Group A streptococcal infections: trend and strain emm typing in an area of central Italy, 1985-2002.

A retrospective study of group A streptococcal (GAS) infections was performed for the period 1985-2002 in an area of central Italy. Although very severe diseases such as streptococcal toxic shock syndrome (STSS) were observed, a general increase in invasive infections was not found. Isolates of GAS were classified by M protein genotyping (emm typing) and analysed according to their origin from invasive and non-invasive infections. The predominant emm types were types 1, 4 and 12, followed by types 3, 6 and 28. During the study period the proportion of isolates of types 1 and 12 fell, while other types (3, 6, 22, 28 and 77) appeared. Isolates from invasive and non-invasive infections shared several emm types; however, most invasive strains belonged to five types only (types 1, 4, 12, 28 and 77), while non-invasive isolates were generally more heterogeneous.

Vertical transmission of the hepatitis C virus to infants of anti-human immunodeficiency virus-negative mothers: molecular evolution of hypervariable region 1 in prenatal and perinatal or postnatal infections.

In a prospective study of 33 infants born to hepatitis C virus (HCV)-positive human immunodeficiency virus-negative mothers the vertical transmission of HCV occurred in 6.8%. The evolution of HCV infection in two babies was studied from birth up to 5 or 6 years of age, and the sequencing of the hypervariable region (HVR) of the putative envelope-encoding E2 region of the HCV genome was performed. The HVR1 sequence variability and the different serological profiles during follow-up could reflect the differences in HCV transmission routes, HCV genotypes, and clinical evolution of infection.

Antibody testing and RT-PCR results in hepatitis C virus (HCV) infection: HCV-RNA detection in PBMC of plasma viremia-negative HCV-seropositive persons.

To evaluate the concordance between viremia and antibody testing in hepatitis C virus (HCV) diagnosis, 682 serum or plasma samples collected from patients with known or suspected HCV infection were tested. An overall concordance of 77% between serological and PCR results was found, 5% was RNA positive/antibody negative and 18% antibody positive/RNA negative. The relationship between HCV infection, risk group and clinical diagnosis was studied in 116 patients: the presence of anti-HCV antibody without viremia was shown in 72.7% of asymptomatic subjects and 17.6% of chronic hepatitis subjects without interferon treatment. However, the detection of HCV-RNA in peripheral blood mononuclear cells (PBMC) in four out of 38 plasma viremia-negative HCV-seropositive subjects (10.5%), showed that HCV-RNA could persist in PBMC and could begin the viral replication again at different times. The detection of HCV-RNA in PBMC in anti-HCV-positive subjects without viremia could reduce false-negative results of HCV-RNA testing by RT-PCR in serum or plasma.

Detection of HCV and GBV-C/HGV infection by multiplex PCR in plasma samples of transfused subjects.

A multiplex polymerase chain reaction (PCR) was applied to clinical samples for simultaneous detection of hepatitis C virus (HCV) and GBV-C/HGV genome. With both RNA viruses, the amplification was performed with primers of the 5' UTR region starting from the single viral RNA reverse transcripted (cDNA) with random hexanucleotide primer mix. GBV-C/HGV RNA was detected in plasma sample of seven out of 50 transfused patients (14%). The multiplex PCR demonstrated a sensitivity up to 7.8 x 10(2) copies/ml respectively for GBV-C/HGV and HCV RNA in plasma samples of 5/50 patients with GBV-C/HGV/HCV co-infection and in patients with HCV (27/50) or GBV-C/HGV infection alone (2/50).