宁夏2004—2007年麻疹监测分析

为了客观评价宁夏麻疹监测系统现状,探讨控制和消除麻疹的策略。对宁夏2004—2007年麻疹流行病学和实验室监测工作进行分析。结果显示,宁夏麻疹监测系统的灵敏性较高,疑似麻疹病例标本采集率和血清学诊断率等主要监测指标已达较高水平。同时,对监测到的36株麻疹野病毒基因型进行了探讨,全部为H1基因型H1a亚型,未发现其它基因亚型。因此,宁夏亟需加速控制麻疹,应继续做好麻疹监测和麻疹疫苗免疫接种。     

Salivary diagnosis of measles: a study of notified cases in the United Kingdom, 1991-3.

OBJECTIVES--To validate a method for salivary diagnosis of measles and to assess the diagnostic accuracy of notified cases of measles. DESIGN--Blood and saliva samples were collected within 90 days of onset of symptoms from patients clinically diagnosed as having measles and tested for specific IgM by antibody capture radioimmunoassay. SETTING--17 districts in England and one in southern Ireland during August 1991 to February 1993. SUBJECTS--236 children and adults with measles notified by a general practitioner. RESULTS--Specific IgM was detected in serum in only 85 (36%) of the 236 cases. In cases associated with outbreaks and tested within six weeks of onset, 53/57 (93%) of samples were IgM positive, thereby confirming the sensitivity of serum IgM detection as a marker of recent infection. The serological confirmation rate was lower in cases with a documented history of vaccination (13/87; 15%) than in those without (70/149; 47%) and varied with age, being lowest in patients under a year, of whom only 4/36 (11%) were confirmed. Measles specific IgM was detected in 71/77 (92%) of adequate saliva samples collected from patients with serum positive for IgM. In cases where measles was not confirmed, 6/101 had rubella specific IgM and 5/132 had human parvovirus B19 specific IgM detected in serum. CONCLUSIONS--The existing national surveillance system for measles, which relies on clinically diagnosed cases, lacks the precision required for effective disease control. Saliva is a valid alternative to serum for IgM detection, and salivary diagnosis could play a major role in achieving measles elimination. Rubella and parvovirus B19 seem to be responsible for a minority of incorrectly diagnosed cases of measles in the United Kingdom and other infectious causes of measles-like illness need to be sought.     

Clinical and epidemiological aspects of human parvovirus B19 infection in an urban area in Brazil (Niterói city area,State of Rio de Janeiro,Brazil)

This study was designed to analyse the clinical and epidemiological data from human parvovirus B19 cases in a six-year study of rash diseases conduct in an urban area in Brazil (Niterói city area, State of Rio de Janeiro). A total of 673 patients with acute rash diseases were seen at two primary health care units and at a general hospital. A clotted blood sample was collected from all subjects at the time of consultation. Forty-nine per cent (330 cases) of the patients were negative for dengue, rubella and measles IgM or for low avidity IgG to HHV-6. Of these 330, 105 (31.8%) were identified as IgM positive to parvovirus B19 by using an antibody capture EIA. During the study period, three distinct peaks of parvovirus infection were detected, suggesting that the disease appears to cycle in approximately 4-5 years. B19 infection was characterized by variable combinations of fever, flu-like symptoms, arthropathy, and gastrointestinal symptoms. Frequency of fever and arthropathy was substantially higher in adults, 75% [chi2 (1 D.F.) = 11.39, p = 0.0007] and 62.5% [chi2 (1 D.F.) = 29.89, p = 0.0000], respectively. "Slapped-cheek" appearance and reticular or lace-like rash were seen in only 30.1% of the children. No adult presented this typical rash. The lack of the typical rash pattern in a large proportion of parvovirus B19 and the similarity of clinical manifestations to other rash diseases, specially to rubella, highlight the difficulty of diagnosing B19 infection on clinical grounds alone.     

