Virological NIVEL/RIVM surveillance of respiratory virus infections in the 1996/97 season
Bestebroer TM Bartelds AIM Peeters MF Andeweg AC Kerssens JJ Bijlsma K Rimmelzwaan GF Kimman TG Verweij C Jong JC de
Bestebroer TM
Bartelds AIM
Peeters MF
Andeweg AC
Kerssens JJ
Bijlsma K
Rimmelzwaan GF
Kimman TG
Verweij C
Jong JC de
Citations
Altmetric:
Series / Report no.
Open Access
Type
Report
Language
en
Date of publication
1999-02-18
Year of publication
Research Projects
Organizational Units
Journal Issue
Title
Virological NIVEL/RIVM surveillance of respiratory
virus infections in the 1996/97 season
Translated Title
Virologische NIVEL/RIVM-surveillance van
respiratoire virusinfecties in het seizoen 1996/97
Published in
Abstract
Het doel van de surveillance van respiratoire
virusinfecties van het Nederlands Instituut voor Onderzoek van de
Gezondheidszorg (NIVEL) en het Rijksinstituut voor Volksgezondheid en Milieu
(RIVM) - is het vaststellen van de incidentie van acute respiratoire
virusinfecties (ARI) bij patienten die hun huisarts raadplegen wegens een
ARI. Voor dit doel zenden huisartsen van het NIVEL-netwerk van
huisartspeilstations sinds het seizoen 1992/93 van een selectie van hun
ARI-patienten neus-keeluitstrijken naar het RIVM. Op het RIVM worden deze
onderzocht op de aanwezigheid van virussen door kweek en, in de seizoenen
1994/95 en 1996/97, ook door polymerase chain reaction (PCR)
detectie-methoden op bepaalde virussen, Mycoplasma pneumoniae of Chlamydia
pneumoniae. In 1996/97 werd een deel van de patienten tevens onderzocht op
conventionele bacterien.In 64% van de 540 onderzochte monsters werd een
virus (55%) of bacterie (16%) aangetoond. Het vaakst werd influenzavirus
(24%) aangetroffen, op de voet gevolgd door rhinovirus (22%). Evenals in
voorgaande jaren werd in september 1996 een verhoogd percentage positieve
monsters waargenomen. Deze verhoging viel samen met de aanvang van het
nieuwe schooljaar. De influenzaepidemie begon half december 1996 en was
normaal wat betreft omvang en duur. De epidemie begon met een golf van
influenza subtype A(H3N2), in de weken 4 - 9 gevolgd door een kleine,
overlappende golf van type B. Bij de huisartspatienten was 61% van de
isolaten subtype A(H3N2), bij de isolaten van de virusdiagnostische
laboratoria 88%. Dit verschil is een jaarlijks terugkerend verschijnsel en
waarschijnlijk het gevolg van de hogere pathogeniteit van subtype A(H3N2)
vergeleken met type B. Berekend over de seizoenen 1992/93 tot en met 1996/97
werd een influenza-virus gekweekt bij tenminste 26% van de IAZ geregistreerd
door het NIVEL. Over dezelfde periode ontwikkelde per seizoen gemiddeld
naar schatting 2.7% van de Nederlandse bevolking een IAZ veroorzaakt door
dit virus. Door de huisartsen van het NIVEL werd een IAZ het vaakst gezien
bij kinderen van 0-4 jaar oud. Na correctie voor het percentage monsters
waaruit een influenza-virus werd gekweekt en voor de fractie IAZ-patinten
die de huisarts raadpleegt blijkt echter dat de influenzaincidentie het
hoogst is bij 5-14 jarigen, nl 5,3%. Influenza kwam het meeste voor op het
- naar het volksgeloof zo "gezonde" - platteland. De noordelijke regio werd
het minst getroffen door deze ziekte.
