Dietary and socio-economic factors in relation to Helicobacter pylori re-infection

AIM:To examine if dietary and socio-economic factors contribute to Helicobacter pylori(H pylori)re-infection. METHODS:The population of patients consisted of subjects in whom H pylori infection had been successfully treated in the past.Patients were divided into two groups:Ⅰ-examined group(111 persons with H pylori re-infection)andⅡ-control group(175 persons who had not been re-infected).The respondents were interviewed retrospectively on their dietary habits and socio-economic factors. RESULTS:A statistically significant lower frequency of fermented dairy products(P<0.0001),vegetables (P=0.02),and fruit(P=0.008)consumption was noted among patients with H pylori re-infection as compared to those who had not been re-infected. CONCLUSION:High dietary intake of probiotic bacteria,mainly Lactobacillus,and antioxidants,mainly vitamin C(contained in fruit and vegetables),might decrease the risk of H pylori re-infection.

Hepatitis E virus re-infection accelerates hepatocellular carcinoma development and relapse in a patient with liver cirrhosis:A case report and review of literature

BACKGROUND Hepatitis E virus(HEV)superinfection is a suspected promoting factor for hepatocellular carcinoma(HCC)in patients with chronic hepatitis and cirrhosis.However,to date,very few cases of HEV-related HCC have been reported.Nevertheless,the role of HEV re-infection in cirrhotic liver without other chronic hepatitis infections has rarely been explored.CASE SUMMARY A 53-year-old male farmer was diagnosed with liver cirrhosis and splenomegaly in August 2016,accompanied with negative HEV-IgM and positive HEV-IgG.No evidence of hepatitis B virus or hepatitis C virus infection was found.Since then the patient was evaluated for liver function and viral parameters every 3 mo.In June 2017,the patient presented severe fatigue with whole body itching and was diagnosed with HCC.Afterwards this patient experienced quick HCC development,progression,relapse,and metastasis in the following 8 mo,and presented persistent dual positivity of HEV-IgM and HEV-IgG.This patient had a long history of smoking and alcohol consumption.CONCLUSION This unique case invokes the importance of HEV surveillance and treatment among cirrhotic patients,HCC cases,and blood donors.

Factors influencing syphilis treatment failure and/or re-infection in HIV co-infected patients： immunosuppression or behaviors

Background Recent studies have reported overall increasing rates of syphilis with a high rate of human immunodeficiency virus （HIV） co-infection. However, there is little information about factors influencing syphilis treatment failure and/or re-infection in HIV co-infected patients. We conducted a study to evaluate factors associated with syphilis treatment failure/re-infection in HIV co-infected patients.Methods We reviewed 3542 medical records of HIV-infected patients from January 2005 to December 2007 followed up at HIV Clinic in New York City. Patients were categorized by rapid plasma regain titer （RPR） into success/serofast （4-fold decrease in RPR by 12 months after treatment, RPR conversion to nonreactive, persistently stable reactive RPR with no 4-fold increase）, and failure/re-infection （failure to decrease 4 folds in RPR by 12 months after treatment, 4-fold increase in RPR from baseline）.Results Among a total of 156 patients who met the eligibility criteria, 122 （78.2％） were under success/serofast category,and 34 （21.8％） were under failure/re-infection category. HIV viral load, CD4 cell count, and use of highly active antiretroviral therapy （HAART） were not associated with syphilis treatment failure/re-infection. However, early syphilis stage （OR：11.036, 95％ CI： 2.499-48.740, P=0.002） and high （＞1∶64） RPR titers （OR： 715.921, 95％ CI： 422.175-23 113.396, P ＜0.001） were significantly associated.Conclusions No correlations were seen with depressed immune states with syphilis treatment failure and/or re-infection. However, association with early stage syphilis suggests that risky psychological sexual behaviors may be the most important leading factor, emphasizing needs for safe sex education.

Severe fever with thrombocytopenia syndrome with re-infection in China: a case report

Background:Severe fever with thrombocytopenia syndrome(SFTS),an emerging tickborne infectious disease caused by a novel banyangvirus(SFTS virus,SFTSV),was endemic in several Asian countries with a high mortality up to 30%.Until recently,SFTSV-associated re-infection have not been reported and investigated.

