Journal of medical virology
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Lower respiratory tract infections are the leading cause of death in children worldwide. Studies on the epidemiology and clinical associations of the four human non-SARS human coronaviruses (HCoVs) using sensitive polymerase chain reaction (PCR) assays are needed to evaluate the clinical significance of HCoV infections worldwide. Pediatric respiratory specimens (1,683) submitted to a diagnostic virology laboratory over a 1-year period (December 2004-November 2005) that were negative for seven respiratory viruses by conventional methods were tested for RNA of four HCoVs using sensitive RT-PCR assays. ⋯ HCoVs are associated with a small, but significant number (at least 2.4% of total samples submitted), of both upper and lower respiratory tract illnesses in children in Colorado. Our data raise the possibility that HCoV may play a role in gastrointestinal and CNS disease. Additional studies are needed to investigate the potential roles of HCoVs in these diseases.
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Case Reports
Cytomegalovirus and Epstein-Barr virus coinfection in three toddlers with prolonged illnesses.
Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) usually cause primary and latent infections during childhood; thus, coinfection with these viruses occurs occasionally in children. However, its clinical impact has not been established, and may be underestimated. Three cases of coinfection involving these two viruses in toddlers are described: a 14-month-old male with infectious mononucleosis, an 18-month-old female with hemophagocytic lymphohistiocytosis, and a 13-month-old female with acute hepatitis. ⋯ Serial serological testing and quantitation of viral DNA for CMV and EBV using peripheral blood from the patients suggested primary infections with both viruses. In all three cases, the viral load of EBV and CMV in the early stage of disease exceeded 6.4 x 10(3) and 8.8 x 10(2) copies/ml of whole blood, respectively, suggesting that the viruses were associated with the clinical condition. Recognizing that coinfection with these viruses may modulate the clinical course of disease is important.
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Serological tests for Epstein-Barr virus (EBV) have been used for many years as diagnostic predictors of nasopharyngeal carcinoma. It has been shown previously that the conventional immunofluorescence assay has a limited diagnostic value, especially in young patients from North African area. In the search for more reliable immunoglobulin (Ig) G or IgA antibody markers for the diagnosis of nasopharyngeal carcinoma, immunoblot analysis was performed using a full spectrum of EBV proteins. ⋯ Since the IgA EBNA1 response showed the highest sensitivity value for the detection of nasopharyngeal carcinoma, a novel enzyme-linked immunosorbent assay (ELISA) was established using a GST-EBNA1 protein expressed in bacteria, containing the P-threonine EBNA1 subtype cloned from DNA EBV sequence of C15 xenograft cells. Detection rates were 85.7% and 94.9% in young and older patients with nasopharyngeal carcinoma respectively, while only 3.6%, 11.1%, and 16.6% in healthy EBV carriers, patients with lymphoma and patients with autoimmune diseases, respectively. Thus, IgA EBNA1 ELISA may be useful for early diagnosis and mass screening of nasopharyngeal carcinoma in Tunisia even in young patients.
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While human rhinoviruses (HRVs) are well accepted as a major cause of common cold syndromes (rhinitis), their role in the etiology of lower respiratory tract infections is still controversial, and their detection in asymptomatic patients is relatively common. The HRV pathogenic role in four groups of hospitalized patients (pediatric immunocompetent and immunocompromised patients, and adult immunocompetent and immunocompromised patients) was investigated by quantifying HRV load in nasopharyngeal aspirates or bronchoalveolar lavage samples by real-time reverse transcription PCR (RT-PCR). Real-time RT-PCR was performed in duplicate on all respiratory samples resulting positive by qualitative RT-PCR. ⋯ In immunocompetent pediatric patients HRVs were mostly associated with lower respiratory tract infections (in the absence of other viral agents) and wheezing, when viral load was > or =10(6) RNA copies/ml. In young immunocompromised patients (stem cell transplantation recipients), an inverse correlation between HRV persistence over time and time at which the infection occurred after transplantation was observed, whereas in adult immunocompromised patients (lung transplant recipients) HRVs could be detected at a medium-low level (<10(5) RNA copies/ml) in bronchoalveolar lavage samples taken routinely from asymptomatic patients. In conclusion, when detected at high viral load, HRVs may cause severe upper and lower respiratory tract infections, whereas when detected at a medium-low viral load, an event more frequent in immunocompromised subjects, they may represent only bystander viruses.
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Randomized Controlled Trial Multicenter Study
Benefits of increasing the dose of influenza vaccine in residents of long-term care facilities: a randomized placebo-controlled trial.
Increased vaccine doses and mid-season boosting may increase the proportion of residents with protective immunity from influenza in long-term care facilities. In a multi-center study (1997-1998), 815 residents from 14 long-term care facilities were assigned at random to receive 15 or 30 microg of inactivated influenza vaccine, followed by a 15 microg booster vaccine or a placebo vaccine at Day 84. Seroresponses were re-analyzed by hemagglutination-inhibition (> or =4-fold titer increases, protective titer > or =40, geometric mean titers. ⋯ Booster vaccination after an initial 15 microg dose of the vaccine did not increase the protective rate (61.9% vs. 63.9% after placebo). The number of participants needed to vaccinate to protect one additional resident by a dose of 15 microg was 4, by a dose of 30 microg 3, and 15 when using a 30 microg dose instead of 15 microg. Doubling the dose of influenza vaccine increased protection-related responses among residents of long-term care facilities, especially in those with low pre-vaccination titers.