Notification data and criteria during a large Q-fever epidemic reassessed.

From 2007 to 2010, the largest reported Q-fever epidemic occurred in the Netherlands with 4026 notified laboratory-confirmed cases. During the course of the epidemic, health-seeking behaviour changed and awareness among health professionals increased. Changes in laboratory workflows were implemented. The aim of this study was to analyse how these changes instigated adjustments of notification criteria and how these adjustments affected the monitoring and interpretation of the epidemic. We used the articles on laboratory procedures related to the epidemic and a description of the changes that were made to the notification criteria. We compared the output of a regional laboratory with notifications to the regional Public Health Service and the national register of infectious diseases. We compared the international notification criteria for acute Q-fever. Screening with ELISA IgM phase II and PCR was added to the diagnostic workflow. In the course of the epidemic, serology often revealed a positive IgG/IgM result although cases were not infected recently. With increasing background seroprevalence, the presence of IgM antibodies can only be suggestive for acute Q-fever and has to be confirmed either by seroconversion of IgG or a positive PCR result. Differences in sero-epidemiology make it unlikely that full harmonisation of notification criteria between countries is feasible.

The health status of a village population, 7 years after a major Q fever outbreak.

From 2007 to 2010, The Netherlands experienced a major Q fever outbreak with more than 4000 notifications. Previous studies suggested that Q fever patients could suffer long-term post-infection health impairments, especially fatigue. Our objective was to assess the Coxiella burnetii antibody prevalence and health status including fatigue, and assess their interrelationship in Herpen, a high-incidence village, 7 years after the outbreak began. In 2014, we invited all 2161 adult inhabitants for a questionnaire and a C. burnetii indirect fluorescence antibody assay (IFA). The health status was measured with the Nijmegen Clinical Screening Instrument (NCSI), consisting of eight subdomains including fatigue. Of the 70·1% (1517/2161) participants, 33·8% (513/1517) were IFA positive. Of 147 participants who were IFA positive in 2007, 25 (17%) seroreverted and were now IFA negative. Not positive IFA status, but age <50 years, smoking and co-morbidity, were independent risk factors for fatigue. Notified participants reported significantly more often fatigue (31/49, 63%) than non-notified IFA-positive participants (150/451, 33%). Although fatigue is a common sequel after acute Q fever, in this community-based survey we found no difference in fatigue levels between participants with and without C. burnetii antibodies.

Severely impaired health status of non-notified Q fever patients leads to an underestimation of the true burden of disease.

Q fever patients are often reported to experience a long-term impaired health status, including fatigue, which can persist for many years. During the large Q fever epidemic in The Netherlands, many patients with a laboratory-confirmed Coxiella burnetii infection were not notified as acute Q fever because they did not fulfil the clinical criteria of the acute Q fever case definition (fever, pneumonia and/or hepatitis). Our study assessed and compared the long-term health status of notified and non-notified Q fever patients at 4 years after onset of illness, using the Nijmegen Clinical Screening Instrument (NCSI). The study included 448 notified and 193 non-notified Q fever patients. The most severely affected subdomain in both patient groups was 'Fatigue' (50·5% of the notified and 54·6% of the non-notified patients had severe fatigue). Long-term health status did not differ significantly between the notified and non-notified patient groups, and patients scored worse on all subdomains compared to a healthy reference group. Our findings suggest that the magnitude of the 2007-2009 Q fever outbreak in The Netherlands was underestimated when only notified patients according to the European Union case definition are considered.

Antibiotic therapy for acute Q fever in The Netherlands in 2007 and 2008 and its relation to hospitalization.

Data about the effectiveness of different antibiotic regimens for the treatment of acute Q fever from clinical studies is scarce. We analysed the antibiotic treatment regimens of acute Q fever patients in 2007 and 2008 in The Netherlands and assessed whether hospitalization after a minimum of 2 days antibiotic therapy was related to the initial antibiotic therapy. Clinical data on antibiotic treatment and risk factors of acute Q fever patients were obtained from general practitioner medical records and self-reported by patients. For the 438 study patients, doxycycline was the most commonly prescribed initial antibiotic in both study years. After adjustments for confounding factors, doxycycline (200 mg/day), moxifloxacin, as well as other possibly effective antibiotics [including other new fluoroquinolones and doxycycline (100 mg/day)] showed significant lower risks for hospitalization compared to ß-lactam antibiotics and azithromycin (reference group), with the lowest risk for doxycycline (200 mg/day) (odds ratio 0·04, 95% confidence interval 0·01-0·22). These data support current guidelines that recommend doxycycline as the first choice antibiotic for treating acute Q fever.

