The severity of disease in patients admitted with acute RSV infections can be correlated to the RSV type as determined by PCR, to the RSV genotype as determined by nucleic acid restriction analysis and to the ratio IL-6:TNF-alpha in NPS.

Parvovirus B19 (hereafter referred to as B19) exhibits a marked tropism to human bone marrow (BM), and infection may lead to erythema infectiosum, arthropathy, hydrops fetalis, and various hematologic disorders. Recently, a distinct parvovirus isolate termed V9 with an unknown clinical spectrum was discovered. In contrast to the many studies of B19 serology and viremia, valid information on the frequency of B19 or V9 DNA in the BM of healthy individuals is limited. To develop a reference value, paired BM and serum samples from healthy subjects were tested for the presence of B19 and V9 DNA and specific antibodies. Immunoglobulin M (IgM) was not found in any of the serum samples. The prevalence of IgG showed a gradual and steady increase from 37% in children aged 1 to 5 years to 87% in people aged >50 years. When 190 well-characterized subjects were examined, B19 DNA was detected in the BM of 4 individuals (2.1%; 95% confidence interval, 0.58 to 5.3%) while none of the paired serum samples showed evidence of circulating viral DNA. V9 DNA was not found in any of the BM or serum samples. The finding of B19 DNA probably indicated a primary infection in one 7-year-old individual and reinfection or reactivation of persistent infection in the remaining three persons, aged 47 to 58 years. Serving as a benchmark for future studies, these findings are useful when interpreting epidemiologic data, performing BM transplantation, or considering clinical implications of parvovirus infection.Human parvovirus B19 (hereafter referred to as B19) is a member of the genus Erythrovirus of the family Parvoviridae (18). B19 exhibits a marked tropism to human bone marrow (BM) and replicates only in erythroid progenitor cells (3). Infection may lead to erythema infectiosum, arthropathy, hydrops fetalis, and various hematologic disorders, including aplastic crisis, chronic anemia, and idiopathic thrombocytopenic purpura (3). Diagnosis of B19 relies on serology and the detection of viral DNA by PCR or dot blot analysis. A possible emerging parvovirus isolate termed V9 with an unknown clinical spectrum and markedly different from B19 (Ͼ11% nucleotide disparity) was recently discovered (19). Sequencing, combined with PCR studies, has since demonstrated the need for specific and differentiated techniques when examining samples for possible B19 or V9 viremia (11). Conversely, cloning and production of the V9 capsid proteins and subsequent enzymelinked immunosorbent assay studies have revealed a 100% serologic cross-reactivity between the B19 and V9 isolates (13).The prevalence of immunoglobulin G (IgG) antibodies directed against B19 ranges from 15 to 60% in children 6 to 19 years old: and from 30 to 60% in adults and is more than 85% in the geriatric population (1,7,22). The frequency of B19 viremia in voluntary blood donors has been estimated at rates of 1:167 to 1:35,000 (11,14,17,(22)(23)(24). As opposed to the many studies on B19 serology and viremia, information on the presence of B19 DNA in the BM of healthy individuals is limited. Thou...

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Nasopharyngeal and middle-ear colonization with bacteria and viruses, including Mycoplasma pneumoniae and chlamydiae, was investigated in a survey of 54 children with acute otitis media (AOM) and 201 control children without AOM in Greenland. In total, 98% with AOM and 91% without AOM carried potentially pathogenic bacteria in the nasopharynx. Two or more potentially pathogenic species were carried by 78% with AOM and 57% without AOM. Haemophilus influenzae was found in 92% and 77%, respectively, but only Streptococcus pneumoniae was found significantly more often in the nasopharynx of children with AOM than in age-matched controls (P < .03). The two species were found in 22 of 24 ear-discharge specimens. Nine children (three with AOM) had chlamydiae in the nasopharynx, and seven of them reported rhinitis. Enteroviruses or rhinoviruses were detected in 23 nasopharyngeal specimens from 39 children with AOM, in 13 such specimens from 39 children without AOM (P = .040), and in 4 of 14 ear-discharge specimens. The potentially pathogenic load in the nasopharynx was massive, suggesting an association with the high prevalence of otitis media among children in Greenland.

