BackgroundTo assess the association between maternal human immunodeficiency virus (HIV) infection and low birth weight (LBW)/prematurity (PTD), we conducted a meta-analysis of cohort studies of HIV infected and uninfected women.MethodsSeveral English and Chinese databases were searched (updated to May 2015) to find the studies reporting infant outcomes associated with exposure to maternal HIV infection during pregnancy. Relevant articles were manually selected based on several inclusion and exclusion criteria.ResultsFifty-two cohort studies including 15,538 (for LBW) and 200,896 (for PTD) HIV infected women met the inclusion criteria. There was significant heterogeneity among studies for maternal HIV infection associated with LBW/PTD (I2 = 71.7 %, P < 0.05, and I2 = 51.8 %, P < 0.05 for LBW and PTD, respectively). The meta-analysis demonstrated that the maternal HIV infection was significantly associated with both LBW (pooled odds ratio (OR): 1.73, 95 % confidence interval (CI): 1.64, 1.82, P < 0.001) and PTD (pooled OR: 1.56, 95 % CI: 1.49, 1.63, P < 0.001). No significant difference in the relationship between maternal HIV infection and adverse pregnancy outcomes was detected among the groups of different study periods. HIV infected women were at slightly higher risk of LBW in developing countries compared with women in developed countries (OR: 2.12 (95 % CI: 1.81, 2.48) vs. 1.75 (95 % CI: 1.44, 2.12)). Antiretroviral drugs usage did not significantly change the associations of maternal HIV exposure with LBW and PTD.ConclusionsHIV infected women were at higher risk of having a low birth weight infant or a preterm delivery infant compared with uninfected women. Such associations did not change significantly over time or were not significantly affected by the usage of antiretroviral drugs.Electronic supplementary materialThe online version of this article (doi:10.1186/s12884-015-0684-z) contains supplementary material, which is available to authorized users.

Over the past decades China has made a great stride in controlling schistosomiasis, eliminating transmission of Schistosoma japonicum in 5 provinces and remarkably reducing transmission intensities in the rest of the seven endemic provinces. Recently, an integrated control strategy, which focuses on interventions on humans and bovines, has been implemented throughout endemic areas in China. This strategy assumes that a reduction in transmission of S. japonicum from humans and bovines to the intermediate Oncomelania snail host would eventually block the transmission of this parasite, and has yielded effective results in some endemic areas. Yet the transmission of S. japonicum is relatively complicated – in addition to humans and bovines, more than 40 species of mammalians can serve as potential zoonotic reservoirs. Here, we caution that some factors – potential roles of other mammalian reservoirs and human movement in sustaining the transmission, low sensitivity/specificity of current diagnostic tools for infections, praziquantel treatment failures, changes in environmental and socio-economic factors such as flooding in key endemic areas - may pose great obstacles towards transmission interruption of the parasite. Assessing potential roles of these factors in the transmission and implications for current control strategies aiming at transmission interruption is needed.

In 2004 an aggressive plan was instituted aiming to achieve nationwide transmission control of schistosomiasis by 2015. Here, we report a longitudinal study on the control of schistosomiasis in Anhui province, China. Using a mathematical model, we compared the effects of different control strategies implemented in the study area. During the 5-year study period, a 60.8% reduction in human prevalence was observed from 2005 (7.95%) to 2009 (3.1%), and snail infection decreased from 0.063% in 2005 to zero in 2009. Results of the model agree well with the first 3-year field observations and suggest continuous decrease in human infections in the last 2 years, whereas the last 2-year field observations indicated that human infections appeared to be stable even with continuous control. Our findings showed that the integrated control strategy was effective, and we speculated that other factors besides bovines might contribute to the local transmission of the disease.

A total of 1,811 individuals from two villages located in the areas of China endemic for Schistosoma japonicum were analyzed by the Kato-Katz parasitologic examination, indirect hemagglutination assay (IHA), and enzyme-linked immunosorbent assay (ELISA). Statistical analysis of the results showed the kappa indices ranged from 0.106 to 0.234 between IHA and the stool examination and ranged from 0.037 to 0.134 between ELISA and the fecal examination. The sensitivity value of the IHA was 83.7% in Village A and 92.3% in Village B; the specificity value of the IHA was 55.8% in Village A and 67.3% in Village B. The sensitivity value of the ELISA was 88.4% in Village A and 96.2% in Village B; the specificity value of the ELISA was 38.4% in both Village A and Village B. A search for a good diagnostic test that can be applied in field situations in China should be given high priority.

Schistosomiasis control in China is facing a new challenge due to the rebound of epidemics in many areas and the unsustainable effects of the chemotherapy-based control strategy. Identifying high-risk regions for schistosomiasis is an important first step for an effective and sustainable strategy. Direct surveillance of snail habitats to detect high-risk regions is costly and no longer a desirable approach, while indirect monitoring of acute schistosomiasis may be a satisfactory alternative. To identify high-risk regions for schistosomiasis, we jointly used multiplicative and additive models with the kernel smoothing technique as the main approach to estimate the relative risk (RR) and excess risk (ER) surfaces by analyzing surveillance data for acute schistosomiasis. The feasibility of detecting high-risk regions for schistosomiasis through nonparametric spatial analysis was explored and confirmed in this study, and two significant high-risk regions were identified. The results provide useful hints for improving the national surveillance network for acute schistosomiasis and possible approaches to utilizing surveillance data more efficiently. In addition, the commonly used epidemiological indices, RR and ER, are examined and emphasized from the spatial point of view, which will be helpful for exploring many other epidemiological indices.