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ObjectivesOur objective was to determine the impact of maternal HIV–hepatitis B virus (HBV) coinfection on pregnancy outcomes.MethodsThe current study was conducted in a county of Yi Autonomous Prefecture in southwest China. Data were abstracted from hospitalisation records, including maternal and infant information. The seroprevalences of HIV and HBV infections and HIV–HBV coinfection were determined and the impact of maternal HIV–HBV coinfection on adverse pregnancy outcomes was assessed using logistic regression analysis. A treatment effects linear regression model was also applied to examine the effect of HBV, HIV or coinfection to quantify the absolute difference in birth weight from a reference of HBV–HIV negative participants.ResultsA total of 13 198 pregnant women were included in our study, and among them, 99.1% were Yi people and 90.8% lived in rural area. The seroprevalences of HIV and HBV infections and HIV–HBV coinfection were 3.6% (95% CI: 3.2% to 3.9%), 3.2% (95% CI: 2.9% to 3.5%) and 0.2% (95% CI: 0.1% to 0.2%) among the pregnant women, respectively. Maternal HIV–HBV coinfection was a risk factor for low birth weight (adjusted OR (aOR)=5.52, 95% CI: 1.97 to 15.40). Compared with the HIV mono-infection group, the risk of low birth weight was significantly higher in the HIV–HBV coinfection group (aOR=3.62, 95% CI: 1.24 to 10.56). Maternal HIV infection was associated with an increased risk of low birth weight (aOR=1.90, 95% CI: 1.38 to 2.60) and preterm delivery (aOR=2.84, 95% CI: 1.81 to 4.47). Perinatal death was more common when mothers were infected with HBV (aOR=2.85, 95% CI: 1.54 to 5.26).ConclusionsThe prevalence of HIV infection was high among pregnant women of the Yi region. Both HIV and HBV infections might have adverse effects on pregnancy outcomes. Maternal HIV–HBV coinfection might be a risk factor for low birth weight in the Yi region, which needs to be confirmed.

Cryptosporidium is a protozoan parasite that can infect both humans and animals and cause cryptosporidiosis. We aimed to estimate the global prevalence of Cryptosporidium infection. In this study, Web of Science, Medline and PubMed were searched for relative articles, published between January 1, 1960 and January 1, 2018. Included articles were restricted to English language and that sample size of articles was not less than 50. Studies with no information on the study period, location, method of diagnosis, sample size and number of infected people were excluded. Studies about outbreak, laboratory report or immunocompromised population were excluded as well. The quality of the included publications was assessed. The prevalence of cryptosporidiosis was estimated by DerSimonian–Laird random-effects model, after converting by the Freeman–Tukey type double arcsine transformation. From 13,064 publications selected by literature search, 221 studies were included in the meta-analysis. The global pooled prevalence of Cryptosporidium infection was 7.6 % (95% CI: 6.9–8.5). The highest estimated prevalence of Cryptosporidium infection was in Mexico (69.6%, 95% CI 66.3–72.8), Nigeria (34.0%, 95% CI 12.4–60.0), Bangladesh (42.5%, 95% CI 36.1–49.0) and Republic of Korea (8.3%, 95% CI 4.4–13.2) among general residents, patients, school children and healthy population, respectively. The estimated prevalence was high in people from low-income country, people with gastrointestinal symptoms, people younger than 5 years old and residents not living in urban areas. These estimates indicate the substantial prevalence of Cryptosporidium infection in the world, which may provide a theoretical basis for the formulation of the prevention strategy about Cryptosporidium.

