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A transfusion‐transmitted hepatitis B virus (HBV) infection caused by blood only positive for anti‐hepatitis B surface antigen (anti‐HBs) was reported. Occult HBV infection (OBI) with sole anti‐HBs among blood donors is an issue. The incidence of HBV infection among repeat blood donors was investigated with a detailed HBV infection phase, focusing on the influence of anti‐HBs level. This study followed 3 435 653 donors for HBV DNA conversion over 4 years and 9 months. Infection phase was determined based on marker changes over DNA conversion. This study identified 115 hepatitis B surface antigen (HBsAg) conversions, 72 DNA‐only conversions, and 15 DNA plus anti‐hepatitis B core (anti‐HBc) conversions among donors all negative for HBV DNA, HBsAg, and anti‐HBc. Total incidence was 2.38/100 000 person‐years (PY). None of these 202 new HBV infections arose in the group with anti‐HBs titer ≥ 10 mIU/mL. In total, 30 anti‐HBc‐negative OBIs were identified (incidence; 0.35/100 000 PY); 7 showed typical secondary anti‐HBs response, and 23 showed stable anti‐HBc and anti‐HBs levels at DNA conversion. The HBV infection‐protective ability of anti‐HBs ≥ 10 mIU/mL was reinforced. In addition to new infections, the blood donor population includes anti‐HBc‐positive‐ and negative OBI with immune reactions or abortive HBV infection. [ABSTRACT FROM AUTHOR]

Background: Nucleic acid testing (NAT) is widely used for screening blood donors for infectious diseases to enhance transfusion safety. Roche's advanced cobas® MPX assay detects human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B virus (HBV) using the cobas® 6800/5800 Systems, based on real-time PCR technology, providing improved sensitivity. This study aims to evaluate the clinical sensitivity and specificity of the cobas® MPX assay and its effectiveness in identifying infected donors in HBV endemic areas, particularly those with occult HBV infection (OBI). Materials and methods: A total of 12,067 donor samples from the Dalian Blood Center (DLBC, northern China) were tested for HIV, HCV, and HBV using both the cobas® MPX assay on the cobas® 6800 system and the previous generation cobas® TaqScreen MPX test v2.0 on the cobas s 201 system as the reference method. Testing was conducted using individual-donation testing (IDT) and primary pool of six donations (PP6), following the manufacturer's instructions and the operational procedures of the instruments. Samples with inconsistent results underwent repeated confirmation tests. Results: Cobas® MPX demonstrated 100.00 % overall percent agreement (95 % CI, 99.22 %-100.00 %) for IDT and 99.89 % (95 % CI, 99.82 %-99.95 %) for PP6. Kappa coefficients were 1.0 for IDT and 0.76 for PP6. Cobas® MPX specificity was 100.00 % (95 % CI, 99.22 %-100.00 %) for IDT and 99.99 % (95 % CI, 99.94 %-100.00 %) for PP6. Sensitivity was 100.00 % (95 % CI, 2.50 %-100.00 %) for IDT and 86.67 % (95 % CI, 68.36 %-95.64 %) for PP6. A total of 12 HBV NAT-yield cases were detected by cobas® MPX. Conclusion: Cobas® MPX demonstrated outstanding sensitivity and specificity in screening HIV, HCV, and HBV in routine blood donations, particularly enhancing occult HBV detection in endemic regions.

Despite good vaccine coverage and careful blood donor selection policies, hepatitis B virus (HBV) is still the most frequent viral infection among blood donors (BDs) in Italy, mostly in the occult form (OBI). We studied the virological features of OBI in BDs from South Italy by serology, molecular testing for HBV-DNA, and sequencing for HBV genotypes and mutations. One hundred and two samples from 95 BDs (22.1% first time, 87.9% regular, median age 57 years) positive for HBV-DNA and negative for HBsAg were retrospectively analyzed. HBV biomarkers were detected in 96.9% (anti-HBc in 44.2%, anti-HBc plus anti-HBs in 49.5%, anti-HBs alone in 3.2%). No risk factor was declared by 45.3% of donors. HBV-DNA levels were very low (median: 7 IU/mL). All samples harbored HBV genotype D and single or multiple mutations in the S gene were found in 28/36 sequences analyzed and in 75% of donors. Mutations were unrelated to gender, donor group or serological patterns. An HBsAg assay with enhanced sensitivity was positive in samples from seven donors (7.4%), two of which negative for HBV-DNA by real-time PCR. OBI still represents a risk for HBV transmission from blood donations; screening by highly sensitive serological and molecular assays is warranted. [ABSTRACT FROM AUTHOR]

Abstract We report a case of hepatitis B virus (HBV) reactivation in a renal transplant recipient. Reactivation manifested as an occult infection with detectable HBV-DNA and negativity for hepatitis B surface antigen (HBsAg). The anti-HBs antibody titre was above the protective threshold and continued to rise, to 951.36 mIU/ml, after HBV reactivation. Sequencing revealed multiple vaccine- and diagnostic-escape mutations in the major hydrophilic region of HBsAg. This case demonstrates both reactivation of an HBV escape mutant in a vaccinated patient and host immunity after virus mutation.

Aim: Cytokine profile in occult HBV infection (OBI) was systematically investigated to identify the immunopathogenesis of OBI. Materials & methods: A total of 46 OBI, ten asymptomatic hepatitis B surface antigen carriers, ten chronic hepatitis B and 12 healthy blood donors were recruited. A total of 21 plasma cytokines were detected. Results: Compared with healthy blood donors, elevated plasma Th1, Th2, Th17 and immune regulatory associated cytokines were observed in OBI. Almost no significant difference was found for these cytokines among OBI, asymptomatic hepatitis B surface antigen carriers and chronic hepatitis B. OBI displayed the predominance of type 2 and regulatory immunity. Conclusion: OBI displayed the general cytokine profile of chronic HBV infection, which might contribute to virus persistence and the presence of the liver microinflammatory environment. The clinical implications of OBI deserve more attention. [ABSTRACT FROM AUTHOR]

Abstract Background Veillonella species are an opportunistically pathogenic commensal anaerobic Gram-negative coccus commonly found in the oral, genitourinary, respiratory, and intestinal tract of humans and some animals. Infection is rare, even in immunocompromised hosts, and has been identified to cause a wide array of different infections, including endocarditis, osteomyelitis, and meningitis. Case presentation An 82-year-old Caucasian male retired ex-gymnast presented to the emergency department with a 2-week history of acute on chronic lower back pain without clear precipitant. He displayed no systemic symptoms, and had not sustained any recent injuries. Initial blood and radiological investigation did not reveal an infective or mechanical cause for his pain; however, a few days into admission, he developed a fever and signs of sepsis. A thorough septic screen was performed, including a spinal magnetic resonance imaging scan, which did not reveal any abnormalities. Blood cultures revealed Veillonella parvula bacteremia, with subsequently repeated magnetic resonance imaging displaying rapid disseminated infection including bilateral psoas abscess, discitis, and osteomyelitis. Infective endocarditis was later identified with echocardiogram. He received intravenous ceftriaxone and later oral amoxicillin and clavulanic and recovered on 6-month follow-up. Conclusions This case illustrates the potential pathogenicity and unexpected rapid course of Veillonella parvula infection even in an immunocompetent host presenting with back pain. This case highlights the critical importance of a thorough septic screen when investigating patients for early signs of sepsis.

