ObjectiveTo explore the species composition, abundance, and seasonal dynamics of Anopheles mosquitoes in Hepu County of Beihai, Guangxi, and to lay a foundation for improving local malaria prevention and control strategies. MethodsFrom 2015 to 2023, during the first half and the second half of each month from April to November, two typical villages (specifically, Dajiang Village of Lianzhou Town and Dazhuangjiang Village of Shikang Town, both in Hepu County) were selected as fixed points for continuous monitoring of Anopheles mosquitoes. Adult mosquito density monitoring was conducted in different habitats, including human dwellings, outdoors (outside human dwellings), and livestock sheds (cow/pig pens), using light traps for collection. ResultsIn these two areas of Hepu County, the number of Anopheles mosquitoes captured had shown a decreasing trend year by year since 2015, with Anopheles sinensis consistently accounting for the majority. A total of 9 567 Anopheles mosquitoes were captured, with the highest number in livestock sheds (cow/pig pens). The season of Anopheles activity peaked from August to October. ConclusionThe main vector of malaria transmission in Hepu County has been Anopheles sinensis. Therefore, it is necessary to continuously strengthen the monitoring of mosquitoes and implement effective prevention and control measures.

Abstract: Objective To compare the screening effects of RDT, microscopy and PCR for malaria among residents in low malaria areas and elimination areas, and to investigate the presence of malaria in residents of border Villages in Cangyuan Va County and asymptomatic infections in surrounding areas, providing a basis for preventing re-introduction of malaria after elimination. Methods From August 2020 to March 2021, the fingertip blood of the investigated subjects was collected from three survey sites in the border area between China and Myanmar, namely Banlao Township in Cangyuan Va Autonomous County of Lincang City, Banwai District, Mengmao County, the Second Special Zone of Shan State, Myanmar, Yongmo and Dayan Township, Nandeng Special Zone, the Second Special Zone of Shan State, Myanmar. The malaria parasite antigen detection test kit, malaria parasite microscopic examination, fluorescent quantitative PCR and nested PCR were used to detect the asymptomatic infection of malaria parasites. Results A total of 1 040 blood samples were collected, including 606 from China and 434 from Myanmar, with 506 males and 534 females. Among them, , there were 51 individuals aged 0 to <5 years, 283 aged 5 to < years, 187 aged 15 to < years, 232 aged 30 to <45 years, 205 aged 45 to < years, and 82 aged ≥60 years. All 1 040 people tested negative for plasmodium antigen detection kit. One case of Plasmodium vivax detected by plasmodium microscopic etiology, with a detection rate of 0.10%. One case of P. vivax was also detected by fluorescent quantitative PCR and nested PCR, with a detection rate of 0.10%. Among them, one case of P. vivax was detected in Banwai District, Mengmao County, the Second Special Zone of Shan State, Myanmar, with a detection rate of 0.35%. The detection rates of malaria parasites in Banlao Township in Cangyuan Va Autonomous County of Lincang City, Yunnan Province and Yongmo Township and Dayan Township, Nandeng Special District, the Second Special Zone of Shan State, Myanmar were both 0. The difference in the detection rate of malaria parasites among the three survey sites was not statistically significant (χ2 =2.682, P>0.05). The asymptomatic P. vivax infection was detected in a 6-year-old girl from Banwai District, Mengmao County, the Second Special Zone of Shan State, Myanmar. Conclusions RDT is not suitable for malaria screening in low malaria area and elimination area. Microscopic examination and PCR can be used for malaria screening, but PCR operation is complex and costly. In surrounding areas outside of China, malaria is still prevalent, while there is no source of malaria infection in border villages of Cangyuan Va County. However, there is a risk of importation, and timely and effective measures should be taken to prevent reintroduction and transmission.

