自愿咨询体检血液标本进行乙型肝炎病毒血清学、核酸联合检测结果分析

目的 分析自愿咨询检测者血液标本进行乙型肝炎病毒血清学、核酸联合检测的结果。方法 采集商丘市疾病预防控制中心感染科自愿咨询检测者的2 000份血液标本,使用两个不同类型厂家的ELISA试剂对乙肝表面抗原进行检测, 两种试剂均阳性则使用单人份的NAT对HBV－DNA进行检验,当两种试剂表现为均阴性或是单试剂为阳性时,则实施6人份的混样检测,若是混样阳性则实施单人份的拆分检测,对两种检测方法的检出率是否符合进行比较。结果 核酸检测以及血清学检测均阴性的共有1 891份;核酸与血清学的检验均阳性共53份; 血清学检验为阳性而核酸检验为阴性的43份;血清学检测为阴性而核酸检测为阳性的13份。 HBsAg双试剂均为阳性的为93份, HBV-DNA为阳性的52份; HBsAg以及HBV-DNA符合率分别为55.91%、33.33%。结论 在入职体检、健康体检和输血等有关传染病的检测中血清学同核酸二者联合检测能够有效提升准确率,降低漏检率,任何一种检测方式的缺失都会导致血液漏检风险。     

2006年广州市流行性感冒监测分析

目的　对2006年广州市流行性感冒（流感）监测结果进行分析。方法　病例标本来自广州市4家哨点医院的流感样病例和暴发疫点现患病例的漱口液或咽拭子，采用犬肾传代细胞进行病毒分离；人群血清标本于3月和10月在其中一家哨点医院按年龄组分层随机抽取健康体检人群进行采集，采用微量半加敏红细胞抑制试验检测各型流感抗体。 结果　1143份哨点医院采集的标本中有95份（8.31%）分离出流感病毒（H1N1型80株，B型15株）；接到暴发疫情146起，罹患率0.40%～16.97%。疫情主要发生在3-4月，全市12个区（市）均有报告且全部来自学校。人群血清抗体H3N2、B（维多利亚系）、 B（巴拿马系）型阳性率两次监测结果无统计学差异，但H1N1抗体10月高于3月（sup2/sup=41.94,IP/I0.05）。 结论　广州市2006年流感流行优势毒株为H1N1；暴发疫情的流行高峰出现在3-4月，以局部暴发为主要特征；学校等集体单位应加强流感监测； B型流感病毒在广州地区仍有继续引起局部暴发流行的潜在危险。     

Exploratory investigation of Q fever in apparently healthy meat sheep flocks in Belgium

Q fever is a cosmopolitan disease affecting both humans and many animal species. Although sheep are often implicated in human Q fever outbreaks, the disease remains largely underestimated in meat sheep flocks. In order to fulfil this gap, a preliminary study was performed aiming to investigate the serological and molecular aspects of infection with Coxiella burnetii among meat sheep flocks in Belgium. Five Belgian sheep flocks were recruited for this work. Indirect ELISA was used, and in addition, real‐time PCR was performed on samples of milk, rectal and vaginal swabs, to understand the dynamics of bacterial shedding. Despite the low overall apparent seroprevalence of 1.39% (95% CI : 0.04–7.5), a high rate of bacterial shedding was found, with 27.7% of tested sheep (N  = 72) with a positive result to PCR , especially through the rectal and vaginal routes and in seronegative animals. Furthermore, Coxiella burnetii DNA was detected in 26.76% of seronegative animals. It can be concluded that an overall good clinical condition of the sheep cannot be used to exclude the presence of C. burnetii in a flock. Furthermore in the diagnosis of Q fever in sheep, serology alone was not a sensitive diagnostic tool. On the contrary, molecular biology allowed to detect bacterial shedding, which is an essential element in order to assess the risk due to the contact with shedding animals. At the light of these results, the role of meat sheep flocks in the epidemiology of Q fever in Belgium needs to be better understood.     

Leishmaniasis in cat shelters: A serological,molecular and entomological study

An epidemiological Leishmania spp. and entomological Phlebotomine sandflies survey was performed in cat shelters at leishmaniasis endemic area of Brazil. Blood and conjunctival swab (CS) samples were collected from 94 cats in two animal protection shelters. These samples were subjected to serological tests using the indirect immunofluorescence antibody test (IFAT) and indirect enzyme‐linked immunosorbent assay (ELISA) and to molecular test by polymerase chain reaction (PCR). In addition, a Phlebotomine sandflies survey was performed in the same shelters. The analyses revealed a positivity of 31.91% (30/94) through ELISA and 29.79% (28/94) through IFAT. The two serological tests showed a positive association with perfect agreement (k = 0.925). None of the cats were positive by Leishmania spp. DNA. One Lutzomyia (Lutzomyia) longipalpis male was found in one of the cat shelters. The results and the implications of our findings are discussed below.     

Serological relationship between a novel ovine pestivirus and classical swine fever virus

The genus Pestivirus comprises globally distributed members of the family Flaviviridae, which cause severe losses in livestock. The most common species of the genus are bovine viral diarrhoea virus type 1 (BVDV‐1) and type 2 (BVDV‐2), classical swine fever virus (CSFV) and border disease virus (BDV). Recently, a novel ovine pestivirus was repeatedly detected in aborted lamb foetuses on a farm located in the Brescia Province (Italy). Complete genome characterization of this isolate showed that it was highly divergent from known pestivirus species and that it was genetically closely related to CSFV. The aim of this study was to determine the serological relatedness between the identified novel pestivirus and BVDV, BDV and CSFV selected strains for which homologous serum was available, by antigenic characterization performed using cross‐neutralization assays. The serological relatedness was expressed as the coefficient of antigenic similarity (R). Both field and specific antisera raised against the ovine pestivirus neutralized the CSFV reference strain Diepholz with titres significantly higher than those specific for the BDV and BVDV strains. Furthermore, the calculated R values clearly indicated that the novel ovine pestivirus is antigenically more related to CSFV than to ruminant pestiviruses, in agreement with the results of the genomic analysis. This would have severe consequences on CSFV serology in the event of a switch to porcine hosts with implications for CSFV surveillance and porcine health management.