Determinants of Aedes mosquito density as an indicator of arbovirus transmission risk in three sites affected by co-circulation of globally spreading arboviruses in Colombia, Ecuador and Argentina.

BACKGROUND: The global impact of Zika virus in Latin America has drawn renewed attention to circulating mosquito-borne viruses in this region, such as dengue and chikungunya. Our objective was to assess socio-ecological factors associated with Aedes mosquito vector density as a measure of arbovirus transmission risk in three cities of potentially recent Zika virus introduction: Ibagué, Colombia; Manta, Ecuador; and Posadas, Argentina, in order to inform disease mitigation strategies. METHODS: We sampled Aedes mosquito populations in a total of 1086 households, using indoor and peridomestic mosquito collection methods, including light traps, resting traps, traps equipped with chemical attractant and aspirators. For each sampled household, we collected socio-economic data using structured questionnaires and data on microenvironmental conditions using iButton data loggers. RESULTS: A total of 3230 female Aedes mosquitoes were collected, of which 99.8% were Aedes aegypti and 0.2% were Aedes albopictus. Mean female Aedes mosquito density per household was 1.71 (standard deviation: 2.84). We used mixed-effects generalized linear Poisson regression analyses to identify predictors of Aedes density, using month, neighborhood and country as random-effects variables. Across study sites, the number of household occupants [incidence rate ratio (IRR): 1.08, 95% confidence interval (CI): 1.01-1.14], presence of entry points for mosquitoes into the household (IRR: 1.51, 95% CI: 1.30-1.76) and presence of decorative vegetation (IRR: 1.52, 95% CI: 1.22-1.88) were associated with higher Aedes density; while being in the highest wealth tertile of household wealth (IRR: 0.78, 95% CI: 0.66-0.92), knowledge of how arboviruses are transmitted (IRR: 0.94, 95% CI: 0.89-1.00) and regular emptying of water containers by occupants (IRR: 0.79, 95% CI: 0.67-0.92) were associated with lower Aedes density. CONCLUSIONS: Our study addresses the complexities of arbovirus vectors of global significance at the interface between human and mosquito populations. Our results point to several predictors of Aedes mosquito vector density in countries with co-circulation of multiple Aedes-borne viruses, and point to modifiable risk factors that may be useful for disease prevention and control.

Patterns of prescription and self-medication for treating primary dysmenorrhea in a Mexican population.

Dysmenorrhea is defined as cramping pain in the lower abdomen occurring just before or during menstruation. Non-steroidal anti-inflammatory drugs (NSAIDs) are the mainstay of treatment, with the addition of oral contraceptive pills when necessary. With the widespread availability of over-the-counter NSAIDs, it is often assumed that women are treating themselves adequately. Unfortunately, this is not always the case. Therefore we evaluated the use of drugs for treating primary dysmenorrhea in Mexican students. A multiple-choice questionnaire was administered to 285 psychology students (20.6 +/- 2.4 yrs; range, 17-33 yrs), to assess the prevalence of dysmenorrhea and medications employed. The reported prevalence of dysmenorrhea among these women was 67%. Dysmenorrhea was mild in 34% moderate in 43% and severe in 21%. Of the dysmenorrheic sample, only 33.5% consulted physician in 2.6 +/- 0.2 cycles per year for their problem and the most common prescriptions were an over-the-counter medication with paracetamol pamabrom and pyrilamine maleate (Syncol; 22.4%) naproxen (18.4%), metamizole plus butylhyoscine bromide (10.2%), ibuprofen (6.1%) and butylhyoscine bromide (6.1%). On the other hand, self-medication was practiced by 64.9% of the women with dysmenorrhea in 6.1 +/- 3.8 cycles per year and the most common drugs by self-medication were Syncol (35.5%), naproxen (16.9%), metamizole plus naproxen butylhyoscine bromide (13.7%), an over-the-counter medication with adiphenine and propyphenazon (Espasmo-cibalgina; 10.5%), paracetamol (5.6%) butylhyoscine alone (4%) and ibuprofen (4%). Our data suggest that dysmenorrheic women use numerous drugs by self-medication for pain but infrequently accessed formal medical care.