Objective To investigate the awareness of malaria-related knowledge, the use of mosquito nets and their influencing factors among residents in Banlao Township, Cangyuan County, Yunnan Province.. Methods In August 2020, 19 settlement sites in Banlao Township, Cangyuan County, Lincang City, Yunnan Province were selected as study areas, and permanent residents at ages of 10 years and older were enrolled for a questionnaire survey, including residents’ demographics, family economic status, malaria control knowledge and use of mosquito nets. In addition, the factors affecting the use of mosquito nets in the night prior to the survey were identified using multivariate logistic regression analysis. Results A total of 320 questionnaires were allocated, and all were recovered (a 100% recovery rate). There were 316 valid questionnaires, with an effective recovery rate of 98.75%. The 316 respondents included 152 men and 164 women and 250 Chinese respondents and 66 foreign respondents. The awareness of clinical syndromes of malaria was significantly higher among Chinese residents (71.60%) than among foreign residents (50.00%) (χ² = 11.03, P < 0.01), and the proportions of Chinese and foreign residents sleeping under mosquito nets were 46.00% and 69.70% on the night prior to the survey, respectively (χ² = 11.73, P < 0.01). Multivariate logistic regression analysis identified ethnicity group and type of residence as factors affecting the use of mosquito nets in the night prior to the survey. Conclusions The awareness of malaria control knowledge, the coverage and the use of mosquito nets were low among residents in Banlao Township, Cangyuan County, Yunnan Province. Targeted health education is recommended to improve the awareness of malaria control knowledge and self-protection ability. In addition, improving the allocation of long-lasting mosquito nets and health education pertaining to their uses and increasing the proportion of using mosquito nets correctly is needed to prevent re-establishment of imported malaria.

Objective:To investigate the pathological characteristics and the clinical significance of novel coronavirus (2019-nCoV)-infected pneumonia (termed by WHO as coronavirus disease 2019, COVID-19).Methods:Minimally invasive autopsies from lung, heart, kidney, spleen, bone marrow, liver, pancreas, stomach, intestine, thyroid and skin were performed on three patients died of novel coronavirus pneumonia in Chongqing, China. Hematoxylin and eosin staining (HE), transmission electron microcopy, and histochemical staining were performed to investigate the pathological changes of indicated organs or tissues. Immunohistochemical staining was conducted to evaluate the infiltration of immune cells as well as the expression of 2019-nCoV proteins. Real time PCR was carried out to detect the RNA of 2019-nCoV.Results:Various damages were observed in the alveolar structure, with minor serous exudation and fibrin exudation. Hyaline membrane formation was observed in some alveoli. The infiltrated immune cells in alveoli were majorly macrophages and monocytes. Moderate multinucleated giant cells, minimal lymphocytes, eosinophils and neutrophils were also observed. Most of infiltrated lymphocytes were CD4-positive T cells. Significant proliferation of type Ⅱ alveolar epithelia and focal desquamation of alveolar epithelia were also indicated. The blood vessels of alveolar septum were congested, edematous and widened, with modest infiltration of monocytes and lymphocytes. Hyaline thrombi were found in a minority of microvessels. Focal hemorrhage in lung tissue, organization of exudates in some alveolar cavities, and pulmonary interstitial fibrosis were observed. Part of the bronchial epithelia were exfoliated. Coronavirus particles in bronchial mucosal epithelia and type Ⅱ alveolar epithelia were observed under electron microscope. Immunohistochemical staining showed that part of the alveolar epithelia and macrophages were positive for 2019-nCoV antigen. Real time PCR analyses identified positive signals for 2019-nCoV nucleic acid. Decreased numbers of lymphocyte, cell degeneration and necrosis were observed in spleen. Furthermore, degeneration and necrosis of parenchymal cells, formation of hyaline thrombus in small vessels, and pathological changes of chronic diseases were observed in other organs and tissues, while no evidence of coronavirus infection was observed in these organs.Conclusions:The lungs from novel coronavirus pneumonia patients manifest significant pathological lesions, including the alveolar exudative inflammation and interstitial inflammation, alveolar epithelium proliferation and hyaline membrane formation. While the 2019-nCoV is mainly distributed in lung, the infection also involves in the damages of heart, vessels, liver, kidney and other organs. Further studies are warranted to investigate the mechanism underlying pathological changes of this disease.