A preliminary study on serological assay for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 238 admitted hospital patients

In this study, we aimed to evaluate the diagnostic value of serological assay for SARS-CoV-2. A newly-developed ELISA assay for IgM and IgG antibodies against N protein of SARS-CoV-2 was used to screen the serums of 238 admitted hospital patients between February 6 and February 14, 2020 with confirmed or suspected SARS-CoV-2. SARS-CoV-2 RNA was detected on pharyngeal swab specimens using real time RT-PCR. 194 (81.5%) of the serums were detected to be antibody (IgM and/or IgG) positive, significantly higher than the positive rate of viral RNA (64.3%). There was no difference in the positive rate of antibodies between the confirmed patients (83.0%, 127/153) and the suspected patients (78.8%, 67/85), whose nucleic acid tests were negative. The antibody positive rates were very low in the first five days after initial onset of symptoms, and then rapidly increased as the disease progressed. After 10 days, the antibody positive rates jumped from below 50% to over 80%. However, the positive rates of viral RNA maintained above 60% in the first 11 days after initial onset of symptoms, and then rapidly decreased. Overall, the suspected patients were most likely infected by SARS-CoV-2. Before the 11th day after initial onset of symptoms, nucleic acid test is key for confirmation of viral infection. The combination of serological assay can greatly improve the diagnostic efficacy. After the 11th day post-disease onset, the diagnosis for viral infection should be majorly dependent on serological assay.     

Etiology of Maculopapular Rash in Measles and Rubella Suspected Patients from Belarus

As a result of successful implementation of the measles/rubella elimination program, the etiology of more and more double negative cases remains elusive. The present study determined the role of different viruses as causative agents in measles or rubella suspected cases in Belarus. A total of 856 sera sent to the WHO National Laboratory between 2009 and 2011 were tested for specific IgM antibodies to measles virus (MV), rubella virus (RV) and human parvovirus B19 (B19V). The negatives were further investigated for antibodies to enterovirus (EV) and adenovirus (AdV). Children of up to 3 years were tested for IgM antibodies to human herpesvirus 6 (HHV6). A viral etiology was identified in 451 (52.7%) cases, with 6.1% of the samples being positive for MV; 2.6% for RV; 26.2% for B19V; 9.7% for EV; 4.6% for AdV; and 3.6% for HHV6. Almost all measles and rubella cases occurred during limited outbreaks in 2011 and nearly all patients were at least 15 years old. B19V, EV and AdV infections were prevalent both in children and adults and were found throughout the 3 years. B19V occurred mainly in 3–10 years old children and 20–29 years old adults. EV infection was most common in children up to 6 years of age and AdV was confirmed mainly in 3–6 years old children. HHV6 infection was mostly detected in 6–11 months old infants. Laboratory investigation of measles/rubella suspected cases also for B19V, EV, AdV and HHV6 allows diagnosing more than half of all cases, thus strengthening rash/fever disease surveillance in Belarus.     

The value of ultrasonography alone in screening surveys of cystic echinococcosis in children in Turkey

A total of 1205 primary school children were examined for cystic echinococcosis in five villages of Manisa, Turkey, to evaluate the efficacy of diagnostic methods of this infection in community-based screening surveys. Six hundred and thirty children from three villages, examined by a portable ultrasound scanner, chest microfilm and serological methods (ELISA, indirect hemagglutination) in our previous study, were designated as Study Group 1; and 575 children, from two adjacent villages, examined by ultrasonography alone in the present study, were designated as Study Group 2. In Study Group 1, hepatic cystic echinococcosis was detected in two cases (0.3%) by ultrasonography, while 43 (8.9%) and 49 (10.1%) cases were found to be positive for cystic echinococcosis by ELISA and indirect hemagglutination, respectively. Three of 575 children (0.5%) were diagnosed with cystic echinococcosis (two hepatic and one renal involvement) by ultrasonography alone in Study Group 2; and lung lesions were later detected in both cases with liver involvement by chest radiography.

