Current status of stroke in Qatar: Including data from the BRAINS study.

BACKGROUND: Qatar is located on the north-eastern coast of the Arabian Peninsula. Qatari natives account for less than 15% of the population while the largest migrant group comprising 60% derives from South Asia. Despite projections that stroke burden in Qatar will increase with population ageing, epidemiological studies focusing on stroke in Qatar are relatively scarce. METHOD: We reviewed the available epidemiological publications relating to Qatar. In addition, we have added to this knowledge by incorporating Qatari data from the on-going Bio-Repository of DNA in Stroke, an independent multinational database of stroke patients. RESULTS: Qatar has low reported incidence and mortality rates of 58 and 9.17 per 100,000 per year, respectively, which may be explained by its middle-aged migrant worker majority population. Correspondingly, South Asian migrants in Qatar suffered younger strokes than Qatari natives (48.7 vs 63.4 years, P < 0.001). Among the most common risk factors identified in stroke patients were hypertension (77.9%), diabetes (43.8%) and hypercholesterolemia (28.5%). Ischaemic stroke was the most frequent subtype amongst migrant South Asians (71.1%). The majority of stroke cases had computed tomography and/or magnetic resonance imaging scans, but only 11.1% of ischaemic strokes were thrombolysed. Qataris on one-year follow up were more often found to have died (6.5% vs 0.3%) and had further stroke/transient ischaemic attack events (17.4% vs 6.4%, P = 0.009) compared to South Asians. CONCLUSION: The burden of stroke is increasing in Qatar, and considerable disparities are observed between the native and migrant populations which likely will require different approaches to management by its healthcare system.

Dry season ecology of Anopheles gambiae complex mosquitoes in The Gambia.

BACKGROUND: Malaria in The Gambia is highly seasonal, with transmission occurring as Anopheles gambiae s.l. populations expand during and immediately after a single annual rainy season that lasts from June to October. There has been very limited investigation of the ecology of vectors during the dry season, when numbers are very limited and distributions may be restricted. METHODS: Weekly adult mosquito collections (pyrethrum spray, light trap, and search collections from rooms, as well as light trap collections from animal shelters, abandoned wells and grain stores), and artificial sentinel breeding site surveys were performed in four villages near the upper tidal and partially saline part of the Gambia River in the last four months of an annual dry season (March to June). Mosquito species were identified by morphological and DNA analysis, and ELISA assays were performed to test for Plasmodium falciparum sporozoites and human blood meal components. RESULTS: Adults of An. gambiae s.l. were collected throughout the period, numbers increasing towards the end of the dry season when humidity was increasing. Adult collections were dominated by An. melas (86%), with An. gambiae s.s. (10%) and An. arabiensis (3%) also present throughout. Most females collected in room search and spray collections contained blood meals, but most from light traps were unfed. None of the females tested (n = 1709) contained sporozoites. Larvae (mostly An. gambiae s.s.) were recovered from artificial sentinel breeding sites in the two villages that had freshwater pools. These two villages had the highest proportions of An. gambiae s.s. adults, and experienced the most substantial increase in proportions of An. gambiae s.s. after the onset of rains. CONCLUSION: During the dry season population minimum, An. melas was the predominant vector species, but differences among villages in availability of fresh-water breeding sites correlate with egg laying activity and relative numbers of An. gambiae s.s. adults, and with the increase in this species immediately after the beginning of the rains. Local variation in dry season vector persistence is thus likely to influence spatial heterogeneity of transmission intensity in the early part of the rainy season.

Non-genetic and genetic risk factors for adult cerebral venous thrombosis.

INTRODUCTION: A wide variety of non-genetic and genetic factors have been shown to associate with increased risk for cerebral venous thrombosis (CVT). However, there is a paucity of risk factor data and conclusions about their impact are often conflicting. Herein, we quantified the associations of non-genetic and genetic risk factors for CVT in adults. MATERIALS AND METHODS: Electronic databases were searched up to January 2017. Meta-analyses were performed (RevMan v5.3) to determine pooled odds ratios (ORs and 95% CIs) for risk factors, interstudy heterogeneity and publication bias. RESULTS: Twenty non-genetic (n = 2314) and 33 genetic (n = 2117) studies up to January 2017 met the selection criteria. For non-genetic factors, CVT risk increased in the presence of glucocorticosteroid therapy by 18.3-fold (3.3-102.6), alcohol consumption 2.7-fold (1.8-3.9), infection 7.5-fold (2.6-21.6), surgery 9.6-fold (1.1-83.5), hypercholesterolaemia 2.4-fold (1.3-4.4), hyperhomocysteinaemia 3.1-fold (2.1-4.6), antiphospholipid antibodies 7.0-fold (2.1-23.6), autoimmune diseases 5.6-fold (2.3-13.6), anaemia 4.0-fold (2.1-7.9), malignancy 3.2-fold (1.4-7.1) and pregnancy/puerperium 11.4-fold (5.7-24.3). Smoking, hypertension and diabetes did not associate with CVT risk. For genetic factors, CVT risk increased in the presence of factor V Leiden (G1691A) by 2.5-fold (1.9-3.3), protein C deficiency 10.7-fold (3.1-37.7), protein S deficiency 5.7-fold (1.4-22.4), antithrombin deficiency 3.8-fold (1.0-13.8), prothrombin (G20210A) 5.5-fold (4.0-7.27) and TAFI gene variant (C1040T) 1.6-fold (1.0-2.4). Prothrombin G20210A and factor V Leiden polymorphisms tended to have higher ORs for CVT than for ischaemic stroke. CONCLUSIONS: We provide quantitative data supporting a strong basis for genetic and non-genetic risk factors in CVT. Its genetic liability seems higher when compared with sporadic ischaemic stroke.