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Panton-Valentine leukocidin (PVL) is common in African Staphylococcus aureus and can be associated with skin and soft tissue infection. PVL-positive S. aureus colonization is associated with a variant of complement receptor 5a, the cellular target of the lukS PVL subunit. [ABSTRACT FROM AUTHOR]

Background: As an immune modulator, vitamin D is involved in various pathophysiological mechanisms in a plethora of diseases. This study aims to correlate the vitamin D deficiency status and clinical progression of liver diseases associated with hepatitis B virus (HBV) infection in patients in Vietnam and to compare it to healthy controls. Methods: We quantified the levels of total vitamin D [25-(OH) D2 and D3] in serum samples from 400 HBV patients (chronic hepatitis B infection [CHB], n = 165; HBV-associated liver cirrhosis [LC], n = 127; HBV-associated hepatocellular carcinoma [HCC], n = 108) and 122 unrelated healthy controls (HC). Univariate and multivariate analyses were performed in order to determine the association between vitamin D levels and distinct clinical parameters. Results: The prevalence of vitamin D inadequacy (<30 ng/mL) was high among healthy individuals (81.7 %) as well as in HBV patients (84.3 %). Vitamin D deficiency (<20 ng/ml) or severe deficiency (<10 ng/ml) was observed more frequently among HBV patients (52 %) and subgroups (CHB, 47.8 %; LC, 54.4 %; HCC, 55.3 %) compared to the control group (32.5 %) (P < 0.001). Vitamin D levels and HBV-DNA load were strongly and inversely correlated (rho = -0.57, P < 0.0001). Multivariate regression analysis also revealed an independent association of HBV-DNA loads with low vitamin D levels (P = 0.0004). In addition, reduced vitamin D levels were associated with significant clinical progression of LC (Child-Pugh C versus Child-Pugh A, P = 0.0018; Child-Pugh C versus Child-Pugh B, P = 0.016). Conclusions: Vitamin D deficiency was observed in the majority of HBV-infected patients and associated with adverse clinical outcomes. Our findings suggest that substitution of vitamin D may be a supportive option in the treatment of chronic liver diseases, in particular of HBV-associated disorders. [ABSTRACT FROM AUTHOR]

Background: Blood cultures are commonly employed to identify bacterial pathogens causing sepsis. PCR assays to diagnose septicemia require extraction of bacterial DNA from blood samples and thus, delay the initiation of appropriate antimicrobial treatment. The presence of abundant human DNA may hamper the sensitivity of PCR in the detection of bacteria.Methods: We used serial dilutions of E. Coli spiked pseudo-blood-sepsis samples to develop a simple method that combines the use of a polar detergent solvent and adjustment of the basic pH to remove human DNA. A 16S rRNA gene-based screening algorithm was established to differentiate Gram-positive and Gram-negative groups of bacteria and the family of Enterobacteriaceae. A stringent validation with appropriate controls was implemented. The method of human DNA removal was then applied on 194 sepsis blood samples and 44 cerebrospinal fluid (CSF) samples by real-time PCR.Results: This uncomplicated and straightforward approach allows to remove up to 98 % of human DNA from peripheral blood of septic patients. The inhibitory effect of human DNA is efficiently prevented and the detection limit of real-time PCR is increased to 10 E. Coli CFUs/ml. This sensitivity is 10 times higher compared to conventional real-time PCR assays. The classical blood culture detected 58/194 (30 %) of sepsis and 9/44 (21 %) of CSF samples. Out of the 194 blood samples tested, the conventional real-time PCR targeting 13 common sepsis causing pathogens correctly detected the bacterial DNA in 16/194 (8 %) only and 14/44 (32 %) in cerebrospinal fluid samples. Our newly established approach was able to provide correct diagnoses in 78 (40 %) of the 194 blood samples and in 14 (32 %) of the CSF samples. The combination of both blood cultures and our technique raised the rate of sepsis diagnoses to 112/194 (58 %). Of the total group tested positive, 46 (24 %) cases showed overlap with the classical methodology.Conclusion: We report a simple optimized in-house protocol for removal of human DNA from blood sepsis samples as a pre-analytical tool to prepare DNA for subsequent PCR assays. With the detection increase of our in-house DNA removal approach, subsequent PCR assays can reach detection limits of 10 E. coli CFUs/ml and significantly improve the diagnostic rate in blood sepsis cases. [ABSTRACT FROM AUTHOR]