• OBI was detected in a certain proportion of blood donors in Huzhou City. • Prevalence rate of OBI is relatively low in Huzhou may affect by sensitivity of detection methods and screening strategy. • HBV genotype C was the main genotype associated with OBI in Huzhou. • Mutations in S gene may play an important role in OBI development. • This study provides new data on the characteristics of OBI in blood donors. Occult hepatitis B virus (HBV) infection (OBI) is a significant challenge for HBV prevention and control. We investigated the prevalence and surface (S) gene mutations of OBI among blood donors in Huzhou City, eastern China. The hepatitis B surface antigen (HBsAg) was routinely screened among 44,256 blood donors. HBV-DNA was detected using the Roche cobas®system. Serum samples that were HBsAg negative and HBV-DNA positive were selected, and the HBV S gene was amplified and sequenced. HBV genotype and S gene mutations were analyzed. The OBI rate in these blood donors was 0.070 % (31/44,256). Among the blood donors with OBI, only two cases (2/31, 6.5 %) were anti-HBc negative. The S gene sequences of 28 samples were successfully obtained, and we found that HBV genotype C (21/28, 70 %) was predominant among blood donors with OBI. Most S gene mutations were associated with OBI, and the high frequency mutations included N40S, G44E, Q51R/P, T113A/S,T118K/M, P120Q/S/T, and Y161F/S. Notably, amino acid substitutions at some sites differed from those reported previously, such as Y72F, G102V, P127L, Q129P, and S143T. Additionally, six novel mutations (S31I/N/R, P46L, S58C, C76Y, Y200F/C, and I208T) that may be associated with OBI were found. OBI was detected in a certain proportion of blood donors in Huzhou City. S gene mutations play an important role in OBI development. Further research is required to explore the functions of novel S gene mutants in OBI pathogenesis. The findings of this study may provide important insights to prevent HBV transmission through blood transfusions. [ABSTRACT FROM AUTHOR]

Accurate laboratory confirmation for Hepatitis B diagnosis and monitoring are crucial. Recently an ultrasensitive immunoassay test, the HBsAg Next (HBsAgNx), has been reported approximately eight times more sensitive than current HBsAg assays. The aim of our study was to assess the analytical performances of this new test. 253 clinical samples from Saint Louis University Hospital were analyzed, splitted into four panels: (1) routine prospectively screening serums (n = 196), (2) retrospective serum samples before HBV reactivation (HBV-R) (n = 18), (3) occult HBV infection (OBI) (n = 10) and (4) a selection of wild type HBV genotypes (n = 29) Panel 1, showed robust agreement with the HBsAg Qualitative II (HBsAgQII) assay (Cohen's kappa = 0.83). Despite this agreement, 7 false positive with the HBsAgQII assay were found negative with HBsAgNx. One OBI was detected only with HBsAgNx. Panel 2 showed potential time savings in diagnosing HBV-R using HBsAgNx among 4/18 HBsAg positives samples. Panel 3 highlighted the ability of HBsAgNx to detect HBsAg in OBI patients defined by negative for HBsAg with HBsAgQII assay and positive for HBV DNA. Furthermore, the HBsAgNx assay detected all different genotypes. The study highlights the effectiveness of the HBsAgNx assay, showing its performance. It excels in detecting weakly positive samples and addressing challenging cases. HBsAgNx assay demonstrates promising analytical performances, with improved sensitivity and specificity compared to standard HBsAgQII assay, able to detect all genotypes. Its potential impact on early detecting and monitoring reactivations, and occult infections could be very useful in clinical practice. [ABSTRACT FROM AUTHOR]

Despite good vaccine coverage and careful blood donor selection policies, hepatitis B virus (HBV) is still the most frequent viral infection among blood donors (BDs) in Italy, mostly in the occult form (OBI). We studied the virological features of OBI in BDs from South Italy by serology, molecular testing for HBV-DNA, and sequencing for HBV genotypes and mutations. One hundred and two samples from 95 BDs (22.1% first time, 87.9% regular, median age 57 years) positive for HBV-DNA and negative for HBsAg were retrospectively analyzed. HBV biomarkers were detected in 96.9% (anti-HBc in 44.2%, anti-HBc plus anti-HBs in 49.5%, anti-HBs alone in 3.2%). No risk factor was declared by 45.3% of donors. HBV-DNA levels were very low (median: 7 IU/mL). All samples harbored HBV genotype D and single or multiple mutations in the S gene were found in 28/36 sequences analyzed and in 75% of donors. Mutations were unrelated to gender, donor group or serological patterns. An HBsAg assay with enhanced sensitivity was positive in samples from seven donors (7.4%), two of which negative for HBV-DNA by real-time PCR. OBI still represents a risk for HBV transmission from blood donations; screening by highly sensitive serological and molecular assays is warranted.