Effect of awareness,quarantine and vaccination as control strategies on COVID-19 with Co-morbidity and Re-infection

In this paper,a deterministic compartmental model is presented to assess the impact of vaccination and non-pharmaceutical interventions(social distance,awareness,face mask,and quarantine)on the transmission dynamics of COVID-19 with co-morbidity and reinfection.An expression for the basic reproduction number is then derived for this model.Theoretical analysis shows that the model exhibits backward bifurcation phenomenon when the basic reproduction number is less than unity.But for the case of no reinfection,the model has a globally asymptotically stable disease-free equilibrium(DFE)when the basic reproduction number is less than unity.Furthermore,it is shown that in the case of no re-infection,a unique endemic equilibrium point(EEP)of the model exists which is globally asymptotically stable whenever the reproduction number is greater than unity.From the global sensitivity and uncertainty analysis,we have identified mask coverage,mask efficacy,vaccine coverage,vaccine efficacy,and contact rate as the most influential parameters influencing the spread of COVID-19.Numerical simulation results show that the use of effective vaccines with proper implementation of non-pharmaceutical interventions could lead to the elimination of COVID-19 from the community.Numerical simulations also suggest that the control strategy that ensures a continuous and effective mass vaccination program is the most cost-effective control strategy.The study also shows that in the presence of any co-morbidity and with the occurrence of re-infection,the disease burden may increase.

What could re-infection tell us about R0? A modeling casestudy of syphilis transmission

Many infectious diseases can lead to re-infection.We examined the relationship between the prevalence of repeat infection and the basic reproductive number(R0).First we solved a generic,deterministic compartmental model of re-infection to derive an analytic solution for the relationship.We then numerically solved a disease-specific model of syphilis transmission that explicitly tracked re-infection.We derived a generic expression that reflects a non-linear and monotonically increasing relationship between proportion reinfection and R0 and which is attenuated by entry/exit rates and recovery(i.e.treatment).Numerical simulations from the syphilis model aligned with the analytic relationship.Re-infection proportions could be used to understand how far regions are from epidemic control,and should be included as a routine indicator in infectious disease surveillance.

The immunological underpinnings of vaccinations to prevent cvtomegalovirus disease

A universal cytomegalovirus （CMV） vaccination promises to reduce the burden of the developmental damage that afflicts up to 0.5% of live births worldwide. An effective vaccination that prevents transplacental transmission would reduce CMV congenital disease and CMV-associated still births and leave populations less susceptible to opportunistic CMV disease. Thus, a vaccination against this virus has long been recognized for the potential of enormous health-care savings because congenital damage is life-long and existing anti-viral options are limited. Vaccine researchers, industry leaders, and regulatory representatives have discussed the challenges posed by clinical efficacy trials that would lead to a universal CMV vaccine, reviewing the links between infection and disease, and identifying settings where disrupting viral transmission might provide a surrogate endpoint for disease prevention. Reducing the complexity of such trials would facilitate vaccine development. Children and adolescents are the targets for universal vaccination, with the expectation of protecting the offspring of immunized women. Given that a majority of females worldwide experience CMV infection during childhood, a universal vaccine must boost natural immunity and reduce transmission due to reactivation and re-infection as well as primary infection during pregnancy. Although current vaccine strategies recognize the value of humoral and cellular immunity, the precise mechanisms that act at the placental interface remain elusive. Immunity resulting from natural infection appears to limit rather than prevent reactivation of latent viruses and susceptibility to re-infection, leaving a challenge for universal vaccination to improve upon natural immunity levels. Despite these hurdles, early phase clinical trials have achieved primary end points in CMV seronegative subjects. Efficacy studies must be expanded to mixed populations of CMV-naive and naturally infected subjects to understand the overall efficacy and potential. Together with CMV vaccine candidates currently in clinical development, additional promising preclinical strategies continue to come forward; however, these face limitations due to the insufficient understanding of host defense mechanisms that prevent transmission, as well as the age-old challenges of reaching the appropriate threshold of immunogenicity, efficacy, durability and potency. This review focuses on the current understanding of natural and CMV vaccine-induced protective immunity.