Vaccination against sexually transmitted infections:

Neisseria gonorrhoeae vaccines: a contemporary overview

Neisseria gonorrhoeae infection is an important public health issue, with an annual global incidence of 87 million. N. gonorrhoeae infection causes significant morbidity and can have serious long-term impacts on reproductive and neonatal health and may rarely cause life-threatening disease. Global rates of N. gonorrhoeae infection have increased over the past 20 years. Importantly, rates of antimicrobial resistance to key antimicrobials also continue to increase, with the United States Centers for Disease Control and Prevention identifying drug-resistant N. gonorrhoeae as an urgent threat to public health. This review summarizes the current evidence for N. gonorrhoeae vaccines, including historical clinical trials, key N. gonorrhoeae vaccine preclinical studies, and studies of the impact of Neisseria meningitidis vaccines on N. gonorrhoeae infection. A comprehensive survey of potential vaccine antigens, including those identified through traditional vaccine immunogenicity approaches, as well as those identified using more contemporary reverse vaccinology approaches, are also described. Finally, the potential epidemiological impacts of a N. gonorrhoeae vaccine and research priorities for further vaccine development are described.

Dynamic, Helminth-Induced Immune Modulation Influences the Outcome of Acute and Chronic Hepatitis B Virus Infection

BACKGROUND

Chronic hepatitis B develops more frequently in countries with high prevalence of helminth infections. The crosstalk between these 2 major liver-residing pathogens, Schistosoma mansoni and hepatitis B virus (HBV), is barely understood.

METHODS

We used state-of-the-art models for both acute and chronic HBV infection to study the pathogen-crosstalk during the different immune phases of schistosome infection.

RESULTS

Although liver pathology caused by schistosome infection was not affected by either acute or chronic HBV infection, S mansoni infection influenced HBV infection outcomes in a phase-dependent manner. Interferon (IFN)-γ secreting, HBV- and schistosome-specific CD8 T cells acted in synergy to reduce HBV-induced pathology during the TH1 phase and chronic phase of schistosomiasis. Consequently, HBV was completely rescued in IFN-γ-deficient or in TH2 phase coinfected mice demonstrating the key role of this cytokine. It is interesting to note that secondary helminth infection on the basis of persistent (chronic) HBV infection increased HBV-specific T-cell frequency and resulted in suppression of virus replication but failed to fully restore T-cell function and eliminate HBV.

CONCLUSIONS

Thus, schistosome-induced IFN-γ had a prominent antiviral effect that outcompeted immunosuppressive effects of TH2 cytokines, whereas HBV coinfection did not alter schistosome pathogenicity.

Epidemiology and prevention of sexually transmitted infections in men who have sex with men at risk of HIV

Since 2012, the increasingly widespread promotion and uptake of HIV treatment as prevention and pre-exposure prophylaxis in men who have sex with men has been associated with increased sexually transmitted infections (STIs). However, numbers of STI cases have been rising for more than 20 years and the introduction of biomedical HIV interventions cannot explain the majority of the rises in STIs. The increases appear to have occurred mostly because of gradual changes in behaviour over many years, coupled in some settings with more condomless anal intercourse, and as a result of the increased screening for previously undetected asymptomatic infections. If control of STIs is to be improved, then a far greater emphasis on increased use of existing effective STI control strategies will be required, in addition to the investigation of new interventions. Central to effective STI control is accessible clinical care and screening services, which are currently inadequate in most settings. Insufficient action carries a risk of increased STI epidemics, including of newly resistant organisms.

Mechanisms of Huangqi Decoction Granules () on Hepatitis B Cirrhosis Patients Based on RNA-Sequencing

OBJECTIVE

To explore the action mechanisms of Huangqi Decoction Granules (, HQDG) on hepatitis B cirrhosis.

METHODS

A total of 85 patients with hepatitis B cirrhosis were randomly divided into HQDG group (42 cases) and control group (43 cases) by a random number table and were treated with HQDG or placebo for 48 weeks (6 g per times and orally for 3 times a day), respectively. After RNA-sequencing of serum samples extracted from the patients, the differentially expressed genes (DEGs) in HQDG and control groups before and after treatment were separately screened. The DEGs were then performed pathway enrichment analysis and proteinprotein interaction (PPI) network analysis. The expression levels of key genes were detected by quantitative realtime polymerase chain reaction (qRT-PCR).