We report a case of hepatitis B virus (HBV) reactivation in a renal transplant recipient. Reactivation manifested as an occult infection with detectable HBV-DNA and negativity for hepatitis B surface antigen (HBsAg). The anti-HBs antibody titre was above the protective threshold and continued to rise, to 951.36 mIU/ml, after HBV reactivation. Sequencing revealed multiple vaccine- and diagnostic-escape mutations in the major hydrophilic region of HBsAg. This case demonstrates both reactivation of an HBV escape mutant in a vaccinated patient and host immunity after virus mutation. [ABSTRACT FROM AUTHOR]

Background: Occult infections in spinal pseudarthrosis revisions have been reported in the literature, but the relevance of such an infection on patient outcomes is unknown. We aimed to elucidate clinical outcomes and re-revision risks between patients with and without occult infections in spinal revision surgery for pseudarthrosis. Methods: In this matched case-control study, we identified 128 patients who underwent thoracolumbar revision surgery from 2014–2019 for pseudarthrosis of the spine. Among them, 13 (10.2%) revealed an occult infection (defined by at least two positive intraoperative tissue samples with the same pathogen), and nine of these 13 were available for follow-up. We selected 18 of the 115 controls using a 2:1 fuzzy matching based on fusion length and length of follow-up. The patients were followed up to assess subsequent re-revision surgeries and the following postoperative patient-reported outcome measures (PROMs): overall satisfaction, Oswestry Disability Index, 5-level EQ-5D, and Short Form 36. Results: Patient characteristics, surgical data, and length of follow-up were equal between both study groups. The rate of re-revision free survival after the initial pseudarthrosis revision surgery was higher in the occult infection group (77.8%) than the non-infectious controls (44.4%), although not significantly (0.22). The total number of re-revision surgeries, including re-re-revisions, was thirteen (in ten patients) in the control and two (in two patients) in the occult infection group (p = 0.08) after a median follow-up of 24 months (range 13-75). Four cases in the control group underwent re-revision for pseudarthrosis compared to none in the infected group. Satisfactory scores were recorded in all PROMs, with similar scores between the two groups. Conclusions: The presence of an occult infection accompanying spinal pseudarthrosis revision was not inferior to non-infected pseudarthrosis revisions in a matched, small sample size cohort study. This may be explained due to the possibility of targeted treatment of the identified cause of pseudarthrosis.

Background: Via hemodialysis, viral infections can be transmitted in patients a new definition of this infection with no increase in liver enzymes, negative HCV-PCR in serum and presence of virus in the liver and peripheral blood mononuclear cell (PBMC) called occult hepatitis C virus (HCV) infection (OCI). We decided to examine the prevalence of occult hepatitis C infection on hemodialysis cases. Methods: The current research is a cross-sectional study on patients with end-stage renal disease (ESRD) who were at three hemodialysis centers in Mazandaran province in Iran during 2012-2014. In this study of 356 patients who were undergoing hemodialysis, 54 patients were excluded due to positive HCV Ab, and the remaining 302 patients were enrolled. The test of all serum samples for HCV-RNA detection of plasma and PBMCs was done by real-time polymerase chain reaction (real-time PCR). Results: There was a significant association between the duration of dialysis with the prevalence of occult HCV infection (P=0.017). Eight (2.65%) patients were positive for HBs Ag and with OCI, but none of them was infected with both hepatitis C and B obviously. Also among the total number of patients, nine patients tested positive for HCV RT-PCR in PBMC in which one of them was positive for serum HCV RNA PCR and was excluded from the study. Conclusion: The results showed that eight patients had an OCI. There was not any association found between age and sex with OCI, but there was a significant relationship between the duration of dialysis with the prevalence of OCI.

Abstract Background Recent studies suggest that lncRNAs may play significant roles in the development of hepatitis B virus (HBV) infection. However, as a special stage of HBV infection, the lncRNA expression in occult HBV infection (OBI) remains unclear. Methods The plasma level of 15 HBV infection-related lncRNAs was initially detected using qRT-PCR in 10 OBI and 10 healthy controls (HCs) in discovery phase. Significantly dysregulated lncRNAs were subsequently validated in another 64 OBI, 20 HCs, 31 chronic hepatitis B (CHB) and 20 asymptomatic HBsAg carriers (ASC). Moreover, the AP000253 expression in liver tissues and its potential biological functions in HBV infection were further investigate with public transcriptomic data and HBV-expressing cell lines. Results Among candidate lncRNAs, the plasma level of AP000253 decreased significantly in OBI, ASC and CHB patients compared to HCs, while no difference was found among OBI, ASC and CHB patients. In liver tissues, similar AP000253 expression was also observed from the GSE83148 dataset, while that in HBV-expressing hepatoma cells was opposite. ROC curve analysis indicated that plasma AP000253 yielded an AUC of 0.73 with 60% sensitivity and 75% specificity when differentiating OBI from HCs, but it could not specifically separate the stage of chronic HBV infection. Furthermore, functional experiments suggested that AP000253 could promote HBV transcription and replication in hepatoma cell lines. Conclusions AP000253 might be involved in HBV replication, and be served as a potential biomarker for HBV infection. In the setting of blood donations, plasma AP000253 would be more useful to moderately distinguish OBI in HBsAg-negative donors. However, the AP000253 expression in liver tissues and associated molecular mechanism of HBV infection deserve further study in future.

This retrospective study was performed on 71 dogs which had been admitted for heartworm screening or with clinical suspicion of heartworm disease. The examination methods included polymerase chain reaction (PCR) to identify Dirofilaria immitis and/or Dirofilaria repens infections and a heartworm antigen (Ag) test (VetScan). By using PCR, 26 dogs were found positive only for Dirofilaria immitis (Group 1), while 21 dogs for both D. immitis and D. repens (Group 2). Group 3 included 24 dogs with D. repens infection only according to the PCR results. The sensitivity of the VetScan Ag test for the Group 1 and 2 animals proved to be 97.7% (95% Blaker confidence interval; CI 89.0%–99.9%). The specificity of the VetScan Ag test, calculated from the results of Group 3, was found to be 66.7% (95% CI 45.6%–83.1%), which was lower than that reported from the USA, where D. repens does not occur. In cases when PCR results were positive for D. repens but negative for D. immitis, the occult dirofilariosis was the likely explanation for the positive D. immitis Ag tests. These observations highlight the importance of performing more Ag tests simultaneously in those areas where both Dirofilaria species are present. [ABSTRACT FROM AUTHOR]

Background: Veillonella species are an opportunistically pathogenic commensal anaerobic Gram-negative coccus commonly found in the oral, genitourinary, respiratory, and intestinal tract of humans and some animals. Infection is rare, even in immunocompromised hosts, and has been identified to cause a wide array of different infections, including endocarditis, osteomyelitis, and meningitis.Case Presentation: An 82-year-old Caucasian male retired ex-gymnast presented to the emergency department with a 2-week history of acute on chronic lower back pain without clear precipitant. He displayed no systemic symptoms, and had not sustained any recent injuries. Initial blood and radiological investigation did not reveal an infective or mechanical cause for his pain; however, a few days into admission, he developed a fever and signs of sepsis. A thorough septic screen was performed, including a spinal magnetic resonance imaging scan, which did not reveal any abnormalities. Blood cultures revealed Veillonella parvula bacteremia, with subsequently repeated magnetic resonance imaging displaying rapid disseminated infection including bilateral psoas abscess, discitis, and osteomyelitis. Infective endocarditis was later identified with echocardiogram. He received intravenous ceftriaxone and later oral amoxicillin and clavulanic and recovered on 6-month follow-up.Conclusions: This case illustrates the potential pathogenicity and unexpected rapid course of Veillonella parvula infection even in an immunocompetent host presenting with back pain. This case highlights the critical importance of a thorough septic screen when investigating patients for early signs of sepsis. [ABSTRACT FROM AUTHOR]