Our results suggested that serological tests may be beneficial in suspected cases for confirmation and differential diagnosis, but have some drawbacks, such as discrepancy in results and high false seropositivity rates. Chest microfilm is not easy in field studies and exposure to X-ray is undesirable. As a reliable, simple, inexpensive and rapid technique, ultrasonography alone is recommended to be used in community-based screening surveys for cystic echinococcosis with confirmatory tests for suspected cases found during the screening program.     

A new luciferase immunoprecipitation system assay provided serological evidence for missed diagnosis of severe fever with thrombocytopenia syndrome

Severe fever with thrombocytopenia syndrome (SFTS), caused by SFTS virus (SFTSV) infection, was first reported in 2010 in China with an initial fatality of up to 30%. The laboratory confirmation of SFTSV infection in terms of detection of viral RNA or antibody levels is critical for SFTS diagnosis and therapy. In this study, a new luciferase immunoprecipitation system (LIPS) assay based on pREN2 plasmid expressing SFTSV NP gene and tagged with Renilla luciferase (Rluc), was established and used to investigate the levels of antibody responses to SFTSV. Totally 464 serum samples from febrile patients were collected in the hospital of Shaoxing City in Zhejiang Province in 2019. The results showed that 82 of the 464 patients (17.7%) had antibody response to SFTSV, which were further supported by immunofluorescence assays (IFAs). Further, qRT-PCR and microneutralization tests showed that among the 82 positive cases, 15 patients had viremia, 10 patients had neutralizing antibody, and one had both (totally 26 patient). However, none of these patients were diagnosed as SFTS in the hospital probably because of their mild symptoms or subclinical manifestations. All the results indicated that at least the 26 patients having viremia or neutralizing antibody were the missed diagnosis of SFTS cases. The findings suggested the occurrence of SFTS and the SFTS incidence were higher than the reported level in Shaoxing in 2019, and that LIPS may provide an alternative strategy to confirm SFTSV infection in the laboratory.     

Recurring measles epidemic in Vietnam 2005-2009: implication for strengthened control strategies

Background: Measles remains a serious vaccine preventable cause of mortality in developing nations. Vietnam is aiming to achieve the level of immunity required to eliminate measles by maintaining a high coverage of routine first vaccinations in infants, routine second vaccinations at school entry and supplementary local campaigns in high-risk areas. Regular outbreaks of measles are reported, during 2005-2009.Methods: National measles case-based surveillance data collected during 2005-June 2009 was analyzed to assess the epidemiological trend and risk factors associated with measles outbreak in Vietnam.Results: Of the 36,282 measles suspected cases reported nationwide, only 7,086 cases were confirmed through laboratory examination. Although cyclical outbreaks occurred between 2005 and 2009, there was no definite trend in measles outbreaks during these periods. Overall, 2438 of measles confirmed cases were among children ≤5 years and 3068 cases were among people ≥16 years. The distribution with respect to gender skewed towards male (3667 cases) significant difference was not observed (P= 0.1693). Unsurprisingly, 4493 of the confirmed cases had no history of vaccination (X² <0.01). The northern and highland regions were identified as the main endemic foci and the spatial distribution changed with time. The occurrence of cases, in a considerable proportion of vaccinated population, is not only a reflection of the high vaccination coverage in Vietnam but also portrays a possibility of less than 100% vaccine efficacy. More so, in order to prevent measles in adults, high-risk groups must be identified and catch-up for selected groups selected.Conclusions: This study therefore reinforces the need for continued improvement of surveillance system and to probe into the possible role of changes in age-distribution of cases if the effective control of measles is to be achieved.     