Few studies have investigated the spatial variation in road traffic indicators associated with lung cancer risk. The purpose of this study was to explore the relationship between road traffic-related indicators and lung cancer risk and to estimate its spatial variability. The population-based case control study was conducted, including all the newly diagnosed lung cancer patients (cases) and colorectal cancer patients (controls) in Jiading District, Shanghai from 2014 to 2016. Traffic intensity variable (traffic intensity in a 500 m buffer), residential distance to major road or highway, and greenness exposure at the residence were estimated for each individual. We conducted unconditional logistic regression with adjustment for age, sex, smoking status and NDVI values and geographically weighted logistic regression (GWLR). The clustering of lung cancer risk was analyzed by Bernoulli model of the SaTScan software. This study included 1461 lung cancer patients and 954 colorectal cancer patients. In multivariate logistic regression, smoking [OR 1.25 95% CI (1.15-1.35)], living50 m from the major road [OR 1.43 95% CI (1.02-2.03)] were significantly associated with lung cancer risk. Residential Proximity to highway, residential greenness, and traffic intensity were not significantly associated with lung cancer risk. The GWLR model showed that the degree of correlation between residential proximity to major road and lung cancer risk varied geographically. The SaTScan results showed a lung cancer cluster in the southwest of Jiading District, Shanghai. Our study suggested that the distance from residence to the main road was significantly associated with lung cancer risk, which varied geographically. It is helpful to further study the traffic factors' spatial variation related to lung cancer risk and carry out reasonable regional planning.

Background Schistosomiasis remains an important public health issue in China and worldwide. Oncomelania hupensis is the unique intermediate host of schistosoma japonicum, and its change influences the distribution of S. japonica. The Three Gorges Dam (TGD) has substantially changed the ecology and environment in the Dongting Lake region. This study investigated the impact of water level and elevation on the survival and habitat of the snails. Methods Data were collected for 16 bottomlands around 4 hydrological stations, which included water, density of living snails (form the Anxiang Station for Schistosomiasis Control) and elevation (from Google Earth). Based on the elevation, sixteen bottomlands were divided into 3 groups. ARIMA models were built to predict the density of living snails in different elevation areas. Results Before closure of TGD, 7 out of 9 years had a water level beyond the warning level at least once at Anxiang hydrological station, compared with only 3 out of 10 years after closure of TGD. There were two severe droughts that happened in 2006 and 2011, with much fewer number of flooding per year compared with other study years. Overall, there was a correlation between water level changing and density of living snails variation in all the elevations areas. The density of living snails in all elevations areas was decreasing after the TGD was built. The relationship between number of flooding per year and the density of living snails was more pronounced in the medium and high elevation areas; the density of living snails kept decreasing from 2003 to 2014. In low elevation area however, the density of living snails decreased after 2003 first and turned to increase after 2011. Our ARIMA prediction models indicated that the snails would not disappear in the Dongting Lake region in the next 7 years. In the low elevation area, the density of living snails would increase slightly, and then stabilize after the year 2017. In the medium elevation region, the change of the density of living snails would be more obvious and would increase till the year 2020. In the high elevation area, the density of living snails would remain stable after the year 2015. Conclusion The TGD influenced water levels and reduced the risk of flooding and the density of living snails in the study region. Based on our prediction models, the density of living snails in all elevations tends to be stabilized. Control of S. japonica would continue to be an important task in the study area in the coming decade., Author Summary Oncomelania hupensis, an amphibious animal, is the unique intermediate host of schistosoma japonicum. Three Gorges Dam (TGD) is a tremendous hydrological project, and it influences the survival of animals downstream. It is studied for several reasons. First, schistosomiasis is still a world-wide parasitic disease which needs to be prevented and controlled. Second, TGD causes the change of water level, and it will impact the existence of snails, but how TGD causes the change of snails and even the epidemics of schistosomiasis is not revealed. In this study, the authors explore the association between TGD and snails. The time-series data contains over 10-year water level downstream TGD and 10-year density of living snails downstream TGD in Dongting Lake Region. These can help to find out the relationship between the change of water level and the change of density of living snails. After this exploration, we attempt to predict the density of living snails 7years later using ARIMA model.

