virus-specific CD8(+) T cells. The coordinated responses to two different viruses suggest that the fluctuations within the T cell repertoire may be driven by sub-clinical viral reactivation or a more generalized 'bystander' effect. The later contention was supported by the observation that, while absolute number of CD3(+) T cells and their subsets and also the cell surface phenotype of antigen-specific T cells remained relatively constant, a loss of CD62L expression in the total CD8(+) T cell population was coincident with the expansion of tetramer-positive virus-specific T cells. This study demonstrates that the dynamic process of T cell expansion and contractions in persistent viral infections is not limited to the acute phase of infection, but also continues during the latent phase of infection.

Perspective on the host response to human metapneumovirus infection: what can we learn from respiratory syncytial virus infections?

Human metapneumovirus (HMPV) is a recently discovered pathogen first identified in respiratory specimens from young children suffering from clinical respiratory syndromes ranging from mild to severe lower respiratory tract illness. HMPV has worldwide prevalence, and is a leading cause of respiratory tract infection in the first years of life, with a spectrum of disease similar to respiratory syncytial virus (RSV). The disease burden associated with HMPV infection has not been fully elucidated; however, studies indicate that HMPV may cause upper or lower respiratory tract illness in patients between ages 2 months and 87 years, may co-circulate with RSV, and HMPV infection may be associated with asthma exacerbation. The mechanisms and effector pathways contributing to immunity or disease pathogenesis following infection are not fully understood; however, given the clinical significance of HMPV, there is a need for a fundamental understanding of the immune and pathophysiological processes that occur following infection to provide the foundation necessary for the development of effective vaccine or therapeutic intervention strategies. This review provides a current perspective on the processes associated with HMPV infection, immunity, and disease pathogenesis. (c) 2005 Elsevier SAS. All rights reserved.

The suitability of biodegradable poly(dl-lactide-co-glycolide)75:25 microspheres for the sustained release of antibiotics

Post-operative infections resulting from total hip arthroplasty are caused by bacteria such as Staphylococcus aureus and Pseudomonas aeruginosa entering the wound perioperatively or by haemetogenous spread from distant loci of infection. They can endanger patient health and require expensive surgical revision procedures. Gentamicin impregnated poly (methyl methacrylate) bone cement is traditionally used for treatment but is often removed due to harbouring bacterial growth, while bacterial resistance to gentamicin is increasing. The aim of this work was to encapsulate the antibiotics vancomycin, ciprofloxacin and rifampicin within sustained release microspheres composed of the biodegradable polymer poly (dl-lactide-co-glycolide) [PLCG] 75:25. Topical administration to the wound in hydroxypropylmethylcellulose gel should achieve high local antibiotic concentrations while the two week in vivo half life of PLCG 75:25 removes the need for expensive surgical retrieval operations. Unloaded and 20% w/w antibiotic loaded PLCG 75:25 microspheres were fabricated using a Water in Oil emulsification with solvent evaporation technique. Microspheres were spherical in shape with a honeycomb-like internal matrix and showed reproducible physical properties. The kinetics of in vitro antibiotic release into newborn calf serum (NCS) and Hank's balanced salt solution (HBSS) at 37°C were measured using a radial diffusion assay. Generally, the day to day concentration of each antibiotic released into NCS over a 30 day period was in excess of that required to kill St. aureus and Ps. auruginosa. Only limited microsphere biodegradation had occurred after 30 days of in vitro incubation in NCS and HBSS at 37°C. The moderate in vitro cytotoxicity of 20% w/w antibiotic loaded microspheres to cultured 3T3-L1 cells was antibiotic induced. In conclusion, generated data indicate the potential for 20% w/w antibiotic loaded microspheres to improve the present treatment regimens for infections occurring after total hip arthroplasty such that future work should focus on gaining industrial collaboration for commercial exploitation.

Development of a multicellular co-culture model of normal and cystic fibrosis human airways in vitro

Cystic fibrosis (CF) is the most common lethal inherited disease among Caucasians and arises due to mutations in a chloride channel, called cystic fibrosis transmembrane conductance regulator. A hallmark of this disease is the chronic bacterial infection of the airways, which is usually, associated with pathogens such as Pseudomonas aeruginosa, S. aureus and recently becoming more prominent, B. cepacia. The excessive inflammatory response, which leads to irreversible lung damage, will in the long term lead to mortality of the patient at around the age of 40 years. Understanding the pathogenesis of CF currently relies on animal models, such as those employing genetically-modified mice, and on single cell culture models, which are grown either as polarised or non-polarised epithelium in vitro. Whilst these approaches partially enable the study of disease progression in CF, both types of models have inherent limitations. The overall aim of this thesis was to establish a multicellular co-culture model of normal and CF human airways in vitro, which helps to partially overcome these limitations and permits analysis of cell-to-cell communication in the airways. These models could then be used to examine the co-ordinated response of the airways to infection with relevant pathogens in order to validate this approach over animals/single cell models. Therefore epithelial cell lines of non-CF and CF background were employed in a co-culture model together with human pulmonary fibroblasts. Co-cultures were grown on collagen-coated permeable supports at air-liquid interface to promote epithelial cell differentiation. The models were characterised and essential features for investigating CF infections and inflammatory responses were investigated and analysed. A pseudostratified like epithelial cell layer was established at air liquid interface (ALI) of mono-and co-cultures and cell layer integrity was verified by tight junction (TJ) staining and transepithelial resistance measurements (TER). Mono- and co-cultures were also found to secrete the airway mucin MUC5AC. Influence of bacterial infections was found to be most challenging when intact S. aureus, B. cepacia and P. aeruginosa were used. CF mono- and co-cultures were found to mimic the hyperinflammatory state found in CF, which was confirmed by analysing IL-8 secretions of these models. These co-culture models will help to elucidate the role fibroblasts play in the inflammatory response to bacteria and will provide a useful testing platform to further investigate the dysregulated airway responses seen in CF.

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.

Cynomolgus monkeys ( Macaca fascicularis ) experimentally infected with B19V and hepatitis A virus: no evidence of the co-infection as a cause of acute liver failure

This study was conducted to analyse the course and the outcome of the liver disease in the co-infected animals in order to evaluate a possible synergic effect of human parvovirus B19 (B19V) and hepatitis A virus (HAV) co-infection. Nine adult cynomolgus monkeys were inoculated with serum obtained from a fatal case of B19V infection and/or a faecal suspension of acute HAV. The presence of specific antibodies to HAV and B19V, liver enzyme levels, viraemia, haematological changes, and necroinflammatory liver lesions were used for monitoring the infections. Seroconversion was confirmed in all infected groups. A similar pattern of B19V infection to human disease was observed, which was characterised by high and persistent viraemia in association with reticulocytopenia and mild to moderate anaemia during the period of investigation (59 days). Additionally, the intranuclear inclusion bodies were observed in pro-erythroblast cell from an infected cynomolgus and B19V Ag in hepatocytes. The erythroid hypoplasia and decrease in lymphocyte counts were more evident in the co-infected group. The present results demonstrated, for the first time, the susceptibility of cynomolgus to B19V infection, but it did not show a worsening of liver histopathology in the co-infected group.