重庆地区无偿献血人群隐匿性乙型肝炎病毒感染的特征

目的了解重庆地区无偿献血人群中隐匿性乙型肝炎病毒感染(occult hepatitis B virus infection,OBI)情况,分析其血清学和病毒学特征。方法应用酶联免疫法(筛查HBs Ag、抗-HCV、抗-HIV)及核酸检测(nucleic acid testing,NAT)法(筛查HBV、HCV、HIV)筛查重庆地区93 625份初筛合格的无偿献血者血液标本。对其中HBs Ag(-)但HBV DNA(﹢)的标本进行抗-HBs、抗-HBc、HBe Ag、抗-HBe 4项血清学标志物测定,进一步对抗-HBc(﹢)标本做病毒载量测定以及基因分型。结果 93 625份标本中HBs Ag(-)但HBV DNA(﹢)的检出率为0.097%(91/93 625)。91份阳性标本中79份为抗-HBc(﹢),检出率为0.084%(79/93 625)。该部分标本阳性者被视为OBI献血者。OBI献血者的血清学特征可以分为4种模式:单抗-HBc(﹢)、抗-HBc(﹢)/抗-HBs(﹢)、抗-HBc(﹢)/抗-HBe(﹢)以及抗-HBc(﹢)/抗-HBs(﹢)/抗-HBe(﹢)。病毒载量为0~1056.8IU/ml(中位数为108.6 IU/ml),基因型以B型为主。结论重庆地区无偿献血者中OBI检出率较高,其血清学和病毒学特征具有地区性。NAT能提高OBI检出的灵敏度,但也存在一定的假阳性,对血液安全具有重要影响。     

无偿献血人群隐匿性乙型肝炎病毒感染调查

目的 调查无偿献血人群隐匿性乙型肝炎病毒感染(OBI)情况。方法 2021年1月～2021年12月我站无偿献血者血液样本107397份,采用两种ELISA法检测试剂盒进行HBsAg的初次筛查,采用核酸检测(NAT)法对两次HBsAg结果均为阴性的样本进行HBV DNA检测。对血清HBsAg阴性而HBV DNA阳性样本进行HBV血清学标志物检测,并采用实时荧光定量聚合酶链式反应(PCR)法检测核酸和病毒基因分型。结果 在筛查的107397例无偿献血人群血样本中,经血清标志物检测后确认为OBI者29例(0.27‰);血清抗-HBc阳性者12例(35.3%),抗-HBe/抗-HBc阳性者8例(23.5%),抗-HBs/抗-HBc阳性者6例(17.7%),抗-HBs/抗-HBe/抗-HBc阳性者3例(8.8%);19～29岁年龄段献血人群OBI感染率为0.09‰,30～39岁人群为0.32‰,40～49岁人群为0.39‰,50～55岁年龄段献血人群OBI感染率为0.41‰,且该年龄段重复献血者OBI感染率为0.31‰;血清抗-HBs/抗-HBc阳性和抗-HBs/抗-HBe/抗-HBc OBI献...     

Occult hepatitis B virus infection: implications in transfusion

Hepatitis B virus (HBV) presents a higher residual risk of transmission by transfusion than hepatitis C virus (HCV) or human immunodeficiency virus (HIV). While most infectious blood units are removed by screening for hepatitis B surface antigen (HBsAg), there is clear evidence that transmission by HBsAg-negative components occurs, in part, during the serologically negative window period, but more so during the late stages of infection. Donations negative for HBsAg, but positive for HBV DNA, with or without the presence of HBV antibodies, correspond to 'occult' HBV infection (OBI). The frequency of OBI depends on the relative sensitivity of both HBsAg and HBV DNA assays. It also depends on the prevalence of HBV infection in the population. OBI may follow recovery from infection, displaying antibody to hepatitis B surface antigen (anti-HBs) and persistent low-level viraemia, escape mutants undetected by the HBsAg assays, or healthy carriage with antibodies to hepatitis B e antigen (anti-HBe) and to hepatitis B core antigen (anti-HBc). Over time, in the latter situation, anti-HBe and, later, anti-HBc may become undetectable. The critical question is whether or not OBI is infectious by transfusion. All forms have been shown to be infectious in immunocompromised individuals, such as organ- or bone marrow-transplant recipients. In immunocompetent recipients, there is no evidence that anti-HBs-containing components (even at low titre) are infectious. Anti-HBc only, with HBV DNA, can be associated with infectivity, as can rare cases of HBV DNA without any serological HBV marker. If HBV nucleic acid amplification technology (NAT) is considered, the OBI viral load would usually be < 500 IU/ml, making testing of plasma pools unsuitable unless the sensitivity of NAT significantly increases by genome enrichment or test improvement.     

