Hepatitis C virus RNA (HCV-RNA) in blood donors and family members seropositive for anti-HCV antibodies.

BACKGROUND: Non-A, non-B virus is responsible for 75-90% of all cases of blood transfusion-related hepatitis. The aim of this work was to determine hepatitis C virus RNA (HCV-RNA) in a group of blood donors and their household contacts. Serotype and genotype of the isolates were also studied. METHODS: HCV antibodies were investigated in 44,588 blood donors with a commercial immunoassay. Forty-four seropositive donors and 72 household members were further studied. Quantitative analysis of viral RNA was performed with Amplicor HCV 2.0 test, while genotype was determined by INNO-LiPA test and serotype with Murex HCV test. RESULTS: Among the 44,588 donors studied, 333 (0.74%) were positive for anti-HCV. Viral RNA was found in 35 (80%) of the 44 seropositive cases studied. Among the 72 household members, HCV antibodies were detected in six (8.3%) and HCV-RNA in four of these individuals. Serotype 1 and genotype 1 were the most frequent types detected (48 and 64%, respectively). The genotype in the blood donor matched that of his seropositive family member in four of six cases. CONCLUSIONS: Our results suggest that intrafamilial transmission of HCV may occur and we stress the need to study household members of seropositive blood donors, as they have a high risk of infection. In this community, genotype 1 is the most prevalent type in blood donors and family members.

[Congenital rubella syndrome in infants treated at a pediatrics hospital]. / Síndrome de rubéola congénita en lactantes atendidos en un hospital pediátrico.

UNLABELLED: Congenital rubella syndrome (CRS) has been considered an uncommon problem in Mexico. OBJECTIVE: To analyze and describe clinical features of CRS cases in infants from a pediatric hospital in Mexico City during an 8 year period. DESIGN: retrospective study. Patients younger than 18 months of age with a positive serologic test for IgG and IgM rubella antibodies were included. Antibodies were measured by an immunoenzymatic microparticles assay. RESULTS: Fifty-six cases were identified, 42 complete clinical records were available for review. Of these, 23 (54.7%) were female and 19 (45.3%) male. Median for age was five months. A total of 9/42 mothers (21%) had history of rash during pregnancy. IgM antibodies were detected in 15 infants and IgG in 27. Major manifestations were ocular (74%), neurologic (66%), and congenital heart disease (67%). Congenital cataracts were detected in 69%, in 52% hepatomegaly, in 43% jaundice, in 40% anemia, in 48% thrombocytopenia, and hearing loss 19%. CONCLUSION: Five confirmed cases with CRS per year in one hospital indicate a high frequency. Only a small percentage of women had a history of rash during pregnancy. CRS must be investigated in infants with ocular, neurologic, and congenital heart diseases.

Rapid screening of phenotypic resistance to nevirapine by direct analysis of HIV type 1 reverse transcriptase activity in plasma.

Drug susceptibility testing for the clinical management of human immunodeficiency virus type 1 (HIV-1)-infected persons is often curtailed because such testing is expensive and time consuming. We describe a non-culture-based phenotypic assay for the rapid analysis of HIV-1 resistance to nevirapine. The assay measures the susceptibility of plasma reverse transcriptase (RT) activity to inhibition by nevirapine by using the PCR-based Amp-RT assay. Assay validation was made using two reference wild-type (WT) and six other nevirapine-resistant (>100-fold) HIV-1 isolates. Amp-RT IC50 values were found to correlate with those obtained by a conventional replication-based assay. The results also indicated that 50 microM nevirapine can be used in a single screening test to detect nevirapine resistance. Analysis of virus mixtures showed a detection threshold of 10% of nevirapine-resistant HIV-1 in a background of WT virus. To evaluate the assay on clinical samples, 30 plasma specimens collected longitudinally from 4 patients before and after treatment with nevirapine were analyzed, and results were compared with codon 181 genotypes. Preteatment samples and those obtained during the first 6 days of therapy (n = 21) were sensitive to nevirapine, and none had detectable Y181C mutation. Phenotypic resistance was seen in eight samples obtained after 1 week of treatment and was correlated with detection of the Y181C mutation. An increase in the level of phenotypic resistance was seen over time. These data validate this rapid and simple assay for monitoring phenotypic resistance to nevirapine.

Blood culture and respiratory syncytial virus identification in acute lower respiratory tract infection.

Even though the incidence of pneumonia in developed and developing countries is similar, the mortality is five times higher in developing countries. This study aimed to determine the prevalence of bacteremia in children with acute lower respiratory tract infection (LRTI) and relative contribution of respiratory syncytial virus (RSV). One hundred and one children under five years of age who attended a primary care level clinic with diagnosis of acute LRTI, were enrolled. Diagnosis and management of pneumonia were done according to the WHO guidelines. Two blood cultures were drawn at the time of admission. A nasopharyngeal sample was taken for detection of RSV by indirect immunofluorescence. Blood cultures were positive for pathogenic bacteria (Streptococcus pneumoniae, Haemophilus influenzae and Staphylococcus aureus) in three patients. The detection for RSV was positive in 24 patients (23.7%). The clinical and radiographic presentations were not significantly different between patients with and without RSV (p > 0.05). RSV is a common cause of LRTI in children younger than five years old. Blood cultures are not commonly positive in outpatients with acute LRTI. The practice of obtaining blood cultures in primary and secondary care clinics is not useful to guide the treatment of patients with community-acquired pneumonia.