Relative transmissibility of shigellosis among male and female individuals:a modeling study in Hubei Province,China

Background:Developing countries exhibit a high disease burden from shigellosis.Owing to the different incidences in males and females,this study aims to analyze the features involved in the transmission of shigellosis among male(subscript m)and female(subscript f)individuals using a newly developed sex-based model.Methods:The data of reported shigellosis cases were collected from the China Information System for Disease Control and Prevention in Hubei Province from 2005 to 2017.A sex-based Susceptible-Exposed-Infectious/Asymptomatic-Recovered(SEIAR)model was applied to explore the dataset,and a sex-age-based SEIAR model was applied in 2010 to explore the sex-and age-specific transmissions.Results:From 2005 to 2017,130770 shigellosis cases(including 73981 male and 56789 female cases)were reported in Hubei Province.The SEIAR model exhibited a significant fitting effect with the shigellosis data(P<0.001).The median values of the shigellosis transmission were 2.3225×10^8 for SARmm(secondary attack rate from male to male),2.5729×10^8 for SARmf 2.7630×10^8 for SARfm,and 2.1061×10^8 for SARff.The top five mean values of the transmission relative rate in 2010(where the subscript 1 was defined as male and age<5 years,2 was male and age 6 to 59 years,3 was male and age>60 years,4 was female and age<5 years,5 was female and age 6 to 59 years,and 6 was male and age>60 years)were 5.76×10^8 forβ61;5.32×10^8 forβ31,4.01×10^8 forβ34,7.52×10^9 forβ62,and 6.04×10^9 for Conclusions:The transmissibility of shigellosis differed among male and female individuals.The transmissibility between the genders was higher than that within the genders,particularly female-to-male transmission.The most important route in children(age<5 years)was transmission from the elderly(age>60 years).Therefore,the greatest interventions should be applied in females and the elderly.

Shigellosis seasonality and transmission characteristics in different areas of China: A modelling study

Objective:In China,the burden of shigellosis is unevenly distributed,notably across various ages and geographical areas.Shigellosis temporal trends appear to be seasonal.We should clarify seasonal warnings and regional transmission patterns.Method:This study adopted a Logistic model to assess the seasonality and a dynamics model to compare the transmission in different areas.The next-generation matrix was used to calculate the effective reproduction number(Reff)to quantify the transmissibility.Results:In China,the rate of shigellosis fell from 35.12 cases per 100,000 people in 2005 to 7.85 cases per 100,000 people in 2017,peaking in June and August.After simulation by the Logistic model,the‘peak time’is mainly concentrated from mid-June to mid-July.China's‘early warning time’is primarily focused on from April to May.We predict the‘peak time’of shigellosis is the 6.30th month and the‘early warning time’is 3.87th month in 2021.According to the dynamics model results,the water/food transfer pathway has been mostly blocked off.The transmissibility of different regions varies greatly,such as the mean Reff of Longde County(3.76)is higher than Xiamen City(3.15),higher than Chuxiong City(2.52),and higher than Yichang City(1.70).Conclusion:The‘early warning time’for shigellosis in China is from April to May every year,and it may continue to advance in the future,such as the early warning time in 2021 is in mid-March.Furthermore,we should focus on preventing and controlling the personto-person route of shigellosis and stratified deploy prevention and control measures according to the regional transmission.

Antibacterial and anti-parasitic activities of Terfezia claveryi methanolic extract against some common pathogenic agents of infectious diarrhea

Objective:To assess the antidiarrheal effects of Terfezia claveryi methanolic extract against Escherichia coli,Salmonella typhimurium,Shigella flexneri,and Giardia lamblia.Methods:Antibacterial effects of the Terfezia claveryi methanolic extract were carried out by determining the minimum inhibitory concentration(MIC)and minimum bactericidal concentration through micro broth dilution technique.Furthermore,reactive oxygen species production and protein leakage were evaluated.To evaluate the in vitro anti-giardial effects of Terfezia claveryi methanolic extract,Giardia lamblia WB(ATCC®30957)trophozoites were treated with various concentrations of Terfezia claveryi methanolic extract for 10-360 min.In addition,the plasma membrane permeability of trophozoites treated with Terfezia claveryi methanolic extract was determined.The cytotoxicity effects of Terfezia claveryi methanolic extract against normal(HEK293T)and cancer(MCF-7)cells were also assessed using the MTT assay.Results:The MIC and minimum bactericidal concentration of Terfezia claveryi methanolic extract against bacterial strains were in the range of 0.52-1.04 and 1.04-2.08 mg/mL,respectively.The results revealed that reactive oxygen species production and protein leakage were significantly increased after the bacteria were treated with the Terfezia claveryi methanolic extract,especially at 1/3 and 1/2 MICs(P<0.001).Furthermore,Terfezia claveryi methanolic extract decreased the viability of Giardia lamblia trophozoites in a dose-dependent manner.Terfezia claveryi methanolic extract at 1,2,and 4 mg/mL resulted in 100%mortality in Giardia lamblia trophozoites after 360,240,and 120 min,respectively.Moreover,Terfezia claveryi methanolic extract altered the permeability of plasma membrane of Giardia lamblia trophozoites by increasing the concentration.MTT assay revealed that the 50%cytotoxic concentrations values for HEK293T and MCF-7 cells were 4.32 mg/mL and 6.40 mg/mL,respectively,indicating that Terfezia claveryi methanolic extract had greater cytotoxicity against cancer cells than normal cells.Conclusions:Terfezia claveryi methanolic extract had potent in vitro antibacterial and anti-parasitic effects on Escherichia coli,Salmonella typhimurium,Shigella flexneri,and Giardia lamblia by affecting cell membrane permeability and reactive oxygen species generation with no significant cytotoxicity on normal cells.

Effects of rhubarb(Rheum ribes L.)syrup on dysenteric diarrhea in children:a randomized,double-blind,placebo-controlled trial

BACKGROUND：Rheum ribes L.is a plant native to China,Iran,Turkey,India,and a few other countries.Antidiarrheal activity is considered to be one of its important properties according to various systems of traditional medicine.An increasing rate of bacterial resistance to antibiotics has led to treatment failure in some cases of shigellosis in children,and underlines a need for safe,efficient and valid options.OBJECTIVE：The purpose of this study is to evaluate the efficacy of R.ribes syrup as a complementary medicine for treatment of shigellosis in children.DESIGN,SETTING,PARTICIPANTS AND INTERVENTIONS：This randomized,doubleblind,placebocontrolled trial started with a group of 150 children aged between 12–72 months with suspected Shigella dysentery.R.ribes syrup or placebo syrup was administered to the intervention and control groups,respectively for 5 days.In addition,the standard antibiotic treatment（ceftriaxone for the first 3 days and cefixime syrup for 2 further days）was administered to both groups.MAIN OUTCOME MEASURES：Body temperature,abdominal pain,need for antipyretics,defecation frequency,stool volume and consistency and microscopic stool examination were recorded as outcome measures.Any observed adverse effects were also recorded.RESULTS：Mean duration of fever and diarrhea in the R.ribes group was significantly lower than that in the placebo group（P=0.016 and 0.001,respectively）.In addition,patients in the R.ribes group showed shorter duration of need for antipyretics and shorter duration of abdominal pain（P=0.012 and 0.001,respectively）.However,there were no significant differences between the two groups regarding the microscopic stool analyses.Furthermore,no adverse effect was reported.CONCLUSION：R.ribes syrup can be recommended as a complementary treatment for children with Shigella dysentery.