Polymerase Chain Reaction In Amniotic Fluid Research Articles

Minimizing the risk of occupational Q fever exposure: A protocol for ensuring Coxiella burnetii-negative pregnant ewes are used for medical research.

Q fever is a worldwide zoonosis caused by Coxiella burnetii that can lead to abortion, endocarditis, and death in humans. Researchers utilizing parturient domestic ruminants, including sheep, have an increased risk of occupational exposure. This study evaluated the effectiveness of our screening protocol in eliminating C. burnetii-positive sheep from our facility. From August 2010 to May 2018, all ewes (N = 306) and select lambs (N = 272; ovis aries) were screened twice for C. burnetii utilizing a serum Phase I and Phase II antibody immunofluorescence assay (IFA). The first screen was performed by the vendor prior to breeding, and the second screen was performed on arrival to the research facility. Ewes that were positive on arrival screening were quarantined and retested using repeat IFA serology, enzyme-linked immunosorbent assay, buffy coat polymerase chain reaction (PCR), and amniotic fluid PCR. The overall individual seroprevalence of C. burnetii in the flocks tested by the vendor was 14.2%. Ewes with negative Phase I and Phase II IFA results were selected for transport to the research facility. Upon arrival to the facility, two (0.7%) ewes had positive Phase I IFA results. Repeat testing demonstrated seropositivity in one of these two ewes, though amniotic fluid PCR was negative in both. The repeat seropositive ewe was euthanized prior to use in a research protocol. No Q fever was reported among husbandry, laboratory or veterinary staff during the study period. Serologic testing for C. burnetii with IFA prior to transport and following arrival to a research facility limits potential exposure to research staff.

Follow-up of Toxoplasmosis during Pregnancy: Ten-Year Experience in a University Hospital in Southern Brazil.

To describe a population of pregnant women diagnosed with toxoplasmosis and their respective newborns, describing the hospital protocol for treatment and follow-up. Retrospective cohort of pregnant women with acute toxoplasmosis infection and risk of transplacental transmission who were sent to the Fetal Medicine Group of Hospital de Clínicas de Porto Alegre (HCPA) between - January 1, 2006 and December 31, 2016. All patients with confirmed disease were included. The diagnostic protocol and treatment were applied; a polymerase chain reaction (PCR) analysis of the amniotic fluid was used to diagnose toxoplasmosis and determine the treatment. The newborns were followed up at the pediatric outpatient clinic specializing in congenital infection. The patients who were not followed up or were not born in the HCPA were excluded. A total of 65 patients were confirmed to have gestational toxoplasmosis; 40 performed amniocentesis, and 6 (15%) were identified as having positive PCR in the amniotic fluid. In five of those cases, this result associated with the gestational age defined the triple therapy during pregnancy, and in one case, it defined the monotherapy (advanced gestational age). A total of 4 of these newborns were treated from birth with triple therapy for 10 months, 1 was not treated (due to maternal refusal), and 1 progressed to death within the first 54 hours of life due to complications of congenital toxoplasmosis. Of the 34 remaining cases with a negative PCR, 33 were treated with monotherapy and 1 was treated with triple therapy (ultrasound findings); of these children, 9 (26.5%) presented negative immunoglobulin G (IgG), 24 (70.6%) presented positive IgG (but none presented positive immunoglobulin M [IgM]), and 1 (2,9%) presented alterations compatible with congenital disease and started treatment with the triple therapy soon after birth. Out of the total sample of 60 patients, among the 25 who did not perform amniotic fluid PCR, 5 were treated with triple therapy (ultrasound findings/prior treatment) and 20 patients were submitted to monotherapy; only two newborns underwent treatment for congenital toxoplasmosis. Among the 65 cases of gestational toxoplasmosis, 6 (9,2%) children had a diagnosis of congenital toxoplasmosis, and 2 patients with triple therapy felt severe adverse effects of the medications. The present study suggests that research on PCR screening of the amniotic fluid may be useful to identify patients with a higher potential for fetal complications, who may benefit from the poly-antimicrobial treatment. Patients with negative PCR results must continue to prevent fetal infection with monotherapy, without risk of fetal or maternal impairment.