Infectious Diarrhea caused by rotavirus and adenovirus, is a leading cause of death in children in sub-Sahara Africa but there is limited published data on the diverse rotavirus genotypes and adenovirus serotypes circulating in the Republic of Congo. In this study, we investigated the prevalence of severe diarrhea caused by rotavirus A (RVA) and Adenovirus serotype 40 and 41 in Congolese children hospitalized with severe gastroenteritis. Stool samples were collected from 655 Congolese children less than 60 months of age hospitalized with acute gastroenteritis between June 2012 and June 2013. Rotavirus and adenovirus antigens were tested using commercially available ELISA kits and the RVA G- and P- genotypes were identified by seminested multiplex RT-PCR. Three hundred and four (46.4%) children were tested positive for RVA. Adenovirus infection was found in 5.5% of the 564 tested children. Rotavirus infection was frequently observed in children between 6-12 months (55.9%). The dry season months recorded increased RVA infection while no seasonality of adenovirus infection was demonstrated. The most common RVA genotypes were G1 (57.5%), G2 (6.4%), G1G2 mixture (15.5%), P[8] (58%), P[6] (13.2%), and P[8]P[6] mixture (26%). Additionally, the genotype G12P[6] was significantly associated with increased vomiting. This first study on Congolese children demonstrates a high prevalence and clinical significance of existing rotavirus genotypes. Adenovirus prevalence is similar to that of other Central African countries. This baseline epidemiology and molecular characterization study will contribute significantly to the RVA surveillance after vaccine implementation in the country. J. Med. Virol. 88:596-605, 2016. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Opisthorchiasis is a neglected infectious disease caused by liver flukes, which affect populations in tropical regions of East Asia, as well as temperate and semi-arctic areas of Europe and Asia. These parasites can cause liver-related health issues, including bile duct fibrosis, cholangitis, and bile duct cancer. Despite its importance, opisthorchiasis has not received much attention from health authorities, grant-giving agencies, and the pharmaceutical industry. Ongoing research aims to understand the epidemiology, clinical features, treatment, and host-parasite interaction of these infections. The article also discusses the induction of regulatory cells by these parasites, which can suppress immune responses and potentially contribute to cancer development. Further research is needed on the innate immune components and genetic regulation of susceptibility to Opisthorchiidae, as well as the development of diagnostic tests and potential drug targets. The authors suggest the formation of a consortium to collaborate on research and control efforts for Opisthorchiidae infections. [Extracted from the article]

Background The human major histocompatibility complex class I polypeptide-related sequence B (MICB) is a protein that modulates the NK and T cell activation through the NKG2D receptor and is related to several diseases including cancer. Methods The study investigated the prognostic role of soluble MICB (sMICB) protein in the progression of HBV-related liver diseases and to HBV-related HCC treatment. The sMICB serum levels were measured in 266 chronic HBV-infected Vietnamese patients and in healthy controls, and correlated with clinical and laboratory parameters and with therapeutic interventions for HBV-related HCC. Results Significant differences in both clinical and laboratory parameters were observed among the patient groups with different stages of hepatitis. The platelet counts were significantly decreased with disease progression (P < 0.001). The sMICB serum levels were significantly increased in HBV patients compared to healthy controls (P < 0.0001). Among the patients with different stages of hepatitis, asymptomatic individuals (ASYM) revealed higher sMICB serum levels while liver cirrhosis (LC) patients revealed lower sMICB serum levels (P < 0.0001) compared to other patient groups. Notably, the sMICB serum levels were decreased in treated HCC patient group compared to not-treated HCC patient group (P = 0.05). Additionally, the sMICB levels were significantly correlated with platelet counts in ASYM and HCC patients (r = -0.37, P = 0.009; and r = 0.22, P = 0.025, respectively). Conclusions Our results demonstrate a potential role of sMICB serum levels and platelet counts during immune response to the HBV infection, liver disease progression and response to the HCC treatment. [ABSTRACT FROM AUTHOR]

