Cold sores are caused by certain strains of the herpes simplex virus (HSV). HSV-1 usually causes cold sores. HSV-2 is usually responsible for genital herpes. However, either type can cause sores in the facial area or on the genitals. Most people who are infected with the virus that causes cold sores never develop signs and symptoms. The herpes simplex virus usually enters the body through a break in the skin around or inside the mouth. It is usually spread when a person touches a cold sore or touches infected fluid-such as from sharing eating utensils or razors, kissing an infected person, or touching that person's saliva. A parent who has a cold sore often spreads the infection to his or her child in this way. Cold sores can also be spread to other areas of the body. In Spain a sample size of about 150 subjects per pre-specified age group was planned to assure that a two-sided 95% confidence interval (CI) for the prevalence of HSV antibodies would extend at most 8% from the observed value for a prevalence range of 5–95%. Antibody prevalence was calculated using the number of seropositive cases divided by the number of all subjects tested. Assuming a binominal distribution, the two-sided exact 95% CI was calculated. Differences in antibody prevalence between the sexes, age groups as well as between pregnant women and female blood donors were evaluated by logistic regression odds ratios based on Wald statistics. The level of significance was 0.05 (two-sided). We used SAS V9.2 software for statistical analyses.The amount of agreement between gG-1 and gC-1 ELISAs was computed using the number of sera with concordant results divided by the number of sera tested.Results: Prevalence of HSV-1 IgG: Data on the prevalence of IgG antibodies against HSV-1 in the samples tested are shown in Table 1. In Spain in the children aged 0–18 years tested, the overall prevalence of antibodies against HSV-1 was 47.6% (95% CI: 44.6–50.6). During the first year of life, the prevalence was 48.0% (95% CI: 40.9–55.2). It then fell to 19.3% (95% CI: 13.3–26.6) among those aged 2–3 years. The prevalence increased to 39.3% (95% CI: 31.5–47.6) among the 4–6 year-olds, to 44.7% (95% CI: 36.6–53.0) among the 7–9 year-olds and to 57.3% (95% CI: 49.0–65.4) among the 10–12 year-olds.
In adolescents aged 13–15 years, 55.3% (95% CI: 47.0–63.4) had been infected; in the16–18 year-olds, the prevalence was 69.3% (95% CI: 61.3–76.6). Cold sores usually clear up without treatment within 7 to 10 days. Antiviral tablets or cream can be used to ease your symptoms and speed up the healing time. Antiviral creams such as aciclovir or penciclovir (also known as Fenistil) may speed up the healing time of a recurrent cold sore infection if used correctly.Cold sore creams are widely available over the counter from pharmacies without a prescription. They are only effective if you apply them as soon as the first signs of a cold sore appear, when the herpes simplex virus is spreading and replicating. Using an antiviral cream after this initial period is unlikely to have much effect. Cold sore patches that contain a special gel called hydrocolloid are also available. They are an effective treatment for skin wounds and are placed over the cold sore to hide the sore area while it heals Various vaccine candidates have been developed, the first ones in the 1920s, but none has been successful to date. Due to the genetic similarity of both herpes simplex virus types (HSV-1 and HSV-2), the development of a prophylactic-therapeutic vaccine which is proven effective against one type of the virus would provide fundamentals for vaccine-development for the other virus type. As of 2015, several vaccine candidates are in different stages of clinical trials as they are being tested for safety and efficacy, including at least three vaccine candidates in the US and one in Australia.