As a major foodborne pathogen, Campylobacter jejuni receives much attention in quantitative risk assessment. To date, all dose-response assessments have been based on a single human feeding study which unfortunately provides incomplete and possibly biased information on the dose-response relation. An incident at a dairy farm, where several children from a school class became ill as a result of drinking raw milk contaminated with C. jejuni, appeared to show a very clear dose-response relation between the amount of milk consumed and the attack rate. This relation was very nearly exponentially shaped and, therefore, seemed to conflict with the rather slowly rising dose-response relation established in the feeding study. Here we show that both datasets can be reconciled when illness and infection are considered separately. This not only provides new information on the illness dose-response relation for Campylobacter, but also amends the infection dose-response relation because of their conditional dependence.

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RESEARCH LETTERSteams are key mechanisms for helping public health authorities manage the COVID-19 crisis. Our findings revealed that the P.1 VOC was introduced into Uruguay multiple times over a period of increasing mobility in binational cities along the Brazil-Uruguay border and in Uruguay between mid-February and early March 2021. The introduction of the highly transmissible P.1 VOC coupled with the increasing human mobility probably contributed to the rapid local spread of this variant and the worsening COVID-19 epidemic in Uruguay during January-July 2021.

We evaluated different approaches for diagnosing measles virus (MV) infection in unvaccinated children and in healthy contact persons (n=194) during a measles epidemic in The Netherlands. MV RNA was detected by reverse-transcriptase polymerase chain reaction in throat-swab specimens from 93% of the patients with clinical symptoms. MV RNA was detected from 5 days before until 12 days after the onset of symptoms. Most patients (88%) also secreted MV RNA in their urine until 5 weeks after the onset of symptoms. Oral fluid proved to be the most practical specimen for the simultaneous detection of MV-specific IgM antibody and viral RNA, which, together, confirmed 93% of measles cases. Viral RNA was also detected in oropharyngeal specimens from 3 healthy contact persons with serological proof of MV infection. The results of this study emphasize the feasibility of combined detection of viral RNA and MV-specific IgM antibodies in oropharyngeal specimens for the diagnosis of clinical and subclinical MV infection.

, an increase in the number of Salmonella Thompson cases was noticed by the Salmonella surveillance in the Netherlands. A casecontrol study was performed, followed by a food investigation. In total 1,149 cases were laboratoryconfirmed between August and December 2012 of which four elderly (76-91 years) were reported to have died due to the infection. The cause of the outbreak was smoked salmon processed at a single site. The smoked salmon had been continuously contaminated in the processing lines through reusable dishes, which turned out to be porous and had become loaded with bacteria. This is the largest outbreak of salmonellosis ever recorded in the Netherlands. The temporary closure of the processing site and recall of the smoked salmon stopped the outbreak. An estimated four to six million Dutch residents were possibly exposed to the contaminated smoked salmon and an estimated 23,000 persons would have had acute gastroenteritis with S. Thompson during this outbreak. This outbreak showed that close collaboration between diagnostic laboratories, regional public health services, the national institute for public health and the food safety authorities is essential in outbreak investigations.