Vol.5 No.8(2013), Article ID:35497,11 pages DOI:10.4236/health.2013.58165
Impact of sexually transmitted infections on women health*
1Dr. B. R. Ambedkar Centre for Biomedical Research, University of Delhi, Delhi, India; #Corresponding Author: email@example.com, firstname.lastname@example.org
2Department of Translational and Regenerative Medicine, Post Graduate Institute of Medical Education & Research, Chandigarh, India
Copyright © 2013 Manisha Yadav et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Received 1 June 2013; revised 2 July 2013; accepted 20 July 2013
Keywords: Sexually Transmitted Infections; Syphilis; Gonorrhea; Chlamydia; Trichomonas; Genital Herpes; HPV; HIV
Sexually transmitted infections (STIs) are the infections that can be transmitted from one sex partner, who already has such infection, to another. The causes of STIs in human are very well elucidated and their causative agents are identified as bacteria, parasites and viruses. The worldwide epidemiology of more than 20 types of STIs has been established, which includes diseases like Chlamydia, Gonorrhea, Genital herpes, HIV/ AIDS, HPV, Syphilis and Trichomoniasis. Though STIs affect both men and women indiscriminately, however, the pathophysiology of disease is more obvious among women. Other than abstinence, the most effective way to prevent the transmission or acquisition of STIs is to use a condom during sexual intercourse. Condoms are effective in decreasing the transmission of HIV. However, once contacted, STIs caused by bacteria or parasites can be treated with antibiotics. STIs caused by a virus may not virtually have any cure though the medicines may keep the disease under control. Correct usage of preventive measures greatly reduces but does not completely eliminate the risk of catching or spreading STIs.
Sexually transmitted infections (STIs) also known as venereal diseases are transmitted by means of human sexual relationships. Bacteria, fungi, protozoa or viruses are the major known causative agents for such diseases. According to 2005 WHO estimate, annually 448 million new cases of curable STIs occur throughout the world in adults aged group which mainly includes infections caused by organisms like C. trachomatis, T. vaginalis and Neisseria gonorrhea. However, this evaluation does not include HIV and other STIs. The prevalence of STIs in developing countries like India is found to be 6% and out of this, approximate 40% of women have various STIs at any given point of time . On acquiring STIs, women become prone to acquire a non-curable STIs like the human immunodeficiency virus (HIV) or the herpes simplex type II virus.
Approximately 21% of the people with HIV infection are unaware of them being infected and thus increase the transmission of the virus to their sexual partners, although it has been found that individuals who have ulcerated type of STIs are more susceptible to HIV infection [2-4] as compared to non-ulcerated types . Viral infections in pregnancy are known causes of morbidity and mortality for both child and the mother. Infections are also capable of occurring through placenta, perinatally (from vaginal secretions or blood) or postnatally (from breast milk or other sources) . It is known that most of the STIs exist without symptoms (asymptomatic) since it is reported that more than half of the women and also a significant proportion of men with Gonococcal, Chlamydial, Trichomonial and other infections experience no symptoms at all . But such symptomatic and asymptomatic infections can lead to the development of serious complications like cervical erosion, endometritis, pyosalpinx, low birth weight, preterm birth, peritonitis, ectopic pregnancy, increased risk of HIV infection in women, if left untreated.
It is widely believed that factors like the assortative mixing between people with large numbers of sexual partners, low literacy status, high-risk sexual activities, past infections in male partners and cases of transfusion of blood can play a major role in transmission of STIs . STIs like HIV are known to spread among non-infected individuals with the use of infected needles which they use for injection of drugs. Einwalter  reported that the Caucasians and the younger African-American women, with multiple sexual partners, are at increased risk of acquiring STIs like Chlamydia and Gonorrhea. The best and effective way to prevent the transmission of such STIs, other than abstinence, is to use a condom during sexual intercourse. Condoms are very effective in decreasing the transmission of not only Gonorrhea, Chlamydia, Trichomonas and Hepatitis  but also HIV [4,10]. However, the condom fails to provide the effectiveness to a large extent in transmission of known infections like syphilis, HPV, chancroid and genital herpes. . STIs may act as stronger risk factors for HIV transmission in developing countries like India because of socio-economic barriers to treatment . The main aim of this article is to emphasize the impact of different sexually transmitted infections on health of women and further consequences of these infections on health of new born child.
2. MAJOR PATHOGENS
The major pathogens responsible for causing various STIs are as follows.