Background Increased resistance by Plasmodium falciparum parasites led to the withdrawal of the antimalarial drugs chloroquine and sulphadoxine-pyrimethamine in Ethiopia. Since 2004 artemether-lumefantrine has served to treat uncomplicated P. falciparum malaria. However, increasing reports on delayed parasite clearance to artemisinin opens up a new challenge in anti-malarial therapy. With the complete withdrawal of CQ for the treatment of Plasmodium falciparum malaria, this study assessed the evolution of CQ resistance by investigating the prevalence of mutant alleles in the pfmdr1 and pfcrt genes in P. falciparum and pvmdr1 gene in Plasmodium vivax in Southern and Eastern Ethiopia. Methods Of the 1,416 febrile patients attending primary health facilities in Southern Ethiopia, 329 febrile patients positive for P. falciparum or P. vivax were recruited. Similarly of the 1,304 febrile patients from Eastern Ethiopia, 81 febrile patients positive for P. falciparum or P. vivax were included in the study. Of the 410 finger prick blood samples collected from malaria patients, we used direct sequencing to investigate the prevalence of mutations in pfcrt and pfmdr1. This included determining the gene copy number in pfmdr1 in 195 P. falciparum clinical isolates, and mutations in the pvmdr1 locus in 215 P. vivax clinical isolates. Results The pfcrt K76 CQ-sensitive allele was observed in 84% of the investigated P.falciparum clinical isolates. The pfcrt double mutations (K76T and C72S) were observed less than 3%. The pfcrt SVMNT haplotype was also found to be present in clinical isolates from Ethiopia. The pfcrt CVMNK-sensitive haplotypes were frequently observed (96%). The pfmdr1 mutation N86Y was observed only in 14.9% compared to 85.1% of the clinical isolates that carried sensitive alleles. Also, the sensitive pfmdr1 Y184 allele was more common, in 96% of clinical isolates. None of the investigated P. falciparum clinical isolates carried S1034C, N1042D and D1246Y pfmdr1 polymorphisms. All investigated P. falciparum clinical isolates from Southern and Eastern Ethiopia carried only a single copy of the mutant pfmdr1 gene. Conclusion The study reports for the first time the return of chloroquine sensitive P. falciparum in Ethiopia. These findings support the rationale for the use of CQ-based combination drugs as a possible future alternative. [ABSTRACT FROM AUTHOR]

Highlights: [•] MBL has a central role in the activation of Complement Lectin Pathway. [•] Trypanosoma cruzi displays strains resistant or sensitive to complement Lysis. [•] The resistant to complement lysis could be crucial to proceed with the infection. [•] Dual role of MBL in invasion: facilitating entry or as complement activator. [Copyright &y& Elsevier]

Background With 75% of the Ethiopian population at risk of malaria, accurate diagnosis is crucial for malaria treatment in endemic areas where Plasmodium falciparum and Plasmodium vivax coexist. The present study evaluated the performance of regular microscopy in accurate identification of Plasmodium spp. in febrile patients visiting health facilities in southern Ethiopia. Methods A cross-sectional study design was employed to recruit study subjects who were microscopically positive for malaria parasites and attending health facilities in southern Ethiopia between August and December 2011. Of the 1,416 febrile patients attending primary health facilities, 314 febrile patients, whose slides were positive for P. falciparum, P. vivax or mixed infections using microscopy, were re-evaluated for their infection status by PCR. Finger-prick blood samples were used for parasite genomic DNA extraction. Phylogenetic analyses were performed to reconstruct the distribution of different Plasmodium spp. across the three geographical areas. Results Of the 314 patients with a positive thick blood smear, seven patients (2%) were negative for any of the Plasmodium spp. by nested PCR. Among 180 microscopically diagnosed P. falciparum cases, 111 (61.7%) were confirmed by PCR, 44 (24.4%) were confirmed as P. vivax, 18 (10%) had mixed infections with P. falciparum and P. vivax and two (1.1%) were mixed infections with P. falciparum and P. malariae and five (2.8%) were negative for any of the Plasmodium spp. Of 131 microscopically diagnosed P. vivax cases, 110 (84%) were confirmed as P. vivax, 14 (10.7%) were confirmed as P. falciparum, two (1.5%) were P. malariae, three (2.3%) with mixed infections with P. falciparum and P. vivax and two (1.5%) were negative for any of the Plasmodium spp. Plasmodium falciparum and P. vivax mixed infections were observed. Plasmodium malariae was detected as mono and mixed infections in four individuals. Conclusion False positivity, under-reporting of mixed infections and a significant number of species mismatch needs attention and should be improved for appropriate diagnosis. The detection of substantial number of false positive results by molecular methodologies may provide the accurate incidence of circulating Plasmodium species in the geographical region and has important repercussions in understanding malaria epidemiology and subsequent control. [ABSTRACT FROM AUTHOR]

