Quantitative Microbial Risk Assessment of Cryptosporidium and Giardia in Public Drinking Water in China.

We aimed to assess the risks of Cryptosporidium and Giardia infections associated with drinking water for local residents, based on a quantitative microbial risk assessment, in three densely populated regions of China. In total, 45 source water samples and 45 treated water samples were collected from June to December 2014. Five Cryptosporidium-positive samples and 5 Giardia-positive samples were found. The annual probability of infection for individuals in Jintan (6.27 × 10 -4-2.05 × 10 -3 for Cryptosporidium and 7.18 × 10 -4-2.32 × 10 -3 for Giardia), Ezhou (6.27 × 10 -4-1.10 × 10 -2 for Cryptosporidium and 3.65 × 10 -4-1.20 × 10 -3 for Giardia), and Binyang (3.79 × 10 -4-1.25 × 10 -3 for Cryptosporidium) exceeded the tolerable risk of infection of 10 -4 set by the United States Environmental Protection Agency. Moreover, the corresponding disease burdens of cryptosporidiosis and giardiasis, due to direct drinking and residual water in these regions, exceeded the threshold of 10 -6 disability-adjusted life years per person per year set by the World Health Organization. These results provide insights into strategies to improve the safety of drinking water.

[Expression and Activity of Arginase from Monocytic-type Myeloid-derived Suppressor Cells in Rats Infected with Echinococcus granulosus].

Objective: To investigate the alteration of expression and activity of arginase from monocytic-type myeloid-derived suppressor cells（M-MDSC） in BALB/c mice infected with Echinococcus granulosus. Methods: Twelve BALB/c female mice were randomly divided into control and infected groups. The mice were injected intraperitoneally with 2 000 live protoscoleces or an equivalent volume of normal saline. After 120 days, peripheral blood was collected through venae orbitaeta, and mice were sacrificed for pathological examination. The spleen was collected under aseptic conditions and single-cell suspension was prepared for M-MDSC isolation using the magnetic bead separation technology. Total RNA was extracted from M-MDSC, cDNA was generated, and genes with differential expression without and with infection were screened using the chip hybridization method. The resulting genes were further validated using real-time PCR. The activity of arginase from peripheral blood was also measured. Results: Single cyst was formed within the abdomen and internal organs 120 days after infection. Chip hybridization and real-time PCR showed that the relative expression of arginase from M-MDSC in the infected group （7.92±0.85 and 11.97±5.39, respectively） was significantly higher than that in the control group （1.65±0.19 and 1.00±0.57, respectively） （P<0.05）. The activity of arginase was also significantly higher in the infected group ［（3.83±0.44）U/Lï¼½ than in the control [(1.57±0.57）U/L]. Conclusion: The expression and activity of arginase from mouse M-MDSC both increase significantly after infection with Echinococcus granulosus.

[Serological Analysis of Antibodies against Cysticercus cellulosae and Toxoplasma gondii in 122 Patients with Meningitis Encephalitis Syndrome].

Objective: To examine the IgG and IgM antibodies for parasites Cysticercus cellulosae and Toxoplasma gondii in 122 patients with meningitis encephalitis syndrome, and provide basis for clinical diagnosis of the meningitis encephalitis syndrome. Methods: The sera were collected from patients with meningitis encephalitis syndrome in Shanghai Jiaotong University Affiliated Sixth People's Hospital, People's Hospital of Danyang City, and Jiangsu University Affiliated Hospital from August, 2014 to December, 2015. Serum IgG and IgM antibodies for cysticercus and T. gondii were examined using antibody test kits. The antibody positive rate was calculated and its distribution was analyzed by gender, season, age and occupation. Results: A total of 122 patients with meningitis encephalitis syndrome were included. Seventeen and 22 patients of them were positive for IgG （13.9%, 17/122） and IgM（18.0%, 22/122） against cysticercus, respectively, while 29 and 8 cases were positive for IgG （23.8%, 29/122） and IgM （6.6%, 8/122） against T. gondii. The positive rate of cysticercus and T. gondii in males was 30.6%（22/72） and 31.9%（23/72） respectively, while that in females was 26.0%（13/50） and 24.0% （12/50）. The positive rate of IgM against cysticercus was 12.0%（3/25）, 27.0%（17/63）, 6.9% （2/29）, and 0（0/5） from spring to winter, highest within 13-25 years（45.0%, 9/20） among age groups, and highest in workers（7/14） among various occupations. The positive rate of IgM against T. gondii was 4.0%（1/25）, 11.1% （7/63）, 0（0/29）, and 0（0/5） from spring to winter, highest in ages >65 years（44.0%, 11/25）, and highest in patients with other occupations（4/10）. There was no statistically significant difference in the positive rate between males and females, and among different seasons, ages and occupations. Conclusion: The positive rate of antibodies against cysticercus and T. gondii is high in the patients included, suggesting that a serological test for parasite infection might be performed during clinical diagnosis of meningitis encephalitis syndrome.