Ethnic variation in type of genital herpes simplex virus infection in a South London genitourinary medicine clinic

Contriving a chimeric polyvalent vaccine to prevent infections caused by herpes simplex virus (type-1 and type-2): an exploratory immunoinformatic approach

Herpes simplex virus type 1 (HSV-1) and 2 (HSV-2) cause a variety of infections including oral-facial infections, genital herpes, herpes keratitis, cutaneous infection and so on. To date, FDA-approved licensed HSV vaccine is not available yet. Hence, the study was conducted to identify and characterize an effective epitope based polyvalent vaccine against both types of Herpes Simplex Virus. The selected proteins were retrieved from ViralZone and assessed to design highly antigenic epitopes by binding analyses of the peptides with MHC class-I and class-II molecules, antigenicity screening, transmembrane topology screening, allergenicity and toxicity assessment, population coverage analysis and molecular docking approach. The final vaccine was constructed by the combination of top CTL, HTL and BCL epitopes from each protein along with suitable adjuvant and linkers. Physicochemical and secondary structure analysis, disulfide engineering, molecular dynamic simulation and codon adaptation were further employed to develop a unique multi-epitope peptide vaccine. Docking analysis of the refined vaccine structure with different MHC molecules and human immune TLR-2 receptor demonstrated higher interaction. Complexed structure of the modeled vaccine and TLR-2 showed minimal deformability at molecular level. Moreover, translational potency and microbial expression of the modeled vaccine was analyzed with pET28a(+) vector for E. coli strain K12 and the vaccine constructs had no similarity with entire human proteome. The study enabled design of a novel chimeric polyvalent vaccine to confer broad range immunity against both HSV serotypes. However, further wet lab based research using model animals are highly recommended to experimentally validate our findings.Communicated by Ramaswamy H. Sarma.

Carbazole Derivatives as Antiviral Agents: An Overview

Keywords: carbazole; tetrahydrocarbazole; antiviral agents.

An estimate of the global prevalence and incidence of herpes simplex virus type 2 infection

OBJECTIVE

To estimate the global prevalence and incidence of herpes simplex virus type 2 (HSV-2) infection in 2003.

METHODS

A systematic review was undertaken of published seroprevalence surveys describing the prevalence or incidence of HSV-2 by age and gender. For each of 12 regions, pooled prevalence values by age and gender were generated in a random-effect model. HSV-2 incidence was then estimated from these pooled values using a constant-incidence model. Values of the HSV-2 seroprevalence from the model fits were applied to the total population to estimate the numbers of people infected.

FINDINGS

The total number of people aged 15-49 years who were living with HSV-2 infection worldwide in 2003 is estimated to be 536 million, while the total number of people who were newly infected with HSV-2 in 2003 is estimated to be 23.6 million. While the estimates are limited by poor availability of data, general trends are evident. For example, more women than men were infected, and the number infected increased with age. Although prevalence varied substantially by region, predicted prevalence was mostly higher in developing regions than developed regions.

CONCLUSION

The prevalence of HSV-2 is relatively easy to measure since infection is lifelong and has a specific serological test. The burden of disease is less easy to quantify. Despite the often sparse data on which these estimates are based, it is clear that HSV-2 infection is widespread. The dramatic differences in prevalence between regions are worthy of further exploration.