In recent years, genome wide association studies have discovered a large number of gene loci that play a functional role in innate and adaptive immune pathways associated with leprosy susceptibility. The immunological control of intracellular bacteria M. leprae is modulated by NOD2-mediated signaling of Th1 responses. In this study, we investigated 211 clinically classified leprosy patients and 230 ethnically matched controls in Indian population by genotyping four variants in NOD2 (rs9302752A/G), LRRK2 (rs1873613A/G), RIPK2 (rs40457A/G and rs42490G/A). The LRRK2 locus is associated with leprosy outcome. The LRRK2 rs1873613A minor allele and respective rs1873613AA genotypes were significantly associated with an increased risk whereas the LRRK2 rs1873613G major allele and rs1873613GG genotypes confer protection in paucibacillary and leprosy patients. The reconstructed GA haplotypes from RIPK2 rs40457A/G and rs42490G/A variants was observed to contribute towards increased risk whereas haplotypes AA was observed to confer protective role. Our results indicate that a possible shared mechanisms underlying the development of these two clinical forms of the disease as hypothesized. Our findings confirm and validates the role of gene variants involved in NOD2-mediated signalling pathways that play a role in immunological control of intracellular bacteria M. leprae. [ABSTRACT FROM AUTHOR]

Background: L-ficolin (encoded by FCN2) binds to acetylated sugar moieties of many pathogens, including Trypanosoma cruzi, promoting their phagocytosis and lysis by the complement system. Methods: We investigated L-ficolin levels in 160 T. cruzi infected patients with chronic Chagas disease and 71 healthy individuals, and FCN2 polymorphisms (−986 G>A, −602 G>A, and −4 A>G in the promoter and A258S in exon 8) in 243 patients, being 88 indeterminate (asymptomatic), 96 with cardiac, 23 with digestive and 33 with cardiodigestive manifestations (two were unspecified) and 305 controls (135 for A258S). Results: Patients presented lower L-ficolin plasma levels than controls (p<0.0001). Among the different groups of cardiac commitment, individuals with moderate forms had higher L-ficolin levels than the severe forms (P = 0.039). Lower L-ficolin levels were found associated with the 258S variant in the patients (P = 0.034). We found less −4A/G heterozygotes in the cardiac patients, than in the controls (OR = 0.56 [95% CI = 0.33–0.94], P = 0.034). Heterozygote −4A/G genotypes with the 258S variant and 258SS homozygotes were nevertheless more frequent among cardiodigestive patients than in controls (OR = 14.1 [95% CI = 3.5–56.8], P = 0.0001) and in indeterminate patients (OR = 3.2 [95% CI = 1.1–9.4], P = 0.037). We also found an association of the allelic frequency of the 258S variant with cardiodigestive Chagas disease compared to controls (OR = 2.24 [95% CI = 1.1–4.5], P = 0.037). Thus, decreased patient levels of L-ficolin reflect not only protein consumption due to the disease process, but also the higher frequency of the 258S variant in patients with cardiodigestive symptoms. Conclusion: The very first study on Brazilian cohort associates both L-ficolin plasma levels and FCN2 variants to Chagas disease and subsequent disease progression. The prognostic value of L-ficolin levels and the FCN2*A258S polymorphism should be further evaluated in other settings. [ABSTRACT FROM AUTHOR]

Institute for Tropical Medicine, University Hospital Tübingen, Tübingen, Germany Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon The affiliations have been renumbered. Correction to: I Scientific Reports i https://doi.org/10.1038/s41598-021-87537-9, published online 08 April 2021 In the original version of this Article, Peter G. Kremsner was incorrectly affiliated with 'Vietnamese-German Center for Medical Research (VG-CARE), Hanoi, Vietnam'. [Extracted from the article]

Background: Occult hepatitis B infection (OBI) is characterized by the presence of hepatitis B virus (HBV) DNA at low levels in serum (<200 IU/mL) with a negative hepatitis B surface antigen (HBsAg) test. OBI remains a major challenge to blood safety, particularly in HBV-endemic regions like Cameroon, where HBV detection relies solely on HBsAg testing. This cross-sectional study aimed to investigate the actual incidence and genotype characteristics of OBI in Cameroonian blood donors. Methods: Between March and June 2023, samples were collected from 288 HBsAg-negative blood donors aged 18 to 55 years and analysed for antibodies against the HBV core (anti-HBc) and surface antigens (anti-HBs). Following DNA extraction from the serum samples, qualitative nested PCR and quantitative real-time PCR were used to detect HBV viral DNA and viral load respectively. For positive samples, sequencing of a fragment of the S gene was performed to identify the circulating HBV genotypes. Results: The findings revealed that 58% (n = 167/288) of blood donors tested positive for anti-HBc, 29% (n = 83/288) tested positive for anti-HBs, and 26% (n = 75/288) being positive for both anti-HBc and anti-HBs. Occult hepatitis was confirmed in 4.5% of the blood donors, all of whom belonged to either HBV genotypes A or E, which are predominant in Cameroon. The amino acid substitution sA184V associated with HBsAg detection failure in genotype E was observed in 70% of OBI sequences, and the HBsAg immune escape variants (sT131N and sS143L) implicated in OBI were also observed. The mutation rtN139K in the reverse transcriptase (RT) domain of the overlapping HBV polymerase (P) gene was present in 17% of OBI-positive sequences of genotype E, likely contributing to masking HBsAg secretion. Conclusion: The results suggest a considerable risk of transfusion-transmitted HBV in this region. Therefore, to ensure blood safety, nucleic acid testing (NAT) is recommended, as relying solely on HBsAg assays is insufficient to eliminate this risk. [ABSTRACT FROM AUTHOR]

