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Objective To analyze the quality of blood smear examinations for malaria parasites in Chenzhou City, so as to provide insights into sustainable consolidation of malaria elimination achievements. Methods All positive blood smears from fever patients were irregularly sampled from each county (district) of Chenzhou City from 2018 to 2022 and reexamined, and no less than 3% negative blood smears were reexamined. The preparation, dyeing, cleanliness and microscopic examination results of blood smear were reexamined, and the quality of blood smear reexaminations was assessed using a descriptive statistical method. Results A total of 13 625 fever patients received blood smear examinations for malaria parasites in Chenzhou City from 2018 to 2022, of which 21 were positive and 13 604 were negative; 687 blood samples were reviewed, and the percentage of negative blood smear reexaminations was 4.90% (666/13 604), with a 63.51% rate of qualified negative blood smears preparation, a 67.87% rate of qualified dyeing and a 76.13% rate of qualified cleanliness, and no missing diagnosis found. There were 21 positive blood smears reexamined, and the proportions of qualified blood smears preparation, dyeing and cleanliness were all 85.71%, with 2 smears mistaking Plasmodium species (9.52%). The percentage of qualified negative blood smears preparation was 51.41% in 2022, which reduced by 31.61% in relative to that (75.17%) in 2019 (χ2 = 9.033, P < 0.05), and the percentage of qualified negative blood smears dyeing was 60.19% in 2022, which reduced by 28.82% in relative to that (84.56%) in 2019 (χ2 = 19.498, P < 0.05), while the percentage of qualified negative blood smears cleanliness was 62.96% in 2022, which reduced by 28.93% in relative to that (88.59%) in 2019 (χ2 = 23.826, P < 0.001). In addition, there were no significant differences in the proportion of qualified negative blood smears preparation (χ2 = 0.260, P > 0.05) or dyeing (χ2 = 1.094, P > 0.05) among the three years, while a significant difference was detected in the percentage of qualified negative blood smears cleanliness (χ2 = 12.175, P < 0.05). Conclusions No missing diagnosis was seen in blood smear examinations for malaria parasites among fever patients in Chenzhou City after malaria elimination; however, there were reductions in proportions of qualified blood smears preparation, dyeing and cleanliness. Quality control of blood smear examinations is recommended to be reinforced in key regions of Chenzhou City.
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Objective To study the epidemiological characteristics and risk factors of human brucellosis in Chenzhou City and provide a scientific basis for controlling brucellosis.Methods Descriptive epidemiological method was used to analyze the distribution of the cases,the source of transmission and the transmission route of human brucellosis reported in 2016 from the China Information System For Disease Control and Prevention and the Chenzhou Center for Disease Control and Prevention.Results In 2016,a total of 43 cases of human brucellosis were reported,with an incidence rate of 0.91/105.Among them,34 males and 9 famales;age is (47.79 ± 15.16) years old.The peak period of brucellosis cases was reported from April to August,totally 36 cases.The age of brucellosis cases was mainly middle-aged,and thirty-one cases were reported in the age 40 to 60 years,accounting for 72.09％ (31/43) of all cases.Fever,weak and hyperhidrosis were main clinical symptoms of brucellosis.Among the 43 cases of brucellosis,42 cases had a history of animal contact,and sheep was the main source of infection,accounting for 78.57％ (33/42).Conclusions In 2016,the cases of human brucellosis in Chenzhou City were mainly concentrated in spring and summer,the age of onset was mainly middle-aged,and males were higher than females.It is necessary to carry out in-depth knowledge and health education on disease prevention and control for high-risk groups in direct contact with animals,and effectively control the occurrence of human brucellosis.
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Objective To understand the pathogen spectrum and epidemic status of major human parasites in Chenzhou City,Hunan Province,so as to provide the evidence for parasitic diseases control. Methods The survey sites were selected by the stratified cluster sampling method. The intestinal helminthic eggs were detected by Kato?Katz technique. The trophozoites or cysts of intestinal protozoa were detected by saline smear and iodine staining methods. The eggs of Enterubius vermicularis of chil?dren from 3 to 6 years old were detected by the cellophane anal swab method. The species of hookworm were identified by the fil?ter paper strip culture method. Results A total of 7 031 people were detected with the intestinal helminthic infective rate of 1.83%(129 cases). The major parasite was hookworm and there was a statistically significant difference of the infection rates among various parasites(c2=107.77,P<0.01). All the hookworm larvae were Necator americanus. No intestinal protozoon was detected. There were statistically significant differences of the infection rates among the counties(c2=25.77,P<0.01). The age of the patients was mainly focused on 30 and above years old and the infection rate was increased with the growth of age(c2=26.21,P<0.01). Farmers were the main population of the patients and there was a statistically significant difference of the in?fection rates between farmer and others(c2=29.67,P<0.01). Conclusions The infection rates of parasites are low and hook?worm is the main parasite in the pathogen spectrum in Chenzhou City. However,the infection factors still exist,therefore,effec?tive and scientific measures should be taken to consolidate the achievement.