Introduction: Recent literature has associated pseudarthrosis and pedicle screw loosening with subchronic infection at the pedicle of the vertebra. The positive culture results of a previous retrieval analysis show that such patients have a high frequency of bacterial contamination. The objective of this study is to visually capture the architecture of these undiagnosed infections, which have been described in other studies as biofilms on supposedly “aseptic” screw loosening. Methods: Explants from 10 consecutive patients undergoing revision spine surgery for pseudarthrosis were collected and fixed in glutaraldehyde solution. Each of these implants was imaged thoroughly by using scanning electron microscopy and x-ray spectroscopy to evaluate the architecture of the biofilm. Additionally, eight patient swabs from tissues around the implants were sent for cultures to assess bacterial infiltration in tissues beyond the biofilm. The implants were also analyzed using energy dispersive x-ray spectroscopy. The exclusion criteria included clinically diagnosed infection (current or previous) and/or mechanical failure of the implant due to falls/accidents. Results: The study was successful in capturing the visual architecture of the biofilm on retrieved implants. A total of 77% of pseudarthrosis cases presented with loose pedicle screws, which were diagnosed by a preoperative computed tomography scan showing radiolucency along the screw track and were confirmed intraoperatively, and 72% of the cases showed biofilm on explants. Conclusions: In the absence of the clinical presentation of infection, impregnated bacteria could form a biofilm around an implant, and this biofilm can remain undetected via contemporary diagnostic methods, including swabbing. Implant biofilm is frequently present in “aseptic” pseudarthrosis cases.

Background: A 25-year-old patient was treated for post-traumatic neck pain with intradiscal injections at the C3-4 and C4-5 levels using radiopaque gelified ethanol. After the injections, the axial neck pain increased. Laboratory infection parameters were normal despite the progressive disc destruction observed on CT scans at both index levels. The patient underwent debridement and anterior cervical discectomy and fusion. Staphylococcus epidermidis and Cutibacterium acnes grew in all the intraoperative cultures. The patient was subsequently treated with Rifampicin and Moxifloxacin and after 3 months no signs of infection were observed. CT scan showed solid fusion of the at the index segments 7 months postoperatively. Conclusion: Infections after intradiscal injections are rare and we believe this is the first case describing iatrogenic spondylodiscitis after DiscoGel injection. When increased axial neck pain is experienced after injection with DiscoGel, post-operative spondylodiscitis should be suspected. Even if laboratory parameters are normal, examinations with MRI and CT should be performed and if these studies show signs of infection, surgical revision should be conducted.

The current communication seeks to provide an updated narrative review on latest methods of reducing implant contaminations used during spine surgery. Recent literature review has shown that both preoperative reprocessing and intraoperative handling of implants seem to contaminate implants. In brief, during preoperative phase, the implants undergo repeated bulk cleaning with dirty instruments from the OR, leading to residue buildup at the interfaces and possibly on the surfaces too. This, due to its concealed nature, remains unnoticed by the SPD (sterile processing department) or other hospital staff. Nevertheless, these can be avoided by using individually prepackaged presterilized implants. In the intraoperative phase, the implants (in the sterile field) are directly touched by the scrub tech with soiled (assisting the surgeon dispose the tissues from the instruments in use) gloves for loading onto an insertion device. It is then kept exposed on the working table (either separately or next to the used instruments as the pedicles hole are being prepared). Latest investigation has shown that by the time it is implanted in the patient, it can harbor up to 10e7 bacterial colony-forming units. The same implants were devoid of such colony-forming units, when sheathed by an impermeable sterile sheath around the sterile implant.

Background: Via hemodialysis, viral infections can be transmitted in patients a new definition of this infection with no increase in liver enzymes, negative HCV-PCR in serum and presence of virus in the liver and peripheral blood mononuclear cell (PBMC) called occult hepatitis C virus (HCV) infection (OCI). We decided to examine the prevalence of occult hepatitis C infection on hemodialysis cases. Methods: The current research is a cross-sectional study on patients with end-stage renal disease (ESRD) who were at three hemodialysis centers in Mazandaran province in Iran during 2012-2014. In this study of 356 patients who were undergoing hemodialysis, 54 patients were excluded due to positive HCV Ab, and the remaining 302 patients were enrolled. The test of all serum samples for HCV-RNA detection of plasma and PBMCs was done by real-time polymerase chain reaction (real-time PCR). Results: There was a significant association between the duration of dialysis with the prevalence of occult HCV infection (P=0.017). Eight (2.65%) patients were positive for HBs Ag and with OCI, but none of them was infected with both hepatitis C and B obviously. Also among the total number of patients, nine patients tested positive for HCV RT-PCR in PBMC in which one of them was positive for serum HCV RNA PCR and was excluded from the study. Conclusion: The results showed that eight patients had an OCI. There was not any association found between age and sex with OCI, but there was a significant relationship between the duration of dialysis with the prevalence of OCI. [ABSTRACT FROM AUTHOR]

Since the outbreak of novel coronavirus (SARS-CoV-2)-infected pneumonia (COVID-19), numerous medical staff are fighting on the frontline. However, the possibility of occult infection in medical staff is ignored in many recent studies. Herein, we collected data in a COVID-19 designated hospital from January 22, 2020 to March 10, 2020. A total of 33 medical staff had at least one nucleic acid test of throat swab, immunoglobulin G (IgG) or IgM serum antibody test, and chest computed tomography (CT), were enrolled. Finally, we identified 25 cases (75.8%) were isolated for hospitalized treatment after positive virus detection. In addition, 4 cases who were all negative for nucleic acid test detection with no clinical symptoms, and none of their chest CT were abnormal. However, the results of serum IgG or IgM antibody test in these 4 cases were positive, suggesting the presence of occult infection. In conclusion, data from our single center indicated that SARS-CoV-2 had a high medical infection rate (29/33 = 87.9%) and might have a potential risk of occult infection.