Chlamydia infection is cosmopolitan and caused by the bacterium Chlamydia trachomatis. According to the WHO, 90 million people worldwide are found to be infected with Chlamydia annually . C. trachomatis is the major and common cause of mucopurulent cervicitis , urethritis , pelvic inflammatory diseases , ectopic pregnancy  associated with Chlamydia infection in women. They can also lead to complications like premature rupture of membranes, chorionamniontis, premature delivery and neonatal infections [18-20]. Along with this C. trachomatis is also known to play cofactor role in cervical carcinomas . Chlamydia can be transmitted through vaginal sex and other modes of sex that includes oral sex and anal sex and are known to be transmitted from an infected mother to her baby during the time of birth. More than 50 percent of women who have a Chlamydia infection of the cervix are asymptomatic. If untreated, chlamydial infections can cause serious reproductive and other health problems with both short-term and long-term problems like ectopic pregnancy and serious pelvic pain . It is well known that C. trachomatis infection increases chances of squamous cell carcinoma in women .
Since Chlamydia infection can be easily treated, therefore it becomes an important therapeutic target for treatment of cervical neoplasia. Its contribution in dysplasia and neoplasia has been attributed to epithelial damage allowing easy HPV virion entry . Chlamydia is known to be associated with 8 fold increase in risk of unhealthy cervix . These deceptively mild symptoms allow the infection to go unnoticed. With minimal patient awareness, the secondary or the tertiary symptoms develop with time and thus become noticeable . Infertile women with tubal diseases are 2 to 4 times more likely to have increased immune response than either infertile women with normal tubes or pregnant women. Surana et al.  stated that the Chlamydial infections were more likely to be associated with peripheral endosalpingitis, thus making a large contribution towards bilateral tubal damage causing infertility.
Gonorrhea is a STI caused by Neisseria gonorrhea for which humans are the natural host . Following Chlamydia, Gonorrhea is the second most commonly reported bacterial STI in the United States. The highest rates of Gonorrhea are among teenagers, young adults and African American who are involved in sexual activities. The causative organism is highly adapted to the genital tract keeping the infection asymptomatic and undetected in most of the women. Women have a 60% - 80% risk of getting the infection from a single act of vaginal intercourse with an infected man . A mother may transmit gonorrhea to her newborn during childbirth. But it has also been estimated that 8% - 16% of women with untreated endocervical gonococcal infections tend to develop acute salpingitis causing an ascending spread of the pathogens. Even after a single episode of acute salpingitis, almost 10% of women may become infertile due to the complete tubal occlusion. In similar manner, the chances for women to develop pelvic inflammation disease, ectopic pregnancy  after salpingitis is 6 - 10 times greater. Ectopic pregnancies in areas where there are insufficient health services carry a high mortality risk.
Gonorrhea can spread into the complete or a part of reproductive system of women, resulting in pelvic inflammatory disease (PID). PID affects more than 1 million women in the United States every year and can cause tubal (ectopic) pregnancy and infertility in as many as 10 percent of infected women.
Syphilis is a STI caused by the spirochete bacterium Treponema pallidum. Though the primary route of transmission is through various sexual activities, however it is also transmitted from mother to fetus either during pregnancy or at the time of child birth, which may result in chances of congenital syphilis. The various symptoms shown by patients may vary depending in which of the four stages it represents (primary, secondary, latent and tertiary) . The primary stage classically represents with a single chancre (a firm, painless, non-itchy skin ulceration); secondary syphilis with a diffuse rash which frequently involves the palms of the hands and soles of the feet; latent syphilis with little or no symptoms; and tertiary syphilis with gummas, neurological, or cardiac symptoms. Syphilis is thought to have infected 12 million people worldwide in 1999, with greater than 90% of cases in the developing world . It affects around 1.6 million pregnancies a year, resulting in spontaneous abortions and stillbirths. It has also been stated that syphilis has the tendency to increase risk of HIV transmission by two to five times, and co-infection with other pathogens is very common [28,29].
Institutes like the US Preventive Service Task Force (USPSTF) recommends syphilis screening for those women who are engaged in high risk sexual behavior which includes multiple partners, inconsistent use of condom, engaged in sex under the influence of abusive substances like alcohol and drugs, or for financial purposes [30,31]. Therefore, screening for syphilis is majorly done in case of pregnant females as the complications in the treatment of newborn are very high. Mother to child transmission of this infection is due to the undiagnosed, untreated, or inadequately treated maternal syphilis, which can result in a number of adverse pregnancy outcomes like preterm birth fetal death, low birth weight and sometimes neonatal death also. This occurs because of the direct damage that is being caused to both placenta and umbilical cord, which further compromises with the fetal health and growth. It has been estimated that if left untreated, syphilis in pregnancy can directly cause severe outcomes in around 50% of cases . As compared to this, in HIV infected pregnant female, the in-utero transmission is around 20% with an additional transmission at the time of delivery or during breastfeeding.