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Objective To study the iodine nutritional status among the key population in Chenzhou City of Hunan Province,and to provide scientific basis for prevention and control of iodine deficiency disorders (IDD).Methods According to the "Hunan Iodized Salt Monitoring Pilot Scheme",total of 11 counties (cities,districts) were selected in Chenzhou City in 2015.One township was selected by east,west,south,north and center in each county (city,district).Four villages were drawn from each township,and 15 households were selected from each village to collect salt samples.Forty children aged 8 to 10 years old (half male half female) were selected from each primary school in each township.Urine samples were taken and the goiter was examined.Totally 20 pregnant women were selected from each township and urine samples were collected.The content of iodine in salt samples and urine samples were detected by the method of direct titration and As-Ce catalytic spectrophotometry,respectively.The status of goiter was detected using palpation.Results Totally 3 300 salt samples were detected in 2015,the median of salt iodine content was 25.2 mg/kg.The coverage and qualified iodized salt consumption rates were 99.61％ (3 287/3 300) and 95.30％ (3 145/3 300),respectively,which achieved the standard for the elimination of IDD.Totally 2 200 urine samples of children aged 8 to 10 years old were tested,the median of urinary iodine was 238.98 μg/L.There was variations of urinary iodine in children aged 8 to 10 years old in each county (H =32.25,P ＜ 0.01).Totally 2 200 children aged 8 to 10 years old were checked,and no goiter was found.Totally 1 100 urine samples of pregnant women were detected,the median of urinary iodine was 204.25 μg/L.There was variations of urinary iodine in pregnant women in each county (H =117.47,P ＜ 0.01).Conclusions Totally,the iodine nutritional status among the key population is appropriate in Chenzhou City.However,surveillance and health education should be continuously strengthened in the future.
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Objective To study the iodine nutritional status among the key population in Chenzhou City of Hunan Province,and to provide scientific basis for prevention and control of iodine deficiency disorders (IDD).Methods According to the "Hunan Iodized Salt Monitoring Pilot Scheme",total of 11 counties (cities,districts) were selected in Chenzhou City in 2015.One township was selected by east,west,south,north and center in each county (city,district).Four villages were drawn from each township,and 15 households were selected from each village to collect salt samples.Forty children aged 8 to 10 years old (half male half female) were selected from each primary school in each township.Urine samples were taken and the goiter was examined.Totally 20 pregnant women were selected from each township and urine samples were collected.The content of iodine in salt samples and urine samples were detected by the method of direct titration and As-Ce catalytic spectrophotometry,respectively.The status of goiter was detected using palpation.Results Totally 3 300 salt samples were detected in 2015,the median of salt iodine content was 25.2 mg/kg.The coverage and qualified iodized salt consumption rates were 99.61％ (3 287/3 300) and 95.30％ (3 145/3 300),respectively,which achieved the standard for the elimination of IDD.Totally 2 200 urine samples of children aged 8 to 10 years old were tested,the median of urinary iodine was 238.98 μg/L.There was variations of urinary iodine in children aged 8 to 10 years old in each county (H =32.25,P ＜ 0.01).Totally 2 200 children aged 8 to 10 years old were checked,and no goiter was found.Totally 1 100 urine samples of pregnant women were detected,the median of urinary iodine was 204.25 μg/L.There was variations of urinary iodine in pregnant women in each county (H =117.47,P ＜ 0.01).Conclusions Totally,the iodine nutritional status among the key population is appropriate in Chenzhou City.However,surveillance and health education should be continuously strengthened in the future.
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Objective To establish a simple,convenient,quick and high sensitive method of loop-mediated isothermal amplification (LAMP) for detection of Plasmodium vivax-carrying mosquitoes.Methods The species conservative regions of P.v CSP gene were selected to design 2 pairs of primers which recognized 6 distinct regions.To evaluate the specificity of detection by LAMP,infected Anopheles,An.sinensis (An.s),Plasmodium falciparum (P.f),and healthy human blood DNA were selected as templates.To assess the sensitivity of detection,1.3×10~6,1.3×10~5,1.3×10~4,1.3×10~3,1.3×10~2,1.3×10~1 and 1.3×10~0 copies of P.v CSP plasmid DNA mixed with 1.0 μl An.s DNA were used as the templates of LAMP.The infected An.s DNAs were diluted with negative An.s DNA by 1:2,1:4,1:8,1:16,1:32,1:64,1:128 and 1:256 and then detected by LAMP to show the sensitivity of batch quantity detection.The applied value of this method was evaluated by detecting the same batch of 67 artificial infected An.s mosquitoes,and compared with the detection of microscopic examination and nested PCR in parallel.Results By using LAMP,the detection of infected An.s was positive,while the control samples were all negative.The limits of detection of different proportion dilutions of the mixture of P.v CSP plasmid DNA with An.s DNA were 1.3×10~2 copies.The limits of detection of different proportion dilutions of the mixture of infected An.s DNA with An.s DNA were 1:128.The positive rate of detecting the same batch of 67 artificial infected mosquitoes was 47.76% by LAMP,25.37% by the microscopic examination (X~2 = 7.24,P0.05).Compared with the test of the microscopic examination and then with a statistical analysis,the sensitivity of LAMP was 100%,which agreed well with the sensitivity of nested PCR (100%).Conclusion The method of LAMP is simple,convenient and high sensitive,and it is a potential method for detecting Plasmodium vivax-carrying mosquitoes in the field.
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Detection of Plasmodium sporozoites-carrying mosquitoes is an important indicator in monitoring mosquitoes, evaluating the control of malaria and forecasting the incidence of malaria. Here, we review the detection techniques in Plasmodium sporozoites-carrying mosquitoes and the progress of their applied research, and then briefly discuss the principles of the detection and the prospects for the field.