ABSTRACTOccult hepatitis B virus infection (OBI) is a low-level asymptomatic phase of HBV infection. Evidence of OBI clinical relevance is emerging but the mechanisms of its occurrence remain unclear. In this study, the molecular characteristics of 97 confirmed OBI from Chinese blood donors were analyzed and relevant mutations were identified. Recombinant HBsAg bearing these mutations were expressed in vitro and the antigenicity and HBsAg secretion properties were analyzed. Results showed that 45 (46.4%) genotype B, 50 (51.5%) genotype C, and 2 (2.1%) genotype D sequences were identified. Two groups of mutations in the S gene were significantly associated with OBI. The first group included mutations creating new N-linked glycosylation sites at positions s116, s123, s130, and s131 + s133 or removing the existing one at s146. Mutations TCT123-125NCT/NFT were associated with reduced antigenicity, while TST116-118NST, GTS130-132NTS, and TSM131-133NSS/NYT/NST were associated with varying levels of impaired HBsAg secretion. N146 mutations had no effect on HBsAg production pattern. The second group included substitutions within the S transmembrane domains TMD1-3. Only mutations C85R, L87R, L88R, and C90R within TMD2 were associated with defective HBsAg production. These mutations appear to be rare and mostly strain specific but they may contribute to the multifactorial occurrence of OBI.

Background: Recent studies suggest that lncRNAs may play significant roles in the development of hepatitis B virus (HBV) infection. However, as a special stage of HBV infection, the lncRNA expression in occult HBV infection (OBI) remains unclear. Methods: The plasma level of 15 HBV infection-related lncRNAs was initially detected using qRT-PCR in 10 OBI and 10 healthy controls (HCs) in discovery phase. Significantly dysregulated lncRNAs were subsequently validated in another 64 OBI, 20 HCs, 31 chronic hepatitis B (CHB) and 20 asymptomatic HBsAg carriers (ASC). Moreover, the AP000253 expression in liver tissues and its potential biological functions in HBV infection were further investigate with public transcriptomic data and HBV-expressing cell lines. Results: Among candidate lncRNAs, the plasma level of AP000253 decreased significantly in OBI, ASC and CHB patients compared to HCs, while no difference was found among OBI, ASC and CHB patients. In liver tissues, similar AP000253 expression was also observed from the GSE83148 dataset, while that in HBV-expressing hepatoma cells was opposite. ROC curve analysis indicated that plasma AP000253 yielded an AUC of 0.73 with 60% sensitivity and 75% specificity when differentiating OBI from HCs, but it could not specifically separate the stage of chronic HBV infection. Furthermore, functional experiments suggested that AP000253 could promote HBV transcription and replication in hepatoma cell lines. Conclusions: AP000253 might be involved in HBV replication, and be served as a potential biomarker for HBV infection. In the setting of blood donations, plasma AP000253 would be more useful to moderately distinguish OBI in HBsAg-negative donors. However, the AP000253 expression in liver tissues and associated molecular mechanism of HBV infection deserve further study in future. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to explore the prevalence and characteristics of OBI in pregnant women positive for the hepatitis B core antibody (anti-HBc). Methods: The serum samples of 416 pregnant women positive for anti-HBc were collected from the Second Affiliated Hospital of Anhui Medical University and the clinical records were obtained. The qualitative and quantitative serological markers of HBV were detected. HBV DNA was tested using nested polymerase chain reaction (PCR), and the products of the PCR were sequenced. Results: HBV DNA was detected in 63 of 416 HBsAg-negative subjects with a median HBV DNA level of 50.6 (0, 411) IU/mL, and the prevalence of OBI in the anti-HBc-positive pregnant women were 15.14% (63/416, 95% CI: 11.7% - 18.58%). The positive HBV DNA test rate was significantly higher in the Rotor-Gene Q than in the Mx3000P. The sequencing results showed that HBV genotype B (97.28%) was the predominant type and I57F, I150T, C64R/P/Y, S61P, and T125M/A were the predominant amino acid (AA) mutation sites. Conclusions: Multiple types of mutants coexist with small amounts of wild-type HBV and interact to maintain low viral loads. These mutations may influence HBsAg detection by impairing the binding of antibodies to antigens. [ABSTRACT FROM AUTHOR]

Background: Although sensitive screening assays for hepatitis B virus surface antigen (HBsAg) are available, special cases of post-transfusion hepatitis B virus infection still occur. The present study was conducted to evaluate the prevalence of anti-hepatitis B core (anti-HBc) positivity and the presence of HBV-DNA in serum samples of healthy blood donors negative for both HBsAg and anti-HCV antibodies in Benha, Egypt. Materials and methods: The study included a screening of 450 selected blood donors. The distribution of blood donors was 288 males (64%) and 162 females (36%). The recruited blood donors who met the criteria for blood donation were routinely screened for HBsAg, HIV I/2-Ab, and syphilisantibodies. The blood units for donations were further analyzed for the presence of HBc-IgM and HBV-DNA levels by PCR method. Results: Testing of the accepted units for the donation was about 12 (2.7%) HBc-IgM positive, and 9 (2%) HBV-DNA positive units. The standard screening of blood unit failed to recognize early acute or window HBV infection where HBsAg is missing. Conclusions: Our investigations proposed that sensitive methods for the detection of HBV by PCR might be recommended in the screening of donated blood. Furthermore, anti-HBc antibodies should be tested regularly on all blood donation units. [ABSTRACT FROM AUTHOR]

The hepatitis B (HB) vaccine is effective for the prevention of HB virus infection. It has been widely accepted that an anti‐HB surface antibody (HBs) level ≥10 mIU/mL is protective against HB virus infection. Although transient infection can occur in individuals who attain a peak level of anti‐HBs ≥10 mIU/mL after primary vaccination, long‐term follow‐up studies show that successful primary vaccination can prevent individuals from acute clinical hepatitis and chronic infection. Healthcare workers (HCWs) are at‐risk individuals. Based on the accumulated data, the USA considers an anti‐HBs level ≥10 mIU/mL to constitute successful vaccination for HCWs. In contrast, because some anti‐HBs assays cannot accurately measure in the low anti‐HBs range, including 10 mIU/mL, the UK and Germany consider an anti‐HBs level ≥100 mIU/mL to constitute successful vaccination for HCWs. In the USA and UK, a booster dose is unnecessary for HCWs after successful vaccination. In Germany, anti‐HBs testing is recommended for HCWs who are at particularly high individual exposure risk 10 years after successful primary immunization, and a booster dose is offered if the anti‐HBs level has declined to ˂100 mIU/mL. The differences in the goal of HB vaccination, reliability of anti‐HBs assays, and use of booster vaccination cause discordance in HB vaccination policies for HCWs. [ABSTRACT FROM AUTHOR]

