Human parvovirus B19 in pregnancy

Parvovirus B19 infection can result in an adverse outcome when acquired during pregnancy. However, in the majority of cases a successful outcome can be anticipated. Public awareness of this condition is essential and obstetricians should be familiar with the options available to them if they are presented with this clinical problem.     

Guidance for control of parvovirus B19 infection in healthcare settings and the community

Interventions for parvovirus B19 infection need to balance the low risk of infection at a population level with the potential for serious adverse outcome for particular groups, notably the fetus, people with haemoglobinopathies and the immunocompromised. This guidance aims to assist the local decision-making process to be as evidence-based as the available evidence allows.     

Outbreak of human parvovirus B19 in hospital workers

We report an outbreak of human parvovirus B19 (HPV B19) infection affecting five nursing staff, four hospital office workers and one physiotherapist and its possible transmission between hospital staff. We investigated the presence of the virus in serum specimens using a nested PCR assay to confirm HPV B19 infection. The viral genome was detected in serum specimens from a nurse with a rash and arthralgia and from three hospital office workers with a febrile illness. The DNA sequence of the PCR products from three staff members was identical. Our findings suggest that transmission of HPV B19 between hospital staff members occurred.     

Rheumatologic manifestations of parvovirus B19 infection

Rheumatologic manifestations of parvovirus B19 infection is a recent individualization. They are rather frequent and varied and meet at the young adult's. Generally, it is responsible for acute, bilateral and symmetrical arthritis, usually involving distal joints and sometimes associated to signs caused by viral infections. Prolonged articular forms were discribed but are rare being able to sometimes feign a nocive rheumatoid arthritis because of their clinical aspect and of a seropositivity. Axial manifestations were also reported. The diagnosis of the recent infection by the parvovirus B19 can be confirmed by ELISA identification of specific IgM antibodies. The mechanism of the articular manifestations is still unknown and the link between parvovirus B19 and systemic vasculitis is questioned.     

Seroprevalence of parvovirus B19 infection in daycare educators

This study was undertaken to provide first-time estimates for the seroprevalence of parvovirus B19 infection among daycare educators in Montréal, Canada, and to identify factors associated with seropositivity. A cross-sectional design was used. Directors and educators from 81 daycare centres (DCCs) were surveyed about DCC and personal characteristics respectively, and serum samples from 477 female educators were tested for parvovirus B19 IgG antibodies. The seroprevalence of parvovirus B19 was 70%. Parvovirus B19 seropositivity was significantly associated with age and with working experience in DCCs, but the latter association was restricted to educators aged less than 40 years. In conclusion, working as a daycare educator appears to be associated with increased risk of acquiring parvovirus B19 infection, but this finding will require further investigation. Because of the large proportion of educators susceptible to acquiring parvovirus B19 infection, our findings also highlight the need for preventive measures.     

Human parvovirus B19 infection within a family and risk for pregnant women.

During an outbreak of parvovirus B19 infection among four related families at least 70% of the household contacts, including a woman at the 33rd week of pregnancy, became infected. Twins were born at the 39th week of pregnancy, both with B19 infection. B19 DNA was detected in their sera by a nested PCR, anti-B19 IgM was detectable only by an immunofluorescence assay, and low levels of maternal anti-B19 IgG were demonstrable by an immunoenzymatic test in the serum of both children. All the haematological parameters were normal at birth and 6 months later, when B19 DNA and anti-B19 antibody were no longer detectable in serum samples. This observation emphasizes the high risk of B19 infection among household contacts and the possibility of a favourable outcome of the foetal infection, possibly related to infection late in the pregnancy.     

