36 research outputs found

    Back to field: uncertainty and risk in field research

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    The rapid spread of COVID-19 beginning in early 2020 caused global disruption. As the risk of infection rose and public health authorities around the world enacted measures to contain the virus, everyday life ground to a halt. Activities that seemed routine in late 2019 became fraught with uncertainty. Fieldwork was no exception. Most field researchers had to change or cancel at least some of their plans; some left their field in a hurry before travel was shut down while others had to lock down on site; most academic institutions restricted travel, with some even prohibiting all forms of international movement. In brief, many traditional forms of fieldwork became all but impossible during the pandemic

    Analysis of clinical and virologic features in Hepatitis B e Antigen (HbeAg)-negative and HbeAg-positive Egyptian chronic hepatitis B patients

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    Background: HBeAg\u2013negative chronic hepatitis B infection has a divergent clinical course from that of HBeAg-positive infection. Objectives: To analyze the frequency and to compare the different features of HBeAg-negative and HBeAg-positive chronic hepatitis B patients. Methods: One hundred and twenty one Egyptian patients with chronic hepatitis B (CHB), underwent laboratory investigations and transient elastography (TE). Comparisons according to HBeAg status were conducted regarding their demographic, liver biochemical and virologic characters. Results: 97 patients (80.2%) were HBeAg-negative while 24 patients (19.8%) were HBeAg-positive. HBeAg-negative patients were significantly older in age than CHBeAg-positive patients (p=0.001). ALT levels in HBeAg-negative patients were significantly lower than those in HBeAg-positive patients (p=0.02), whereas serum albumin was lower in the HBeAg-positive group (p=0.03). The percentage of HBV DNA higher than 20000 IU/mL in HBeAg-negative patients was lower than those in HBeAg-positive patients (p=0.24). Stages of fibrosis by TE showed that 30.9% of HBeAg-negative and 41.7% of HBeAg-positive had a fibrosis score >F2. Four patients (3.3%) were diagnosed with HCC; all of whom were HBeAg-negative. Conclusion: HBeAg-negative patients compared with HBeAg-positive patients had older age, lower ALT and serum HBVDNA levels, but more incidence of HCC

    Cytotoxicity, Intracellular Replication, and Contact-Dependent Pore Formation of Genotyped Environmental Legionella pneumophila Isolates from HospitalWater Systems in the West Bank, Palestine

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    Legionella pneumophila is the causative agent of Legionnaires’ disease. Due to the hot climate and intermittent water supply, the West Bank, Palestine, can be considered a high-risk area for this often fatal atypical pneumonia. L. pneumophila occurs in biofilms of natural and man-made freshwater environments, where it infects and replicates intracellularly within protozoa. To correlate the genetic diversity of the bacteria in the environment with their virulence properties for protozoan and mammalian host cells, 60 genotyped isolates from hospital water systems in the West Bank were analyzed. The L. pneumophila isolates were previously genotyped by high resolution Multi Locus Variable Number of Tandem Repeat Analysis (MLVA-8(12)) and sorted according to their relationship in clonal complexes (VACC). Strains of relevant genotypes and VACCs were compared according to their capacity to infect Acanthamoeba castellanii and THP-1 macrophages, and to mediate poreforming cytotoxicity in sheep red blood cells (sRBCs). Based on a previous detailed analysis of the biogeographic distribution and abundance of the MLVA-8(12)-genotypes, the focus of the study was on the most abundant L. pneumophila- genotypes Gt4(17), Gt6 (18) and Gt10(93) and the four relevant clonal complexes [VACC1, VACC2, VACC5 and VACC11]. The highly abundant genotypes Gt4(17) and Gt6(18) are affiliated with VACC1 and sequence type (ST)1 (comprising L. pneumophila str. Paris), and displayed seroroup (Sg)1. Isolates of these two genotypes exhibited significantly higher virulence potentials compared to other genotypes and clonal complexes in theWest Bank. Endemic for theWest Bank was the clonal complex VACC11 (affiliated with ST461) represented by three relevant genotypes that all displayed Sg6. These genotypes unique for the West Bank showed a lower infectivity and cytotoxicity compared to all other clonal complexes and their affiliated genotypes. Interestingly, the L. pneumophila serotypes ST1 and ST461 were previously identified by in situ-sequence based typing (SBT) as main causative agents of Legionnaires’ disease (LD) in the West Bank at a comparable level. Overall, this study demonstrates the site-specific regional diversity of L. pneumophila genotypes in theWest Bank and suggests that a combination of MLVA, cellular infection assays and hierarchical agglomerative cluster analysis allows an improved genotype-based risk assessment

    Characterization of Legionella pneumophila Populations by Multilocus Variable Number of Tandem Repeats (MLVA) Genotyping from Drinking Water and Biofilm in Hospitals from Di erent Regions of the West Bank

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    The West Bank can be considered a high-risk area for Legionnaires’ disease (LD) due to its hot climate, intermittent water supply and roof storage of drinking water. Legionella, mostly L. pneumophila, are responsible for LD, a severe, community-acquired and nosocomial pneumonia. To date, no extensive assessment of Legionella spp and L. pneumophila using cultivation in combination with molecular approaches in the West Bank has been published. Two years of environmental surveillance of Legionella in water and biofilms in the drinking water distribution systems (DWDS) of eight hospitals was carried out; 180 L. pneumophila strains were isolated, mostly from biofilms in DWDS. Most of the isolates were identified as serogroup (Sg) 1 (60%) and 6 (30%), while a minor fraction comprised Sg 8 and 10. Multilocus Variable number of tandem repeats Analysis using 13 loci (MLVA-8(12)) was applied as a high-resolution genotyping method and compared to the standard Sequence Based Typing (SBT). The isolates were genotyped in 27 MLVA-8(12) genotypes (Gt), comprising four MLVA clonal complexes (VACC 1; 2; 5; 11). The major fraction of isolates constituted Sequence Type (ST)1 and ST461. Most of the MLVA-genotypes were highly diverse and often unique. The MLVA-genotype composition showed substantial regional variability. In general, the applied MLVA-method made it possible to reproducibly genotype the isolates, and was consistent with SBT but showed a higher resolution. The advantage of the higher resolution was most evident for the subdivision of the large strain sets of ST1 and ST461; these STs were shown to be highly pneumonia-relevant in a former study. This shows that the resolution by MLVA is advantageous for back-tracking risk sites and for the avoidance of outbreaks of L. pneumophila. Overall, our results provide important insights into the detailed population structure of L. pneumophila, allowing for better risk assessment for DWDS.Funding: This work was supported by DFG grant (HO 930/5-1&2) and the Hildegard-Elisabeth Foundation. Acknowledgments: We thank the administration of the hospitals for allowing us to collect the samples. We thank the PalestinianWater Authority (PWA) for helpful support, information and data. We are grateful to Dalia Abu Hilal, Verena Maiberg and Josefin Koch for technical assistance. Christian Lück of the TU Dresden kindly provided the Sequence Types of the isolates

    Water, Energy, and Human Insecurity in the Middle East and North Africa

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