Purpose of review Climate change, deforestation, urbanization, and increased population mobility have made the risk of large outbreaks of yellow fever more likely than ever. Yellow fever vaccine... Show morePurpose of review Climate change, deforestation, urbanization, and increased population mobility have made the risk of large outbreaks of yellow fever more likely than ever. Yellow fever vaccine production barely meets demands. In this review, we address the causes of the recent yellow fever outbreaks, why fractional dose yellow fever vaccination works, the role of virus neutralizing antibodies in the protection against yellow fever, and the need for revaccination. Recent findings Human activities have profoundly changed the epidemiology of yellow fever. The excess of infectious viral particles in routine yellow fever vaccine batches allows for off-label use of fractional dose yellow fever vaccination in response to emergency situations. Two studies have confirmed long-term protection after fractional dose yellow fever vaccination. The need for the presence of virus neutralizing antibodies (VNA) to protect an individual against yellow fever depends on the epidemiological setting. In case of sylvatic transmission, population immunity is irrelevant for individual protection, as mosquitoes are transmitting the virus from infected nonhuman primates to human. With the growing connectivity through air travel, countries with high densities of nonimmune populations and of the urban mosquito vector, Aedes aegypti, should ensure that their citizens are properly vaccinated against yellow fever before traveling to a yellow fever endemic country. In the situation of sylvatic transmission, the presence of protective levels of VNA will determine the outcome and may require revaccination at some point in time. Show less
Stalenhoef, J.E.; Dissel, J.T. van; Nieuwkoop, C. van 2015
Purpose of review To update the reader on the latest developments in the laboratory diagnosis of intestinal protozoa. Recent findings Correct identification of a diarrhoea causing pathogens is... Show morePurpose of review To update the reader on the latest developments in the laboratory diagnosis of intestinal protozoa. Recent findings Correct identification of a diarrhoea causing pathogens is essential for the choice of treatment in an individual patient as well as to map the aetiology of diarrhoea in a variety of patient populations. Classical diagnosis of diarrhoea causing protozoa by microscopic examination of a stool sample lacks both sensitivity and specificity. Alternative diagnostic platforms are discussed. Summary Recent literature on the diagnosis of intestinal protozoa has focused mainly on nucleic acid-based assays, in particular the specific detection of parasite DNA in stool samples using real-time PCR. In addition, the trend has been moving from single pathogen detection to a multiplex approach, allowing simultaneous identification of multiple parasites. Different combinations of targets can be used within a routine diagnostic setting, depending on the patient population, such as children, immunocompromised individuals and those who have been travelling to tropical regions. Large-scale monitoring and evaluation of control strategies become feasible due to automation and high-throughput facilities. Improved technology also has become available for differentiating protozoa subspecies, which facilitates outbreak investigations and extensive research in molecular epidemiology. Show less
