ABSTRACT
To analyze the frequency and spectrum of thalassemia mutations in amniotic fluid samples collected from Han and Li people in Hainan province of China. Methods: We carried out a retrospective analysis on prenatal diagnosis of amniotic fluid samples collected from pregnant women who may have next generation with high risks of medium or severe thalassemia between 2005 and 2016. Diverse fetal thalassemia genotypes and mutated alleles in Han and Li people were analyzed and cmpared. Results: We examined 536 amniotic fluid samples from Han people and 588 from Li people, among which 406 Han and 500 Li samples were found to carry at least one thalassemia gene mutation, with a detection rate of 75.75% and 85.03%, respectively. Among all - and β-thalassemia mutant alleles detected, the most frequently found mutations in Han and Li samples were SEA-type of -thalassemia and 41/42 (-CTTT) of β-thalassemia, respectively. A total of 75 severe thalassemia cases were identified in Han samples and 53 in Li samples. In most of these severe cases, parents chose to terminate pregnancy after being informed of thalassemia-related risks. Conclusions: The thalassemia mutations shows ethnic and area specificity, and that prenatal diagnosis for high-risk thalassemia carrier pregnant women is an efficient approach to prevent and control the occurrence of severe thalassemia in the high-prevalence areas.
ABSTRACT
Objective To investigate the space structure of plague natural foci in the area of Lantsang, Yellow and Yangtse River in Qinghai Province to provide references for making decisions to eontrol the occurrence of human plague. Methods Data was collected from the survey on natural foci and surveillance of plague from 1954 to 2006 and descriptive epidemiological method was used to analyze the data. Results Marmata hirnalayana and Microtus fuscua natural foci were known in Sanjiangyuan area. Callopsylla dolabris, Oropsylla silantiewi, Citellophilus sparsilis and Amphipsylla tuta were vectors; Microtus fuscus plague natural foci was in a range of about 9500 km2, distributing in Zhenqin Town, Chengduo County. Marmata himalayana plague natural foci distributed over 13 countries, a range nearly 107 000 km2. By the end of 2006, 450 strains of Yersinia pestis were detected and separated from 6 kinds of rodents, 6 kinds of carnivora, 3 kinds of artiodactyls and 9 insects vectors. Between 1960 and 2006, 238 cases and 134 deaths from plague were reported. Most human plague cases occurred in the months from May to November and usually presented as one of three primary forms-bubonic 17.23%(41/238), septicemic 16.81% (40/238), pneumonic 61.34% (146/238) and other types 4.62% (11/238). However, the first epidemic plague case was mainly the glandular plague. Conclusions Date suggested that plague is still a critical public health problem in Sanjiangyuan area, against which countermaeasure needs to be strengthened in the main epidemic areas. More scientific researches on plague should be carried out. Surveillance networks of reporting suspected plague have been established and reduce the number of human plague cases.