2.4. Genital Herpes
Genital Herpes is a viral disease caused by both Herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2). The visible symptoms of the most common forms are in the form of oral herpes. These are evident by cold sores or fever blisters as infections of the face or mouth. Genital herpes, commonly known as herpes, is said to be the second most common form of herpes infection . The typical clinical features shown are painful shallow anogenital ulceration. HSV-1 is also known to cause gingivostomatitis and oro-labial ulcers whereas HSV-2 can also cause vesicular and ulcerative lesions in adults . Along with this, both virus types have the tendency to cause infection of the central nervous system. HSV-1 and HSV-2 are capable of causing a first episode of infection to the genital areas, but HSV-2 causes repeated cases of infection . Most of the people infected with HSV-2 present only mild symptoms and remain unaware of the infection. However, such people can still pass on the infection to their sexual partners and newborns [35,36]. The other effects of herpes simplex virus infection include aseptic meningitis, urinary retention, infection to neonatal, opportunistic infection in those patients who are suffering from infections like HIV or the ones who give reports of recurrent infections and psychosocial morbidity . Moreover, HSV-2 infection is known to be associated with an increased risk of HIV transmission and acquisition . In a series of cross-sectional national surveys from 1976 to 2004 conducted by the National Center for Health Statistics, it was observed that overall HSV-2 sero prevalence rises rapidly in younger age groups and then remains stable among older population [38,39]. However, HSV-2 prevalence is negligible among persons who have never been sexually active .
Worldwide rates of either HSV-1 and/or HSV-2 are between 60% - 95% in adults . HSV-1 rates are between 70% to 80% in populations of low socio-economic status and 40% to 60% in populations of improved socio-economic status . Prevalence of HSV-2 in those between the ages of 15 and 50 was reported to be approximately 535 million or 16% of the population with greater rates among women and in those in the developing world . An estimated 536 million people worldwide were infected with HSV-2 worldwide, with the highest rates in sub-Saharan Africa and the lowest rates in Western Europe . In the US, 58% of the population is infected with HSV-1 and 16% are infected with HSV-2 . Therefore, HSV-1 is more common than HSV-2 with rates of both increasing as people age.
2.5. Human Papilloma Virus (HPV)
HPV is one of the most important factors which play a major role in causing cervical cancer in women. Annual incidence of cervical cancer in India is about 130,000 cases with 75 - 80,000 deaths. Thus India shares about one fourth of the global cervical cancer burden . According to the Centers for Disease Control and Prevention, approximately 6 million new cases of sexually transmitted HPV infections are reported every year. At least 20 million people in India are already infected. Genital warts are the most easily recognized sign of genital HPV infection. There are reported cases of genital HPV infection with or without genital warts. Genital warts appear to be soft, moist colored and appear in the genital area within weeks or months of infection. They at times give the appearance of cauliflower-like bumps which are raised or flat, small or large. Genital warts show up in women on the vulva and cervix and inside and surrounding the vagina and anus. There are cases where genital warts have been found on the thigh and groin. Persistent infection with “high-risk” HPV types which are different from the ones that may cause invariant skin warts, it may also progress to precancerous lesions . HPV infection is a cause of nearly all cases of cervical cancer .
Over 120 HPV types have been identified and are referred to by number. But around dozen HPV types (including types 16, 18, 31 and 45) are called “high-risk” types because they can lead to various cancers like that of cervical and anal. However, several types of HPV, like type 16 has been found to be associated with HPVpositive oropharyngeal cancer (OSCC), a form of head and neck cancer . HPV-induced cancers often have viral sequences integrated into the cellular DNA. Some of the HPV early genes like E6 and E7 act as oncogenes that promote tumor growth and malignant transformation. Infection caused to oral regions due to presence of HPV may increase the risk of OSCC independent of tobacco and alcohol use . In the United States, HPV is expected to replace tobacco as the main causative agent for oral cancer. High-risk oncogenic HPV types (including HPV 16 and HPV 18) are associated with 99.7% of all cervical cancers .