Emerging suggest that microRNAs (miRNAs) play vital roles in the occurrence and development of hepatitis B virus (HBV) infectious disease. However, miRNAs in occult hepatitis B virus infection (OBI), a special stage of HBV infection, remain largely unknown. Herein, we conducted this study to identify differentially expressed miRNAs and then to investigate the potential roles of these miRNAs in OBI. Plasma miRNA expression profiles of three OBI patients and three healthy controls were analyzed with high through‐put miRNA sequencing technology. Altered expression of miRNAs was further confirmed with reverse transcription quantitative polymerase chain reaction (qRT‐PCR). Finally, bioinformatics analysis was conducted to investigate the involved pathways and target genes for these differentially expressed miRNAs. Totally, 32 differentially expressed miRNAs were identified between OBI and healthy controls by miRNA sequencing (fold change ≥ 1.5, P <.1, and counts per million reads ≥ 1), including 16 downregulated and 16 upregulated miRNAs. Differential expression of hsa‐miR‐486‐5p, ‐25‐3p, and ‐92a‐3p and ‐1‐3p was further validated by qRT‐PCR analysis, which was consistent with miRNA sequencing analysis. Moreover, these four miRNAs might distinguish OBI from HCs efficiently. Bioinformatics analyses indicated that the differentially expressed miRNAs were primarily involved in various biological processes related to gene expression and transcription, cell development and metabolism, protein modification and kinase activity regulation, as well as multiple signaling pathways such as PI3K/Akt signaling pathway. This study provided a global view of miRNA expression in plasma from OBI patients. These differentially expressed miRNAs might play important roles in the development of OBI, which provided intriguing insights into the screening and molecular mechanism of OBI. Highlight: This study provided a global view of miRNA expression in plasmafrom OBI patients.These miRNAs might provide a new insight for the further elucidation of the pathogenesis of OBI and for the screening of auxiliary screening markers for OBI in the future. [ABSTRACT FROM AUTHOR]

Latar belakang. Occult hepatitis B infection (OBI) adalah suatu keadaan ditemukannya deoxyribose-nucleic acid (DNA) virus Hepatitis B (VHB) pada pemeriksaan HBsAg negatif. Mutasi pada preS2/S menyebabkan sekresi HBsAg menurun sehingga kadar HBsAg dalam serum terlalu rendah yang menyebabkan HBsAg tidak terdeteksi. Virus hepatitis B cenderung mengalami mutasi sebab tidak memiliki sistem koreksi selama replikasi karena tidak adanya 3’,5’exonuclease untuk mengkoreksi kesalahan insersi nukleotida saat transkripsi balik. Tujuan. Mengetahui insiden occult infection setelah 10 tahun mendapat imunisasi hepatitis B. Metode. Penelitian observasional dengan menggunakan desain cross sectional study pada anak sekolah dasar di Kota Padang dengan jumlah subjek penelitian 40 anak. Hasil. Jenis kelamin perempuan lebih banyak daripada laki-laki dan status gizi baik lebih banyak dari status gizi kurang. Insiden occult infection ditemukan 10% pada anak setelah 10 tahun mendapat imunisasi hepatitis B. Tidak terdapat hubungan antara antiHBs dengan occult infection. Kesimpulan. Occult infection pada anak setelah 10 tahun mendapat imunisasi hepatitis B adalah 10 %.

INTRODUCTION: Hepatitis B virus (HBV) infection is a major health challenge in sub-Saharan African countries. Chronic HBV infection is a risk factor for severe disease progression. Perinatal and sexual transmissions of Hepatitis B virus are the main routes of infection in HBV endemic countries like Nigeria. However, there is paucity of data as regards the major contributory route of transmission to chronic HBV infection in this region. Also, in Nigeria, not everyone at high risk of the infection has been identified. Therefore our study investigated the prevalence of HBV infection among sexually active individuals in Nigeria. METHODS: blood samples collected from 463 participants (360 sexually active individuals and 103 teenagers) recruited from health institutions across the country were tested for the presence of HBsAg, and HBV nucleic acid related antigen (HBVNRAg) by ELISA. Positive samples were further tested for the presence of HBeAg and antiHBe by ELISA. Data were analyzed using Chi-square and binary logistic regression at p = 0.05. RESULTS: HBsAg and HBVNRAg were detected in 10.4% and 7.6% of the participants respectively. STI clinic attendees had the highest prevalence for HBsAg (17%; p = 0.002). Teenagers had the lowest HBsAg (1.9; p = 0.002) and HBVNRAg (2.9%; p = 0.0001) prevalence rates. Male gender (p = 0.01) and reproductive age group (p = 0.009) were the major predictors of chronic HBV infection. CONCLUSION: sexual transmission was identified as the major contributor to chronic HBV infection. Sexually active individuals especially those with STIs are high risk groups for chronic HBV infection. Interventions targeted at this group is therefore recommended.

Since the outbreak of novel coronavirus (SARS-CoV-2)-infected pneumonia (COVID-19), numerous medical staff are fighting on the frontline. However, the possibility of occult infection in medical staff is ignored in many recent studies. Herein, we collected data in a COVID-19 designated hospital from January 22, 2020 to March 10, 2020. A total of 33 medical staff had at least one nucleic acid test of throat swab, immunoglobulin G (IgG) or IgM serum antibody test, and chest computed tomography (CT), were enrolled. Finally, we identified 25 cases (75.8%) were isolated for hospitalized treatment after positive virus detection. In addition, 4 cases who were all negative for nucleic acid test detection with no clinical symptoms, and none of their chest CT were abnormal. However, the results of serum IgG or IgM antibody test in these 4 cases were positive, suggesting the presence of occult infection. In conclusion, data from our single center indicated that SARS-CoV-2 had a high medical infection rate (29/33 = 87.9%) and might have a potential risk of occult infection. [ABSTRACT FROM AUTHOR]

Despite good vaccine coverage and careful blood donor selection policies, hepatitis B virus (HBV) is still the most frequent viral infection among blood donors (BDs) in Italy, mostly in the occult form (OBI). We studied the virological features of OBI in BDs from South Italy by serology, molecular testing for HBV-DNA, and sequencing for HBV genotypes and mutations. One hundred and two samples from 95 BDs (22.1% first time, 87.9% regular, median age 57 years) positive for HBV-DNA and negative for HBsAg were retrospectively analyzed. HBV biomarkers were detected in 96.9% (anti-HBc in 44.2%, anti-HBc plus anti-HBs in 49.5%, anti-HBs alone in 3.2%). No risk factor was declared by 45.3% of donors. HBV-DNA levels were very low (median: 7 IU/mL). All samples harbored HBV genotype D and single or multiple mutations in the S gene were found in 28/36 sequences analyzed and in 75% of donors. Mutations were unrelated to gender, donor group or serological patterns. An HBsAg assay with enhanced sensitivity was positive in samples from seven donors (7.4%), two of which negative for HBV-DNA by real-time PCR. OBI still represents a risk for HBV transmission from blood donations; screening by highly sensitive serological and molecular assays is warranted.

