Epidemiological and phylogenic study of human metapneumovirus infections during three consecutive outbreaks in Normandy, France.

Human metapneumovirus (hMPV) is responsible for respiratory tract disease, particularly in the young and elderly population. An epidemiological and phylogenic study was performed on children admitted to hospital with an acute lower respiratory tract infection (LRI). Data were obtained and analyzed over three consecutive winters, from 2002-2003 to 2004-2005. Each year during the winter period, from November to March, 2,415 nasal swabs were tested by a direct immunofluorescence assay (DFA) for influenza viruses A and B, respiratory syncytial virus, parainfluenza viruses, and adenoviruses. Rhinoviruses, enteroviruses, and coronaviruses OC43 and 229E were detected by RT-PCR. A RT-PCR designed for the M gene was performed on negative samples for hMPV detection and phylogenic analyses. For the three consecutive winters, hMPV represented 10%, 22.6%, and 8.8% of virus-negative samples, respectively. In most cases, clinical symptoms indicated a LRI with a final diagnosis of bronchiolitis. During the winter of 2003-2004, all viral clusters (A1, A2, B1, and B2) that circulated in France shifted progressively from the A group to the B group. This study determined the prevalence of hMPV in Normandy, its clinical impact and permitted the analysis of the molecular evolution during the successive outbreaks.

Human (non-severe acute respiratory syndrome) coronavirus infections in hospitalised children in France.

AIM: This study has two objectives: to study the clinical symptoms associated with the detection of the four human coronaviruses (HCoVs), 229E, OC43, NL63 and HKU1 types, in the respiratory specimens sampled from hospitalised children in France between September 2004 and May 2005; and to develop a multiplex reverse transcription polymerase chain reaction (RT-PCR) assay allowing for the simultaneous detection of the four HCoVs. METHODS: 1002 respiratory specimens were tested for HCoVs. The clinical and epidemiological data were compared on the basis of the type HCoV infection. RESULTS: A hundred coronaviruses, 33 NL63, 2229E, 27 OC43 and 38 HKU1, were detected in 97 (9.8%) of 1002 samples negative in routine tests. The clinical and epidemiological characteristics of the study children were compared in three groups, 24 OC43-, 27 NL63- and 34 HKU1-infected children. HCoVs were identified mainly in children with upper and lower respiratory tract infections (50.5% vs. 29.4%). The significant difference in clinical presentation between the three coronavirus groups was the very low association between lower respiratory tract illness and HKU1 detection. CONCLUSIONS: HCoV detection in hospitalised children without any other respiratory virus detection was associated with upper and a significant rate of lower respiratory tract illness. The four types of HCoVs were detected, and new types NL63 and HKU1 represented a substantial portion of detection. The multiplex RT-PCR enabled a sensitive one-time detection and the characterisation of all of the known HCoV types with the exception severe acute respiratory syndrome-coronavirus.