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.

Risk assessment of vector-borne diseases for public health governance.

OBJECTIVES: In the context of public health, risk governance (or risk analysis) is a framework for the assessment and subsequent management and/or control of the danger posed by an identified disease threat. Generic frameworks in which to carry out risk assessment have been developed by various agencies. These include monitoring, data collection, statistical analysis and dissemination. Due to the inherent complexity of disease systems, however, the generic approach must be modified for individual, disease-specific risk assessment frameworks. STUDY DESIGN: The analysis was based on the review of the current risk assessments of vector-borne diseases adopted by the main Public Health organisations (OIE, WHO, ECDC, FAO, CDC etc…). METHODS: Literature, legislation and statistical assessment of the risk analysis frameworks. RESULTS: This review outlines the need for the development of a general public health risk assessment method for vector-borne diseases, in order to guarantee that sufficient information is gathered to apply robust models of risk assessment. Stochastic (especially spatial) methods, often in Bayesian frameworks are now gaining prominence in standard risk assessment procedures because of their ability to assess accurately model uncertainties. CONCLUSIONS: Risk assessment needs to be addressed quantitatively wherever possible, and submitted with its quality assessment in order to enable successful public health measures to be adopted. In terms of current practice, often a series of different models and analyses are applied to the same problem, with results and outcomes that are difficult to compare because of the unknown model and data uncertainties. Therefore, the risk assessment areas in need of further research are identified in this article.

Superior reproductive success on human blood without sugar is not limited to highly anthropophilic mosquito species.

Anthropophilic mosquitoes such as Aedes aegypti L. (Diptera: Culicidae) have been shown to have superior reproductive success on human blood when sugar is not available. Life-table experiments were conducted with Aedes albopictus Skuse and Ae. aegypti to compare the effects of sugar availability on age-specific survivorship, lifetime and daily fecundity, and blood-feeding frequency when offered human blood daily. There were no significant interactions between the effects of sugar availability and mosquito species for these four variables, indicating similar effects of sugar availability for both species. Lifetime fecundity was not significantly affected by sugar availability, but sugar-deprived females had significantly reduced age-specific survivorship than did sugar-fed females. In absence of sugar, females took bloodmeals twice as often, resulting in a higher daily fecundity. The results indicate that superior reproductive success on human blood without sugar does not seem to be limited to highly anthropophilic mosquito species, such as Ae. aegypti. We conclude that evolution of a highly anthropophilic feeding strategy is not an inevitable result of the ability to thrive on human blood alone.