Background Owing to the harmfulness and seriousness of Schistosomiasis japonica in China, the control and prevention of S. japonica transmission are imperative. As the unique intermediate host of this disease, Oncomelania hupensis plays an important role in the transmission. It has been reported that the snail population in Qiangliang Lake district, Dongting Lake Region has been naturally declining and is slowly becoming extinct. Considering the changes of environmental factors that may cause this phenomenon, we try to explore the relationship between circumstance elements and snails, and then search for the possible optimum scopes of environmental factors for snails. Methods Moisture content of soil, pH, temperature of soil and elevation were collected by corresponding apparatus in the study sites. The LISA statistic and GWR model were used to analyze the association between factors and mean snail density, and the values in high-high clustered areas and low-low clustered areas were extracted to find out the possible optimum ranges of these elements for snails. Results A total of 8,589 snail specimens were collected from 397 sampling sites in the study field. Besides the mean snail density, three environmental factors including water content, pH and temperature had high spatial autocorrelation. The spatial clustering suggested that the possible optimum scopes of moisture content, pH, temperature of the soil and elevation were 58.70 to 68.93%, 6.80 to 7.80, 22.73 to 24.23°C and 23.50 to 25.97 m, respectively. Moreover, the GWR model showed that the possible optimum ranges of these four factors were 36.58 to 61.08%, 6.541 to 6.89, 24.30 to 25.70°C and 23.50 to 29.44 m, respectively. Conclusion The results indicated the association between snails and environmental factors was not linear but U-shaped. Considering the results of two analysis methods, the possible optimum scopes of moisture content, pH, temperature of the soil and elevation were 58.70% to 68.93%, 6.6 to 7.0, 22.73°C to 24.23°C, and 23.5 m to 26.0 m, respectively. The findings in this research will help in making an effective strategy to control snails and provide a method to analyze other factors.

To understand the change trend of Oncomelania hupensis snails in the bottomland areas of Qian Liang Lake district in Eastern Dongting Lake area so as to provide the evidence for formulating a schistosomiasis control strategy.The monitoring data of snails of Qianliang Lake district from 1988 to 2011 were collected retrospectively and analyzed by using the method of the trend Chi-square test. The correlations among the snail density indicators were analyzed.1988 to 2011, the area of snails surveyed did not change and was 433.2 hm(2). The monitoring data showed that the change trend of the density of living snails and the schistosome infection rates of snails were not obvious (P0.05), but the mortality of snails showed a falling trend (P0.05); There were positive correlations between the average density of infected snails and the mortality of snails (r = 0.640, P0.05) , the infection rate of snails (r = 0.639, P0.05) , and the average density of living snails (r = 0.646, P0.05) , respectively. There was no correlation among other snail indicators. In 1999, only 7 snails were found, of them, only one snail was alive. The alive snails were not found after 2000.In the bottomland areas of Qianliang Lake district, the change trend of the density of alive snails were not obvious from 1988 to 1998, but the number of snails underwent a sharp drop in 1999 and snails have been not found till now.

To evaluate the effects of comprehensive measures with emphasis on schistosomiasis infectious source control at the embankment level.The comprehensive measures with emphasis on schistosomiasis infectious source control were carried out, and the data of human and Oncomelania snail infection rates were collected and analyzed statistically at embankment levels.In Anbao Embankment, except the other comprehensive measures were performed, 2606 buffaloes were removed. The infection rates of residents reduced from 8.04% before the intervention to 0.7% after the intervention, and the infection rates of snails reduced from 0.56% to 0.05%. In Anli Embankment, 535 buffaloes were removed. In the third year after the intervention, the infection rates of residents reduced from 5.87% to 1.09%, and the infection rates of snails reduced from 0.17% to 0.07%. In Anzao Embankment, 62 buffaloes were removed. In the second year after the intervention, the infection rates of residents reduced from 2.67% to 0.39%, and the infection rates of snails reduced from 1.12% to 0.00%. In Anchang Embankment, the buffaloes were not removed. The human infection rates reduced from 1.76% before the intervention to 1.23% after the intervention.The comprehensive measures with emphasis on schistosomiasis infectious source control, especially the buffalo's removal, are effective in the control of schistosome infection rates of residents and snails.