RESULTS

After the investigation, 4 and 3 cases were respectively excluded from HQD and control groups because of the incomplete data. Additionally, 3 and 5 cases were lost to follow up in HQD and control groups respectively. Finally, a total of 70 cases with good compliance were included for further DEGs analysis. A total of 1,070 DEGs (including 455 up-regulated genes and 615 down-regulated genes) in HQDG group and 227 DEGs (including 164 up-regulated genes and 63 down-regulated genes) in the control group were identified after treatment. Compared with the control group, 1,043 DEGs were specific in HQDG group. Besides, 1 up-regulated transcription factor (TF, such as GLI family zinc finger 1, GLI1) and 25 down-regulated TFs (such as drosophila mothers against decapentaplegic proteinfamily member 2, SMAD2) were identified. Pathway enrichment analysis showed that down-regulated Ras homolog gene family member A (RHOA) was enriched in pathogenic Escherichia coli infection. In the PPI network, up-regulated epidermal growth factor receptor (EGFR), and down-regulated cell division cycle 42 (CDC42) as well as v-akt murine thymoma viral oncogene homolog 1 (AKT1) had higher degrees. Moreover, long non-coding RNAs (lncRNA) growth arrest-specific 5 (GAS5) was involved in the lncRNA-target regulatory network. Furthermore, qRT-PCR revealed that expression levels of CDC42 and GLI1 had significant differences in HQDG group before and after treatment (P<0.05).

CONCLUSIONS

CDC42 and GLI1 may be the targets of HQDG in patients with hepatitis B cirrhosis. Additionally, SMAD2, EGFR, AKT1, RHOA and GAS5 might be associated with the curative effect of HQDG on hepatitis B cirrhosis patients.

Clinical and virological implications of A1846T and C1913A/G mutations of hepatitis B virus genome in severe liver diseases

OBJECTIVE

Mutations occurring within different genes of hepatitis B virus (HBV) genome may have different clinical implications. This study aimed to observe the clinical and virological implications of the A1846T and C1913A/G mutations of HBV genome in the development and treatment outcome of severe liver diseases, which has not been previously determined.

MATERIALS AND METHODS

A total of 438 cases of patients with liver diseases were retrospectively reviewed, including 146 with mild chronic hepatitis B infection (CHB-M), 146 with severe chronic hepatitis B infection (CHB-S), and 146 with acute-on-chronic liver failure (ACLF). Partial or full-length HBV genome was directly sequenced. Replicons containing A1846T, C1913A or other mutant sequences, or the wild-type counterparts were constructed respectively, and then transfected into HepG2 cells for phenotype analysis.

RESULTS

There was significant difference in the detection rates of A1846T (30.82%, 40.41% and 55.48%, respectively) and C1913A/G (15.52%, 28.77%, and 35.62%, respectively) among patients with CHB-M, those with CHB-S, and those with ACLF (p < .01). A1846T was significantly associated with the mortality of ACLF patients within six months after the disease onset (OR 1.704, p = .041). In vitro experiment revealed that A1846T mutant resulted in 3.20-fold and 1.85-fold increase of replication capacity and promoter activity, respectively compared with wild type counterpart (p < .001), while C1913A led to a significant decrease of core protein expression (p < .05).

CONCLUSION

Occurrence of A1846T and C1913A is positively associated with clinical presentations of severe liver disease. A1846T mutation is significantly associated with poor prognosis of ACLF.

Knowledge, attitudes and practices toward prevention of hepatitis B virus infection among medical students at Northern Border University, Arar, Kingdom of Saudi Arabia

Background and aim

Health care workers’ risk of occupational exposure to HBV is a chief concern, particularly with young students in the health profession.

This study was carried out to assess the knowledge regarding symptoms, risk factors and prevention of hepatitis B virus infection among medical students.

Methods

A cross-sectional study was carried out from November 01, 2016 to May 30, 2017 on medical students at the Northern Border University (Arar, Kingdom of Saudi Arabia). Data were collected from 200 students from all academic years using pre-designed questionnaire which included questions designed to fulfill the study objectives.