Most HPV infections in young females are temporary and have little long-term significance. 70% of infections are gone in one year and 90% in two years . However, the infection persists in 5% to 10% of infected women, with a high risk of developing precancerous lesions of the cervix, further leading to cervical cancer. The period involved may extend to 10 to 15 years of detection. Various preventive measures in this process can be the application of standard preventive strategies. The various sexual behavioral practices that are performed by many people arises the possibility that genital HPVs may transmit to breast through oro-genital route or directly through genital-breast contacts, leading to transmission of HPV infection to the area where scrubbed. However, the lack of detection of HPV in breast cancer indicates that the virus has no role to play in breast carcinogenesis in Indian women . In a study conducted by US Armed Forces, it has been found that HPV infections were most frequent, followed by infections associated with Herpes, Chlamydia, Syphilis and Gonorrhea. Along with this, they also compared that women, younger service members, soldiers had higher incidence rates of each STIs.
2.6. Hepatitis B Virus (HBV)
HBV is transmitted by both heterosexual and homosexual mode, which accounts for a majority of the transmission occurring in adult life . However, transmission also occurs through vertical transmission from mother to child during pregnancy and horizontal transmission, which occurs from child to child. In a study conducted by Tandon et al. , it was estimated that 4% of the population act as a carrier of this infection, out of which 36 million are found to be from India. HBV is reported to be responsible for about 70% of cases of chronic hepatitis and 80% of cases of liver cirrhosis. About 80% of Indian patients with hepato-cellular carcinoma have hepatitis virus associated liver disease . Dual infection of both HIV and HBV can lead to the reactivation of HBV infection and also increase in replication of HIV. A high prevalence of HBV infection has also been reported among individuals practicing risky behaviors and HIV infected individuals . Prevalence of HBV markers was higher in HIV positive subjects compared with HIV negative subjects . It has been stated that countries where HBV infection is known to be endemic, the transmission occurs mostly in childhood through the parenteral route .
2.7. Human Immunodeficiency Virus (HIV)
HIV is a lentivirus that causes Acquired Immunodeficiency Syndrome (AIDS), a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections in human beings. Various routes of infection known to occur are blood transfusion, genital fluid or at times breast milk where mother is infected . Within these bodily fluids, HIV is present as both free virus particles and virus within infected immune cells . HIV weakens the immune system thus making the one more susceptible to infections including all STIs . Two types of HIV are known, HIV-1 and HIV-2. Among these HIV-1 is more virulent and infective  and is the cause of the majority of HIV infections worldwide .
It has been documented in many studies that ulcerative STIs such as Syphilis, Candidiasis, genital Herpes and Chlamydia increases the heterosexual transmission of HIV infections, by creating susceptible portals for viral entry through genital lesions or chancres . It is known that the concentration of HIV in the mother’s blood at the time of delivery determines the risk of neonatal infection . It has also been reported that HIV and HBV are known to share almost same routes of transmission . The other factors like old age, commercial sex work, number of sexual partners during his life time, history of genital ulcer/discharge/warts, and lack of education is the risk determinants of HIV infection . The results of study done by Arora et al.  suggests that sexual behavior outside of regular partnerships is a key driver of the HIV epidemic in India.
Candidiasis is a most common fungal infection caused by Candida albicans . Candidiasis is capable of casing infections that range from superficial systemic and life threatening diseases. Severe Candida infections are also referred to as candidemia and are usually confined to the ones that are immuno compromised either because of AIDS, cancer or transplant . The Vulvovaginal candidiasis is caused by an overgrowth of yeast species named Candida in the vagina and is characterized by curd-like vaginal discharge accompanied with itching and erythema. It is well known that women suffering from candidiasis are more prone to HIV infection and carries a high risk of preterm birth . This is because C. albicans produces only mild infections and thus women do not seek treatment. Infection caused by C. albicans causes vaginal inflammation that compromise with the integrity of the vaginal mucosa and usually overcome the normal bacterial vaginal flora found in vagina and invades the vaginal epithelium.
