Relation between Q fever notifications and Coxiella burnetii infections during the 2009 outbreak in The Netherlands.

Large outbreaks of Q fever in the Netherlands from 2007 to 2009 were monitored using notification data of acute clinical Q fever. However, the notification system provides no information on infections that remain subclinical or for which no medical attention is sought. The present study was carried out immediately after the peak of the 2009 outbreak to estimate the ratio between Coxiella burnetii infections and Q fever notifications. In 23 postcode areas in the high-incidence area, notification rates were compared with seroconversion rates in blood donors from whom serial samples were available. This resulted in a ratio of one Q fever notification to 12.6 incident infections of C. burnetii. This ratio is time and place specific and is based on a small number of seroconversions, but is the best available factor for estimating the total number of infections. In addition, as subclinical C. burnetii infection may lead to chronic Q fever, the ratio can be used to estimate the expected number of chronic Q fever patients in the coming years and as input for cost­benefit analyses of screening options.

Shifting priorities in the aftermath of a Q fever epidemic in 2007 to 2009 in The Netherlands: from acute to chronic infection.

From 2007 to 2009, the Netherlands faced large seasonal outbreaks of Q fever, in which infected dairy goat farms were identified as the primary sources. Veterinary measures including vaccination of goats and sheep and culling of pregnant animals on infected farms seem to have brought the Q fever problem under control. However, the epidemic is expected to result in more cases of chronic Q fever among risk groups in the coming years. In the most affected area, in the south of the country, more than 12% of the population now have antibodies against Coxiella burnetii. Questions remain about the follow-up of acute Q fever patients, screening of groups at risk for chronic Q fever, screening of donors of blood and tissue, and human vaccination. There is a considerable ongoing research effort as well as enhanced veterinary and human surveillance.

[The molecular epidemiology of hepatitis A in The Netherlands; the usefulness of typing isolated viral strains]. / Moleculaire epidemiologie van hepatitis A in Nederland; het nut van het typeren van geïsoleerde virusstammen.

OBJECTIVE: To investigate the epidemiological links between several outbreaks of hepatitis A in The Netherlands (2001-2004). DESIGN: Descriptive. METHOD: Blood samples taken in connection with reports of hepatitis A to municipal health centres from 2001-2004, were typed by determining the nucleotide sequence of the VP3-VP1 and the VP1-P2A regions of the genome of the hepatitis A virus (HAV). Genetic distances were represented graphically by means of a phylogenetic tree. RESULTS: The study into the spread of various subtypes of HAV showed a clear link between the HAV-(sub)genotype and risk of transmission: in men that have sex with men only genotype 1A occurred, in travellers to African countries genotype 1B was predominantly seen. CONCLUSION: A database containing various viral strains from people with hepatitis A in The Netherlands could, if kept up to date, be used as an aid in confirming the classical way of tracing sources as well as for the evaluation of preventative measures.

[More and faster notification of infectious disease if notification is carried out by the laboratories instead of the diagnosing physician]. / Meer en snellere meldingen van infectieziekten bij melding door het laboratorium in plaats van door de diagnosticerend arts.

OBJECTIVE: To investigate if notification by the laboratories of a number of Group B diseases (meningococcal disease, whooping cough and hepatitis A) which according to the Communicable Disease Law of 999 must be reported to the local public health authority, would increase the number of reports and the speed at which the reports were made. DESIGN: Comparative study. METHOD: In the participating regions (Den Bosch and north-east Brabant) it was decided that the laboratories would notify the authorities of cases ofmeningococcal disease, whooping cough and hepatitis A. The notifications were compared with those from the middle-Brabant region which was used as a control. This took place in 1997/'98, prior to the start of the notification project and in 2000/'02 when it was running. The number of positive cases of infectious disease confirmed by the laboratories that were reported to the local health authorities and to the Inspectorate of Public Health Services was examined - this is known as the degree of notification. The number of days from diagnosis to notification of the local health authorities was also examined - this is known as the speed of notification. RESULTS: The degree of notification for these three diseases improved from 6I-89% to 87-95% if the authorities were notified by the laboratories. In the control region the degree of notification improved from 29-4I% to 54-60%. The speed of notification increased significantly if notification was done by the laboratories. CONCLUSION: Based on these results it is recommended that the Communicable Disease Law be adapted to allow the laboratories to notify the authorities of cases of infectious disease.

Molecular epidemiology of hepatitis A in Noord-Brabant, The Netherlands.

BACKGROUND: Previous studies on the molecular epidemiology of hepatitis A virus (HAV) in Amsterdam, The Netherlands, show that subgenotype 1A is mainly seen among homosexual men practising anonymous oral-anal sex in saunas and darkrooms, while subgenotype 1B is usually detected among children originating from Morocco, and subgenotype 3A is mostly found among travellers to Pakistan. OBJECTIVE: We studied the genotype distribution in a more rural area of The Netherlands, Noord-Brabant, and compared it with Amsterdam. STUDY DESIGN: We collected blood and feces samples from 34 HAV IgM(+) individuals who were reported from August 2001-March 2003 at the Municipal Health Service (MHS) Heart for Brabant (Brabant). We also collected feces samples from nine household contacts of whom the HAV IgM status was not known. HAV RNA was isolated and subsequently amplified by reverse transcriptase polymerase chain reaction (RT-PCR) at the VP1-P2a and the VP3-VP1 region, sequenced and analysed. RESULTS AND CONCLUSIONS: In most cases, relations between risk groups and HAV subgenotypes in Noord-Brabant were similar to those in Amsterdam. Next to genotypes 1 and 3 we also detected a genotype 2/7 strain in a Noord-Brabant case. Also, in contrast to the Amsterdam study, sporadic transmission occurred among various risk groups. Children involved in a school-related outbreak were infected with strains identical to one that was previously isolated from a man who has sex with men (MSM). Also, Dutch patients having no epidemiological link with Turkish or Moroccan children harboured strains imported from high-endemic countries. Furthermore, we report a special case in which HAV may be causally involved in meningitis. The results of this study show that the molecular epidemiology of HAV in The Netherlands can be more complicated than previously anticipated and that HAV phylogenetic studies can provide important information for the design of appropriate public health measures.