[Enfermedad de Chagas en México].

Chagas disease, which is caused by Trypanosoma cruzi, is considered to be the most serious parasitic disease in America. It is transmitted mainly by triatominae ("kissing bugs"). Mazzoti reported the first two human cases in Mexico. The form of transmission is by parasites entering the organism in feces of the insect, by blood transfusion, from mother to child, by organ transplant and laboratory accidents. In Mexico, 1.1 million people are estimated to be infected; the incidence in 2012 was 0.70 per 1,00,000 population. In 2017, the highest incidence rates were registered in Yucatán, Oaxaca and Hidalgo. The infection causes cardiomyopathies and mega-organs of the digestive tract. Diagnosis in the acute phase is by parasitological approach and, in the chronic phase, by laboratory screening studies. In Mexico's blood banks, screening for Chagas disease is mandatory; from 2007 to 2016, seroprevalence has decreased from 0.40 to 0.32 due to the improvement of donor selection processes and the ad hoc questionnaire. The targets of the parasite are neurons and smooth and myocardial muscle cells. The association of neuronal and smooth muscle destruction defines the presentation of chagas mega-syndromes. Initial manifestations of the disease can go unnoticed; 5% show apparent signs and symptoms and 30% will progress to the chronic asymptomatic phase. Currently available treatments have effect in the acute phase. For the control of Chagas disease, the Specific Action Program for the Prevention and Control of Chagas Disease (PAE Chagas 2013-2018) is available to initiate activities aimed at eliminating transfusion and congenital transmission and controlling vector transmission. The success of medical care depends on oportune detection, early etiological treatment and coverage broadening. On the other hand, monitoring and screening of pregnant women living in risk areas and blood and organ donors universal screening will enable the elimination congenital and transfusion transmission.

La enfermedad de Chagas, causada por el Trypanosoma cruzi, está considerada como la parasitosis más grave en América. Se transmite principalmente por triatominos (chinches). El doctor Mazzoti reportó los dos primeros casos humanos en México. La forma de transmisión es por la entrada al organismo de los parásitos en heces del insecto, por transfusión sanguínea, de madre a hijo, por trasplante de órganos y por accidentes de laboratorio. En México se estima que 1.1 millones de personas están infectadas; la incidencia en 2012 fue de 0.70 por 100 000 habitantes. En 2017, las mayores tasas de incidencia se registraron en Yucatán, Oaxaca e Hidalgo. La infección ocasiona miocardiopatías y megaórganos del tracto digestivo. El diagnóstico en fase aguda es por abordaje parasitológico y en fase crónica, por estudios de tamizaje por laboratorio. En los bancos de sangre de México, el estudio de la enfermedad de Chagas es de observancia obligatoria; de 2007 a 2016, la seroprevalencia ha disminuido de 0.40 a 0.32 debido a la mejora de los procesos de selección al donante y al cuestionario ad hoc. Los blancos del parásito son las células neuronales y las de los músculos liso y miocárdico. La asociación de la destrucción neuronal y del músculo liso define la presentación de los síndromes megachagásicos. Las manifestaciones iniciales de la enfermedad pueden pasar desapercibidas; 5 % de los pacientes presenta signos y síntomas aparentes y 30 % evolucionará a la fase crónica asintomática. Los tratamientos actuales tienen efecto en la fase aguda. Para el control de la enfermedad de Chagas se dispone del Programa de Acción Específico para la Vigilancia Prevención y Control de la Enfermedad de Chagas (PAE Chagas 2013-2018), encaminado a eliminar la transmisión transfusional y congénita y a controlar la transmisión vectorial. De la detección oportuna, el tratamiento etiológico temprano y la ampliación de cobertura depende el éxito de la atención médica. Por su parte, la vigilancia y tamizaje de las mujeres embarazadas que viven en zonas de riesgo y el tamizaje universal de donadores de sangre y órganos harán posible la eliminación de la transmisión connatal y transfusional.

Cost-effectiveness of the national dog rabies prevention and control program in Mexico, 1990-2015.

BACKGROUND: Rabies is a viral zoonosis that imposes a substantial disease and economic burden in many developing countries. Dogs are the primary source of rabies transmission; eliminating dog rabies reduces the risk of exposure in humans significantly. Through mass annual dog rabies vaccination campaigns, the national program of rabies control in Mexico progressively reduced rabies cases in dogs and humans since 1990. In 2019, the World Health Organization validated Mexico for eliminating rabies as a public health problem. Using a governmental perspective, we retrospectively assessed the economic costs, effectiveness, and cost-effectiveness of the national program of rabies control in Mexico, 1990-2015. METHODOLOGY: Combining various data sources, including administrative records, national statistics, and scientific literature, we retrospectively compared the current scenario of annual dog vaccination campaigns and post-exposure prophylaxis (PEP) with a counterfactual scenario without an annual dog vaccination campaign but including PEP. The counterfactual scenario was estimated using a mathematical model of dog rabies transmission (RabiesEcon). We performed a thorough sensitivity analysis of the main results. PRINCIPAL FINDINGS: Results suggest that in 1990 through 2015, the national dog rabies vaccination program in Mexico prevented about 13,000 human rabies deaths, at an incremental cost (MXN 2015) of $4,700 million (USD 300 million). We estimated an average cost of $360,000 (USD 23,000) per human rabies death averted, $6,500 (USD 410) per additional year-of-life, and $3,000 (USD 190) per dog rabies death averted. Results were robust to several counterfactual scenarios, including high and low rabies transmission scenarios and various assumptions about potential costs without mass dog rabies vaccination campaigns. CONCLUSIONS: Annual dog rabies vaccination campaigns have eliminated the transmission of dog-to-dog rabies and dog-mediated human rabies deaths in Mexico. According to World Health Organization standards, our results show that the national program of rabies control in Mexico has been highly cost-effective.

