Infectious disease implications of large-scale migration of Venezuelan nationals.

Background: The ongoing economic and political crisis in Venezuela has resulted in a collapse of the healthcare system and the re-emergence of previously controlled or eliminated infectious diseases. There has also been an exodus of Venezuelan international migrants in response to the crisis. We sought to describe the infectious disease risks faced by Venezuelan nationals and assess the international mobility patterns of the migrant population. Methods: We synthesized data on recent infectious disease events in Venezuela and among international migrants from Venezuela, as well as on current country of residence among the migrant population. We used passenger-level itinerary data from the International Air Transport Association to evaluate trends in outbound air travel from Venezuela over time. We used two parameter-free mobility models, the radiation and impedance models, to estimate the expected population flows from Venezuelan cities to other major Latin American and Caribbean cities. Results: Outbreaks of measles, diphtheria and malaria have been reported across Venezuela and other diseases, such as HIV and tuberculosis, are resurgent. Changes in migration in response to the crisis are apparent, with an increase in Venezuelan nationals living abroad, despite an overall decline in the number of outbound air passengers. The two models predicted different mobility patterns, but both highlighted the importance of Colombian cities as destinations for migrants and also showed that some migrants are expected to travel large distances. Despite the large distances that migrants may travel internationally, outbreaks associated with Venezuelan migrants have occurred primarily in countries proximate to Venezuela. Conclusions: Understanding where international migrants are relocating is critical, given the association between human mobility and the spread of infectious diseases. In data-limited situations, simple models can be useful for providing insights into population mobility and may help identify areas likely to receive a large number of migrants.

The Effect of Changes in Cervical Cancer Screening Guidelines on Chlamydia Testing.

PURPOSE: Many chlamydia infections are identified through screening, which is frequently offered to females concomitantly with cervical cancer screening. Recent cervical cancer screening guidelines recommend screening less frequently and starting later. We sought to evaluate the impact of the May 2012 Ontario, Canada, cervical cancer screening guideline change on Papanicolaou (Pap) and chlamydia trachomatis (chlamydia) testing and incidence. METHODS: We extracted population-based physician billing claims data to identify Pap and chlamydia tests and public health surveillance data to identify chlamydia cases. We used interrupted time series analysis of quarterly data spanning 2 years before and after the guideline change and fitted segmented linear regression or rational functions to the outcomes using autoregressive integrated moving average models. Outcomes were stratified by sex and age group. RESULTS: Two years after the guideline change, we observed reduced chlamydia testing in females, with the greatest relative reduction (25.5%) among those aged 15 to 19 years. We also observed decreases in reported chlamydia incidence for females aged 15 to 19 years and 20 to 24 years (relative reductions of 16.8% and 14.4%, respectively). Chlamydia incidence remained the same for males, despite increased chlamydia testing. CONCLUSIONS: Recent cervical cancer screening guideline changes in Ontario were associated with reduced chlamydia testing and reported new cases of chlamydia in females. Females aged 15 to 19 years, who are at high risk for chlamydia if sexually active, and who no longer warrant cervical cancer screening, were disproportionately affected. Females should be tested for chlamydia based on risk, regardless of need for Pap testing.