The etiology of the most common intraoral mucosal disease, recurrent aphthous ulceration (RAU), remains obscure. Here, attempts were made to diagnose reactivation of varicella zoster (VZV), cytomegalovirus (CMV), Epstein-Barr (EBV) and human hepes virus 6 (HHV-6) infections from paired sera in association with RAU recurrences. The first sample was obtained within 3 days after a new recurrence (1) and the second 10-14 days later (2). The study initially comprised 18 otherwise healthy RAU patients (gr A) and 17 sex- and age-matched healthy non-RAU individuals. Values of specific antibody subclasses (IgM, IgG, IgA) were determined by ELISA (VZV, CMV, EBV) and IFA (HHV-6). Patients and controls exhibited differences in parameters on specific VZV IgM and CMV IgM. In order to substantiate these findings, specific VZV IgM and CMV IgM were subsequently also evaluated in 17 other RAU patients (gr B). Ten patients in gr A and 11 in gr B were IgM seropositive for either VZV and/or CMV in at least one of the serum samples, whereas in the controls only one was VZV IgM positive and none CMV IgM positive. Evaluated as groups, optometric density (OD) antibody levels of VZV IgM were significantly higher in the patients (gr A (1,2) vs controls: p < 0.0001; gr B (1,2) vs controls: p < 0.001). CMV OD IgM antibody values were significantly higher in gr B only (1,2 vs controls: p < 0.01). The study lends support for reactivation of VZV and/or CMV infection associated with RAU recurrences.

Treatment of parvovirus infections among immunocompromised hosts using immunoglobulin has provided the clinician with a useful therapeutic tool but has also highlighted the problems concerning chronic disease states. The discovery of the human parvovirus B19 in 1975 and subsequent studies of its effects in humans have identified this virus as the causative agent of a broad spectrum of diseases. Recent improvements regarding the development of sensitive PCR techniques and methods for cultivation have provided new insight into its pathogenic role, its virology and immunology, and the varied clinical manifestations. The current state of knowledge concerning parvovirus enabled us to divide the long list of diseases caused by this virus into three main categories: (1) disease found among normal hosts (asymptomatic disease, erythema infectiosum, arthropathy, hydrops fetalis), (2) hematologic diseases (aplastic crisis, chronic anemia, idiopathic thrombocytopenic purpura, transient erythroblastopenia of childhood, Diamond-Blackfan anemia) and, finally, (3) a heterogeneous group of diseases, in which the etiologic role of parvovirus is less clear and sometimes putative (neurologic disease, rheumatologic disease, vasculitic and myocarditic syndromes). In particular, arthropathy, hydrops fetalis and the hematologic disorders may be of pediatric concern. Consequently, it is of paramount importance that in all of these cases the clinician includes parvovirus as a differential diagnosis.

Samples of nasopharyngeal secretions (NPS) obtained from 140 infants and children with acute respiratory disease were examined for the presence of respiratory syncytial (RS) virus by ELISA. An antiserum produced in rabbits against RS-virus polypeptides was used both as the "capture" antibody and as conjugate in a double-antibody sandwich technique. RS virus was detected by ELISA in specimens of NPS obtained from 72 (51%) of the patients. By comparison RS virus was shown to be present in 86 (61%) of the patients when the immunofluorescent antibody (IF) technique was employed. Samples obtained from 78 of the 140 patients were also examined by inoculation into tissue cultures, and RS-virus was isolated from 47 patients. RS virus was detected by ELISA in 37 (79%) and by IF technique in 43 (91%) of these 47 patients. The IF technique was found to be more sensitive than ELISA, especially in patients older than 9 months and for the examination of specimens of NPS containing only a small percentage of RS-virus antigen-positive cells.