Trichomoniasis is STI caused by the protozoa Trichomonas vaginalis. T. vaginalis infection is associated with adverse health consequences to both men and women, including infertility, atypical pelvic inflammatory disease  and increased HIV transmission . Trichomoniasis is also associated with preterm birth, lowbirth-weight infants, predisposition to development of cervical neoplasia in women . Worldwide, 170 million people are infected with T. vaginalis every year and out of these 154 million are in resource-limited settings. The incidence of T. vaginalis infection occurs more than Chlamydia and Gonorrhea put together. However, this may have been underestimated worldwide since they have been largely based on wet mount microscopy, which has 35% - 82% sensitivity as compared to a more sensitive culture technique or PCR diagnostics . Also, current statistics may not represent the general population, as infection is asymptomatic in at least one-third of women. An alarming fact is the high prevalence of trichomoniais recorded in otherwise healthy asymptomatic women: one-fifth of asymptomatic women attending family planning clinic in South Africa  and 47% in the general population attending an obstetrics and gynecology clinic in India . Hence, trichomoniasis is the most common non-viral STI and has reached the level of a global epidemic.
T. vaginalis is known to be very common STI, however its prevalence is quite variable. This may be due to the fact that most of the infection caused by this parasite remains asymptomatic . Even if the symptoms are persistent, seems to be generally mild, manifesting a general irritation or infection to the urogenital tract. It is possible that spreading of T. vaginalis non-sexually, may also increase the chances of T. vaginalis infection in youngsters. T. vaginalis is also known to have the ability of survival outside the human body in a wet environment for up to 3 hours. The various complications that may arise due to T. vaginalis infection include cervical erosion and premature birth during pregnancy . Furthermore, the parasite can cause infertility in both men and women. Infection with this parasite also increases the risk of acquiring HIV, cervical cancer and aggressive prostate cancer [71,72]. The parasite has the ability to inhabit different host environment that includes urethra, vagina and cervix in women and turn this diverse environment into its nutritional source. Studies in India have shown the prevalence of T. vaginalis infection ranged from 1.2% to 28.5% across a variety of populations including obstetrics and gynaecology clinic attendees [73, 74], STI clinic attendees , commercial sex workers , and community-based populations [77,78]. It has been shown that the ability of Trichomonas to undergo genetic change has significant implications for the epidemiology and control of trichomoniasis .
3. STIs AFFECTS WOMEN MORE SEVERELY
The pathophysiology of STIs becomes more obvious among women especially with infections of Chlamydia, Candida, Trichomonas, Gonnorhea, Hepatitis B, Genital Herpes and HIV. Women may show mild or severe symptoms, however men usually remain asymptomatic . Furthermore, the diagnosis is less sought in men. Though such infections are capable of causing infertility to both men and women at a considerable rate however women are known to be more prone. In addition the transmission of infection from mother to children is also cause serious threat to the neonatal health. Various symptoms recorded in female patients suffering from such infections include vaginal discharge, itching, erythrema, PID, preterm birth, recurrent abortions, burning micturition, abdominal pain, discomfort, urethritis, prostatitis etc in both the sexes respectively. Chlamydia and Trichomonas are more common in women as compared to men. Women infected with Chlamydia are up to five times more susceptible to acquire HIV infection, if gets a chance to be exposed.
The USPSTF recommends STI screening for the women who engage themselves in high risk sexual behavior. This is because the chances of such infections of being sexually transmitted increases with increase in number of sexual partners. Other factors include use of condoms for more than one time, having sex under the influence of drugs and alcohol . For instance, the pregnant women suffering from trichomoniasis are found to suffer from preterm rupture of membranes and preterm labour resulting in a number of adverse pregnancy outcomes like fetal loss at third trimester, neonatal death, low birth weight of the newborn or an infant with reactive serology and clinical symptoms and signs. The extremely high rate of adverse outcomes seen in syphilis is probably due to direct damage caused by the spirochete (T. Pallidum) to both the placenta and the umbilical cord, and the damage to both will compromise foetal growth and viability. These women have also traditionally been considered as an important source of transmission of STIs to their sexual partners .
The worldwide prevalence of STIs in high-risk groups can vary depending on the geographic origin . Consequently, female infertility is attributed to the tubal factors in about 14% - 38% of such cases . The tubal damage is presumed to be secondary to salpingitis since a two-third of the subjects remains asymptomatic while the remaining third shows symptoms [84,85]. In addition, the recurrence rate of genital herpes appears to be higher in pregnant than in non-pregnant women . The acquisition of genital herpes during pregnancy has been associated with multiple and spontaneous abortions, preterm labour and congenital herpes . Few studies have proven that females are at a greater risk of acquiring genital herpes from male partners than vice versa [88, 89].