Urban and semi-urban mosquitoes of Mexico City: A risk for endemic mosquito-borne disease transmission.

Since past century, vector-borne diseases have been a major public health concern in several states of Mexico. However, Mexico City continues to be free of endemic mosquito-borne viral diseases. The city is the most important politic and economic state of Mexico and one of the most important city of Latin America. Its subtropical highland climate and high elevation (2240 masl) had historically made the occurrence of Aedes species unlikely. However, the presence of other potential disease vectors (Culex spp, Culiseta spp), and the current intermittent introductions of Aedes aegypti, have revealed that control programs must adopt routine vector surveillance in the city. In this study, we provide an updated species list from a five-years of vector surveillance performed in Mexico City. A total of 18,553 mosquito larvae were collected. Twenty-two species from genus Culex, Aedes, Culiseta, Anopheles, Lutzia and Uranotaenia were observed. Nine new mosquito records for the city were found. Ae. albopictus was recorded for the first time in Mexico City. Interestingly, a new record, Ae. epactius was the most frequent species reported. Cx. pipiens quinquefasciatus exhibited the highest number of individuals collected. We detected six areas which harbor the highest mosquito species records in the city. Cemeteries included 68.9% of our collection sites. Temporarily ponds showed the highest species diversity. We detected an increasing presence of Ae. aegypti, which was detected for three consecutive years (2015-2017), predominantly in the warmer microclimates of the city. We found a possible correlation between increasing temperature and Ae. aegypti and Ae. albopictus expanding range. This study provides a starting point for developing strategies related to environmental management for mosquito control. The promotion of mosquito control practices through community participation, mass media and education programmes in schools should be introduced in the city.

Detection of Zika virus in Aedes mosquitoes from Mexico.

Background: We report on the results of an entomovirological surveillance system of Aedes populations performed by the Ministry of Health of the central state of San Luis Potosí, Mexico. Methods: Indoor adult Aedes aegypti and Aedes albopictus pools collected at San Martín, Tamazunchale, Ciudad Valles, Metlapa, Ebano, Tamuin and Axtla during the dry season of 2016 were examined for the presence of dengue (DENV), chikungunya (CHIKV) and Zika (ZIKV) viruses using real-time PCR. Results: Both Ae. aegypti and Ae. albopictus were found to be infected with ZIKV in the absence of confirmed symptomatic human cases. Conclusions: The entomovirological surveillance system analysed here identified both Ae. aegypti and Ae. albopictus infected with ZIKV which triggered an immediate aggressive vector control campaign.

Association of Pulmonary Tuberculosis and Diabetes in Mexico: Analysis of the National Tuberculosis Registry 2000-2012.

BACKGROUND: Tuberculosis (TB) remains a public health problem in Mexico while the incidence of diabetes mellitus type 2 (DM) has increased rapidly in recent years. OBJECTIVE: To describe the trends of incidence rates of pulmonary TB associated with DM and not associated with DM and to compare the results of treatment outcomes in patients with and without DM. MATERIALS AND METHODS: We analysed the National Tuberculosis Registry from 2000 to 2012 including patients with pulmonary TB among individuals older than 20 years of age. The association between DM and treatment failure was analysed using logistic regression, accounting for clustering due to regional distribution. RESULTS: In Mexico from 2000 to 2012, the incidence rates of pulmonary TB associated to DM increased by 82.64%, (p<0.001) in contrast to rates of pulmonary TB rate without DM, which decreased by 26.77%, (p<0.001). Patients with a prior diagnosis of DM had a greater likelihood of failing treatment (adjusted odds ratio, 1.34 (1.11-1.61) p<0.002) compared with patients who did not have DM. There was statistical evidence of interaction between DM and sex. The odds of treatment failure were increased in both sexes. CONCLUSION: Our data suggest that the growing DM epidemic has an impact on the rates of pulmonary TB. In addition, patients who suffer from both diseases have a greater probability of treatment failure.

Results of the implementation of a pilot model for the bidirectional screening and joint management of patients with pulmonary tuberculosis and diabetes mellitus in Mexico.

