Search

Epidemiological differences between tropical and temperate regions regarding viruses causing acute respiratory infection are poorly understood. This is in part because methodological differences limit the comparability of data from these two regions. Using identical molecular detection methods, we tested 1174 Ghanaian and 539 German children with acute respiratory infections sampled over 12 months for the 15 most common respiratory viruses by PCR. A total 43.2% of the Ghanaian and 56.6% of the German children tested positive for at least one respiratory virus. The pneumoviruses respiratory syncytial virus and human metapneumovirus were most frequently detected, in 13.1% and 25.1% within the Ghanaian and German children, respectively. At both study sites, pneumoviruses were more often observed at younger ages (p <0.001). In the Ghanaian rainy season, enveloped viruses were detected twice as often as non-enveloped viruses (prevalence rate ratio (PR) 2.0, 95% CI 1.7–2.4). In contrast, non-enveloped viruses were more frequent during the Ghanaian dry season (PR 0.6, 95% CI 0.4–0.8). In Germany, enveloped viruses were also more frequently detected during the relatively colder winter season (PR 1.6, 95% CI 1.2–2.1) and non-enveloped viruses during summer (PR 0.7, 95% CI 0.5–0.9). Despite a distance of about 5000 km and a difference of 44° latitude separating Germany and Ghana, virus spectra, age associations and seasonal fluctuation showed similarities between sites. Neither respiratory viruses overall, nor environmentally stable (non-enveloped) viruses in particular were more frequent in tropical Ghana. The standardization of our sampling and laboratory testing revealed similarities in acute respiratory infection virus patterns in tropical and temperate climates. [ABSTRACT FROM AUTHOR]

Background: In a substantial proportion of respiratory tract diseases of suspected infectious origin, the etiology is unknown. Some of these cases may be caused by the recently described human bocavirus (hBoV). The aim of this study was to investigate the frequency and the potential clinical relevance of hBoV in pediatric patients. Methods: We tested 835 nasopharyngeal aspirates (NPA) obtained between 2002 and 2005 from pediatric in-patients with acute respiratory tract diseases at the University of Würzburg, Germany, for the presence of hBoV DNA. The specificity of positive PCR reactions was confirmed by sequencing. Results: HBoV DNA was found in 87 (10.3 %) of the NPAs. The median age of the infants and children with hBoV infection was 1.8 years (mean age 2.0 years; range 18 days - 8 years). Infections with hBoV were found year-round, though most occurred in the winter months. Coinfections were found in 34 (39.1 %) of the hBoV positive samples. RSV, influenza A, and adenoviruses were most frequently detected as coinfecting agents. Sequence determination of the PCR products in the NP-1 region revealed high identity (99 %) between the nucleotide sequences obtained in different years and in comparison to the Swedish viruses ST1 and ST2. An association of hBoV with a distinct respiratory tract manifestation was not apparent. Conclusion: HBoV is frequently found in NPAs of hospitalized infants and children with acute respiratory tract diseases. Proving the clinical relevance of hBoV is challenging, because application of some of Koch's revised postulates is not possible. Because of the high rate of coinfections with hBoV and other respiratory tract pathogens, an association between hBoV and respiratory tract diseases remains unproven. [ABSTRACT FROM AUTHOR]