Approximately 66% of infected infants from congenital syphilis are asymptomatic at the time of birth and are identified only by routine screening done at clinics. Moreover, the cases of untreated syphilis during pregnancy a transmission rate nearing 100%. Fetal or perinatal death occurs in 40% of affected infants. Infections caused by gonococcal play a disproportionate impact on women health. The lack of diagnosis and treatment, scarce opportunity of medical care, and poor health-care behavior makes the impact of gonococcal infection to be more severe among women in the developing world . Another reason for the highest burden among the young women could be because of the fact that young ones are at greater disadvantage due to the absence of information required for early recognition of the symptoms shown.
The STIs epidemic is predominantly defined within the marginalized communities and their partners. A well known drug, Azithromycin works actively against the major bacterial sexually transmitted pathogens notably, C. trachomatis, N. gonorrhoeae and T. pallidum. Azithromycin is an azalide derived from the macrolide class of antibiotics. It offers better oral absorption, better tissue penetration, unique pharmacokinetics and a wider spectrum of antimicrobial activity than erythromycin. It is the recommended treatment for uncomplicated genital infection with C. trachomatis. Gastrointestinal side effects of azithromycin have been reported. The viral infections are not curable with antibiotics, however, recurrent herpes manifestations can be suppressed by a few.
The antiviral treatment with aciclovir, famciclovir, and valaciclovir in late pregnancy are all equally beneficial in reducing the duration for appearance of symptoms, the healing time for lesion and viral shedding and preventing the transmission of herpes simplex virus from mother to neonate. Caesarean delivery in women with genital lesions may reduce the risk of transmission and is associated with an increased risk of maternal morbidity and mortality. Oral antiviral treatments effectively decrease symptoms in people with first episodes of genital herpes, however sufficient data is not available to establish which type of oral antiviral drug is most effective. In the cases of recurrent herpes, daily use of valaciclovir reduces the risk of transmission of herpes simplex virus type 2 to an uninfected sexual partner. Cephalosporin based drugs named Cefixime, Ceftriaxone and cefpodoxime are also found to be effective antibiotics for the treatment of N. gonorrhea. However, the most recommended treatment regime for C. trachomatis includes azithromycin, doxycycline, erythromycin, ofloxacin . Metronidazole is the drug currently licensed for treatment of human trichomoniasis in the United States  and is the main drug of choice for treatment of this infection in India as well.
Vaccines are available to protect against some viral STIs, such as Hepatitis B and HPV. Vaccine administration before being sexually active Vaccination before initiation of sexual is advised to assure maximal protection. Two vaccines are available to prevent infection by some HPV types: Gardasil and Cervarix. Both protect against initial infection with HPV “types 16” and “18”, which cause most of the HPV associated cancer cases. The known vaccination Gardasil is also capable of protecting against HPV types 6 and 11, which cause 90% of genital warts. The vaccines may or may not provide benefit to women who are already being infected with HPV types 16 and 18, which is mostly seen in the ones who are sexually active. The use of penicillin in pregnant women with syphilis significantly reduces the risk of stillbirth and preterm delivery [93-96]. Recent studies indicated that without any antimicrobial treatment being provided to women, the maintenance of such infections is known to be indefinite, while men may resolve infection without any treatment [97,98].
5. CONCLUDING REMARKS
The management of a significant proportion of STIs is difficult and complicated because of the reasons that they need a long and tedious course, persistence of infections for years without any major symptoms clinically. For instance, HSV-2 infection has an important role in the spread of HIV infection and increased risk of transmission to new born from infected pregnant women . The most effective way to prevent the transmission of various STIs, other than avoiding sexual contact, is to promote the use of condom during intercourse [4,100] which is equally effective against Gonorrhea, Chlamydia, Trichomonas and Hepatitis B . In order to be more effective, women must be educated about the differences between ulcerative and non-ulcerative types of STIs and the risk of acquiring HIV with each type. The use of condoms in more than 25% of sexual acts by men infected with genital herpes reduces transmission of herpes simplex virus type 2 to their uninfected sexual partners. Other studies have shown that couples tend to use condoms at an early stage of their relationship but once they have enough faith among themselves, the use of such preventive measures decreases .
Vaccines are available to protect against some viral STIs, however, vaccination should be administered before initiation of sexual contact to assure maximal protection and from acquiring the STIs. Public health prevention messages should be focused on encouraging individuals to modify or adopt safer sexual practices to reduce the incidence of STIs and HIV.
This work was partially supported by the grants from Department of Biotechnology (BT/PR6301/GBD/27/396/2012) and Department of Science and Technology (File No. SR/FT/LS-117/2011), Government of India, India. MY and RSD are DST young scientist fellows.
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*Conflicts of interest: The authors have no conflicting financial interests.