Introduction Central nervous system infections pose significant health challenges, particularly in low- and middle-income countries, because of high morbidity and mortality rates. Rapid and accurate diagnosis is essential for effective treatment to prevent adverse outcomes. Traditional culture-based diagnostics are often slow and lack specificity. This study evaluates the BioFire FilmArray Meningitis/Encephalitis (FAME) Panel against standard diagnostics in Vietnam to assess its clinical impact and suitability for local epidemiology. Methods We conducted a prospective study involving 330 patients with suspected central nervous system infections at 4 hospitals in northern Vietnam from July 2022 to April 2023. Cerebrospinal fluid samples were analyzed using routine culture methods and FAME. We compared pathogen detection rates and assessed the potential clinical impact of FAME results on patient management. Results Of the 330 cerebrospinal fluid specimens, 64 (19%) were positive by either conventional diagnostics (n = 48) and/or FAME (n = 33). The agreement between FAME and conventional diagnostics was 87%. Key pathogens Mycobacterium tuberculosis (n = 7), Klebsiella pneumoniae (n = 5), Streptococcus suis (n = 5), Epstein-Barr virus (n = 3), Acinetobacter baumannii (n = 1), and Trichosporon asahii (n = 1) were not detected by FAME. Classical meningitis parameter clinical symptoms, altered glucose, protein, and pleocytosis were good predictors of FAME positivity, indicating their utility in optimizing local diagnostic algorithms. Conclusions FAME complements traditional diagnostics by offering rapid and broad pathogen detection, crucial for timely and appropriate therapy. However, its effectiveness varies with local epidemiology, and it should not replace conventional methods entirely. Tailoring diagnostic panels to regional pathogen prevalence is recommended to enhance diagnostic accuracy and clinical outcomes in low- and middle-income countries. [ABSTRACT FROM AUTHOR]

The introduction of the rotavirus vaccine, Rotarix, into the Fiji National Immunisation Program in 2012 has reduced the burden of rotavirus disease and hospitalisations in children less than 5 years of age. The aim of this study was to describe the pattern of rotavirus genotype diversity from 2005 to 2018; to investigate changes following the introduction of the rotavirus vaccine in Fiji. Faecal samples from children less than 5 years with acute diarrhoea between 2005 to 2018 were analysed at the WHO Rotavirus Regional Reference Laboratory at the Murdoch Children's Research Institute, Melbourne, Australia, and positive samples were serotyped by EIA (2005–2006) or genotyped by heminested RT-PCR (2007 onwards). We observed a transient increase in the zoonotic strain equine-like G3P[8] in the initial period following vaccine introduction. G1P[8] and G2P[4], dominant genotypes prior to vaccine introduction, have not been detected since 2015 and 2014, respectively. A decrease in rotavirus genotypes G2P[8], G3P[6], G8P[8] and G9P[8] was also observed following vaccine introduction. Monitoring the rotavirus genotypes that cause diarrhoeal disease in children in Fiji is important to ensure that the rotavirus vaccine will continue to be protective and to enable early detection of new vaccine escape strains if this occurs. [ABSTRACT FROM AUTHOR]

Infection with Leishmania parasites can lead to severe disease in humans and dogs, which act as a reservoir in zoonotic transmission. An increasing number of reports suggest that leishmaniosis is not restricted to dogs, but also affects many other mammalian and avian species. Consequently, this expands the potential reservoir and is of great public and veterinary health concern. The present study reviews, based on a comprehensive search of scientific literature published from 1 January 2001 to 31 December 2020, the currently available information on animal leishmaniosis in vertebrates in Europe, other than dogs and humans. This review provides an exhaustive list of mammals and birds in which infections with or exposure to Leishmania parasites have been detected in European countries. Most cases are reported from the Mediterranean region. Domestic animals, in particular cats, pose a concern because of close contact with humans. The wildlife reservoir is less likely to contribute to zoonotic transmission, with the exception of hares. This potentially large reservoir needs to be taken into account when developing control measures for zoonotic leishmaniosis. From a veterinary point of view, it is important that veterinarians are better aware of leishmaniosis and trained in its management. [ABSTRACT FROM AUTHOR]