Purpose: To examine the incidence of occult infection in revision spine surgeries and its correlation with preoperative inflammatory markers.Methods: We retrospectively reviewed all patients who underwent revision spine surgery and hardware removal between 2010 and 2016. Patients who had preoperative clinical signs of infection were excluded. The hardware and surrounding tissue culture results were obtained. The patients' diagnosis and preoperative inflammatory marker (ESR, CRP, and procalcitonin) levels were recorded.Results: A total of 162 consecutive patients were included in this study. The patients' mean age was 61 years (range 14-88). One hundred and three patients (63.6%) were female. Seventy-two patients (44.4%) had loose hardware and 88 patients (54.3%) had pseudarthrosis. Postoperatively, the hardware and/or surrounding tissue culture was positive in 15 patients (9.3%). The most commonly identified organisms were Propionibacterium acnes (7/15, 46.7%) and Staphylococcus (6/15, 40.0%). The other identified organisms were Pseudomonas aeruginosa (1/15, 6.7%) and Serratia marcescens (1/15, 6.7%). Only four patients with positive cultures had elevated preoperative ESR and CRP levels. Only two patients with positive cultures had elevated preoperative procalcitonin levels. There is no correlation between the patients' preoperative ESR, CRP, procalcitonin levels, and positive culture results (p > 0.05).Conclusions: Our study shows that occult infections are present in 9.3% of patients who underwent revision spine surgery and hardware removal although they did not have clinical signs of infection. Those commonly used preoperative inflammatory markers such as ESR, CRP, and procalcitonin may not be sensitive enough to detect occult infections in these patients. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Introduction: Hepatitis B virus (HBV) infection is a major health challenge in sub-Saharan African countries. Chronic HBV infection is a risk factor for severe disease progression. Perinatal and sexual transmissions of Hepatitis B virus are the main routes of infection in HBV endemic countries like Nigeria. However, there is paucity of data as regards the major contributory route of transmission to chronic HBV infection in this region. Also, in Nigeria, not everyone at high risk of the infection has been identified. Therefore our study investigated the prevalence of HBV infection among sexually active individuals in Nigeria. Methods: Blood samples collected from 463 participants (360 sexually active individuals and 103 teenagers) recruited from health institutions across the country were tested for the presence of HBsAg, and HBV nucleic acid related antigen (HBVNRAg) by ELISA. Positive samples were further tested for the presence of HBeAg and antiHBe by ELISA. Data were analyzed using Chi-square and binary logistic regression at p = 0.05. Results: HBsAg and HBVNRAg were detected in 10.4% and 7.6% of the participants respectively. STI clinic attendees had the highest prevalence for HBsAg (17%; p = 0.002). Teenagers had the lowest HBsAg (1.9; p = 0.002) and HBVNRAg (2.9%; p = 0.0001) prevalence rates. Male gender (p = 0.01) and reproductive age group (p=0.009) were the major predictors of chronic HBV infection. Conclusion: Sexual transmission was identified as the major contributor to chronic HBV infection. Sexually active individuals especially those with STIs are high risk groups for chronic HBV infection. Interventions targeted at this group is therefore recommended. [ABSTRACT FROM AUTHOR]

Although a universal newborn hepatitis B ( HB) immunization programme has been implemented in China, hepatitis B virus ( HBV) breakthrough infection, including HB surface antigen ( HBsAg)-positive infection and occult HBV infection ( OBI), still occurs during infancy or childhood. Obtaining the actual prevalence of HBV infection in general children is important for preventing and controlling the spread of HB. Accordingly, we investigated the prevalence of overt infection and OBI in community children and compared the serological and virological characteristics of OBI and HBsAg carrier children to clarify the mechanisms related to OBI. In total, 6 706 community children <12 years of age were included from a population-based HBV seroepidemiological investigation in Northwest China. The HBsAg carrier rate in community children was 1.60% (107/6706), and the anti- HBs positive rate was 57.35% (3846/6706). Additionally, 1192 HBsAg-negative children were examined for OBI using nested PCR. The prevalence of OBI in local children was 1.26% (15/1192), and the predominant OBI genotypes were C and D. The 15 OBI children and 29 HBsAg-positive children from the same population did not have a statistical significant difference in age, gender, alanine aminotransferase ( ALT), proportion of anti- HBs or anti- HBc, viral genotypes or mutations. Children with chronic overt infection had higher viral loads than OBI children ( P=.004). These results suggested that HBV overt and occult infection of children was more serious in underdeveloped north-west regions. HBV neonatal immunization and catch-up programmes should be strengthened and supplemented. None of specific viral mutations or genotypes related to OBI were found. OBI may be a specific stage of HBV infection. [ABSTRACT FROM AUTHOR]

Objective: To determine the clinical course and perinatal transmission of chronic hepatitis B during pregnancy in a real life setting.Methods: A total of 221 singleton pregnant women with detectable HBV-DNA levels (≥103 copies/mL) were enrolled during January 2011 to June 2015. Forty-three high viraemic patients (≥106 copies/mL) received telbivudine in the 2nd or 3rd trimester according to their intention, while 89 high viraemic and 79 low viraemic (≥103 and <106 copies/mL) patients were the control cohorts. Primary endpoint was the pregnancy outcomes and secondary endpoint the perinatal transmission including intrauterine infection, immunoprophylaxis failure and occult infection.Results: In all, 209 patients completed pregnancy with 209 infants, while 2 in telbivudine-treated cohort had unexplained late stillbirths. Twenty-nine (70.7%) of telbivudine-treated patients and 3 (3.4%) of untreated high viraemic controls achieved undetectable HBV-DNA levels prior delivery. At 7 months postpartum, immunoprophylaxis failure was significantly lower (2.4%) in telbivudine-treated cohort, compared with 16.9% and 10.1% in untreated high and low viraemic cohorts, respectively.Conclusions: Low viraemic patients may also need antiviral therapy since they bear moderate risk for perinatal transmission of HBV. However, more multicenter, large-scale studies are required before antepartum antiviral therapy is routinely recommended in patients with detectable viral loads. [ABSTRACT FROM AUTHOR]

