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At least 829 records · Page 46Linked to original sources
PubMed2001

Early detection of maedi-visna (ovine progressive pneumonia) virus seroconversion in field sheep samples.

The aim of this work was to investigate whether an enzyme-linked immunosorbent assay (ELISA) was useful for early detection of maedi-visna virus (MVV) infection in sheep under field conditions. An ELISA based on p25 recombinant protein and a gp46 synthetic peptide was used. Sequentially obtained serum samples (n = 1,941) were studied for 4 years. ELISA results were compared with those of the agar gel immunodiffusion (AGID) test, and results of both tests were compared with a reference result established using consensus scores for at least 2 of 3 serologic techniques (AGID, ELISA, and western blotting, which was used to resolve result discrepancies between the other 2 techniques). A total of 247 discrepancies were observed between ELISA and AGID. Of these, 131 were due to an earlier detection of 120 sera by the ELISA and 11 sera by AGID. The remaining discrepancies (116) were due to the presence of false reactions in both tests. Fewer false-negative results were found by ELISA than with AGID (6 vs. 69 sera, respectively), whereas the number of false-positive results was virtually the same for ELISA and AGID (21 vs. 20, respectively). In relation to the reference result, ELISA sensitivity and specificity were 97.8% and 98.2%, respectively, whereas values for AGID were 76.3% and 98.3%, respectively. The agreement between ELISA and the reference result was higher than that between AGID and the reference result (K value: 0.96 and 0.77, respectively). A variation in the ELISA signal (based on optical density) was observed during the study period, suggesting different antibody levels throughout the animal's life. The ELISA was useful for detecting MVV-infected sheep in field conditions and has potential for use in control and eradication programs.

Animals↗
PubMed2000

[Incidence hepatitis C virus seroconversion after the implementation of a prevention and control program at a hemodialysis unit].

This study aimed at reporting the incidence of the hepatitis C virus as well as the prevention and control measures adopted in an hemodialysis unit. It is a prospective study developed with patients attended from September 1996 to December 1998 in an hemodialysis unit. The consultations from September 1996 to December 1996 were considered the control group and the ones from January 1997 to December 1998 the intervention group. Regarding the period of the control group, the routine of the unit was organized based on the regulation 2042 that systematizes the services of renal therapy. In the subsequent period, complementary measures were implemented. From 1997 to 1998, authors observed the reduction in the number of cases of hepatitis C.

Ambulatory Care Facilities↗
PubMedDate not supplied

Ehrlichia equi infection of horses from Minnesota and Wisconsin: detection of seroconversion and acute disease investigation.

Equine granulocytic ehrlichiosis (EGE) is caused by infection with Ehrlichia equi. EGE has been reported primarily in northern California, where E equi is transmitted by the tick Ixodes pacificus. Reports of EGE and the emergence of human granulocytic ehrlichia in Minnesota prompted a seroprevalence study of E equi in horses of Minnesota and Wisconsin. Tick (Ixodes scapularis) endemic areas of Minnesota and Wisconsin were compared to nonendemic regions of Minnesota. Indirect fluorescent antibody was used to detect the presence of serum antibodies to E equi. Serum samples from healthy horses, 375 samples from I scapularis endemic counties, and 366 samples from nonendemic counties were screened at a 1:40 dilution. Results demonstrated a seroprevalence of 17.6% in endemic areas versus 3.8% in nonendemic areas. Ehrlichial DNA from 2 samples was successfully amplified by polymerase chain reaction and 919 base pairs were sequenced. The DNA sequence of 1 Minnesota/Wisconsin strain differed from the GenBank strain (M73223) of E equi at positions 84 and 886 and from the MRK strain of E equi at position 84, and was identical to the human granulocytic ehrlichiosis (HGE) agent. The 2nd Minnesota/Wisconsin strain was identical to the 1st with the exception of a substitution of "A" at position 453 that is not present in E phagocytophila, E equi, or HGE agent strain sequences. Based on the results of this study, we concluded that E equi is present and causes infection in horses in Minnesota and Wisconsin. The occurrence of infection is higher in tick endemic regions.

Acute Disease↗
PubMed2004

Hepatitis A virus immunity and seroconversion among contacts of acute hepatitis A patients in Amsterdam, 1996-2000: an evaluation of current prevention policy.

OBJECTIVES: We evaluated the hepatitis A virus (HAV) control policy (hygienic precautions and passive immunization with immune globulin) for "household contacts" (defined as all people who lived in the same house and who shared the same toilet with the patient, people who took care of an HAV-infected child, and sexual partners of the patient) of acute hepatitis A patients between 1996 and 2000. METHODS: We examined the characteristics and the serological outcomes of household contacts. All susceptible contacts were invited for retesting 6 weeks after they received immune globulin. RESULTS: Of 1242 contacts of 569 HAV patients, more than 50% (n = 672) were found to be HAV immune. Among the remaining contacts, 161 (28.2%) had a concurrent infection, and 86 of these individuals were symptomatic. The remaining 409 susceptible contacts received immune globulin, with 186 (45%) returning for retesting 6 weeks later (64 [34%] were infected, but only 12 had symptoms). CONCLUSIONS: Immune globulin does not protect all household contacts from HAV infection; however, it attenuates symptoms and effectively reduces further HAV transmission.

Adolescent↗
PubMed2007

Development of hepatocellular carcinoma (HCC) in a patient 17 years after recovery from chronic hepatitis B and seroconversion to anti-HBs.

A 63-year-old man was admitted to hospital in 2003 for treatment of a hepatocellular carcinoma (HCC). He was negative for HBs antigen (HBsAg) and anti-HCV antibody, and positive for anti-HBs. He had a past history of chronic hepatitis B. In 1986, HBsAg had become negative with the development of anti-HBs. In 2003, an HCC was detected and liver resection was carried out. Histological examination revealed moderately differentiated HCC and slightly fibrotic liver. It is suggested that a diagnosis of HCC, combined with negativity for HBsAg and anti-HCV antibody, may include cases of past recovery from chronic hepatitis B, such as this case.

Antibodies, Viral↗
PubMed1994

Seroconversion after additional vaccine doses to non-responders to three doses of intradermally or intramuscularly administered recombinant hepatitis B vaccine.

Hospital staff members who failed to respond (anti-HBs < 10 IU/l) after 3 doses of a recombinant hepatitis B (HBV) vaccine (given either as 20 micrograms intramuscularly (n = 8) or 2 micrograms intradermally (n = 15)) received 1 or 2 additional doses by the same route as the initial vaccination. After the first additional dose, 12/23 responded with anti-HBs levels > or = 10 IU/l and after the second, another 2/5 responded, corresponding to a total response rate of 61%. No significant difference was seen in the response rate according to vaccination route, gender, age, or whether the vaccinee was a smoker or not. In this limited study some 50% of non-responders to 3 intradermal or intramuscular doses of recombinant HBV vaccine seroconverted after an additional 1-2 doses given by the same route as the initial vaccination, suggesting that additional doses can be administered by the same route as the initial one.

Adult↗