Results

Regarding students’ knowledge about hepatitis B infection, 81% of them knew that carriers could transmit infection, 89.5% of them knew that it could not be spread by casual contact, 80% by contact with open wound, 96.5% by contaminated blood and body fluids, 92.5% by unsterilized syringe, needle and surgical instruments and 79.5% by unsafe sex. In total, 86.5% of students knew that a vaccine could prevent HBV infection, 95% knew it had been laboratory tested, 64% knew HBV had post exposure prophylaxis and only 55% knew that it could be cured. In all, 75.5% of students knew that HBV caused liver cancer. Regarding attitude, 23% of students said they had no concern of being infected with HBV, 86.5% agreed that HBV vaccine was safe and effective and 90% believed that following infection, control guidelines would protect them from being infected by HBV at work. Regarding practice, only 56.5% of students had screened for HBV infection 22% had had a needle prick injury but 68% would report that injury. Furthermore, 69.5% have received HBV vaccine but only 38% of them had received 3 doses.

Conclusion

The students’ knowledge of the hepatitis B virus was found to be good. We recommend improving knowledge, attitude and practice of the public as well as students, through health education campaigns and settings.

Anti-retroviral Therapy Based HIV Prevention Among a Sample of Men Who Have Sex with Men in Cape Town, South Africa: Use of Post-exposure Prophylaxis and Knowledge on Pre-exposure Prophylaxis

Men who have Sex with Men (MSM) have been affected disproportionately by the global HIV pandemic. Rates of consistent condom-use are low and there is a need for further biomedical prevention interventions to prevent new HIV infections. Post exposure prophylaxis (PEP) can reduce the risk of HIV, but uptake among MSM is low. Pre-exposure prophylaxis (PrEP), an innovative anti-retroviral-based HIV prevention tool might be an appropriate intervention for MSM who have recently accessed PEP that involves HIV negative individuals taking daily tenofovir+emtricitabine for HIV prevention. 44 MSM, attending a primary health-care level MSM-focused sexual health clinic in Cape Town, South Africa, who had initiated PEP were enrolled in this study. Participants were followed up after 2, 4 and 12 weeks. Self-administered electronic surveys were completed at the initial, 4 and 12 week visit. Barriers and facilitators to accessing PEP and remaining adherent were examined, as was knowledge about PrEP. Thirty-two participants (80 %) were <40 years of age (range 20-65 years). 35 % of the participants reported their reason for requiring PEP as condomless receptive anal intercourse. A further 20 % required PEP following condomless penetrative anal intercourse; 27.5 % required PEP due to a broken condom during receptive anal sex and 2 participants during insertive anal sex. Three participants did not complete 28 days of PEP or were lost to follow up. Over half (58.5 %) of the participants reported being completely adherent to their regime; under a third (31.7 %) reported missing one PEP dose; and 9.8 % reported missing more than one dose. 36/40 (90 %) had heard of PrEP and 30/40 (75 %) indicated that they would use PrEP if it were accessible to them. That we enrolled 44 MSM who accessed PEP from a Department of Health affiliated clinic over 12 months, speaks to the low uptake by MSM of PEP services in South Africa. Adherence was high and demonstrates that adherence support is feasible from a state health clinic. Reported risk behaviors in some high-risk participants did not change over time, demonstrating the need for additional longer-term HIV preventions such as PrEP. PEP users could conceivably be transitioned from PEP to PrEP.

Seroprevalence of Hepatitis B Surface Antigen and Occupational Risk Factors Among Health Care Workers in Ekiti State, Nigeria

INTRODUCTION

Hepatitis B virus (HBV) infection is contracted from blood and other body fluid making healthcare workers (HCW) prone to the infection especially in the developing world. Though it is a vaccine preventable disease, the level of awareness and universal precaution among HCW is low in sub-Saharan African and Asia.

AIM

The study was aimed at determining the seroprevalence of hepatitis B surface antigen and occupational risk factors among health care workers at Ekiti State University Teaching Hospital, Ado Ekiti.

MATERIALS AND METHODS

One hundred and eighty-seven (187) blood samples were collected from volunteer subjects who comprised of medical doctors, nurses, health attendants, and porters who are in regular contact with blood, body fluids and patients after informed consent. Well detailed and structured questionnaires were used to obtain demographic and other relevant data from the subjects. Blood samples were tested by Enzyme Linked Immunosorbent assay (ELISA) for hepatitis B surface antigen.