BACKGROUND: Recently, the World Health Organisation and the International Union Against Tuberculosis and Lung Disease published a Collaborative Framework for the Care and Control of Tuberculosis (TB) and Diabetes (DM) (CFTB/DM) proposing bidirectional screening and joint management. OBJECTIVE: To evaluate the feasibility and effectiveness of the CFTB/DM in Mexico. DESIGN: Prospective observational cohort. SETTING: 15 primary care units in 5 states in Mexico. PARTICIPANTS: Patients aged ≥20 years diagnosed with DM or pulmonary TB who sought care at participating clinics. INTERVENTION: The WHO/Union CFTB/DM was adapted and implemented according to official Mexican guidelines. We recruited participants from July 2012 to April 2013 and followed up until March 2014. Bidirectional screening was performed. Patients diagnosed with TB and DM were invited to receive TB treatment under joint management. MAIN OUTCOME MEASURES: Diagnoses of TB among DM, of DM among TB, and treatment outcomes among patients with DM and TB. RESULTS: Of 783 DM patients, 11 (1.4%) were unaware of their TB. Of 361 TB patients, 16 (4.4%) were unaware of their DM. 95 TB/DM patients accepted to be treated under joint management, of whom 85 (89.5%) successfully completed treatment. Multiple linear regression analysis with change in HbA1c and random capillary glucose as dependent variables revealed significant decrease with time (regression coefficients (ß)  = -0.660, (95% confidence interval (CI), -0.96 to -0.35); and ß = -1.889 (95% CI, -2.77 to -1.01, respectively)) adjusting by sex, age and having been treated for a previous TB episode. Patients treated under joint management were more likely to experience treatment success than patients treated under routine DM and TB programs as compared to historical (adjusted OR (aOR), 2.8, 95%CI 1.28-6.13) and same period (aOR 2.37, 95% CI 1.13-4.96) comparison groups. CONCLUSIONS: Joint management of TB and DM is feasible and appears to improve clinical outcomes.

[Epidemiology of tobacco use in Mexico]. / Epidemiología del tabaquismo en México.

Tobacco use is a worldwide public health problem. According to the World Health Organization (WHO), smoking is the second principal cause of death in the world, with almost five million deaths annually. Information about tobacco consumption is essential in order to improve the focus of prevention and control measures and thereby succeed in the struggle against tobacco use. This literature review, carried out in Mexico in 2006, presents a comparative analysis of information about smoking prevalence from the National Addictions Survey 2002, as it relates to results obtained in previous surveys. This review also presents information about youth and passive smoking, tobacco consumption in the medical profession and impact on mortality as aspects relevant to the analysis of this epidemic. Epidemiological information is viewed in the context of the tobacco use component of the Plan of Action on Addiction and the WHO Framework Convention on Tobacco Control.

[Policies, monitoring and minors access to cigarettes in Mexico City]. / Políticas, vigilancia y acceso de los menores de edad a los cigarros en la Ciudad de México.

In Mexico and other countries, the accessibility that minors have to products derived from tobacco -mainly cigarettes- is a primary contributing factor to smoking, and is currently one of the main public health challenges worldwide. In the fight against tobacco use, effective legislation for decreasing production, distribution and the sale of tobacco products is indispensable to the creation of conditions necessary for achieving a tobacco-free society. The sale of cigarettes to minors is an act that has unique characteristics according to the particular location, particularly in Mexico City, and the time in which it is evaluated. The lack of monitoring compliance with official regulations contributes to the fact that minors directly obtain cigarettes from most of the stores.

Epidemiología del tabaquismo en México / Epidemiology of tobacco use in Mexico

El consumo de tabaco es un problema de salud pública mundial. De acuerdo con la Organización Mundial de la Salud, el tabaquismo es la segunda causa principal de muerte en el mundo, con casi cinco millones de defunciones anuales. Se requiere contar con información y análisis sobre el consumo de tabaco para tener éxito en la lucha contra el tabaquismo y así orientar de mejor manera las medidas de prevención y control. En este artículo de revisión, realizado en México en 2006, se presenta un análisis comparativo de la información de la prevalencia del tabaquismo de la Encuesta Nacional de Adicciones 2002, en relación con los resultados obtenidos en encuestas anteriores. También se presenta la información de los fumadores jóvenes y los pasivos, el consumo de tabaco en la profesión médica y el efecto sobre la mortalidad, así como aspectos relevantes de análisis de esta epidemia. Tal información epidemiológica se observa en el contexto del componente tabaquismo del Plan de Acción de Tabaquismo y el Convenio Marco para el Control del Tabaco.

Políticas, vigilancia y acceso de los menores de edad a los cigarros en la Ciudad de México / Policies, monitoring and minors access to cigarettes in Mexico City

En México y otros países, la accesibilidad que tienen los menores de edad a productos derivados del tabaco -sobre todo cigarros- es un factor primordial que contribuye al desarrollo del tabaquismo, que hoy día constituye uno de los principales desafíos de la salud pública en todo el mundo. En la lucha contra esta adicción, la existencia de una legislación eficaz para disminuir la producción, distribución y venta de productos derivados del tabaco es indispensable para crear las condiciones necesarias y lograr una sociedad libre de tabaco. La venta de cigarros a menores es un acto que posee características específicas en cada lugar y tiempo en que se evalúa. En particular, en el Distrito Federal la falta de vigilancia en el cumplimiento de las disposiciones oficiales contribuye a que los menores de edad consigan los cigarros en la mayoría de los comercios y los adquieran de forma directa.