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.

[Imported Zika virus infection in the Netherlands]. / Import van zikavirus-infectie in Nederland.

Since mid-2015, a rapidly expanding outbreak of Zika virus infection is spreading across Latin America and the Caribbean. Although Zika virus infection usually causes only mild disease, the World Health Organization has declared the epidemiological association with the occurrence of congenital microcephaly and neurological complications a 'Public Health Emergency of International Concern' and urged the international community to mount a coordinated international response aimed to protect people at risk, especially pregnant women. In December 2015, the first case of imported Zika virus infection in the Netherlands was diagnosed in a returned traveler from Surinam. To date, more than 20 cases have been reported in The Netherlands, all imported from Surinam. We describe the epidemiology, clinical aspects, diagnostic challenges and the existing evidence to date that link Zika virus infection to complications.

Outbreak of Salmonella Thompson in the Netherlands since July 2012.

An ongoing outbreak of salmonellosis due to Salmonella Thompson is affecting the Netherlands. Between 2 August and 19 October 2012, 866 cases were confirmed. Their median age was 44 years (range: 0-95 years), 63% were female and 36% were hospitalised. A matched case-control study suggested smoked salmon as the vehicle. Salmonella Thompson was confirmed in four of nine batches of smoked salmon from one producer. A recall of all concerned smoked salmon products was executed starting end of September.

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.

[Measles epidemic in the Netherlands, 1999-2000]. / Mazelenepidemie in Nederland, 1999-2000.

OBJECTIVE: Description of measles epidemic in the Netherlands, 1999-2000. DESIGN: Observational descriptive study. METHODS: Intensified surveillance of measles cases by means of a case register established at the 'Landelijke Coördinatiestructuur Infectieziektebestrijding (LCI)' [National Co-ordination Centre for Communicable Disease Outbreak Management]. RESULTS: There were 3,292 reported measles patients, most of whom came from areas with low vaccine coverage. Of these patients, 94% had not been vaccinated; in 85% of cases this was for religious reasons. Of the 158 (5%) vaccinated patients, 157 had not (yet) received a second dose of vaccine. The incidence of measles increased with decreasing vaccine coverage in a municipality, both for unvaccinated and vaccinated persons. Three of the reported patients died. The percentage of patients with one or more complications was 22% in the group < 15 months of age, 19% in the group 15 months-4 years, 16% in the group 5-9 years, 11% in the group 10-19 years, and 15% in the group > 19 years of age. CONCLUSION: Considering the complications observed, the epidemic described involved a serious disease. Vaccination was accompanied by effective protection against measles infection and its complications. Herd immunity outside the unvaccinated groups was sufficient to prevent an epidemic there. However, incidental spread to vaccinated children did occur; the greatest risk factor for acquiring measles for vaccinated children is a stay in an area with low vaccine coverage.

Four cases of hemolytic uremic syndrome--source contaminated swimming water?

In June '93, 4 children, aged 1.5-3.5 years, all living in one town, were admitted to our hospital with the diagnosis hemolytic uremic syndrome (HUS) within one week. In cooperation with the local health authorities a common source was searched for. Questionnaires indicated that the single condition shared by all patients was swimming water. The patients were not acquainted, visited different daycares, and had no food resources in common. All 4 patients bathed in the same, shallow, recreational lake within a period of 5 days. During this time the air temperature was high according to Dutch standards (around 27 degrees C), and many people visited the lake, estimated several hundreds a day. The water level was lower than normal. Diarrhea followed 3-11 days after swimming and the first clinical symptoms of HUS developed 6-7 days after the onset of diarrhea. The lake was closed for swimming when the fourth HUS patient was diagnosed and the possibility of transmission by way of the lake was mentioned. E. coli O157: H7 was demonstrated in the fecal samples of 2 index patients. The samples were taken 9-20 days after the start of diarrhea. Antibodies to O157 and verotoxin 2 were strongly positive in all patients. A local outbreak of diarrheal illness was not registered. Of 16 family members who also swam in the same lake, 7 developed symptoms of enteritis, 3 had positive cultures of their fecal samples and 5 had positive serology. Pulsed-field gel electrophoresis of the E. coli isolates of the patients and family members showed an identical pattern. No O157: H7-DNA could be detected in filter concentrated lake water samples using polymerase chain reaction (PCR) enhancement. These samples were, however, taken 16 days after the latest possible date of contamination of our patients, 15 days after decrease of the air temperature to 15-17 degrees C, and 14 days after the inlet from water from the environment. It could thus very well be that the microorganism was no longer present. This third report of swimming water associated HUS should direct environmental surveys in similar cases of local HUS outbreaks.

Response to a suspected case of diphtheria in Dordrecht, the Netherlands.

About 50 of the refugees in Dordrecht are from the Newly Independent States (NIS) of the former USSR, where diphtheria is rife. Cases have arisen in western Europe through contact with cases from the NIS. No NIS-related cases of diphtheria have been seen