Macrophages and cytokines in the early defence against herpes simplex virus

Herpes simplex virus (HSV) type 1 and 2 are old viruses, with a history of evolution shared with humans. Thus, it is generally well-adapted viruses, infecting many of us without doing much harm, and with the capacity to hide in our neurons for life. In rare situations, however, the primary infection becomes generalized or involves the brain. Normally, the primary HSV infection is asymptomatic, and a crucial element in the early restriction of virus replication and thus avoidance of symptoms from the infection is the concerted action of different arms of the innate immune response. An early and light struggle inhibiting some HSV replication will spare the host from the real war against huge amounts of virus later in infection. As far as such a war will jeopardize the life of the host, it will be in both interests, including the virus, to settle the conflict amicably. Some important weapons of the unspecific defence and the early strikes and beginning battle during the first days of a HSV infection are discussed in this review. Generally, macrophages are orchestrating a multitude of anti-herpetic actions during the first hours of the attack. In a first wave of responses, cytokines, primarily type I interferons (IFN) and tumour necrosis factor are produced and exert a direct antiviral effect and activate the macrophages themselves. In the next wave, interleukin (IL)-12 together with the above and other cytokines induce production of IFN-gamma in mainly NK cells. Many positive feed-back mechanisms and synergistic interactions intensify these systems and give rise to heavy antiviral weapons such as reactive oxygen species and nitric oxide. This results in the generation of an alliance against the viral enemy. However, these heavy weapons have to be controlled to avoid too much harm to the host. By IL-4 and others, these reactions are hampered, but they are still allowed in foci of HSV replication, thus focusing the activity to only relevant sites. So, no hero does it alone. Rather, an alliance of cytokines, macrophages and other cells seems to play a central role. Implications of this for future treatment modalities are shortly considered.

A systematic review of the epidemiology and interaction of herpes simplex virus types 1 and 2

OBJECTIVES

To explore epidemiological evidence about the interaction of herpes simplex virus (HSV) 1 and HSV-2 infections.

METHODS

A systematic review was undertaken of published epidemiological studies describing the pattern of HSV-1 or HSV-2 by age, and the coincidence of the two viral infections.

RESULTS

In cross sectional studies the unadjusted odds of HSV-2 are greater in those with HSV-1 infection in study populations categorised as "low risk" (p = 0.06) and across European populations (p = 0.001). This was not evident in "high risk" populations or in the United States. This increased risk of HSV-2 in those with HSV-1 infection does not agree with the results of prospective studies where there is a non-significant trend towards a lower risk of HSV-2 infection associated with previous HSV-1 infection.

CONCLUSIONS

"Low risk" and European populations have a relatively low HSV-2 seroprevalence and infection is more concentrated in those with characteristics putting them at high risk for both HSV-1 and HSV-2. This confounding could mask any protective effect of HSV-1, which is hinted at, but not demonstrated, in prospective and adjusted studies.

Changing epidemiology of genital herpes simplex virus infection in Melbourne, Australia, between 1980 and 2003

OBJECTIVE

To investigate changes in the proportions of patients infected with genital herpes simplex virus (HSV) types 1 and 2 from 1980 to 2003 in Melbourne, Australia.

METHODS

A total of 25 372 patients were studied retrospectively. The proportions of HSV-1 and HSV-2 detected in these individuals were analysed by age, sex, and genital site.

RESULTS

In 1980 only 15.8% of HSV positive genital specimens were HSV-1 compared to 34.9% in 2003. In 2003 HSV-1 was detected in 77% of patients aged less than 20 years. Females were more likely to be infected with HSV-1, although the rate of increased detection was more pronounced in males. Except for females over the age of 40, the trend for the increase in HSV-1 was detected in all age groups. No specific genital site in either sex was associated with the increase.

CONCLUSIONS

The proportion of genital HSV-1 has increased in Australian patients, although HSV-2 is still the most common cause of genital infection. Confirmation of HSV type is necessary for optimal patient management.

Seroepidemiology of Herpes Simplex Type 2 in Pregnant Women in Belgium

OBJECTIVE

The objective of this study was to study the prevalence of herpes simplex virus (HSV) type 2 in pregnant women in Belgium.

STUDY DESIGN

The serum of 1000 consecutive women was collected. HSV-1 and HSV-2 control sera were added to the study. HSV-2 antibodies were tested with the HerpeSelect 2 enzyme-linked immunosorbent assay (ELISA; Focus) based on the use of the recombinant gG-2 antigen.

RESULTS

The 21 HSV-2 control subjects were positive. Among the HSV-1 control subjects, 18 were negative and 4 were positive. Among the pregnant women, 80.3% were negative, 1.5% had equivocal results, and 18.2% were positive. No statistical difference was observed according to the origin (European or African) of the women.

CONCLUSIONS

The results obtained with the control sera indicate a high sensitivity of the Focus ELISA, as well as a capacity to discriminate between HSV-1/HSV-2 infection. The HSV-2 prevalence in the studied population raises the question of the possible benefit of a specific preventive program in pregnant women.