Zika virus detected in amniotic fluid and umbilical cord blood in an in vitro fertilization-conceived pregnancy in Venezuela

To describe the consequences of Zika virus infection at 10weeks of gestation in an IVF-conceived pregnancy in Venezuela. A case report. Private assisted reproduction unit. A 36-year-old patient who conceived her first pregnancy through IVF and became infected with Zika virus at 10weeks' gestation in Venezuela. Invitro fertilization with fresh ET. Clinical, laboratory, and imaging Zika diagnostic methods. Zika virus detection by real-time polymerase chain reaction (PCR) in maternal plasma, PCR in amniotic fluid and umbilical cord blood. Ultrasonography findings of anatomic abnormalities. Zika infection was confirmed at 10weeks' gestation by real-time PCR; ultrasound results appeared normal. At 19weeks' gestation, an ultrasound revealed biometry on three SDs below the means for all parameters but with no apparent anatomic abnormality. Zika virus was positive in maternal urine and amniotic fluid by PCR at 19weeks' gestation. Ultrasound at 21weeks + 4days of gestation showed fetal cerebellar hypoplasia with ventricular dysmorphia, particularly marked on the left, consistent with microcephaly and ventriculomegaly. Because of the poor prognosis, pregnancy was interrupted at 24weeks' gestation, in France. The PCR in umbilical cord blood taken in this procedure was positive for Zika virus. Initial ultrasound findings in pregnancy may not be informative. Only at 21weeks + 4days of gestation did an ultrasound reveal fetal microcephaly and ventriculomegaly. Combined clinical, laboratory, and imaging findings provided a complete picture of the severe damage caused by Zika infection.

Amniocentesis for the detection of congenital toxoplasmosis: results from the nationwide Austrian prenatal screening program

Prenatal diagnosis of congenital toxoplasmosis (CT) influences therapeutical management in pregnant women and their offspring. In Austria, a nationwide serological healthcare program to identify potential maternal toxoplasma infections during pregnancy exists. We assessed the clinical use of amniocentesis for toxoplasma-specific polymerase chain reaction (PCR) on amniotic fluid to detect CT. Data on serology, amniocentesis, PCR, complications, treatment, and paediatric clinical outcome were collected retrospectively among the birth cohort 1992–2008. There were 1386 women with amniocentesis, but only in 707 cases (51%) was acute maternal infection confirmed serologically. A high proportion (49%) of amniocenteses with negative PCR results in women with chronic infection or seronegativity were performed without clinical justification for the women or their foetuses. The positive and negative predictive values of PCR were 94.4% and 99.3%, respectively. Thirty-nine foetuses with CT, including four deaths, were reported. The five PCR-negative but infected infants were identified by the serological and clinical follow-up program. Thirty percent of amniocenteses were performed in the third trimester, and gestational age or treatment did not influence PCR sensitivity. Amniocentesis is indicated in women with acute maternal infection, and facilitated targeted therapies in pregnant women and their offspring. In women with late toxoplasma infection, negative amniotic fluid PCR made treatment of infants unnecessary. Serological and clinical follow-up of infants is important to confirm the infection status of the infant. Recommendations, based on our 17-year experience, to improve the current diagnostic strategies and to reduce unnecessary amniocentesis, are given.

Diagnóstico de infección congénita

In general, congenital diagnosis is based on: a) maternal serologic assays; b) microbiologic study of amniotic fluid or fetal blood sampling; and c) serology in children and microorganism detection by polymerase chain reaction (PCR) or culture. Congenital infections due to cytomegalovirus, herpes simplex, varicella, B19 erythrovirus and toxoplasmosis are usually the result of primary infection in the mother. Therefore, when IgG antibodies are detected before pregnancy, these infections are ruled out. Definitive serologic diagnosis of acute infection in pregnant women requires the demonstration of seroconversion (i.e., from seronegative to seropositive). In these cases, amniotic fluid or fetal blood sampling should be performed to determine the presence of intrauterine congenital infection. Cytomegalovirus, rubella and toxoplasmosis can be diagnosed by detection of specific IgM antibodies in fetal blood. However, PCR in amniotic fluid has replaced conventional prenatal diagnostic techniques, including fetal blood sampling, in the diagnosis of these infections. In the newborn, these infections may be confirmed by measuring IgM specific antibodies. B19 erythrovirus can be detected by PCR in amniotic fluid or fetal blood. Congenital varicella-zoster infection may be diagnosed on the basis of persistence of IgG antibodies after birth. Definitive diagnosis of herpes simplex virus infection requires viral isolation. Swabs or scraping from clinical specimens can be inoculated into susceptible cell lines for isolation.

