Viral agents causing lower respiratory tract infections in hospitalized children: evaluation of the Speed-Oligo® RSV assay for the detection of respiratory syncytial virus.

Respiratory syncytial virus (RSV) is the viral agent which is more frequently involved in lower respiratory tract infections (LRTIs) in infants under 1 year of age in developed countries. A new oligochromatographic assay, Speed-Oligo® RSV, was designed and optimized for the specific detection and identification of RSV subtypes A and B. The test was evaluated in 289 clinical samples from 169 hospitalized children using an immunochromatography (IC) test, virus isolation by culture, and an in-house real-time polymerase chain reaction (RT-PCR). Other viruses causing LRTIs were investigated by cell culture or PCR-based tests. Sixty-two patients were infected by RSV (36.7%). In addition, adenovirus, influenza B, parainfluenza 2, and human metapneumovirus were detected in rates ranging from 5 to 8%. A proportion of 10.1% of the patients had mixed infections. The sensitivity, specificity, and positive and negative predictive values were, respectively, 94.9, 99.4, 98.9, and 97.4% for Speed-Oligo® RSV, 92.9, 96.3, 92.9, and 96.3% for RT-PCR/RSV, and 58.4, 98.1, 93.3, and 82.6% for IC. Our rates of viral detection and co-infection were similar to those of previously reported series. Finally, we find that Speed-Oligo® RSV is a rapid and easy-to-perform technique for the detection of RSV and the identification of subtypes A and B.

[Tick-borne recurrent fever. Description of 5 cases]. / Fiebre recurrente transmitida por garrapatas. Descripción de 5 casos.

BACKGROUND: Tick-borne relapsing fever (FRGT) is a worldwide zoonosis. The disease is caused by spirochetes of the genus Borrelia, and is transmitted to man by ticks of the genus Ornithodoros (O. erraticus in Spain). METHODS: 5 FRTG cases attended in our hospital in a 2 years period are described. Diagnosis was established in all cases by demonstration of borreliae in peripheral blood. Three Borrelia strains were isolated from blood of 3 of our patients and they are maintained by passages through mice. RESULTS: High fever, tachycardia and headache were noted in all cases accompanied in 2 of them by hepatosplenomegaly. Three of the patients complained of arthromyalgias or lumbar myalgia. Treatment with doxycicline was curative in all of them. CONCLUSIONS: FRGT incidence in our country is probably underestimated due to the low suspicion of the disease and the specificity of the clinical symptoms. The isolement of the causative Borrelia strain will allow the development of more specific serological tests necessary to establish the prevalence of this disease as well to assess its implication in chronic diseases, as is observed in other borreliosis (i.e. Lyme disease), that might be missed at this moment.

A new Borrelia species isolated from patients with relapsing fever in Spain.

BACKGROUND: Lyme disease and tick-borne relapsing fever are worldwide systemic borrelioses caused by several Borrelia species transmitted by hard ticks (family Ixodidae) and soft ticks (family Argasidae), respectively. A previous seroepidemiological study of Lyme borreliosis showed several serologically reactive patients with clinically atypical presentations, and this discovery led to the hypothesis that some of the cases of Lyme borreliosis had been caused by another borrelia organism. METHODS: Blood from patients in southern Spain who had suspected Lyme disease or relapsing-fever borreliosis was cultured before treatment began. Isolates of Borrelia spp were inoculated into several strains of mice of different ages. The 16S rRNA and flagellin in genes of Borrelia spp were sequenced by PCR and assessed by phylogenetic analyses. FINDINGS: We isolated a species of Borrelia from three patients with relapsing fever and from Ornithodorus spp ticks in southern Spain. This organism (refractory to in-vitro cultivation) caused a relapsing spirochaetaemia with multiple organ involvement in laboratory mice that recreated the human disease. Phylogenetic analysis showed that this organism is a previously unrecognised species. INTERPRETATION: We have discovered a new borrelia pathogen that is closely related to the other tick-borne agents of relapsing fever in Europe and Africa, and which causes a relapsing systemic disease with serological similarities to Lyme borreliosis.