Soil-transmitted helminths, intestinal protozoa and Clonorchis sinensis infections in southeast China.

BACKGROUND: Extensive parasitic diseases epidemiology in Zhejiang province has not been carried out since the second national survey in 2004. Therefore, dynamics in prevalence and infection pattern of the major intestinal parasites should be explored. METHODS: The distribution of three parasites including soil-transmitted helminths (STH), intestinal protozoa and C. sinensis in Zhejiang from 2014 to 2015 were explored. Kato-Katz technique was used for STH and C. sinensis detection, whereas transparent adhesive paper anal swab was used for pinworm detection, and iodine smear was used for protozoa detection. A questionnaire survey on alimentary habits and sanitary behaviors was conducted in half of the studied counties. RESULTS: This study recruited 23,552 participants: 19,935 from rural and 3617 from urban area. Overall prevalence of intestinal helminth infections was 1.80%. In this study, seven helminth species were identified including A. duodenale, N. americanus, Trichuris trichiura, Ascaris lumbricoides, C. sinensis, Fasciolopsis buski and pinworm. The average prevalence of STH infection was 1.71%: 1.94% in rural and 0.44% in urban area. Hookworm was the most prevalent infection at 1.58%: 1.79% in rural and 0.44% in urban area. Prevalence varied considerably in the studied counties. Prevalence was highest in Yongkang county at 10.25%. Only 2.79% of children from rural area were infected with pinworm. A proportion of 0.40% of rural participants were infected with protozoa, whereas Endolimax nana was the most prevalent at 0.23%. C. sinensis showed infection only in one man. Awareness on C. sinensis was 24.47% in rural and 45.96% in urban area, respectively. CONCLUSIONS: Prevalence of STH and protozoa infections declined considerably whereas C. sinensis infections remained few in Zhejiang province compared with the prevalence reported in previous large scale surveys (19.56% for national STH infection in 2004, 18.66% and 4.57% for provincial STH and protozoa infection, respectively in 1999). The findings of this study showed that hookworm, mainly N. americanus remained a parasitic threat to population health, mainly in the central and western Zhejiang. Therefore, more health education regarding fertilization and farming habits is necessary in rural areas. The awareness concerning hookworm infection should be reinforced.

Sea Ice Detection Based on Differential Delay-Doppler Maps from UK TechDemoSat-1.

Global Navigation Satellite System (GNSS) signals can be exploited to remotely sense atmosphere and land and ocean surface to retrieve a range of geophysical parameters. This paper proposes two new methods, termed as power-summation of differential Delay-Doppler Maps (PS-D) and pixel-number of differential Delay-Doppler Maps (PN-D), to distinguish between sea ice and sea water using differential Delay-Doppler Maps (dDDMs). PS-D and PN-D make use of power-summation and pixel-number of dDDMs, respectively, to measure the degree of difference between two DDMs so as to determine the transition state (water-water, water-ice, ice-ice and ice-water) and hence ice and water are detected. Moreover, an adaptive incoherent averaging of DDMs is employed to improve the computational efficiency. A large number of DDMs recorded by UK TechDemoSat-1 (TDS-1) over the Arctic region are used to test the proposed sea ice detection methods. Through evaluating against ground-truth measurements from the Ocean Sea Ice SAF, the proposed PS-D and PN-D methods achieve a probability of detection of 99.72% and 99.69% respectively, while the probability of false detection is 0.28% and 0.31% respectively.

An Improved Compressive Sensing and Received Signal Strength-Based Target Localization Algorithm with Unknown Target Population for Wireless Local Area Networks.

In this paper a two-phase compressive sensing (CS) and received signal strength (RSS)-based target localization approach is proposed to improve position accuracy by dealing with the unknown target population and the effect of grid dimensions on position error. In the coarse localization phase, by formulating target localization as a sparse signal recovery problem, grids with recovery vector components greater than a threshold are chosen as the candidate target grids. In the fine localization phase, by partitioning each candidate grid, the target position in a grid is iteratively refined by using the minimum residual error rule and the least-squares technique. When all the candidate target grids are iteratively partitioned and the measurement matrix is updated, the recovery vector is re-estimated. Threshold-based detection is employed again to determine the target grids and hence the target population. As a consequence, both the target population and the position estimation accuracy can be significantly improved. Simulation results demonstrate that the proposed approach achieves the best accuracy among all the algorithms compared.

[Identification of Trypanosoma Species in Rattus flavipectus and R. losea using Microscopy and PCR Method].

OBJECTIVE: To identify two suspected Trypanosoma species in Rattus found in Zhejiang Province using microscopy and PCR method. METHODS: Blood samples were collected from Rattus losea and R. flavipectus. Blood smears were prepared, and observed under microscope. The morphological indices of trypanosomes were measured and calculated. The genomic DNA was extracted from the trypanosomes, and the specific fragment of Trypanosoma 18S rRNA gene was amplified using PCR. The products were further sequenced and submitted to GenBank. Blast analysis was performed on line in NCBI. RESULTS: Blood samples from Ratts flavipectus and R. losea were collected from Lucheng District and Wencheng County of Wenzhou, respectively. The parasites from R. losea and R. flavipectus were found to possess the characteristic features of Trypanosoma species, such as nucleus, free flagellum, and kinetoplast, etc. The body length was 27.50 µm and 23.80 µm, and the free flagellum length was 9.60 im and 9.20 jim, respectively. The nucleus index was 0.74 and 1.05, the kinetoplast Index was 1.40 and 1.57, respectively. Based on the morphological characteristics and host specificity, the parasites from R. losea and R. flavipectus were identified as Herpetosoma species, mainly found in rodents. The amplified products were about 700 bp by 18S rRNA gene PCR with the DNA isolated from the trypanosomes. The products were further sequenced, and the resulting sequences were submitted to GenBank with assession numbers of KP098535 (from R. losea) and KP098536 (from R. flavipectus). Blast analysis showed that KP098535 was completely homologous with the sequences from Herpetosoma subgenus (AY491765.1, AY491764.1, and AJ223568.1), and KP098536 was completely homologous with Trypanosoma lewisi (AB242273.1, AJ009156.1). CONCLUSION: The Trypanosoma species found from Rattus flavipectus is Trypanosoma lewisi, and the other one belongs to Herpetosoma subgenus, which may be named as Trypanosoma lewisi-like trypanosome.

Malaria in Zhejiang Province, China, from 2005 to 2014.

To summarize the changing epidemiological characteristics of malaria in Zhejiang Province, China, we collected data on malaria from the Chinese Notifiable Disease Reporting System (NDRS) and analyzed them. A total of 2,738 malaria cases were identified in Zhejiang Province from 2005 to 2014, of which 2,018 were male and 720 were female. Notably, only 7% of malaria cases were indigenous and the other cases were all imported. The number of malaria cases increased from 2005 to 2007, peaked in 2007, and then decreased from 2007 to 2011. There were no indigenous cases from 2012 to 2014. Of all cases, 68% of cases contracted Plasmodium vivax, 27% of cases contracted P. falciparum, and two cases contracted P. malariae. About 88% of malaria cases during 2005-2011 occurred yearly between May and October, but the number of malaria cases in different months during 2012-2014 was similar. The median age was 33 years, and 1,892 cases occurred in persons aged 20-50 years. The proportion of businessmen increased and the proportion of migrant laborers decreased in recent years. The median time from illness onset to confirmation of malaria cases was 5 days and it decreased from 2005 to 2014. Some epidemiological characteristics of malaria have changed, and businessmen are the emphases to surveillance in every month.