2012年广州市越秀区疑似麻疹风疹病例血清学检测结果分析

目的:对2012年广州市越秀区疑似麻疹风疹的血清学结果进行整理分析,以了解麻疹风疹病例的流行特点。方法:选取2012年1月-2012年12月的166例疑似麻疹风疹患者的血清作为研究对象,统计血清中IgM阳性抗体的检出情况,以及各年龄段、月份IgM抗体阳性的例数及构成比。结果:麻疹风疹疑似病例中有36.1%的患者检测出IgM抗体阳性,其中麻疹IgM阳性以0-1岁婴幼儿的检出率较高,可达44.4%。从月份来看,12月、8月和5月是麻疹的好发时期。风疹IgM阳性以20岁以上中老年患者检出率最高,为75.0%,7月、4月和5月是风疹的易感季节。结论:疑似麻疹风疹病例有较高的IgM抗体阳性检出率,0-1岁婴幼儿和20岁以上中老年人是麻疹风疹的易感人群,4-5、7-8和12月是发病的高峰时期,临床应注意加强防范。     

甘肃省麻疹监测系统报告病例的流行病学分析

目的分析甘肃省近年来麻疹报告发病特点,为实现消除麻疹目标措施的制定提供参考依据。方法对甘肃省2009—2010年疾病监测信息报告系统和麻疹监测系统报告的疑似麻疹病例进行分析。结果 2009—2010年报告麻疹病例1 463例,主要集中在15岁以下年龄组,占病例总数的74.16%,≥15岁病例占病例总数的25.91%。4～7月为发病的高峰季节。对15岁以下进行流行病学调查的病例分析,20.86%的病例未接种过麻疹类疫苗,32.71%的病例免疫史不详。对病例的接触史分析,在发病前7～21d有5.82%的病例明确接触过发热出疹性病人,有12.43%的病例曾去过医院。分离出麻疹病毒H1a基因型,对麻疹疫苗免疫和疫情的防控有指导意义。结论根据麻疹发病年龄构成及免疫史分析,个别地区常规免疫接种不足是造成麻疹发病的主要原因,同时要注意控制院内感染的发生。需要在提高麻疹疫苗常规免疫覆盖率的基础上,进一步深入和规范监测工作,提高监测调查质量。     

Laboratory diagnosis of Epstein-Barr virus infection

Laboratory confirmation of EBV infection requires proper methods and schema of investigation adequate to aim of diagnostic procedure. In paper the results of routine diagnostic tests of EBV infection performed in Department of Virology NIH in 2005-2006 years was included and also, evaluation of usefulness of different laboratory methods was done. Based on results of ELISA tests 10,7% routine investigated subjects was classified as primary EBV infection, 20,1% was seronegative, 7,4% was classified as reactivation of latent infection and serological markers in 45,6% subjects pointed past EBV infection. Positive result of PCR method was obtain in 11,2% samples subjected of routine laboratory investigation. Comparison of specific and non-specific serological methods results (ELISA versus tests of heterophile antibodies) showed the high percentage of false negative results in children tested by non-specific tests. PCR results in serum samples from patients with primary infection (confirmed by serological tests) were positive in 15% cases only. Based on analyzed results it could be stated that reliable confirmation of infectious mononucleosis, as primary EBV infection, is detection of specific IgM antibodies and in case of heterophile antibodies tests the possibility of false negative results, mainly in children, must be taken into account. The most proper samples for PCR method are whole blood, sections of tissue or cells from swabs.     

检测脊髓灰质炎IgM抗体捕捉法ELISA的建立及其在早期快速诊断中的应用

首次建立了用于脊髓灰质炎快速、分型诊断的血清IgM抗体捕捉法ELISA。检测了52例疑似病人,IgM阳性率为76.9％(40/52),而粪便病毒分离率仅为44.2％(23/52),前者的阳性检出率明显高于后者。做病毒分型诊断结果,与分离病毒中和试验定型的总符合率为92.86％(39/42)。检测601例来自全国各省的脊灰疑似病人血清,其阳性率波动于13％～92.3％,平均为61.1％。阳性率与收集血清的病日相关,发病0～3天收集者,阳性检出率为69.5％,4～25天者为64％,26～54天者为52％,55天以上者则未能检出。本检测方法需时1.5天,简便、敏感、特异,重复性良好,适用于脊灰的早期快速诊断。对其实用性进行了讨论。     