The complement system may be crucial during dengue virus infection and progression to severe dengue. This study investigates the role of MBL2 genetic variants and levels of MBL in serum and complement proteins in Vietnamese dengue patients. MBL2 genotypes (− 550L/H, MBL2 codon 54), MBL2 diplotypes (XA/XO, YA/XO) and MBL2 haplotypes (LXPB, HXPA, XO) were associated with dengue in the study population. The levels of complement factors C2, C5, and C5a were higher in dengue and dengue with warning signs (DWS) patients compared to those in healthy controls, while factor D levels were decreased in dengue and DWS patients compared to the levels determined in healthy controls. C2 and C5a levels were associated with the levels of AST and ALT and with WBC counts. C9 levels were negatively correlated with ALT levels and WBC counts, and factor D levels were associated with AST and ALT levels and with platelet counts. In conclusions, MBL2 polymorphisms are associated with dengue in the Vietnamese study population. The levels of the complement proteins C2, C4b, C5, C5a, C9, factor D and factor I are modulated in dengue patients during the clinical course of dengue. [ABSTRACT FROM AUTHOR]

Background: Antimicrobial resistance (AMR) is of growing concern globally and AMR status in sub-Saharan Africa (SSA) is undefined due to a lack of real-time data recording, surveillance and regulation. World Health Organization (WHO) Joint External Evaluation (JEE) reports are voluntary, collaborative processes to assess country capacities and preparedness to prevent, detect and rapidly respond to public health risks, including AMR. The data from SSA JEE reports were analysed to gain an overview of how SSA is working towards AMR preparedness and where strengths and weaknesses lie. Methods: SSA country JEE AMR preparedness scores were analysed. A cumulative mean of all the SSA country AMR preparedness scores was calculated and compared to the overall mean SSA JEE score. AMR preparedness indicators were analysed, and data were weighted by region. Findings: The mean SSA AMR preparedness score was 53% less than the overall mean SSA JEE score. East Africa had the highest percentage of countries reporting having AMR National Action Plans in place, as well as human and animal pathogen AMR surveillance programmes. Southern Africa reported the highest percentage of countries with training programmes and antimicrobial stewardship. Conclusions: The low mean AMR preparedness score compared to overall JEE score, along with the majority of countries lacking implemented National Action Plans, suggests that until now AMR has not been a priority for most SSA countries. By identifying regional and One Health strengths, AMR preparedness can be fortified across SSA with a multisectoral approach. [ABSTRACT FROM AUTHOR]

Background: Rapid diagnostic tests (RDTs) have been described as a source of genetic material to analyse malaria parasites in proof-of-concept studies. The increasing use of RDTs (e.g., in focal or mass screening and treatment campaigns) makes this approach particularly attractive for large-scale investigations of parasite populations. In this study, the complexity of Plasmodium falciparum infections, parasite load and chloroquine resistance transporter gene mutations were investigated in DNA samples extracted from positive RDTs, obtained in a routine setting and archived at ambient temperature. Methods: A total of 669 archived RDTs collected from malaria cases in urban, semi-urban and rural areas of central Gabon were used for P. falciparum DNA extraction. Performance of RDTs as a source of DNA for PCR was determined using: (i) amplification of a single copy merozoite surface protein 1 (msp1) gene followed by highly sensitive and automated capillary electrophoresis; (ii) genotyping of the pfcrt gene locus 72–76 using haplotype-specific-probe-based real-time PCR to characterize chloroquine resistance; and, (iii) real-time PCR targeting 18S genes to detect and quantify Plasmodium parasites. Results: Out of the 669 archived RDTs, amplification of P. falciparum nucleic materials had a success rate of 97% for 18S real-time PCR, and 88% for the msp1 gene. The multiplicity of infections (MOI) of the whole population was 2.6 (95% CI 2.5–2.8). The highest number of alleles detected in one infection was 11. The MOI decreased with increasing age (β = − 0.0046, p = 0.02) and residence in Lambaréné was associated with smaller MOIs (p < 0.001). The overall prevalence of mutations associated with chloroquine resistance was 78.5% and was not associated with age. In Lambaréné, prevalence of chloroquine resistance was lower compared to rural Moyen-Ogooué (β = − 0.809, p-value = 0.011). Conclusion: RDT is a reliable source of DNA for P. falciparum detection and genotyping assays. Furthermore, the increasing use of RDTs allows them to be an alternative source of DNA for large-scale genetic epidemiological studies. Parasite populations in the study area are highly diverse and prevalence of chloroquine-resistant P. falciparum remains high, especially in rural areas. [ABSTRACT FROM AUTHOR]