乙型肝炎患者血清前S1抗原和HBV DNA与肝功能的关系探讨

目的探讨乙型肝炎病毒前S1抗原(PreS1)及HBV-M和HBV DNA与肝功能检测间的关系。方法对576例血清标本进行PreS1及HBV-M和HBV DNA及丙氨酸氨基转移酶(ALT)、门冬氨酸氨基转移酶(AST)同步检测。结果PreS1、HBV DNA阳性率分别为72.05%和61.81%,两者符合率达74.65%;在HBsAg(-)和正常对照组PreS1、HBV DNA均为阴性;在HBsAg、HBeAg与HBsAg、抗-HBe、抗-HBc和HBsAg、抗-HBc三种阳性模式组中,PreS1阳性率(87.25%、55.71%、68.21%)、HBV DNA阳性率(94.02%、29.29%、45.66%)在各组中相互比较差异均有显著性(P均<0.005);PreS1与HBV DNA阳性符合率为92.03%、53.57%、68.21%,差异有显著性(P<0.05);PreS1阳性组和PreS1阴性组ALT、AST异常率相比,差异有显著性(P<0.05)。结论PreS1主要存在于HbsAg阳性携带者中,且与HBeAg、HBV DNA关系密切,是反映HBV复制及传染性的又一血清学指标,同时PreS1阳性还与肝功能损害有关。PreS1联合HBV-M及HBV DNA和肝功能同步检测具有重要的临床意义。     

Characterization of HBV DNA+/HBsAg- blood donors in Poland identified by triplex NAT

Nucleic acid testing (NAT) for hepatitis B virus (HBV) has been performed in Poland since 2005 on samples seronegative for hepatitis B surface antigen (HBsAg), anti-hepatitis C virus (anti-HCV), and anti-human immunodeficiency virus (anti-HIV). Tools included 24-donation pool testing (PT) using Cobas Amplicor or in individual donations (ID) by Procleix Ultrio. Seven of 761,666 (1:108,800) and 21/250,191 (1:11,900) HBV DNA-positive donations were identified and confirmed by alternative methods. HBV DNA load ranged between 11.6 and 4.6 x 10(4) IU/mL in 11 samples and could not be quantified in 17 samples. HBV genotypes A (56%) and D (4%) were found. The analysis of combined results from index, follow-up, and look-back samples identified four groups: (1) Two cases tested HBsAg positive with alternative, more sensitive, assays; (2) Four cases were in the pre-seroconversion window period; (3) Eight cases had a fluctuating pattern of HBV DNA and anti-HBs detection (recovered infection); and (4) twelve cases carried anti-HBc without anti-HBs, which might correspond to either chronic or recovered "occult" HBV infection. One donor with no HBV markers in the follow-up was excluded, and another was in the window period preceding anti-HBs. HBV NAT identified more confirmed positive donors than HCV or HIV NAT, and 1:250,000 could not be detected by anti-HBc screening. Serological and molecular studies on follow-up and look-back samples are important to classify donors. In conclusion, further studies are needed to determine whether the considerably higher yield of HBV DNA detection obtained with individual donation screening improves blood safety compared with anti-HBc screening.     