RESULTS

Out of the 187 HCWs there were 91 males (48.7%) and 96 (51.3%) females. Only 2 participants tested positive to hepatitis B surface antigen with a prevalence of 1.1%. Also, only 30 (16.0%) of the participants had been fully vaccinated against the infection while the remaining 157(84.0%) had no adult vaccination.

CONCLUSION

It is obvious that the awareness of the infection is low among the HCWs studied thus the need to incorporate screening for HbsAg and vaccination against HBV into the periodic/pre-employment health intervention programmes by employers to help in the protection of HCWs and control the spread of the virus.

Viral carcinogenesis: factors inducing DNA damage and virus integration

Viruses are the causative agents of 10%-15% of human cancers worldwide. The most common outcome for virus-induced reprogramming is genomic instability, including accumulation of mutations, aberrations and DNA damage. Although each virus has its own specific mechanism for promoting carcinogenesis, the majority of DNA oncogenic viruses encode oncogenes that transform infected cells, frequently by targeting p53 and pRB. In addition, integration of viral DNA into the human genome can also play an important role in promoting tumor development for several viruses, including HBV and HPV. Because viral integration requires the breakage of both the viral and the host DNA, the integration rate is believed to be linked to the levels of DNA damage. DNA damage can be caused by both endogenous and exogenous factors, including inflammation induced by either the virus itself or by co-infections with other agents, environmental agents and other factors. Typically, cancer develops years to decades following the initial infection. A better understanding of virus-mediated carcinogenesis, the networking of pathways involved in transformation and the relevant risk factors, particularly in those cases where tumorigenesis proceeds by way of virus integration, will help to suggest prophylactic and therapeutic strategies to reduce the risk of virus-mediated cancer.

Distribution and perinatal transmission of bacterial vaginal infections in pregnant women without vaginal symptoms

BACKGROUND

We evaluated the distribution and vertical transmission of bacterial vaginal infections in asymptomatic pregnant women.

METHODS

We performed multiplex PCR on secretions collected on cervical swabs from pregnant women at over 36 weeks of gestation and on oral secretions collected from their neonates immediately after delivery. We detected sexually transmitted infections (STIs) with the following 6 species: Trichomonas vaginalis, Mycoplasma hominis, Mycoplasma genitalium, Chlamydia trachomatis, Neisseria gonorrhoeae, and Ureaplasma urealyticum.

RESULTS

Infectious agents were detected in 64 of 455 pregnant women (14.1%) and in 11 neonates (2.4%). The rate of vertical transmission was 17.2% and all the infectious agents detected in neonates were concordant with those found in their mothers. U. urealyticum was the most frequently detected in the maternal genitalia, followed by M. hominis. Women who were in labor for a longer period of time had a higher risk of vertically transmitting STI agents to their neonates.

CONCLUSIONS

Vertical transmission of bacterial STIs from mothers to their infants is possible at delivery and influenced by the duration of labor. STIs should be diagnosed in pregnant women to prevent vertical transmission from the mother to the infant at the time of delivery.

Translation of biomedical prevention strategies for HIV: prospects and pitfalls

Early achievements in biomedical approaches for HIV prevention included physical barriers (condoms), clean injection equipment (both for medical use and for injection drug users), blood and blood product safety, and prevention of mother-to-child transmission. In recent years, antiretroviral drugs to reduce the risk of transmission (when the infected person takes the medicines; treatment as prevention) or reduce the risk of acquisition (when the seronegative person takes them; preexposure prophylaxis) have proven to be efficacious. Circumcision of men has also been a major tool relevant for higher prevalence regions such as sub-Saharan Africa. Well-established prevention strategies in the control of sexually transmitted diseases and tuberculosis are highly relevant for HIV (ie, screening, linkage to care, early treatment, and contact tracing). Unfortunately, only slow progress is being made in some available HIV-prevention strategies such as family planning for HIV-infected women who do not want more children and prevention of mother-to-child HIV transmission. Current studies seek to integrate strategies into approaches that combine biomedical, behavioral, and structural methods to achieve prevention synergies. This review identifies the major biomedical approaches demonstrated to be efficacious that are now available. We also highlight the need for behavioral risk reduction and adherence as essential components of any biomedical approach.