Objective: In 2010, only 1 donor blood sample was found to be anti-hepatitis C virus (HCV) negative and HCV RNA positive, as detected by nucleic acid testing. In occult HCV infection (OCI), HCV RNA is found in peripheral blood mononuclear cells (PBMCs). We investigated the prevalence of OCI among blood donors. Methods: We collected 513 samples from 334 eligible and 179 deferred donors, including 55 anti- HCV-positive, 113 alanine aminotransferase (ALT)-elevated, and 11 hepatitis B virus surface antigen (HBsAg)-positive blood donors. PBMCs were isolated, the 5'-untranslated region of HCV RNA was amplified by reverse transcription nested PCR, and the genotype of the core region was determined. Results: No HCV RNA was detected among the eligible samples. Among the deferred donors, 15 (27.2%) had detectable HCV RNA in 55 anti-HCV PBMC specimens. HCV RNA was detected in 1 (9.1%) HBsAg-positive and 9 (8%) ALTelevated samples. The prevalence of OCI in the blood donors was 2.2% (10/458). HCV genotypes were determined in 10 subjects, indicating that 2 (20.0%) were subtype 2a, 7 (70.0%) were 1b, and 1 (10%) was 6a. Conclusions: This study showed that OCI does exist among Chinese blood donors. However, to determine the epidemiology and outcome of this HCV infection, further follow-up with more participants and patients receiving blood components with OCI is needed. [ABSTRACT FROM AUTHOR]

The prevalence of occult hepatitis B virus (HBV) infection was investigated in 149 hepatitis B surface antigen (HBsAg) negative injecting drug users (IDUs) in the Central-West Region of Brazil. Of these individuals, 19 were positive for HBV DNA, resulting in an occult HBV infection prevalence of 12.7% (19/149); six of these 19 individuals had anti-HBV core and/or anti-HBV surface antibodies and 13 were negative for HBV markers. All IDUs with occult hepatitis B reported sexual and/or parenteral risk behaviours. All HBV DNA-positive samples were successfully genotyped. Genotype D was the most common (17/19), followed by genotype A (2/19). These findings reveal a high prevalence of occult HBV infection and the predominance of genotype D among IDUs in Brazil's Central-West Region.

Background: The North Eastern Region in India is endemic for canine heartworm disease but in clinics accurate diagnosis is some times difficult. The aim of the present study was to determine the prevalence of occult infections for heartworm disease in canine in two geographical regions of North Eastern India. Methods: A total of 782 numbers of three categories of dogs namely, working dogs of military and paramilitary forces, pet dogs and stray dogs were screened for the presence of heartworm infection from August 2011 to July, 2012 in Guwahati (Assam) and Aizawl (Mizoram). Conventional, immunological and molecular techniques were followed for this epidemiological study. The criteria to determine the occult heartworm cases were based on the dif­ferences between heartworm positive cases in PCR test and antigen ELISA test. Results: The findings revealed an overall 22.69 percent occult case. The working dogs had highest prevalence (60%) followed by pet (29.16%) and stray dogs (17.75%). Conclusion: The highest percentage of occult heartworm infection was present in working dogs maintained under military or paramilitary forces.

Pyomyositis is an infective involvement of systemic skeletal muscles. We discuss the case of 43-year-old male who presented with quadriparesis, anemia, and hypercalcemia, leading to suspicion of multiple myeloma, and on FDG PET-CT, incidentally, pyomyositis was found. FDG PET-CT thus helped in diagnosing an occult infection which helped in the treatment of the patient. [ABSTRACT FROM AUTHOR]

Pre-heating of serum samples has been shown to reverse false negative antigen tests for Dirofilaria immitis infection in dogs. Here the authors report the results of serum sampling in a population of dogs naturally exposed to D. immitis and Dirofilaria repens infection by testing in ELISA before and after heat treatment. Of 194 dogs sampled from four cities in Romania, D. immitis circulating antigens were found in 16 (8.2%) non heated samples and in 52 (26.8%) heated samples. Of the 108 dogs examined by Knott test, 24 dogs (22.2%) were positive for circulating mf. Subsequent PCR identification showed six dogs had D. immitis mf only, 12 dogs, had only D. repens mf, and 5 were positive for both. Fifty% of dogs with circulating D. immitis mf had positive antigen tests before and after heating, while the other 50% reverted to positive only after heat treatment. Sixty% of dogs with mixed D. immitis/D. repens infection were antigen positive before and after heating, while the other 40% converted to positive after heating. Antigen testing for D. immitis in the 12 dogs with only D. repens mf gave conflicting results. Only two dogs (16%) were antigen negative both before and after heat treatment. Six dogs (50%) became antigen positive after heating and four dogs (30%) were antigen positive both before and after heat treatment. Results would suggest that: false negative result for antigen testing can be reverted by heating of the serum sample; dogs infected with D. repens may have also an occult infection with D. immitis ; heat treatment of serum from D. repens -infected dogs can reveal an occult infection with D. immitis. [ABSTRACT FROM AUTHOR]

Although hepatitis B virus (HBV) and human immunodeficiency virus (HIV) co-infection is common, only few data are available on HBV among HIV patients including occult hepatitis B infection (OBI), regardless of serological markers. This study aims to determine the prevalence of OBI and overall HBV infection, associated factors, HBV genotypes, and surface (S) gene mutations in a population of treatment-naïve HIV-infected patients in Brazil. A cross-sectional study was conducted in treatment-naïve HIV-infected patients in Central Brazil. All samples were tested for HBV serological markers and HBV DNA. Sequence analysis of the S gene and overlapping polymerase gene was preformed. Overall, 25.1% (127/505) of the patients had markers of current or previous HBV infection, which was associated with age over 40 years, history of injection drug use, and homosexual sex. The hepatitis B surface antigen (HBsAg) seroprevalence was 4.9% (25/505). HBV DNA was detected in 39 out of 505 patients: 20 of them were HBsAg-positive and 19 were HBsAg-negative, resulting in an OBI prevalence of 3.8%. Patients with OBI had significantly higher HCV seropositivity rate compared to HBsAg-positive patients. Sequencing of the S gene revealed Y100C, T131N, and D144A mutations. One patient had the M204I and L180M drug-resistance mutations (polymerase). HBV genotypes A (A1, A2), D (D2, D3), and F (F2) were identified. In conclusion, OBI represented almost half of all HBV infections with detectable HBV DNA, suggesting that hepatitis B diagnosis in HIV patients should include in addition to serological markers the detection of HBV DNA. J. Med. Virol. 88:1222-1229, 2016. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]