Sensitivity of individual donor nucleic acid testing (NAT) for the detection of hepatitis B infection by studying diluted NAT yield samples

BackgroundScreening blood donors for the presence of hepatitis B virus surface antigen (HBsAg) has been the backbone of blood safety. However, occult hepatitis B infection (OBI) in donors can be missed when only HBsAg screening is used. Nucleic acid testing (NAT) is capable of detecting OBI among donors. The aim of our study was to analyse the sensitivity of NAT for detecting OBI.ResultsOf the 18 samples studied, nine were NAT-reactive at a dilution of <1:4 and five out of these showed presence of antibody to core antigen (IgG+IgM). Antibody to surface antigen was present in only two of the nine NAT-reactive samples, one with antibody to core antigen and the other without. Six had a viral load in the range from <10 to 38 IU/mL whereas the viral load in the remaining three samples was not determined. Among the other nine samples which were NAT-reactive at dilutions ≥1:4, antibody to core antigen (IgG+IgM) was present in seven.DiscussionOur study showed that ID-NAT testing along with HBsAg screening could detect most potentially HBV infectious donors (including those with OBI). NAT screening for HBV on diluted samples could compromise blood safety because samples with a low viral load will escape detection.     

Anti-HBc screening in Indian blood donors：Still an unresolved issue

AIM：To study the seroprevalence of antibody to hepatitis B core antigen （anti-HBc） in healthy blood donors negative for HBsAg and to evaluate whether anti-HBc detection could be adopted in India as a screening assay for HBV in addition to HBsAg. METHODS： A total of 1700 serum samples collected from HBsAg-negative healthy blood donors were tested for the presence of anti-HBc antibody （IgM ＋ IgG）. All samples reactive for anti-HBc antibody were then investigated for presence of anti-HBs and for liver function tests （LFTs）. One hundred serum samples reactive for anti-HBc were tested for HBV DNA by PCR method. RESULTS： Out of 1700 samples tested, 142 （8.4%） blood samples were found to be reactive for anti-HBc. It was signif icantly lower in voluntary （6.9%） as compared to replacement donors （10.4%, P = 0.011）. Seventy- two （50.7%） anti-HBc reactive samples were also reactive for anti-HBs with levels 〉 10 mIU/mL and 70 （49.3%） samples were non-reactive for anti-HBs, these units were labeled as anti-HBc-only. These 142 anti-HBc reactive units were also tested for liver function test. HBV DNA was detected in only 1 of 100 samples tested. CONCLUSION： Keeping in view that 8%-18% of donor population in India is anti-HBc reactive, inclusion of anti- HBc testing will lead to high discard rate. Anti-HBs as proposed previously does not seem to predict clearance of the virus. Cost effectiveness of introducing universalanti-HBc screening and discarding large number of blood units versus considering ID NAT （Individual donor nuclic acid testing） needs to be assessed.     

Polymorphisms within Fas gene are not associated with occult hepatitis B virus infection: Polymorphisms within Fas gene in occult HBV infection

Background

Occult hepatitis B infection (OBI) is a form of hepatitis in which there is an absence of detectable HBsAg, despite the presence of HBV-DNA in the peripheral blood of patients. It seems that non-effective or attenuated immune system responses against HBV lead to the development of OBI. Previous studies showed that the Fas/Fas ligand (FasL) system is an important death signaling pathway that is used by cytotoxic T lymphocytes to eradicate HBV from the liver.

Objectives

To investigate polymorphisms in the -670 region of the Fas gene in those with OBI.

Patients and Methods

The plasma samples from 3700 blood donors were tested for HBsAg and anti-HBs by ELISA. The HBsAg-/anti-HBc(+) samples were selected and screened for HBV-DNA by PCR. Those with HBV-DNA were diagnosed as OBI and PCR-RFLP technique was performed to examine polymorphisms within their Fas gene.

Results

352 (9.5%) of 3700 blood samples were HBsAg-/anti-HBc(+). HBV-DNA was detected in 57 (16.1%) of 352 HBsAg-/anti-HBc(+) samples. Therefore, 57 HBsAg-/anti-HBc+/HBV-DNA(+) patients were diagnosed as OBI. Patient and control groups had no significant differences in terms of the studied polymorphisms.