Evaluation of Herpes Simplex Detection in Corneal Scrapings by Three Molecular Methods

Herpes simplex virus (HSV)-1 keratitis (HSK) is a sight-threatening ocular infection with worldwide occurrence. A prompt laboratory diagnosis is often very useful. The purpose of this study was to evaluate molecular methods as rapid diagnostic tools compared with cell culture of HSK. Corneal scrapings from patients with clinically suspected HSK were tested by direct immunofluorescence assay (IFA) for HSV-1 antigen and by polymerase chain reaction (PCR) for HSV-1 DNA, and an attempt for viral isolation was performed on Vero cell line culture. Positive samples by cell culture were 20.8%, whereas PCR was positive in 29.2%, and IFA was positive in 33.3%. IFA had better sensitivity (80%) and negative predictive value (81.8%) than PCR (70% and 76.9%, respectively); however, PCR had better specificity (71.4%) and positive predictive value (63.6%). This indicates that a combination of cell culture, IFA and PCR constitutes the best set of tools for diagnosis of clinically suspected cases of HSK. Documented infection can be further assessed by cell-culture technique or PCR depending laboratory availability.     

Utility of neutralization test for laboratory diagnosis of suspected mumps

Mumps is an infectious disease caused by mumps virus (MuV), which belongs to the family Paramyxoviridae and genus Rubulavirus. Typical symptoms of mumps include fever and swelling of the parotid glands; however, mumps can be asymptomatic. Mumps is diagnosed by molecular and serological methods (i.e., PCR and Enzyme Immunoassay [EIA]); however, both methods have pros and cons. This study was performed to compare the diagnostic utility of a focus reduction neutralization test (FRNT) to that of MuV‐specific commercial IgM and IgG antibody EIA in patients suspected of having mumps. One hundred‐eighty six samples collected during mumps outbreak in 2012–16 were studied. Samples (n = 80) were tested by all the three serological assays and showed 70.4%, 83% and 92.5% positivity by IgM EIA, IgG and FRNT, respectively. In all, 58.8% samples (n = 47) tested positive in all three assays. Concordance between mumps RT‐PCR and IgM EIA was highest during the first 2–5 days and decreased with increasing time post‐onset. Mumps FRNT results agreed with those of RT‐PCR/IgM EIA from the second week onwards, whereas the results of mumps IgG EIA agreed with those of RT‐PCR/IgM EIA from post‐onset days 3–10. These findings suggest the utility of a FRNT for laboratory diagnosis of mumps in countries whose populations are not immunized against this infection.

     

Comparison of different methods for diagnosis of bovine tuberculosis from tuberculin- or interferon-gamma-reacting cattle in Spain

Of 1479 cattle from herds in Northwestern Spain previously diagnosed as tuberculosis (TB) positive, 218 animals which gave a positive tuberculin or interferon-gamma reaction were examined at the slaughterhouse. Medial retropharyngeal and caudal mediastinal lymph nodes, and any tissues containing lesions suspected to be tuberculous, were removed and submitted to the laboratory. Three techniques for diagnosis of TB were used: post mortem examination (PME), smear staining by means of auramine O method (AOM), and culture isolation in Coletsos and Lowenstein-Jensen media followed by confirmation of M. tuberculosis complex organisms using PCR (CIM-PCR). Only 123 (29.9%) of the 412 samples collected showed typical tuberculous lesions. Confirmed M. tuberculosis complex organisms were isolated in 144 cases, 114 of which were from tissues showing lesions (success rate of 92.8%). Smears were found positive in 113 cases, 96 of which came from lesions suspected to be tuberculous (success rate of 78.0%). The sensitivities of CIM-PCR compared with those of PME and AOM were 92.7% and 85.7%, respectively. Statistical analysis revealed that PME and AOM are good indicators of the presence of M. tuberculosis complex organisms in tuberculin- or interferon-gamma reacting cattle.     