Norovirus outbreaks in nursing homes: the evaluation of infection control measures.

Effective infection control measures during norovirus outbreaks are urgently needed in places where vulnerable individuals gather. In the present study, the effect of a number of measures was investigated in daily practice. Forty-nine Dutch nursing homes were monitored prospectively for norovirus outbreaks during two winter seasons. A total of 37 norovirus outbreaks were registered. Control measures were most effective when implemented within 3 days after onset of disease of the first patient. Measures targeted at reduced transmission between persons, via aerosols, and via contaminated surfaces reduced illness in staff and in residents. Reducing illness in staff results in fewer costs for sick leave and substitution of staff and less disruption in the care of residents. The effect of control measures on outbreak duration was limited. This is the first intervention study examining the effect of control measures. Further research is needed to extend and refine the conclusions.

[Fish-caused illness: notify food-related outbreaks to the Municipal Health Services]. / Ziek door vis.

BACKGROUND: When two or more people fall ill after eating the same food, this is called an outbreak of food poisoning or food-related infection. In the Netherlands, physicians have to notify the Municipal Health Services (GGD) of such outbreaks. The GGD informs the Netherlands Food and Consumer Product Safety Authority (NVWA). CASE DESCRIPTION: Two clusters of scombroid poisoning (histamine poisoning in this case after eating tuna) occurred in one month. Due to the quick reporting of patients by physicians, the GGD and the NVWA immediately tracked down the source. In both clusters the NVWA confirmed high histamine levels in tuna. In reaction to these findings and the first cluster, the supplier recalled the tuna batch. This may have prevented other cases of food poisoning. In the second cluster, the implicated tuna batch had already been sold. CONCLUSION: Timely notification by physicians of food poisoning or food-related outbreaks to the GGD enables swift tracing of the source and appropriate measures by the GGD and the NVWA..

[An outbreak of Q fever in The Netherlands--possible link to goats]. / Een uitbraak van Q-koorts in Nederland--mogelijk verband met geiten.

In 2007, 73 cases of Q fever were identified through reports and retrospective analyses; the affected region extended from Tilburg in the southwest to Arnhem in the northeast. The infections arose in late spring, particularly in May and June. Several spontaneous abortions due to Q fever occurred on 4 dairy goat farms in the same region. The national incidence of spontaneous abortion due to Q fever was 6 cases in 2006 and 7 in 2007. Climatically, this southern region was extraordinarily dry during April 2007. All pregnant women from a small region with the highest incidence in northeast North Brabant were called for diagnostic testing. Infected patients were followed for symptoms and ultrasound was performed as indicated. A definitive source of the infection could not yet be identified. Favourable climatic conditions were suspected as the cause for the combination of widespread dissemination among goats and transmission to humans. Q fever is a zoonosis caused by Coxiella burnetti, a microorganism dispersed in great numbers in the area in which an infected animal gives birth. C. burnetti is particularly resistant to chemical and physical factors and can disperse by air across large distances under dry climatic conditions. Q fever should be considered in patients in The Netherlands who present with lower airway infection and, in rare cases, hepatitis. Reporting atypical clusters ofpneumonia to the Municipal Health Service (GGD) is advisable. The GGD maintains close contact with Animal Health Services, which is aware of current infectious animal diseases. Targeted investigation can identify the source of infection and eliminate it. Greater awareness can prevent delays in diagnosis and treatment and help identify chronic forms at an early stage or prevent them.

[Two patients with Hantavirus infection in The Netherlands; substantial increase in incidence in neighbouring countries]. / Twee patiënten met een Hantavirus-infectie in Nederland; sterke toename van de incidentie in de ons omringende landen.

A 12-year-old girl and a 57-year-old woman were admitted with fever, general malaise, abdominal pain, nausea and vomiting. Both patients had acute renal insufficiency based on tubulointerstitial nephritis caused by the genus Hantavirus, which was confirmed by blood tests. Both patients recovered spontaneously. The neighbouring countries of France, Germany and Belgium have recently reported 2- to 7-fold increases in the number of Hantavirus infections. Hantavirus is a zoonotic viral disease that is transmitted by mice and is found in humans worldwide. Infection with Hantavirus is associated with severe renal impairment and thrombocytopenia, which usually resolves spontaneously. Recognition of the clinical signs and targeted serological testing can lead to adequate management of the disease. Diagnosing patients with Hantavirus infections will also help to prevent infections in The Netherlands and track epidemiological changes.