Conclusions

The functional polymorphisms in the promoter region of Fas gene are not associated with OBI. Therefore, it may be concluded that polymorphisms at the -670 position of the Fas gene do not have any critical effects on the immune response against HBV in OBI.     

Serum soluble interleukin-2 receptor levels in patients with chronic hepatitis B virus infection and its relation with anti-HBc

AIM:To investigate the relationship between serumsoluble interleukin-2 receptor(sIL-2R)level and anti-HBcin patients with chronic hepatitis B virus(HBV)infection.METHODS:Sera from 100 patients with chronic HBVinfection and 30 healthy controls were included in thisstudy.The patients were divided into group A[HBsAg( ),HBeAg( )and anti-HBc( ),n=50]and group B[HBsAg( ),HBeAg( )and anti-HBc(-),n=50].sIL-2R levelswere determined using ELISA.HBV DNA and alanineaminotransferase(ALT)were also detected.RESULTS:Serum sIL-2R levels were significantly higherin patients with chronic HBV infection than in healthycontrols.Moreover,serum sIL-2R levels were significantlyhigher in patients with HBsAg( ),HBeAg( )and anti-HBc( )(976.56±213.51×10~3 U/L)than in patients withHBsAg( ),HBeAg( )and anti-HBc(-)(393.41±189.54×10~3 U/L,P<0.01).A significant relationship was foundbetween serum sIL-2R and ALT levels(P<0.01)inpatients with chronic HBV infection,but there was nocorrelation between sIL-2R and HBV DNA levels.Theanti-HBc status was significantly related to the age ofpatients(P<0.01).CONCLUSION:The high sIL-2R level is related topositive anti-HBc in chronic hepatitis B patients.Positiveanti-HBc may be related to T-lymphocyte activation andnegative anti-HBc may imply immune tolerance in thesepatients.     

唐山地区献血人群隐匿性乙型肝炎病毒感染分析

目的了解唐山地区无偿献血人群隐匿性乙型肝炎感染情况。方法用ELISA法检测无偿献血者的乙型肝炎血清标志物,对于HBsAg阴性样本,进行HBV核酸检测（NAT）,NAT阳性样本,用罗氏试剂确证HBV DNA载量。结果共检测116 741例血样,证实隐匿性乙型肝炎感染者35例,占总献血人数的0.29‰。其中97.1%隐匿性乙型肝炎感染者样本的HBV DNA滴度低于102IU/ml。在HBV DNA阳性人群中,抗-HBc阳性率较高,占81.5%,抗-HBs阳性或乙型肝炎病毒血清标志物全阴性也可检出HBV DNA分别占55.6%和22.9%。结论唐山地区献血人群中血清HBsAg阴性者存在一定比例的隐匿性HBV感染,其HBV病毒载量均较低,核酸检测能够提高HBV感染的检出率。     

Evidence that anti-HBc but not HBV DNA testing may prevent some HBV transmission by transfusion

Blood donor screening for antibody to hepatitis B core antigen (anti-HBc) implemented in some countries as a surrogate marker for non-A, non-B hepatitis has been superseded by anti-HCV screening. To assess the value of anti-HBc screening for the detection of hepatitis B surface antigen-negative blood donations that might contain infectious HBV, HBV genomic detection and recipient testing were used. Blood donations were screened and confirmed by multiple anti-HBc assays. Donations containing isolated anti-HBc and those with anti-hepatitis B surface antigen (anti-HBs) level < 0.1 IU/ml were tested for the presence of HBV DNA. Recipients of previous donations from the corresponding donors during the previous 5 years were traced and tested for markers of HBV infection. Of 103 869 donations screened, 586 (0.56%) were anti-HBc positive, two of which contained HBsAg, and 413 (0.4%) had protective (>/= 0.1 IU/ml) levels of anti-HBs. Anti-HBs < 0.1 IU/ml was found in 102 of these donations (0.1%) and isolated anti-HBc in 69 (0.07%). No donations with isolated anti-HBc were HBV DNA confirmed positive. Of 278 recipients of previous donations from 171 donors at risk of HBV carriage, 12 had markers of HBV infection. Six recipients had other identified risk factors. An association with blood transfusion was considered probable in two and possible in four recipients. None of the six corresponding donors had detectable HBV DNA 6-40 months after the implicated donation. The frequency of HBV transmission by chronic carriers negative for hepatitis B surface antigen was estimated in this study to be 1 in 52,000 donations (CI 0.3-7.8/100,000) from HBsAg-negative donors. Such HBV infectious donations may not be detected by DNA amplification.     