无偿献血人群人疱疹病毒8型和巨细胞病毒及细小病毒B19感染流行情况调查

目的调查无偿献血人群中人疱疹病毒8型(HHV-8)、人类巨细胞病毒(HCMV)和人细小病毒B19(HPVB19)感染流行情况,为提供输血筛查策略提供数据支持。方法对2015年3月-2016年3月本地区选取1 046例无偿献血者采用酶联免疫吸附法(ELISA)进行血清HHV-8、HCMV和HPVB19IgM/IgG抗体检测。结果 1 046例无偿献血者中,HHV-8、HCMV及HPVB19检测阳性率分别为16.6%、91.3%及33.0%;HHV-8、HCMV和HPVB19阳性率随年龄的增加而增加,差异有统计学意义(P<0.05);女性HPVB19感染阳性率明显高于男性,两组间比较差异有统计学意义(P<0.05);HCMV阳性率随文化程度的增加而减少,差异有统计学意义(P<0.05);HHV-8、HCMV和HPVB19阳性率在不同职业间比较,差异有统计学意义(P<0.05),其中学生HHV-8和HPVB19阳性率最低为10.7%和25.9%;公务员及企事业单位人员HCMV感染阳性率最低为87.5%;不同血型献血者HHV-8、HCMV和HPVB19阳性率,差异无统计学意义。结论HHV-8、HCMV和HPVB19在本地区存在不同程度的感染,在条件允许的情况下,对重点人群输血时需对三种病毒进行检测。     

济宁地区无偿献血者人细小病毒B19感染的相关研究

目的为了解济宁地区献血人群中人细小病毒B19(human parvovirus B19,简称HPV B19)感染情况,探讨血浆合并对其检出率的影响情况,降低临床输血风险提供一定依据。方法采用酶联免疫吸附法(ELISA)和实时荧光定量PCR(RTPCR)法对采集的960份献血员血液样本进行单人份及随机8人份血浆合并样本进行HPV B19-Ig G、Ig M抗体及DNA检测。结果单人份血浆与随机8人份血浆合并样本HPV B19 Ig G抗体、Ig M抗体阳性率分别为36.15%、5.94%、35.83%、12.50%,抗体阳性标本中单人份及血浆合并样本DNA阳性率分别为0.83%、5.00%。其中Ig M抗体阳性组B19 DNA检出率明显高于Ig G阳性组。结论献血人群中存在较高的HPV B19感染率,血浆合并后Ig M抗体及DNA检出率较高,未提示其传播风险降低,应对儿童、老年人、孕妇等免疫功能低下者选择性输注B19-Ig G抗体滴度较高的血液制品。     

2012-2014年苏南地区育龄妇女人类微小病毒B19感染状况调查

目的 分析苏南地区育龄妇女微小病毒B19感染的状况,为本区妇幼保健提供基础数据。 方法 采用酶联免疫检测法(ELISA)检测2012-2014年苏南地区育龄妇女血清中特异性的IgM抗体。 结果 8 927例育龄妇女的微小病毒B19 IgM抗体阳性率为13.83%,近三年差异无统计学意义(χ²=0.35,P>0.05);不良妊娠结局组、正常妊娠组和婚检组感染率分别为16.37%、12.59%和13.39%,差异有统计学意义(χ²=16.76,P<0.05);感染组与非感染组不良妊娠结局发生率差异有统计学意义(χ²=38.71,P<0.05)。 结论 妊娠期HPVB19感染可引起不良妊娠结局。2012-2014年苏南地区育龄妇女感染率并不低,相关的妇幼保健单位应加强微小病毒B19的感染监测,开展全面检查,提高人口素质。     

Delay between COVID-19 complete vaccination and SARS-CoV-2 infection among healthcare workers

