Table of Contents
I. Introduction
• Overview of HSV infection
• Difference between HSV-1 and HSV-2
II. Prevalence
III. Symptoms and Transmission
• Symptoms of HSV-1 and HSV-2 infections
• Transmission of HSV-1 and HSV-2 infections through contact with infected sores, skin, and fluids
• Asymptomatic shedding of the virus
IV. Genital Herpes
• Characteristics of genital herpes caused by HSV-1 and HSV-2 infections
• Risk of transmission during delivery
• Complications of genital herpes in immunocompromised people
V. Other Complications
• Severe complications of HSV-1 infection such as encephalitis and keratitis
• Neonatal herpes
VI. Treatment
• Medication to provide relief
• No known cure for herpes
VII. Prevention
VIII. Conclusion
Herpes simplex virus (HSV) infection is lifelong and its spectrum of clinical manifestations is wide. This infection stays in the body for life and is caused by two different but similar viruses: herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2). Both kinds can make sores pop up on and around vulva, vagina, cervix, anus, penis, scrotum, butt, inner thighs, lips, mouth, throat, and rarely eyes. There’s no cure for herpes, but medication can provide relief. Herpes simplex virus type 1 (HSV-1) is a common and endemic throughout the world. Most of the infections caused by HSV-1 are acquired during childhood, and infection is lifelong. The vast majority of HSV-1 infections are oral herpes (infections in or around the mouth, sometimes called orolabial, oral-labial or oral-facial herpes), but a proportion of HSV-1 infections are genital herpes (infections in the genital or anal area). Whereas Herpes simplex virus type 2 (HSV-2) is almost exclusively sexually transmitted, causing genital herpes. HSV-2 is the main cause of genital herpes, which can also be caused by herpes simplex virus type 1 (HSV-1). In 2012, an estimated 3.7 billion people under the age of 50, or 67% of the population, had HSV-1 infection. Estimated prevalence of the infection was highest in Africa (87%) and lowest in the Americas (40-50%). In the same year 140 million people aged 15-49-years were estimated to have genital HSV-1 infection worldwide. Most genital HSV-1 infections are estimated to occur in the Americas, Europe and Western Pacific, where HSV-1 continues to be acquired well into adulthood. In other regions, for example in Africa, most HSV-1 infections are acquired in childhood, before the age of sexual debut. While in case of HSV-2 an estimated 417 million people worldwide were living with the infection in 2012. Prevalence of HSV-2 infection was estimated to be highest in Africa (31.5%), followed by the Americas (14.4%). It was also shown to increase with age, though the highest numbers of people newly-infected were adolescents. More women are infected with HSV-2 than men; in 2012 it was estimated that 267 million women and 150 million men were living with the infection. This is because sexual transmission of HSV is more efficient from men to women than from women to men. The symptoms include painful blisters or open sores called ulcers in or around the mouth. Sores on the lips are commonly referred to as “cold sores.” Infected persons will often experience a tingling, itching or burning sensation around their mouth, before the appearance of sores. After initial infection, the blisters or ulcers can periodically recur and the frequency varies from person to person. Genital herpes caused by HSV-1 can be asymptomatic or can have mild symptoms that go unrecognized. When symptoms do occur, genital herpes is characterised by 1 or more genital or anal blisters or ulcers. After an initial genital herpes episode, which may be severe, symptoms may recur, but genital herpes caused by HSV-1 often does not recur frequently. HSV-1 is mainly transmitted by oral-to-oral contact via contact with the HSV-1 virus in sores, saliva, and surfaces in or around the mouth. However, HSV-1 can also be transmitted to the genital area through oral-genital contact to cause genital herpes. Herpes is most contagious when sores are open and wet, because fluid from herpes blisters easily spreads the virus. But herpes can also “shed” and get passed to others when there are no sores skin looks totally normal. Individuals who already have HSV-1 oral herpes infection are unlikely to be subsequently infected with HSV-1 in the genital area. In rare circumstances, HSV-1 infection can be transmitted from a mother with genital HSV-1 infection to her infant during delivery. This is a rare condition, occurring in an estimated 10 out of every 100,000 births globally, but can lead to lasting neurologic disability or death. The risk for neonatal herpes is greatest when a mother acquires HSV infection for the first time in late pregnancy in comparison to presence of genital herpes before pregnancy as they are at a very low risk of transmitting HSV to their infants. HSV-2 is mainly transmitted during sex, through contact with genital surfaces, skin, sores or fluids of someone infected with the virus. HSV-2 can be transmitted from skin in the genital or anal area that looks normal and is often transmitted in the absence of symptoms. In rare circumstances, HSV-2 infection can be transmitted from a mother to her infant during delivery. Most infected people are unaware that they have the infection. Typically, about 10-20% of people with HSV-2 infection report a prior diagnosis of genital herpes. Genital herpes is characterised by one or more genital or anal blisters or open sores called ulcers. In addition to genital ulcers, symptoms of new genital herpes infections often include fever, body aches, and swollen lymph nodes. People infected with HSV-2 may experience sensations of mild tingling or shooting pain in the legs, hips, and buttocks before the occurrence of genital ulcers. Even though it is mostly asymptomatic but in immunocompromised people, such as those with advanced HIV infection, HSV-1 can have more severe symptoms and more frequent recurrences. Rarely, HSV-1 infection can also lead to more severe complications such as encephalitis or keratitis. Also, neonatal herpes can occur when an infant is exposed to HSV in the genital tract during delivery. Infection with HSV-2 in people living with HIV (and other immunocompromised individuals) often has a more severe presentation and more frequent recurrences. HSV-2 and HIV have been shown to influence each other. HSV-2 infection increases the risk of acquiring a new HIV infection by approximately three-fold. In addition, people with both HIV and HSV-2 infection are more likely to spread HIV to others. HSV-2 is amongst the most common infections in people living with HIV, occurring in 60-90% of HIV-infected persons. In advanced HIV disease, HSV-2 can lead to more serious, but rare, complications such as meningoencephalitis, esophagitis, hepatitis, pneumonitis, retinal necrosis, or disseminated infection. Often, the appearance of herpes simplex virus is typical and no testing is needed to confirm the diagnosis. To confirm, herpes simplex can be diagnosed with lab tests, including PCR tests and virus cultures. Although there is no cure for herpes, treatments can relieve the symptoms. Antiviral medications, such as acyclovir, famciclovir, and valacyclovir, are the most effective medications available for people infected with HSV. These can help to reduce the severity and frequency of symptoms, but cannot cure the infection. WHO guidelines Medication can decrease the pain related to an outbreak and can shorten healing time. They can also decrease the total number of outbreaks. Warm baths may relieve the pain associated with genital sores. Awareness about the ways to prevent it from transferring to other people is very important. People with active symptoms of oral herpes should avoid oral contact with others and sharing objects that have contact with saliva. They should also abstain from oral sex, to avoid transmitting herpes to the genitals of a sexual partner. Individuals with symptoms of genital herpes should abstain from sexual activity whilst experiencing any of the symptoms. People who already have HSV-1 infection are not at risk of getting it again, but they are still at risk of acquiring herpes simplex virus type 2 (HSV-2) genital infection. The consistent use of condoms can help to prevent the spread of genital herpes however, condoms can only reduce the risk of infection, as outbreaks of genital herpes can occur in areas not covered by a condom. Preventing acquisition of a new genital herpes infection is particularly important for women in late pregnancy, as this is when the risk for neonatal herpes is greatest.