Association of exon 9 but not intron 8 VDR polymorphisms with occult HBV infection in south-eastern Iranian patients

Background and Aim:  Occult hepatitis B infection (OBI) is characterized as a form of hepatitis in which, despite the absence of detectable hepatitis B surface antigen (HBsAg), hepatitis B virus DNA (HBV–DNA) is present in a patient's peripheral blood. Investigators believe that divergent genetics and immunological parameters vary between resistant individuals and patients with OBI. Vitamin D3 and its known receptor appear to be involved in antiviral immune responses. Therefore, because OBI is a form of viral infection, the aim of this study was to investigate the association between polymorphisms in intron 8 and exon 9 of the vitamin D receptor (VDR) with OBI.
Methods:  In this experimental study, the plasma samples of 3700 blood donors were collected and tested for HBsAg and anti-HBs using ELISA. The HBsAg^–/anti-HBc⁺ samples were selected and screened for HBV–DNA using polymerase chain reaction (PCR). HBV–DNA-positive samples assigned as OBI cases and PCR–restricted fragment length polymorphism.
Results:  The results of the current study demonstrated that 352 (9.5%) of 3700 blood samples were HbsAg^-/anti-HBc⁺. HBV–DNA was detected in 57/352 (16.1%) of HBsAg^–/anti-HBc⁺ samples. Our results showed a significant difference in the T/T allele of exon 9 of VDR, but any differences were also observed in the other examined alleles.
Conclusion:  The polymorphisms in the T/T allele of exon 9 of VDR is possibly associated with OBI, thus it can be concluded that VDR and its functional polymorphisms are likely to be related to sensitivity and resistance of the immune system to HBV in OBI patients.     

The prevalence of occult hepatitis B in chronic hepatitis C patients treated with interferon-based antiviral therapy

Background and study aims

Occult hepatitis B infection (OBI) is known to be mostly prevalent in chronic hepatitis C (CHC) patients and OBI reactivation might be life-threatening in patients undergoing interferon (IFN)-free direct acting antiviral (DAA) therapy. As previous studies have revealed a relationship between OBI and non-response to IFN-based antiviral therapy, the aim of the current study was to determine if there was a higher prevalence of OBI in IFN non-responders than responders.

Serological and molecular characterization of hepatitis B virus infection in chronic kidney disease patients from Rio de Janeiro,Brazil

Chronic kidney disease (CKD) patients undergoing hemodialysis (HD) are more vulnerable to blood-borne viral infections due to frequent invasive procedures. Hepatitis B virus (HBV) infection in this cohort of patients has been a matter of concern worldwide. The objective of this cross-sectional study was to evaluate the frequency of serological markers for hepatitis B, and the occurrence of overt and occult HBV infection (OBI) and its molecular characterization in serum samples from 644 CKD patients in HD units located in Rio de Janeiro, Brazil, from 2013 to 2017. HBV DNA was investigated in HBsAg reactive and “anti-HBc alone” samples to determine infecting genotypes and genetic relatedness between sequences. The prevalence of serological markers HBsAg+, anti-HBc alone, anti-HBc+/anti-HBs+, anti-HBs+, anti-HBc/anti-HBs/HBsAg were 5.9%, 2.8%, 30.7%, 26.6%, 34.0%, respectively. HBV DNA was detected in 39.5% (15/38) of the HBsAg+ and in 5/18 (27.8%) of the “anti-HBc alone” individuals, indicating a high prevalence of OBI within this group. We found a higher prevalence of HBV/A1 (65%), followed by HBV/D3 (20%), and HBV/A2 (15%). Bayesian MCC tree with a highly supported clade, genetic distance comparison, and identical nucleotide sequences suggested a nosocomial spread of HBV in some units. The high prevalence of HBV infection and low number of individuals immune to infection reinforces the need for vaccination in this group. The presence of closely related strains in the same HD unit reinforces the importance of continuous improvement of safety control measures and laboratory surveillance of serological markers to prevent the risk of infection and transmission of HBV.     

