Chikungunya virus outbreak in Sint Maarten: Long-term arthralgia after a 15-month period.

BACKGROUND & OBJECTIVES: The first chikungunya (CHIK) epidemic in the Americas was reported in December 2013. Chikungunya virus (CHIKV) causes an acute febrile illness and is transmitted to humans by Aedes mosquitoes. Although earlier studies have described long-term clinical manifestations of CHIK patients infected with the East/Central/South African (ECSA) genotype, little is known about persistent manifestations in the Caribbean region, for which the Asian genotype is responsible. The objective of this study was to describe the presence of persisting clinical manifestations, specifically arthralgia, in CHIKV-infected patients on the Caribbean Island, Sint Maarten, 15 months after onset of the disease. METHODS: This retrospective cohort study included confirmed CHIK patients that were recorded by the participating general practitioners (GPs) during the chikungunya outbreak in 2014 in Sint Maarten. Between March and July 2015, 15 months after the onset of disease, patients were interviewed via telephone about the presence, duration and impact of clinical CHIKV manifestations. RESULTS: In total, 56 patients were interviewed (median age 47 yr), of which 30 (54%) were females. Out of the total interviewed patients, 52 (93%) reported arthralgia for the first three months after the disease onset, of which 23 (44%) patients reported to have persistent arthralgia, 15 months after the disease onset. Pain intensity of persistent arthralgia was perceived as mild in the majority of patients (n = 14; 60%), moderate in 7 (30%) patients and severe in 2 (9%) patients. During the acute phase of disease, most patients had to miss school or work (n = 39; 72%) due to clinical CHIKV manifestations and reported a negative impact on daily activities (n = 36; 57%). INTERPRETATION & CONCLUSION: Results suggested that persisting arthralgia is a frequent complication in CHIK patients included in the study. Future research on strain-specific clinical long-term manifestations and on their impact on daily life of patients, in the form of a comparative study between patients and controls, is recommended.

Infection risks of city canal swimming events in the Netherlands in 2016.

INTRODUCTION: Swimming events in city canals are gaining popularity in the Netherlands, even though canal water is usually not officially designated for recreational use. Knowledge regarding the risk of infection after swimming in canals is limited. An outbreak was reported in 2015 following a canal swimming event in Utrecht, the Netherlands. Local governments were concerned about the health risks of such events. In order to assess the safety of canal swimming, the Public Health Service (PHS) prospectively investigated two city canal swimming events in 2015. In 2016, we repeated this study, aiming to prospectively determine the risks of infection during two urban swimming events, the Utrecht SingelSwim 2016 (USS) and the Amsterdam City Swim 2016 (ACS). METHODS: We sent online questionnaires to 271 USS participants and 2697 ACS participants, concerning personal characteristics, symptoms, and exposure. Participants were asked to forward the questionnaire to three relatives, i.e., non-exposed. We analyzed water samples from the USS venue taken during the event, as well as stool samples of USS participants with acute gastrointestinal illness (AGI). AGI was defined as diarrhea and/or vomiting within seven days after the event. We calculated adjusted risk ratios (RR) for AGI in the exposed group compared with non-exposed respondents, using binomial regression models. RESULTS: The questionnaire was returned by 160 USS participants (exposed) (59%) and 40 non-exposed relatives. Five percent of the exposed (n = 17) and 3% of non-exposed (n = 1) reported AGI (RR = 1.69; 95% CI: 0.23-12.46). Norovirus genogroup II was detected in two of six USS water samples and in none of the three stool samples. In one of three stool samples, rotavirus was detected. The questionnaire was returned by 1169 ACS participants (exposed) (43%) and 410 non-exposed relatives. Six percent of the exposed (n = 71) and 1% of non-exposed (n = 5) reported AGI (RR 4.86; 95% CI: 1.98-11.97). CONCLUSION: Results of the ACS event showed a higher risk for AGI among the exposed, indicating that participants of events in urban canals in the Netherlands could be at a higher risk for AGI than those not participating. The inconclusive results from the USS are likely due to the small sample size. Swimming in non-monitored open water can bring health risks and more knowledge about environmental and human risk factors helps reduce the risk by being able to more specifically advise organizations and governments.

[Tularaemia in a boy following participation in a mud race]. / Een jongen met tularemie na een modderrace.

BACKGROUND: Tularaemia is a rare disease. In Europe it mostly occurs in Scandinavia. Since 2011 more cases are being reported in the Netherlands. Tularaemia may manifest itself in various ways. It is important to take strict precautions during biopsy, drainage and biopsy processing in order to prevent transmission. CASE DESCRIPTION: A 10-year-old boy presented to the paediatrician with a left inguinal lymphadenitis. A week before the onset of symptoms he had participated in a children's mud race. Serology and PCR of pus from the lymph node tested positive for Francisella tularensis. Treatment with ciprofloxacin was insufficiently effective, so surgical drainage of the gland was performed under strict isolation conditions. Water from the mud race location contained genetic material from F. tularensis. CONCLUSION: Given the rising incidence of tularaemia in the Netherlands, it is important to consider 'tularaemia' in the differential diagnosis in patients with lymphadenitis and epidemiological clues in their case history. Since 1 November 2016 it has been mandatory to report tularaemia in the Netherlands.

[When should notification of an infectious disease be mandatory? A decision aid to determine whether mandatory notification is justified]. / Wanneer meldingsplicht voor een infectieziekte? Een beslishulp om te bepalen of meldingsplicht nodig is.

In the Netherlands, all physicians are required to report cases of certain infectious diseases to the public health services, to allow appropriate control measures. In recent years, various requests have been submitted to add certain infectious diseases to the list of notifiable diseases. In order to decide whether such a request should be granted, we developed a structured decision aid based on a range of existing criteria for mandatory notification, applied in the Netherlands and other countries. In this article, we describe the development of this decision aid and illustrate its use in the mandatory notification application reviews for Vibrio vulnificus infection and tularaemia respectively. Based on the decision aid outcomes, mandatory notification for V. vulnificus infection was advised as not necessary whereas notification is considered mandatory for tularaemia.

Use of PCR for detection of faecal HAV as a screening tool in an outbreak of hepatitis A in daycare centres.

Using polymerase chain reaction (PCR) to detect faecal hepatitis A virus (HAV) can be a useful tool for investigating HAV outbreaks, especially in low-endemic countries. We describe the use of faecal HAV PCR as a non-invasive tool for screening. Two Dutch children visiting different daycare centres were diagnosed with hepatitis A in 2011. A systematic contact investigation was started in the daycare centres and relevant contacts were screened. The faecal HAV PCR test was used to screen the children. The employees were screened with a serum IgM. The faecal HAV PCR test proved to be an appropriate tool for screening. The screening of a total of 135 children and employees in the daycare centres resulted in evidence of eight asymptomatic infections and transmission to three related daycare centres. Control measures were taken including immunization. Compared to an epidemiological investigation without screening, 144 extra contacts were vaccinated based on the screening results. This most likely led to improved prevention of expansion of the outbreak.

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.