The purpose of the Netherlands Institute of Primary Health Care (NIVEL)/National Institute of Public Health and the Environment (RIVM) surveillance is to establish the incidence of acute respiratory virus infections (ARI) in patients who consult their family doctor with ARI complaints. Since the 1992/93 season, the general practitioners (GPs) of the NIVEL network have been sending nose-throat swabs for this purpose from a selection of ARI patients to the RIVM. At the RIVM, these swabs were examined using virus culture, and in the 1994/95 and 1996/97 seasons, also polymerase chain reactions (PCR) for the detection of selected viruses, Mycoplasma pneumoniae (Mp) and Chlamydia pneumoniae (Cp). In the 1996/97 season, some of the patients were also examined for conventional bacteria. A potentially respiratory pathogenic agent was detected using culture and/or PCR in 64% of the 540 examined specimens. Viruses were found in 55% and conventional bacteria in 16% of the samples. Influenza virus, cultured from 24% of the samples, was the predominant virus, followed by rhinovirus (22%), respiratory syncytial (RS) virus (5%), and enterovirus (4%). As in previous years, a temporary increase in the rate of positive samples - especially those containing rhinoviruses - was noted in September, coinciding with the opening of schools at the end of August. In the Netherlands, the influenza epidemic of the 1996/97 season started in the second half of December and had the usual size and length. The epidemic began with a major wave of subtype A(H3N2) virus infections, followed by a small overlapping wave of type B virus infections in weeks 4 - 9. Sixty-one percent of the influenza viruses isolated from GP patients were H3N2, while 88% of those isolated in diagnostic laboratories were this subtype. In fact, this is a yearly recurring phenomenon and probably reflects the higher pathogenicity of subtype A(H3N2), compared with type B. Over the five seasons studied, influenza virus infections accounted for at least 26% of the ILI registered by NIVEL. Calculated over the same five seasons, an estimated 2.7% of the Dutch population developed per season an ILI caused by an influenza virus infection. According to the ILI registration, the highest incidence of ILI occurred among 0 to 4-year-old children. After correction for the influenza virus isolation rate and the fraction of ILI patients who consulted their GP, however, the highest incidence of influenza, 5.3%, occurred among the 5 to 14-year olds. Influenza occurred most frequently in the (according to popular belief 'healthy') countryside and least frequently in the northern region of the Netherlands.
The purpose of the Netherlands Institute of Primary Health Care (NIVEL)/National Institute of Public Health and the Environment (RIVM) surveillance is to establish the incidence of acute respiratory virus infections (ARI) in patients who consult their family doctor with ARI complaints. Since the 1992/93 season, the general practitioners (GPs) of the NIVEL network have been sending nose-throat swabs for this purpose from a selection of ARI patients to the RIVM. At the RIVM, these swabs were examined using virus culture, and in the 1994/95 and 1996/97 seasons, also polymerase chain reactions (PCR) for the detection of selected viruses, Mycoplasma pneumoniae (Mp) and Chlamydia pneumoniae (Cp). In the 1996/97 season, some of the patients were also examined for conventional bacteria. A potentially respiratory pathogenic agent was detected using culture and/or PCR in 64% of the 540 examined specimens. Viruses were found in 55% and conventional bacteria in 16% of the samples. Influenza virus, cultured from 24% of the samples, was the predominant virus, followed by rhinovirus (22%), respiratory syncytial (RS) virus (5%), and enterovirus (4%). As in previous years, a temporary increase in the rate of positive samples - especially those containing rhinoviruses - was noted in September, coinciding with the opening of schools at the end of August. In the Netherlands, the influenza epidemic of the 1996/97 season started in the second half of December and had the usual size and length. The epidemic began with a major wave of subtype A(H3N2) virus infections, followed by a small overlapping wave of type B virus infections in weeks 4 - 9. Sixty-one percent of the influenza viruses isolated from GP patients were H3N2, while 88% of those isolated in diagnostic laboratories were this subtype. In fact, this is a yearly recurring phenomenon and probably reflects the higher pathogenicity of subtype A(H3N2), compared with type B. Over the five seasons studied, influenza virus infections accounted for at least 26% of the ILI registered by NIVEL. Calculated over the same five seasons, an estimated 2.7% of the Dutch population developed per season an ILI caused by an influenza virus infection. According to the ILI registration, the highest incidence of ILI occurred among 0 to 4-year-old children. After correction for the influenza virus isolation rate and the fraction of ILI patients who consulted their GP, however, the highest incidence of influenza, 5.3%, occurred among the 5 to 14-year olds. Influenza occurred most frequently in the (according to popular belief 'healthy') countryside and least frequently in the northern region of the Netherlands.
Description
Publisher
Sponsors
IGZ