Background: Calreticulin (CALR) gene mutations are currently recommended as biomarkers in diagnosis of patients with myeloproliferative neoplasms (MPN) with Jak2 V617F negative phenotype. Our aim was to establish a rapid, low cost and sensitive assay for identification of CALR gene mutations and to validate the diagnostic performance of the established assay in a patient cohort with different clinical MPN phenotypes. Methods: One hundred five Philadelphia-negative MPN patients, including polycythemia vera (PV), essential thrombocythaemia (ET), and primary myelofibrosis (PMF) were initially screened for JAK2 mutations by amplification-refractory mutation system (ARMS-PCR) methodology and were further subjected to detection of CALR gene mutations by our in-house assay, a PCR based amplicon length differentiation assay (PCR-ALDA). The PCR-ALDA methodology was compared with real time PCR and Sanger sequencing methods. Furthermore, the analytical sensitivity of the assay was established. Results: PCR - ALDA approach was able to detect and discriminate the pseudo-positive samples containing more than 1% CALR mutant alleles. CALR mutations were not detected in 63 Jak2 V617F positive cases in all three methods. In contrast, amongst 42 Jak2 V617F negative cases, both PCR-ALDA and Sanger sequencing coherently identified 12 CALR mutants compared to 10 CALR mutants detected by real-time PCR method. Conclusion: PCR-ALDA can be utilized as an easy-to-use, rapid, low cost and sensitive tool in the detection of CALR mutations in Philadelphia-negative MPN patients. [ABSTRACT FROM AUTHOR]

Background: Malaria transmission-blocking anti-malarial drugs, such as primaquine, offers an effective strategy for reducing the incidence of falciparum malaria. However, this drug induces haemolytic anaemia among glucose-6-phosphate dehydrogenase (G6PD) deficient individuals. The distribution of G6PD deficiency in Brazzaville, Republic of Congo and the association of G6PD deficiency with haemoglobin levels and blood cell counts were investigated. Methods: A total of 212 febrile children were recruited for this study. Plasmodium falciparum diagnosis was conducted by microscopy and nested PCR. Sanger sequencing was used to assess G6PD deficiency by detecting 202G>A (rs1050828) and 376A>G (rs1050829) single nucleotide polymorphisms. Results: Two hundred and twelve children were successfully genotyped for G6PD variants. Overall, 13% (27/212) of the children were G6PD deficient and 25% (25/100) females were heterozygous (11 BA− and 14 A+A−). The remaining 160 children had a normal G6PD genotype. The mean red blood and mean platelet counts were significantly lower in hemizygous male (G6PD A−) participants than in normal male (G6PD A+ or B) participants (p < 0.05). Conclusion: This study gives an update on G6PD deficiency among Congolese children. Understanding the distribution of G6PD deficiency in other geographical regions is recommended before primaquine is adopted in the malaria control programme. [ABSTRACT FROM AUTHOR]

Plasmodium falciparum histidine-rich proteins 2 (PfHRP2) based RDTs are advocated in falciparum malaria-endemic regions, particularly when quality microscopy is not available. However, diversity and any deletion in the pfhrp2 and pfhrp3 genes can affect the performance of PfHRP2-based RDTs. A total of 400 samples collected from uncomplicated malaria cases from Kenya were investigated for the amino acid repeat profiles in exon 2 of pfhrp2 and pfhrp3 genes. In addition, PfHRP2 levels were measured in 96 individuals with uncomplicated malaria. We observed a unique distribution pattern of amino acid repeats both in the PfHRP2 and PfHRP3. 228 PfHRP2 and 124 PfHRP3 different amino acid sequences were identified. Of this, 214 (94%) PfHRP2 and 81 (65%) PfHRP3 amino acid sequences occurred only once. Thirty-nine new PfHRP2 and 20 new PfHRP3 amino acid repeat types were identified. PfHRP2 levels were not correlated with parasitemia or the number of PfHRP2 repeat types. This study shows the variability of PfHRP2, PfHRP3 and PfHRP2 concentration among uncomplicated malaria cases. These findings will be useful to understand the performance of PfHRP2-based RDTs in Kenya. [ABSTRACT FROM AUTHOR]

