Unpredictable checks of yellow fever vaccination certificates upon arrival in Tanzania.

BACKGROUND: Yellow fever (YF) is a mosquito-borne disease, which can be prevented by vaccination. While YF vaccination (YFV) is not generally recommended for travellers to Tanzania, proof of YFV may be required upon arrival. In April 2013, the World Health Organization concluded that one dose of YFV confers lifelong protection and countries have started to adapt their entry requirements. The traveller's consultant has to balance the risk of YFV and the risk of encountering problems when entering a country without a valid YFV, especially because countries are slowly implementing the requirements. METHODS: We performed a survey among 421 travellers to Tanzania with a pre-travel consultation at the Travel Clinic of the University of Zurich about their experiences with YFV certificate inspections upon arrival in Tanzania between January and November 2015. RESULTS: There were three main findings: (i) most vaccine card checks were done while crossing the land border of Tanzania. Inspections were frequently conducted at Arusha airport, less often in Dar es Salaam and Zanzibar. In the latter a significantly larger percentage of individuals arriving by ferry/boat were checked than those arriving by plane. (ii) Checks appeared to be non-systematic. They were also performed in travellers who did not enter Tanzania from a YF-endemic country. No seasonal or daytime pattern could be identified; the thoroughness of checks varied widely. (iii) In the case of travel without valid YFV, an exemption certificate was always accepted. In travellers with neither a valid YFV nor an exemption certificate, travellers reported forced YF vaccination and fines before entry was granted. CONCLUSIONS: We recommend YFV or a YF exemption certificate for all travellers to Tanzania until further notice. The decision of whether to vaccinate against YF or to issue an exemption should be based on exposure risk to YF infection in other countries during travel.

Association of smoking and nicotine dependence with pre-diabetes in young and healthy adults.

INTRODUCTION: Several studies have shown an increased risk of type 2 diabetes among smokers. Therefore, the aim of this analysis was to assess the relationship between smoking, cumulative smoking exposure and nicotine dependence with pre-diabetes. METHODS: We performed a cross-sectional analysis of healthy adults aged 25-41 in the Principality of Liechtenstein. Individuals with known diabetes, Body Mass Index (BMI) >35 kg/m² and prevalent cardiovascular disease were excluded. Smoking behaviour was assessed by self-report. Pre-diabetes was defined as glycosylated haemoglobin between 5.7% and 6.4%. Multivariable logistic regression models were done. RESULTS: Of the 2142 participants (median age 37 years), 499 (23.3%) had pre-diabetes. There were 1,168 (55%) never smokers, 503 (23%) past smokers and 471 (22%) current smokers, with a prevalence of pre-diabetes of 21.2%, 20.9% and 31.2%, respectively (p <0.0001). In multivariable regression models, current smokers had an odds ratio (OR) of pre-diabetes of 1.82 (95% confidential interval (CI) 1.39; 2.38, p <0.0001). Individuals with a smoking exposure of <5, 5-10 and >10 pack-years had an OR (95% CI) for pre-diabetes of 1.34 (0.90; 2.00), 1.80 (1.07; 3.01) and 2.51 (1.80; 3.59) (p linear trend <0.0001) compared with never smokers. A Fagerström score of 2, 3-5 and >5 among current smokers was associated with an OR (95% CI) for pre-diabetes of 1.27 (0.89; 1.82), 2.15 (1.48; 3.13) and 3.35 (1.73; 6.48) (p linear trend <0.0001). DISCUSSION: Smoking is strongly associated with pre-diabetes in young adults with a low burden of smoking exposure. Nicotine dependence could be a potential mechanism of this relationship.