Genetic variants of human parvovirus B19 in South Africa: cocirculation of three genotypes and identification of a novel subtype of genotype 1.

Parvovirus B19 comprises three distinct genotypes (1, 2, and 3). The distribution of B19 genotypes has not before been examined in South Africa. Two hundred thirty-nine laboratory samples submitted to a diagnostic virology laboratory for parvovirus DNA detection were analyzed retrospectively. Of the 53 PCR-positive samples investigated, 40 (75.4%) were identified as genotype 1 by genotype-specific PCR or consensus NS1 PCR and sequencing and 3 (5.7%) as genotype 2 and 10 (18.9%) as genotype 3 by analysis of NS1 sequences. Furthermore, phylogenetic analysis identified two genotype 1 sequences which were distinct from the previously described genotypes 1A and 1B. Interestingly, a genotype 2 virus was detected in the serum of an 11-year-old child, providing evidence for its recent circulation. This is the first study to demonstrate the concurrent circulation of all three genotypes of B19 in South Africa and the provisional identification of a novel subtype of genotype 1. The implications of parvovirus B19 variation are discussed.

Progressive multifocal leukoencephalopathy after initiation of highly active antiretroviral therapy in a child with advanced human immunodeficiency virus infection: a case of immune reconstitution inflammatory syndrome.

Five weeks after commencing highly active antiretroviral therapy, a 12-year-old boy with advanced human immunodeficiency virus infection presented with acute cerebellar dysfunction and hemiparesis. Progressive multifocal leukoencephalopathy was diagnosed by cerebrospinal fluid polymerase chain reaction for JC virus and magnetic resonance imaging of the brain. Rapid and sustained improvement followed a prolonged course of glucocorticosteroid therapy while continuing antiretrovirals.

Clinical course of hospitalised children infected with human metapneumovirus and respiratory syncytial virus.

AIM: To describe the clinical presentation and outcomes of hospitalised patients infected with human metapneumovirus (hMPV) and human respiratory syncytial virus (hRSV) in a tertiary hospital in Cape Town, South Africa. METHODS: hMPV was identified in 17 respiratory specimens submitted for viral studies during the period 2001-2003. These patients' medical folders were retrospectively reviewed for clinical, radiological and laboratory data, together with a convenience sample of 20 hRSV-infected patients. RESULTS: hMPV-infected patients were older than those infected with hRSV (P = 0.04) and required a longer hospital stay (P = 0.02). Presenting clinical signs and symptoms were similar between groups. Fourteen (87.5%) hMPV- and 16 (80%) hRSV-infected patients presented with co-morbid and/or immunosuppressive conditions (P > or = 0.5). The most common abnormalities on chest radiographs in both groups were bronchial wall thickening, focal consolidation and atelectasis. Six (37.5%) hMPV- and 11 (55%) hRSV-infected patients required admission to the paediatric intensive care unit (P > 0.1) with five (31.3%) hMPV- and eight (40%) hRSV-infected patients requiring intubation and ventilation (P > 0.5). Three (18.7%) hMPV-patients and three (15%) hRSV-infected patients died during this admission (P > 0.5). All hMPV-infected patients who died had significant co-morbid conditions. CONCLUSIONS: These data confirm that hMPV is a significant respiratory pathogen in this setting, with similar presentation and outcome to hRSV infection. This is the largest report of hMPV infection causing significant morbidity, prolonged hospital stay and death, associated with underlying risk factors.

Ultrasensitive monitoring of HIV-1 viral load by a low-cost real-time reverse transcription-PCR assay with internal control for the 5' long terminal repeat domain.

BACKGROUND: Current HIV-1 viral-load assays are too expensive for resource-limited settings. In some countries, monitoring of antiretroviral therapy is now more expensive than treatment itself. In addition, some commercial assays have shown shortcomings in quantifying rare genotypes. METHODS: We evaluated real-time reverse transcription-PCR with internal control targeting the conserved long terminal repeat (LTR) domain of HIV-1 on reference panels and patient samples from Brazil (n = 1186), South Africa (n = 130), India (n = 44), and Germany (n = 127). RESULTS: The detection limit was 31.9 IU of HIV-1 RNA/mL of plasma (> 95% probability of detection, Probit analysis). The internal control showed inhibition in 3.7% of samples (95% confidence interval, 2.32%-5.9%; n = 454; 40 different runs). Comparative qualitative testing yielded the following: Roche Amplicor vs LTR assay (n = 431 samples), 51.7% vs 65% positives; Amplicor Ultrasensitive vs LTR (n = 133), 81.2% vs 82.7%; BioMerieux NucliSens HIV-1 QT (n = 453), 60.5% vs 65.1%; Bayer Versant 3.0 (n = 433), 57.7% vs 55.4%; total (n = 1450), 59.0% vs 63.8% positives. Intra-/interassay variability at medium and near-negative concentrations was 18%-51%. The quantification range was 50-10,000,000 IU/mL. Viral loads for subtypes A-D, F-J, AE, and AG yielded mean differences of 0.31 log(10) compared with Amplicor in the 10(3)-10(4) IU/mL range. HIV-1 N and O were not detected by Amplicor, but yielded up to 180 180.00 IU/mL in the LTR assay. Viral loads in stored samples from all countries, compared with Amplicor, NucliSens, or Versant, yielded regression line slopes (SD) of 0.9 (0.13) (P < 0.001 for all). CONCLUSIONS: This method offers all features of commercial assays and covers all relevant genotypes. It could allow general monitoring of antiretroviral therapy in resource-limited settings.

Investigation of HIV in amniotic fluid from HIV-infected pregnant women at full term.

BACKGROUND: In the absence of interventions and breast-feeding, the in utero transmission rate of human immunodeficiency virus (HIV) is estimated to be 10%-15%, and the role that amniotic fluid (AF) plays in this is unclear. OBJECTIVES: Levels of cytomegalovirus (CMV) in AF and levels of HIV-1 in AF, maternal blood, and fetal cord blood were assessed.Study design. We enrolled 23 HIV-1-positive women with healthy, singleton pregnancies who underwent elective cesarean section (CS) at full term. The Roche Amplicor HIV-1 Monitor test (version 1.5) was used for determination of maternal plasma VLs. The NASBA Nuclisens assay was used for determination of VLs in other samples. To determine the feasibility of detecting viral infections in AF, CMV polymerase chain reaction DNA extraction was performed on the AF samples by use of the QIAamp DNA kit. RESULTS: HIV-1 RNA was not detected in either AF or fetal cord blood. CMV was detected in 4 AF samples. Maternal CD4(+) T cell counts were 158-654 cells/mL (mean, 405 cells/mL). The maternal plasma VLs ranged from below detectable limits to 169,990 copies/mL (mean, 33,700 copies/mL). CONCLUSIONS: In the absence of medical complications and before labor, AF collected during elective CS from women who had received either zidovudine or nevirapine during late-stage pregnancy was free of HIV.