Delineating the Seasonality of Varicella and Its Association With Climate in the Tropical Country of Colombia.

BACKGROUND: Varicella causes a major health burden in many low- to middle-income countries located in tropical regions. Because of the lack of surveillance data, however, the epidemiology of varicella in these regions remains uncharacterized. In this study, based on an extensive dataset of weekly varicella incidence in children ≤10 during 2011-2014 in 25 municipalities, we aimed to delineate the seasonality of varicella across the diverse tropical climates of Colombia. METHODS: We used generalized additive models to estimate varicella seasonality, and we used clustering and matrix correlation methods to assess its correlation with climate. Furthermore, we developed a mathematical model to examine whether including the effect of climate on varicella transmission could reproduce the observed spatiotemporal patterns. RESULTS: Varicella seasonality was markedly bimodal, with latitudinal changes in the peaks' timing and amplitude. This spatial gradient strongly correlated with specific humidity (Mantel statistic = 0.412, P = .001) but not temperature (Mantel statistic = 0.077, P = .225). The mathematical model reproduced the observed patterns not only in Colombia but also México, and it predicted a latitudinal gradient in Central America. CONCLUSIONS: These results demonstrate large variability in varicella seasonality across Colombia and suggest that spatiotemporal humidity fluctuations can explain the calendar of varicella epidemics in Colombia, México, and potentially in Central America.

Restless Legs Syndrome and Hypertension in Mexican Women.

BACKGROUND: RLS is a common chronic disorder characterized by an irresistible need to move the lower limbs that affects sleep. Poor sleep has been associated with increased blood pressure (BP). Thus, we evaluated the cross-sectional relationship between RLS and hypertension (HTN) in a large cohort study in Mexico. METHODS: In 2011, 54,925 female participants from the Mexican Teachers' Cohort responded to a four-item questionnaire based on the International Restless Legs Syndrome Study Group's minimal diagnostic criteria. Women also reported diagnosis and treatment of HTN. We used multivariable logistic regression models to estimate prevalence odds ratios (ORs) for HTN, adjusting for lifestyle and dietary factors. We also estimated adjusted prevalence ORs for HTN by frequency of RLS symptoms. RESULTS: We identified 9,230 cases (17%) of RLS, and the prevalence of HTN was 13.1% among women with RLS and 9.4% among those without RLS. The multivariable-adjusted prevalence OR for HTN comparing women with to those without RLS was 1.18 (95% confidence interval [CI]: 1.10-1.26). Compared to those without RLS, the prevalence OR of HTN in women reporting a symptom frequency of once a month or less was 1.14 (95% CI: 1.00-1.30); among those with symptoms two to four times a month, the OR was 1.17 (95% CI: 1.05-1.30); and for those with symptoms at least two times a week, the OR was 1.22 (95% CI: 1.10-1.35). CONCLUSION: We observed an association between RLS and HTN. Future studies should evaluate the impact of treating RLS on BP.

[Prevalence of restless legs syndrome in 69,830 Mexican women]. / Prevalencia del síndrome de piernas inquietas en 69,830 mujeres mexicanas.

OBJECTIVE: To determine the prevalence of restless legs syndrome (RLS) in a group of Mexican women. MATERIAL AND METHODS: In 2011 a sample 69,830 Mexican women participating in a longitudinal study answered a questionnaire addressing the minimal diagnostic criteria for RLS. RESULTS: RLS prevalence was 15.6% and mean age 44.4 years (+/- 7.4). The prevalence among women < 30 years was 7.7% and among those ≥ 60 years 17.9%. Despite 54.5% of cases reporting high frequency of symptoms only 18.1% received treatment. CONCLUSIONS: RLS may affect a large, previously unrecognized proportion of the Mexican population.