ObjectivesHealthcare workers (HCWs), at increased risk of coronavirus disease 2019 (COVID-19) were among the primary targets for vaccination, which became mandatory for them on September 15th, 2021 in France. In November they were confronted to the fifth COVID-19 wave despite excellent vaccine coverage. We aimed to estimate the incidence of SARS-CoV-2 infection after complete vaccination among HCWs with different vaccination schemes, and its determinants.MethodsWe enrolled all HCWs in the university hospital of Rennes, France who had received complete vaccination (two doses of COVID-19 vaccine). The delay from last vaccination dose to SARS-CoV-2 infection was computed. Fitted mixed Cox survival model with a random effect applied to exposure risk periods to account for epidemic variation was used to estimate the determinants of SARS-CoV-2 infection after complete vaccination.ResultsOf the 6674 (82%) HCWs who received complete vaccination (36% BNT162b2, 29% mRNA-1273, and 34% mixed with ChAdOx1 nCoV-19) and were prospectively followed-up for a median of 7.0 [6.3–8.0] months, 160 (2.4%) tested positive for SARS-CoV-2 by RT-PCR. Incidence density of SARS-CoV-2 infection after complete vaccination was 3.39 [2.89–3.96] infections per 1000 person-month. Median time from vaccine completion to SARS-CoV-2 infection was 5.5 [3.2–6.6] months. Using fitted mixed Cox regression with the delay as a time-dependent variable and random effect applied to exposure risk periods, age (P < 0.001) was independently associated with the incidence of SARS-CoV-2 infection. Vaccine schemes were not associated with SARS-CoV-2 infection (P = 0.068). A period effect was significantly associated with the incidence of SARS-CoV-2 infection (P < 0.001).ConclusionsIn this real-world study, incidence of SARS-CoV-2 infection increases with time in fully vaccinated HCWs with no differences according to the vaccination scheme. The short delay between complete vaccination and incident SARS-CoV-2 infection highlights the need for sustained barrier measures even in fully vaccinated HCWs.     

血液、血制品与人类微小病毒B19的传播

人类微小病毒B19（B19病毒）在人群中传播广泛,0.003%～0.6%的献血员带有B19病毒,在病毒血症早期献血员血液中B19DNA含量很高;血浆及血液制品中也经常能检测到B19DNA。通过输血或应用血制品能引起B19病毒的传播,B19病毒感染与多种疾病的发生有关。     

人微小病毒B19母婴感染的血清学调查

目的调查该地区B19病毒母婴感染情况。方法用ELISA和套式PCR分别检测母婴血清B19病毒IgG、IgM抗体和DNA。结果92例孕妇血清B19病毒IgG抗体阳性率3704%,720例孕妇血清B19病毒IgM抗体阳性率902%,而95例婴儿脐血IgM抗体阴性;720例孕妇血清和95例婴儿脐血B19病毒DNA亦均为阴性。结论部分孕妇存在B19病毒感染既往史,少数孕妇有近期或急性B19病毒感染,但母婴垂直传播B19病毒风险很低。     

微小病毒B19在自然流产患者中的感染状况研究

目的检测自然流产患者中的HPV B19 Ig M、Ig G抗体及DNA,探讨其对自然流产的预防及诊治价值。方法收集病例组(自然流产孕妇)和对照组(中晚期正常妊娠孕妇)静脉血,采用ELISA法检测HPV B19 Ig M、Ig G抗体,PCR检测HPV B19 DNA,比较自然流产患者与正常待产孕妇感染率的差异。结果病例组检测到3例HPV B19 Ig M阳性标本,对照组未检测到阳性标本;病例组HPV B19 Ig G阳性率为46.15%,低于对照组阳性率63.46%;病例组HPV B19 DNA阳性率为21.15%,显著高于对照组阳性率3.85%。两组差异有统计学意义(P0.05)。结论长沙地区自然流产孕妇中HPV B19的感染率高于正常妊娠孕妇,推测HPV B19感染与自然流产有相关性。     

Human parvovirus 4 infection, Cameroon

In a post hoc analysis of samples collected in 2009, we determined seroprevalence of parvovirus 4 (PARV4) among elderly Cameroonians. PARV4 seropositivity was associated with receipt of intravenous antimalarial drugs, intramuscular streptomycin, or an intramuscular contraceptive, but not hepatitis C virus seropositivity. Findings suggest parenteral acquisition of some PARV4 infections.