HBsAg和HBsAb同时阳性慢性HBV感染者血清病毒PreS/S区基因序列分析及临床意义探讨

目的：分析HBsAg和HBsAb同时阳性慢性HBV感染者的血清病毒PreS/S区基因序列,探讨其临床意义。方法：收集HBsAg和HBsAb同时阳性慢性HBV感染者32例,其中HBV DNA阳性者12例（实验组）,其余20例为HBV DNA阴性。另外选取HBsAg阳性、HBsAb阴性和HBV DNA阳性的慢性HBV感染者12例（对照组）。采用聚合酶链反应（PCR）法体外扩增两组患者HBV PreS/S基因序列并测序分析,比较两组间PreS/S基因变异情况,结合临床资料探讨其临床意义。结果：实验组与对照组在性别、年龄、HBeAg阳性率、HBsAg滴度及HBV DNA水平上差异均无显著性意义（P〉0.05）。两组基因型分布亦相似（P〉0.05）。实验组与对照组在PreS1区、PreS2区、S区、MHR（主要亲水）区及＂a＂表位区各区域的核苷酸替换率相当（P〉0.05）。实验组中1例患者的PreS区有一长约144bp的片段缺失,位于PreS/S区nt285~428位（PreS1区末端及PreS2区起始部）。结论：HBsAg和HBsAb同时阳性的现象与PreS/S区基因突变无明显的相关性,HBsAb的出现对HBsAg和HBsAb同时阳性且HBV DNA亦阳性的患者不具有保护作用。     

Molecular and serological characterization of occult hepatitis B infection in blood donors from Mexico

Occult hepatitis B virus (HBV) infection (OBI) is characterized by presence of HBV DNA in blood or liver tissue without detectable HBV surface antigen (HBsAg), with or without antibodies to hepatitis B core antigen (anti-HBc) or antibodies against HBsAg (anti-HBs). A molecular and serological characterization was done of OBI in blood donors from Yucatan, Mexico. HBV DNA was found in 24 (6.4%) of the 372 evaluated samples. Anti-HBs was present in 15/24 samples (62.5%), and no significant difference was observed between HBV DNA positivity and anti-HBs levels. HBV genotype H was detected in 66.7% of samples, followed by genotypes D (20.8%) and F (8.3%). Amino acid substitutions were identified in the core region of nine samples, and most of these changes were located in immunodominant epitopes. No precore stop codon 28 mutant (W28Stop) was identified among the analyzed HBV isolates. In conclusion, genotype H is the main circulating HBV strain among OBI blood donors from Yucatan, Mexico. Mutations in the core region may contribute to viral persistence.     

Occult hepatitis B virus infection and blood transfusion

Transfusion-transmitted infections including hepatitis B virus(HBV) have been a major concern in transfusion medicine. Implementation of HBV nucleic acid testing(NAT) has revealed occult HBV infection(OBI) in blood donors. In the mid-1980 s, hepatitis B core antibody(HBc) testing was introduced to screen blood donors in HBV non-endemic countries to prevent transmission of non-A and non-B hepatitis. That test remains in use for preventing of potential transmission of HBV from hepatitis B surface antigen(HBs Ag)-negative blood donors, even though anti-hepatitis C virus testshave been introduced. Studies of anti-HBc-positive donors have revealed an HBV DNA positivity rate of 0%-15%. As of 2012, 30 countries have implemented HBV NAT. The prevalence of OBI in blood donors was estimated to be 8.55 per 1 million donations, according to a 2008 international survey. OBI is transmissible by blood transfusion. The clinical outcome of occult HBV transmission primarily depends on recipient immune status and the number of HBV DNA copies present in the blood products. The presence of donor anti-HBs reduces the risk of HBV infection by approximately five-fold. The risk of HBV transmission may be lower in endemic areas than in non-endemic areas, because most recipients have already been exposed to HBV. Blood safety for HBV, including OBI, has substantially improved, but the possibility for OBI transmission remains.     