Objective: To explore the screening efficiency of colorectal cancer in urban residents of Kunming, China. Methods: Using the method of cluster sampling, from October 2014 to October 2017, residents of the three jurisdictions of Xishan, Guandu and Chenggong Districts of Kunming city were investigated. The inclusion criteria: (1) resident (for more than 3 years) population of Kunming city aged 40-74 years old; (2) voluntarily participating and receiving colonoscopy; (3) signing informed consent. Based on the Harvard Cancer Risk Index, the questionnaire was built on the consensus of more than 20 years of common cancer epidemiology in China. Through the consensus reached by the multidisciplinary expert panel discussion, a comprehensive evaluation system for cancer risk in China was designed. The high-risk group of colorectal cancer was determined by preliminary screening of the questionnaire, and a free colonoscopy was performed for the appointment to the gastrointestinal endoscopy department of the Yunnan Cancer Hospital. All polypoid lesions and ulcers found by colonoscopy must be biopsied to confirm the diagnosis. χ² test or Fisher exact probability method was used to compare the detection of colorectal cancer in 4 groups of 40-49 years old, 50-59 years old, 60-69 years old, and ≥70-years old. Detection of colonoscopy, compliance, pathological examination, pathological diagnosis, and morbidity of colorectal cancer were analyzed. Results: A total of 127 960 people from 40 to 74 years old of urban residents in Kunming city participated in the preliminary screening of the questionnaire, including 59 748 (46.7%) males and 68 212 females (53.3%) with mean age of (53.6±8.6) years old. The 40-49 years old group had the largest number of participants (48 044, 37.5%), followed by the groups of 50-59 years old (42 473, 33.2%), 60-69 years old (34 111, 26.7%), and ≥70 years old (3332, 2.6%). Till October 2017, a total of 14 971 people were screened as at high risk of colorectal cancer, with the high-risk detection rate of 11.7%, and the high-risk detection rate of women was significantly higher than that of men [13.4% (9 109/68 212) vs. 9.8% (5 862/59 748), χ²=386.947, P<0.001]. The highest high-risk detection rate was in the 50-59 years group in both gender [men: 11.1% (2202/19 831), women: 15.3% (3034/22 642)]. A total of 3449 people among the high-risk population received colonoscopy examination. The compliance rate of colonoscopy was 23.0% (3449/14 971), and the male compliance rate was 19.8% (1162/5862), which was significantly lower than that of females [25.1% (2287/9109), χ²=56.175, P<0.001]. The highest compliance was observed in the 50-59 years group [25.4% (1438/5668)], followed by 40-49 years and 60-69 year group [22.1%(1091/4931) and 22.0%(891/4048), respectively], and the compliance of ≥70 years old group was the lowest [9.0% (29/324)]. Colonoscopy examination revealed 606 cases with lesions, the detection rate of lesions was 17.6%, and the male detection rate was significantly higher than that of females [26.9% (313/1162) vs. 12.8% (293/2287), χ²=106.140, P<0.001]. The detection rate of lesions increased with age [40-49, 50-59, 60-69, ≥70: 10.9% (119/1091), 17.5% (252/1438), 25.0% (223/891) and 41.4% (12/29), respectively, χ²=79.010, P<0.001]. A total of 584 cases underwent endoscopic excision and pathological diagnosis, and 465 cases (13.5%) of precancerous lesions were detected. The prevalence of precancerous lesions in men was higher than that in women [21.3% (247/1162) vs. 9.5% (218/2287), χ²=90.801, P<0.001], the precancerous lesion detection rate increased with age [40-49, 50-59, 60-69, ≥70: 8.0% (87/1091), 14.3% (206/1438), 18.1% (161/891) and 37.9% (11/29); χ²=58.109, P<0.001]. A total of 4 patients with colorectal cancer were detected, including 3 males and 1 female. The detection rate of male colorectal cancer was 258.2/100 000, and the female was 43.7/100 000, whose difference was not statistically significant (χ²=1.488, P=0.223). There was no significant difference in the detection rate of colorectal cancer among 4 age groups [40-49, 50-59, 60-69, ≥70: 91.7/100 000 (1/1091), 69.5/100 000 (1/1438), 224.5/100 000 (2/891) and 0, respectively, P=0.696]. Conclusions Screening for colorectal cancer is an important measure to control the onset and death of colorectal cancer. Through the questionnaire risk assessment plus colonoscopy, two-step screening method can improve the screening efficiency and greatly reduce the screening cost.