The historical surveillance results showed, there were 10 schistosomiasis cases in Huangshan City from 1994 to 2006. The survey in 2007 showed, the positive rates of blood examination for schistosomiasis in migrant workers and immigrant workers were 0.49% and 0.47% , respectively, but no schistosome-infected patients were detected by using the stool examination. An area with snails of 3 000 m~2 was found in the residence of the immigrant workers, but no infected snails were found. It is indicated that the mobile population has some impact on the transmission of schistosomiasis in the transmission-interrupted area. The surveillance and health education for the mobile population should be strengthened, and the imported infectious source should be prevented.

Objective:To analyze the clinical features of patients with severe dengue (SD) in Guangdong Province, and to improve the understanding of the diagnosis and treatment of SD in China.Methods:The clinical data, laboratory examination and etiological test results of 257 SD cases from 29 dengue fever designated hospitals in Guangdong Province from January 1, 2013 to December 31, 2019 were respectively collected. The relevant indicators of the criteria for severe organ involvement were quantified. Logistic regression analysis was performed to analyze the risk factors for the development of multiple organ failure in SD patients.Results:Among the 257 SD patients, age was (64.1±20.1) years old, with 65.4%(168/257) of them ≥60 years old, 142 were male and 115 were female. One hundred and fifty-two (59.1%) patients had underlying conditions, including 115(44.7%) patients with hypertension. The clinical manifestations were mainly fever (98.4%(253/257)), fatigue (70.0%(180/257)), cough or expectoration (44.4%(114/257)), lethargy or irritability (39.3%(101/257)), vomiting (30.4%(78/257)), abdominal pain or tenderness (20.6%(53/257)), hepatomegaly (2.3%(6/257)), bleeding tendency (59.5%(153/257)), and pleural effusion or ascites (43.6%(112/257)). Platelet count levels were decreased in 90.9%(231/254) of the cases, and 97.1%(234/241) of patients had normal or decreased hematocrit. The most common of severe manifestations were severe organ involvement (61.1%(157/257)), followed by severe bleeding (37.0%(95/257)) and severe plasma leakage (30.0%(77/257)). Severe organ involvements were more common in the kidney (27.6%(71/257)) and heart (26.8%(69/257)). Multivariate logistic regression analysis showed that age (odds ratio ( OR)=1.051, 95% confidence interval ( CI) 1.004 to 1.100, P=0.035), hypertension ( OR=5.224, 95% CI 1.272 to 21.462, P=0.022), elevated aspartate aminotransferase (AST) level ( OR=1.002, 95% CI 1.001 to 1.003, P=0.001), blood urea nitrogen (BUN) ( OR=1.050, 95% CI 1.005 to 1.098, P=0.030), and international normalized ratio (INR) ( OR=4.604, 95% CI 1.601 to 13.238, P=0.005) were risk factors for the development of multiple organ failure in SD patients. The detection results of serum samples form 113 SD patients in acute phase showed that dengue virus (DENV)-1 accounted for 89.4%(101/113), DENV-2 accounted for 9.7%(11/113), and DENV-3 accounted for 0.9% (1/113). Conclusions:Elderly and those with co-existing conditions such as hypertension in SD patients in Guangdong Province are more common. Severe organ involvement such as kidney and heart is the main cause of SD. DENV-1 infection is predominant. Significant elevated levels of AST, BUN and INR may be related to a poor prognosis.