Clearance of HBV DNA in immunized children born to HBsAg‐positive mothers,years after being diagnosed with occult HBV infection

In a previous study, we observed immunoprophylaxis failure due to occult hepatitis B virus (HBV) infection (OBI) despite the presence of adequate levels of anti‐HBs in 21 (28%) of 75 children born to HBsAg‐positive mothers. The aim of the study was to explore the maintenance of this cryptic condition in this population. Of 21 OBI‐positive children, 17 were enrolled. HBV serological profiles were determined by enzyme‐linked immunosorbent assay. Highly sensitive real‐time and standard PCR followed by direct sequencing were applied in positive cases. The mean age (±SD) of studied patients was 6.57 ± 2.75 years. All children still were negative for HBsAg. All but one (94%) were negative for HBV DNA. Only two children were positive for anti‐HBc. The results of the most recent anti‐HBs titration showed that 4 (23.5%) and 13 (76.5%) had low (<10 IU/mL) and adequate (>10 IU/mL) levels of anti‐HBs, respectively. The only still OBI‐positive patient had an HBV DNA level of 50 copy/mL, carried the G145R mutation when tested in 2009 and again in 2013 in the ‘a’ determinant region of the surface protein. Further follow‐up showed that after 18 months, he was negative for HBV DNA. In high‐risk children, the initial HBV DNA positivity early in the life (vertical infection) does not necessarily indicate a prolonged persistence of HBV DNA (occult infection). Adequate levels of anti‐HBs after vaccine and hepatitis B immune globulin immunoprophylaxis following birth could eventually clear the virus as time goes by. Periodic monitoring of these children at certain time intervals is highly recommended.     

Hepatitis B Virus Chronic Infection in Blood Donors from Asian and African High or Medium Prevalence Areas: Comparison According to Sex

Immune control of various infectious diseases, particularly viral, was shown to be more efficient for females than males. Response to viral vaccines (HAV, HBV) was higher in females. Data on hepatitis B virus (HBV) markers accumulated over 15 years in blood donors was stratified according to sex, including HBsAg, HBV viral load and levels of anti-HBs in areas where genotypes B and C (China), genotype D (Iran, Lebanon, Tunisia) and genotype E (Ghana, Burkina Faso, Gabon) were prevalent. HBsAg was screened by either ELISA or rapid tests, anti-HBc and anti-HBs by ELISA, HBV DNA load by a standardized method across sites. In Ghanaian children less than 5 years, HBV DNA load was significantly lower in females than in males (p = 0.035). In China, Ghana, Burkina Faso and Gabon blood donors, median HBsAg prevalence was ~5% and 3% in China, ~8.5% and 4.5% in Gabon, ~16% and 11% in Burkina Faso and ~11% and 7% in Ghana for male and female donors, respectively (p < 0.001). In HBsAg+ Ghanaian blood donors, distribution and median viral load were not significantly different between sexes; occult hepatitis B infections (OBI) were significantly more frequent in males. In Chinese blood donor anti-HBc+ and anti-HBs+, anti-HBs levels tended to be higher in males but vaccinated donors’ anti-HBs+ only, while anti-HBs levels were females > males. In areas where genotypes B-E are dominant, the prevalence of chronic HBV infection (HBsAg+) seems better controlled before age 16–18 by females infected vertically or horizontally. OBIs appear considerably more frequent in men, suggesting lower efficacy of HBV infection control. Female blood donors appear significantly safer from HBV than males, and their donation should be encouraged.