Search inside of Supercourse and lectures in HTML and PPT format

 

front |1 |2 |3 |4 |5 |6 |7 |8 |9 |10 |11 |12 |13 |14 |15 |16 |17 |18 |19 |20 |21 |22 |23 |24 |25 |review

The distribution of Aedes albopictus and that of Aedes aegypti can overlap in the same urban environment, Aedes albopictus is more commonly found in suburban and rural areas where open, vegetated spaces are prevalent. Studies have shown that Aedes albopictus was the most abundant species in suburban environments, which were characterized by open areas with plentiful vegetation, surrounded by buildings. By contrast, in more urbanized section of a city, Aedes aegypti appears to remain the dominant species. Interestingly, Aedes albopictus have shown a much greater propensity for using nature's water-holding containers than have Aedes aegypti. Recent outbreaks of dengue in nearby Caribbean and Central and South American countries may increase the likelihood of future autochthonous transmission in Texas. Mosquito vectors are widely distributed in the state, and travelers returning from dengue-endemic areas place at risk the resident population, which has minimal immunity to dengue viruses. Because physicians' awareness of dengue is low and specialized laboratory diagnostic methods are not available locally, low-level dengue transmission may go undetected. In response to an outbreak of dengue in Mexico in 1995, the Texas Department of Health initiated an active surveillance program that detected 29 confirmed cases, including seven in persons with no recent history of travel outside Texas. In 1977, outbreaks caused by dengue virus-type 1 occurred throughout the Caribbean, and in 1978 dengue was reported in Southern Mexico. Dengue reappeared in Mexico in 1979, and in the spring of 1980, when dengue virus-type 1 was isolated from a patient in Merida, it became apparent that dengue-1 might reach the United States-Mexico border. The region of the United States with the most immediate risk of dengue introduction was believed to be South Texas, in particular the Lower Rio Grande Valley area, where large numbers of travelers move across the border from Mexico.