Interleukin‐6 and interleukin‐8 in cervical and amniotic fluid: relationship to microbial invasion of the chorioamniotic membranes

To evaluate the levels of interleukin (IL)-6 and IL-8 in cervical and amniotic fluid in relation to the presence of bacteria in the membranes in women in preterm labour (PTL). A prospective follow up study. Sahlgrenska University Hospital, Göteborg, Sweden. Sample Women with singleton pregnancies (<34 weeks) presenting with PTL (n = 30). Amniotic fluid was retrieved transabdominally and cervical fluid was sampled from the uterine cervix at admission and analysed for IL-6 and IL-8 with enzyme-linked immunosorbent assay (ELISA). At birth, the chorioamniotic membranes were separated and samples for polymerase chain reaction (PCR) for Ureaplasma urealyticum and Mycoplasma hominis and general culture were obtained. IL-6 and IL-8 in relation to microbial invasion of the chorioamniotic membranes. Bacteria were found in the membranes in 8 of 21 patients in PTL for whom chorioamnion as well as amniotic fluid PCR and cultures were available. Cervical IL-6 was associated with detectable bacteria in the chorioamniotic membranes in women in PTL (median 8.2 ng/mL vs 0.73 ng/mL; P = 0.01). The IL-6 (median 13 ng/mL vs 1.7 ng/mL; P = 0.004) and IL-8 (median 7.2 ng/mL vs 0.28 ng/mL; P = 0.01) levels in amniotic fluid were higher in PTL cases in which bacteria were found in the chorioamniotic membranes. IL-6 in cervical fluid and IL-6 and IL-8 in amniotic fluid were higher in those PTL cases in which bacteria were found in the chorioamniotic membranes.

Is adenovirus a fetal pathogen?

Objectives The purpose of this study was to test the relationship between adenovirus genetic material in the amniotic fluid and adverse pregnancy outcome. Study design This was a prospective, observational study of women who were referred in the second trimester of gestation for either genetic amniocentesis or evaluation of fetal malformation. A 2-mL aliquot of amniotic fluid was subjected to multiplex polymerase chain reaction for a panel of viruses that included adenovirus and human genome controls. Fetuses with an abnormal karyotype were excluded from analysis. Results The prevalence of adenovirus was similar in normal (39/652) and anomalous fetuses (23/364; χ 2 test, P = .376). There was significant seasonal variation in the prevalence in both normal and anomalous fetuses (χ 2 exact test, P<.001), but no significant difference between groups. The monthly proportion of patients who underwent amniocentesis remained constant throughout the year (mean, 8.3%; χ 2 test, P = .67). Central nervous system anomalies and echogenic liver foci were significantly more common among fetuses with positive amniotic fluid polymerase chain reaction results for adenovirus ( P<.005, respectively). Conclusion Adenovirus is found in a similar prevalence and seasonal variation in sonographically normal and abnormal pregnancies. Although a specific fetal presentation was not identified, echogenic liver lesions with or without hydrops and neural tube defects were significantly more common in the presence of adenovirus. The significance of these findings deserves further study.

Polymerase chain reaction for prenatal diagnosis of congenital human cytomegalovirus infection

The reliability of the polymerase chain reaction (PCR) for prenatal diagnosis of human cytomegalovirus (HCMV) infection was determined by retrospective testing of 35 amniotic fluids identified previously as positive or negative for HCMV by virus isolation. Amniocentesis was performed in 26 pregnant women with primary HCMV infection at 14-36 weeks gestation, 3-21 weeks after maternal infection. Blood samples were obtained from 20 fetuses for IgM determination and/or virus isolation. Amniotic fluid culture led to antenatal diagnosis of HCMV in 9 of the 13 infected fetuses (sensitivity 69.2%) with one case diagnosed at a second sampling. PCR was able to detect one additional infected fetus (10/13, sensitivity 76.9%). Nested PCR did not increase sensitivity of prenatal diagnosis. Three cases were not diagnosed by all the techniques employed. The specificity of virus isolation from and DNA detection by PCR in amniotic fluid was 100%. The negative predictive value for virus isolation from amniotic fluid was 76.5% and for DNA detection by PCR 81.2%, whereas the positive predictive value was 100% for both techniques. The results showed that neither approach can detect all cases of congenital HCMV infection prenatally, and that the time interval between maternal infection and sampling seems to be a major factor affecting the reliability of prenatal diagnosis.