Brucellacapt、RBT、SAT、iELISA四种血清学检测方法对布鲁氏菌病检测价值的比较研究

目的:探讨布鲁氏菌病血清学试验(Brucellacapt)、虎红平板凝集试验(RBT)、试管凝集试验(SAT)、间接酶联免疫吸附试验(i ELISA)四种血清学检测方法对布鲁氏菌病检测价值的比较研究。方法:收集近两年110例布鲁氏菌病疑似病例人员的静脉血分离得到血清后进行Brucellacapt、RBT、SAT、i ELISA四种血清学检测,以卫生部制定的《布鲁氏菌病诊疗指南》中布鲁氏菌病确诊方法为诊断金标准,将检测结果与其确诊结果进行比较,评价比较各组血清检测方法对布鲁氏菌病的检测价值。结果:110例疑似人员中确诊为布鲁氏菌病阳性91例、阴性19例。Brucellacapt试验阳性89例、阴性21例;RBT试验阳性79例、阴性31例;SAT试验阳性71例、阴性39例;i ELISA检验阳性82例、阴性28例。Brucellacapt试验的灵敏度、符合率、Kappa值、ROC曲线下面积均最大,i ELISA试验、RBT试验、SAT试验依次减小;i ELISA试验的ROC曲线下面积最大,Brucellacapt试验次之,其次为RBT试验,SAT试验的ROC曲线下面积最小。结论:Brucellacapt、RBT、SAT、i ELISA四种血清学检测方法对于布鲁氏菌病检测均有一定的检测价值,对于常规普通患者可采用RBT试验、SAT试验进行检查,而对于疑似病例人员可采用灵敏度更高的Brucellacapt试验、i ELISA试验。     

Effect of thermal environment on the temporal,spatial and seasonal occurrence of measles in Ondo state,Nigeria

We investigated the temporal and spatial dynamics, as well as the seasonal occurrence of measles in Ondo state, Nigeria, to better understand the role of the thermal environment in the occurrence of the childhood killer disease measles, which ranks among the top ten leading causes of child deaths worldwide. The linkages between measles and atmospheric environmental factors were examined by correlating human-biometeorological parameters in the study area with reported clinical cases of measles for the period 1998–2008. We also applied stepwise regression analysis in order to determine the human-biometeorological parameters that lead to statistical changes in reported clinical cases of measles. We found that high reported cases of measles are associated with the least populated areas, where rearing and cohabitation of livestock/domestic animals within human communities are common. There was a significant correlation (P < 0.01) between monthly cases of measles and human-biometeorological parameters except wind speed and vapour pressure. High transmission of measles occurred in the months of January to May during the dry season when human thermal comfort indices are very high. This highlights the importance of the thermal environment in disease demographics since it accounted for more than 40% variation in measles transmission within the study period.     

Laboratory confirmation of Buruli ulcer disease in Togo, 2007-2010

Background

Since the early 1990s more than 1,800 patients with lesions suspicious for Buruli ulcer disease (BUD) have been reported from Togo. However, less than five percent of these were laboratory confirmed. Since 2007, the Togolese National Buruli Ulcer Control Program has been supported by the German Leprosy and Tuberculosis Relief Association (DAHW). Collaboration with the Department for Infectious Diseases and Tropical Medicine (DITM), University Hospital, Munich, Germany, allowed IS2404 PCR analysis of diagnostic samples from patients with suspected BUD during a study period of three years.

Methodology/Principal Findings

The DAHW integrated active BUD case finding in the existing network of TB/Leprosy Controllers and organized regular training and outreach activities to identify BUD cases at community level. Clinically suspected cases were referred to health facilities for diagnosis and treatment. Microscopy was carried out locally, external quality assurance (EQA) at DITM. Diagnostic samples from 202 patients with suspected BUD were shipped to DITM, 109 BUD patients (54%) were confirmed by PCR, 43 (29.9%) by microscopy. All patients originated from Maritime Region. EQA for microscopy resulted in 62% concordant results.

