Spatial Risk Distribution of Dengue Based on the Ecological Niche Model of Aedes aegypti (Diptera: Culicidae) in the Central Mexican Highlands.

Dengue is the most important viral disease transmitted by mosquitoes, predominantly Aedes (Stegomyia) aegypti (L.) (Diptera:Culicidae). Forty percent of the world's population is at risk of contracting the disease, and a large area of Mexico presents suitable environmental conditions for the life cycle of Ae. aegypti. In particular, the Central Mexican Highlands have a high population density, increasing the risk of transmission and propagation of dengue. In the present study, the potential distribution of Ae. aegypti was modeled under an ecological niche approach using the maximum entropy technique with the aim of determining the spatial risk distribution of dengue. The final model of five variables (minimum temperature of the coldest month |Bio6|, precipitation of the wettest month |Bio13|, precipitation seasonality |Bio15|, the normalized difference vegetation index (NDVI), and relative humidity) contributed to more than 90% of the model's performance. The results of the potential distribution model were then compared with the number of dengue cases per locality during the 2009-2015 period considering four suitability of presence categories. Category 4 corresponded with the highest suitability of presence (0.747 to 1) and the greatest risk of dengue (odds ratio [OR] = 103.27; P < 0.001). In conclusion, the present ecological niche model represents an important tool for the monitoring of dengue and the identification of high-risk areas.

Molecular Characterization of Trypanosoma cruzi in Infected Meccus pallidipennis in the Southern Region of the State of Mexico, Mexico.

PCR amplification and sequencing of Trypanosoma cruzi (T. cruzi) spliced-leader intergenic region of the mini-exon gene intergenic region (SL-IR) fragment was performed on intestinal tissue and fecal content DNA extracted from 19 Meccus pallidipennis (M. pallidipennis) specimens collected in the southern region of the State of Mexico. DNA sequence analysis from 49 bp T. cruzi SL-IR showed that all 19 samples corresponded to haplotype TcIa, and all of them were identical to GenBank sequence JQ028863. When extending the analysis to the whole 256 bp amplified sequence of the SL-IR, we found six sequences with a C insertion at position 10, one of which also presented a mutation (T/C) at position 54. One more sequence had an insertion (T) at position 223. Our findings suggest that two dominating TcIa clones are present in M. pallidipennis in the southern region of the State of Mexico. Interestingly, the SL-IR region of the dominating genotype was 100% identical to a circulating clone from Costa Rica present in humans, dogs, Triatoma dimidiata, and Panstrongylus rufotuberculatus. Future regional studies should explore the presence of this haplotype in humans and domestic animals.

Spatial and temporal distribution of tuberculosis in the State of Mexico, Mexico.

Tuberculosis (TB) is one of the oldest human diseases that still affects large population groups. According to the World Health Organization (WHO), there were approximately 9.4 million new cases worldwide in the year 2010. In Mexico, there were 18,848 new cases of TB of all clinical variants in 2010. The identification of clusters in space-time is of great interest in epidemiological studies. The objective of this research was to identify the spatial and temporal distribution of TB during the period 2006-2010 in the State of Mexico, using geographic information system (GIS) and SCAN statistics program. Nine significant clusters (P < 0.05) were identified using spatial and space-time analysis. The conclusion is that TB in the State of Mexico is not randomly distributed but is concentrated in areas close to Mexico City.

Risk factors associated with triatomines and its infection with Trypanosoma cruzi in rural communities from the southern region of the State of Mexico, Mexico.

Trypanosoma cruzi prevalence in triatomines and risk factors associated to the presence of the insect were studied in 990 rural houses in the southern region of the State of Mexico, Mexico. In each house, triatomines were collected, and information related to house construction material was obtained. T. cruzi infection was diagnosed in all triatomines. A primary screening was performed using 2 x 2 contingency tables of exposure variables. All variables with P