Background: Clinical progression of HBV-related liver diseases is largely associated with the activity of HBV-specific T cells. Soluble fibrinogen-like protein 2 (sFGL2), mainly secreted by T cells, is an important effector molecule of the immune system.Methods: sFGL2 levels were determined by ELISA assays in sera of 296 HBV patients clinically classified into the subgroups of acute hepatitis B (AHB), chronic hepatitis B (CHB), liver cirrhosis (LC), hepatocellular carcinoma (HCC) and patients with LC plus HCC. As control group, 158 healthy individuals were included. FGL2 mRNA was quantified by qRT-PCR in 32 pairs of tumor and adjacent non-tumor liver tissues.Results: sFGL2 levels were elevated in HBV patients compared to healthy controls (P <  0.0001). In the patient group, sFGL2 levels were increased in AHB compared to CHB patients (P = 0.017). sFGL2 levels were higher in LC patients compared to those without LC (P = 0.006) and were increased according to the development of cirrhosis as staged by Child-Pugh scores (P = 0.024). Similarly, HCC patients had increased sFGL2 levels compared to CHB patients (P = 0.033) and FGL2 mRNA was up-regulated in tumor tissues compared to adjacent non-tumor tissues (P = 0.043). In addition, sFGL2 levels were positively correlated with HBV-DNA loads and AST (Spearman's rho = 0.21, 0.25 and P = 0.006, 0.023, respectively), but reversely correlated with platelet counts and albumin levels (Spearman's rho = - 0.27, - 0.24 and P = 0.014, 0.033, respectively).Conclusions: sFGL2 levels are induced by HBV infection and correlated with the progression and clinical outcome of HBV-related liver diseases. Thus, sFGL2 may serve as a potential indicator for HBV-related liver diseases. [ABSTRACT FROM AUTHOR]

Background: Dengue is one of the most common diseases in the tropics and subtropics. Whilst mortality is a rare event when adequate supportive care can be provided, a large number of patients get hospitalised with dengue every year that places a heavy burden on local health systems. A better understanding of the support required at the time of hospitalisation is therefore of critical importance for healthcare planning, especially when resources are limited during major outbreaks. Methods: Here we performed a retrospective analysis of clinical data from over 1500 individuals hospitalised with dengue in Vietnam between 2017 and 2019. Using a broad panel of potential biomarkers, we sought to evaluate robust predictors of prolonged hospitalisation periods. Results: Our analyses revealed a lead-time bias, whereby early admission to hospital correlates with longer hospital stays ‐ irrespective of disease severity. Importantly, taking into account the symptom duration prior to hospitalisation significantly affects observed associations between hospitalisation length and previously reported risk markers of prolonged stays, which themselves showed marked inter-annual variations. Once corrected for symptom duration, age, temperature at admission and elevated neutrophil-to-lymphocyte ratio were found predictive of longer hospitalisation periods. Conclusion: This study demonstrates that the time since dengue symptom onset is one of the most significant predictors for the length of hospital stays, independent of the assigned severity score. Pre-hospital symptom durations need to be accounted for to evaluate clinically relevant biomarkers of dengue hospitalisation trajectories. Author summary: Dengue places a significant burden on healthcare settings. Especially in low and middle income settings and during large outbreaks, allocation of limited resources to those at high risk of morbidity and mortality can be critically important. Various risk factors of severe infection outcomes and hospitalisation, such as secondary heterologous infection, have been described, yet reliable biomarkers predictive of prolonged stays once hospitalised are still lacking. In this work we analysed dengue hospitalisation data collected over a period of three consecutive years in Northern Vietnam, which revealed an unexpected negative correlation between dengue severity and length of hospitalisation. Further analysis showed that this was primarily driven by a longer period between symptom onset and admission in those patients with a higher severity score. Moreover, we found that this delay negated other observed correlates of prolonged hospital stays, which themselves revealed significant inter-annual variations. Taken together, this work demonstrates that time to admission is one of the strongest predictors of hospitalisation length and that this needs to be taken into consideration for finding reliable biomarkers of predicted healthcare needs in patients admitted to hospital due to dengue. [ABSTRACT FROM AUTHOR]

We detected a novel GII.4 variant with an amino acid insertion at the start of epitope A in viral protein 1 of noroviruses from the United States, Gabon, South Africa, and the United Kingdom collected during 2017-2022. Early identification of GII.4 variants is crucial for assessing pandemic potential and informing vaccine development. [ABSTRACT FROM AUTHOR]