Conclusions/Significance

This study presents a retrospective analysis of the first cohort of clinically suspected BUD cases from Togo subjected to systematic laboratory analysis over a period of three years and confirms the prevalence of BUD in Maritime Region. Intensified training in the field of case finding and sample collection increased the PCR case confirmation rate from initially less than 50% to 70%. With a PCR case confirmation rate of 54% for the entire study period the WHO standards (case confirmation rate ≥50%) have been met. EQA for microscopy suggests the need for intensified supervision and training. In January 2011 the National Hygiene Institute, Lomé, has assumed the role of a National Reference Laboratory for PCR confirmation and microscopy.     

Evolution of Dengue Disease and Entomological Monitoring in Santa Cruz,Bolivia 2002 – 2008

BackgroundIn the context of a rapid increase of dengue cases in the Americas, a monitoring system based on systematic serological control (IgM) of patients consulting for suspected dengue was developed in Bolivia at the end of the 1990s. In the most affected city of Santa Cruz, this system was complemented by an entomological surveillance program based on periodical search for immature stages of Aedes aegypti in dwelling water-holding containers. Here, we analyze these data and describe dengue patterns over 6 years (2002–2008), highlighting the spatial distribution of patients and vectors.Conclusions/SignificanceOver the years, the increasing trend of dengue cases has been highlighted as well as its widespread distribution over the entire city, but an underestimation of the number of cases is strongly suspected. Contrary to popular belief, the city center appears more affected than the periphery, and dengue is not particularly related to waste. Interestingly, the clinical diagnosis of dengue by physicians improved over the years, whatever the gender, age and residential area of suspected cases.     

2018−2019年四川省伪狂犬病毒的流行病学调查及gC、gE、TK基因遗传进化分析

【背景】伪狂犬病毒(pseudorabies virus,PRV)是养猪生产中的一类重要病原,自2011年以来,我国接种了Bartha-K61疫苗的养殖场暴发了大规模的伪狂犬病疫情。【目的】调查目前四川省PRV的流行病学以及毒株的遗传进化,对2018?2019年从86个猪场收集的384份疑似PRV感染样本进行病原学检测。【方法】根据PRV-gE基因检测引物对采集的384份样品进行PCR扩增,并对不同季节、不同地区的PRV阳性率进行统计,将PRV感染与临床症状的相关性进行统计学分析。选择部分PRV阳性样本在BHK-21细胞上进行病毒的分离,随后进行分离毒株的gC、gE、TK基因的遗传进化分析。【结果】PRV阳性猪只的比率为9.9% (38/384);阳性猪场比率为16.3% (14/86);流产母猪的PRV阳性率为32.1% (27/84);种公猪阳性率为2.0% (4/198);神经症状猪的PRV阳性率为11.4% (4/35);呼吸症状猪的PRV阳性率为4.5% (3/67)。统计学分析表明,PRV感染与母猪和公猪繁殖障碍症状相关(P<0.01)。其中,冬季(12月、1月、2月) PRV阳性率最高,约为33.0% (31/94);春季(3月、4月、5月)的阳性率为9.1% (3/33);夏季和秋季的阳性率分别约为1.5% (2/130)和1.6% (2/127)。在2018?2019年共分离出3株PRV毒株,分别命名为PRV-SN、PRV-DJY、PRV-CD。PRV-XJ为本实验室2016年在四川省分离的一株毒株,为了了解毒株的遗传进化信息,先后扩增了这4个毒株的gC、gE、TK基因。序列比对表明四川分离株与国内株相似,存在额外的零星性突变和缺失。【结论】养殖场仍应加强对种猪群中伪狂犬病的净化。