STI is a broader term than STD. An infection is colonization by a parasitic species, which may not cause any adverse effects. In a disease, the infection leads to impaired or abnormal function. In either case, the condition may not exhibit signs or symptoms. Increased understanding of infections, infecting most sexually active individuals, but causing disease in only a few, has led to increased use of the term STI (
1). Public health officials originally introduced the term STI, which is increasingly used by clinicians alongside the term STD, to distinguish it from the former (
1-
4). As there has been no successful treatment for hepatitis B infection, the principal strategy for controlling hepatitis B infection is vaccination (
8).
In Iran, recombinant hepatitis B vaccines are available at primary care centers free of charge to any applicant (
9). This program entails vaccination of all neonates at birth, and routine immunization of high risk groups (e.g. health care worker). However, there continues to be little focus on adults at risk for hepatitis B infection through sexual transmission (
4,
7,
10,
11). HBV is a hepadnavirus (hepa from hepatotropic (attracted to the liver) and DNA because it is a DNA virus) having a circular genome with partially double-stranded DNA. The HBV genome is unusual because the DNA is not fully double-stranded. The viruses replicate through an RNA intermediate formed by reverse transcription, which in practice relates them to retroviruses. Although replication takes place in the liver, the viruses spread to the blood, where viral proteins and antibodies against them are found in infected people. HBV is 50-100 times more infectious than HIV (
5-
7).
Acute infection with HBV is associated with acute viral hepatitis (an illness beginning with general symptoms); loss of appetite, nausea, vomiting, body aches, mild fever, and dark urine, and then progresses to development of jaundice. Itchy skin has been an indication as a possible symptom of all hepatitis virus types. The illness lasts for a few weeks and then gradually improves in most affected people. A few people may have more severe liver diseases (fulminant hepatic failure), and may die as a result. The infection may be entirely asymptomatic and remain unrecognized. Chronic infection with HBV may be either asymptomatic or associated with chronic inflammation of liver (chronic hepatitis), leading to cirrhosis over a period of several years (
5,
6). This type of infection dramatically increases the incidence of hepatocellular carcinoma (liver cancer).
Chronic carriers are encouraged to avoid consuming alcohol as it increases their risk for cirrhosis and liver cancer. HBV has been linked to development of membranous glomerulonephritis (MGN). Symptoms outside the liver are present in 1%–10% of HBV-infected people and include serum-sickness–like syndrome, acute necrotizing vasculitis (polyarteritis nodosa), membranous glomerulonephritis, and papular acrodermatitis of childhood (Gianotti-Crosti syndrome). Serum-sickness-like syndrome occurs in the setting of acute hepatitis B, often preceding the onset of jaundice. Clinical features are fever, skin rash, and polyarteritis. The symptoms often subside shortly after the onset of jaundice, but can persist throughout the duration of acute hepatitis B. About 30%–50% of people with acute necrotizing vasculitis (polyarteritis nodosa) are HBV carriers.
HBV-associated nephropathy has been described in adults, but is more common in children. Membranous glomerulonephritis is the most common form. There are other immune-mediated hematological disorders, such as essential mixed cryoglobulinemia and aplastic anemia (
1-
5). HBV infection is a health problem worldwide, with approximately 400 million chronically infected people. Nowadays, Iran is classified as having low endemicity for hepatitis B infection. An investigation conducted in Iran revealed that 2.6% of hemodialysis patients suffered from HBV infection. The virus is transmitted by exposure to infectious blood or body fluids such as semen and vaginal fluids, while viral DNA has been detected in saliva, tears, and urine of the chronic carriers.
Perinatal infection is a major route of infection in endemic (mainly developing) countries. Other risk factors for developing HBV infection include working in a healthcare setting, transfusions, dialysis, acupuncture, tattooing, sharing razors or toothbrushes with an infected person, travel to endemic countries, and residence in an institution of endemic. However, HBVs cannot spread by holding hands, sharing eating utensils or drinking glasses, kissing, hugging, coughing, sneezing, or breastfeeding (
4).
Hepatitis B vaccine was introduced via National Immunization Program (NIP) in Iran in 1993 (1). Sexual transmission is the most important mode of HBV spread in most developed countries and accounts for approximately 30% of acute HBV infections in the United States. Interestingly, in contrast to HIV, the risk of heterosexual transmission is greater when the infected individual is female than a male. Over 75% of the wives of male Iranian carriers have natural immunity against HBV. In 2004, an estimated 350 million individuals were infected worldwide. National and regional prevalence ranges from over 10% in Asia to under 0.5% in the United States and northern Europe. Routes of infection include vertical transmission (such as childbirth), early-life horizontal transmission (bites, lesions, and sanitary habits), and adult horizontal transmission (sexual contact, intravenous drug use). The primary method of transmission reflects the prevalence of chronic HBV infection in a given area. In low prevalence areas such as the continental United States and western Europe, injection drug abuse and unprotected sex are the primary methods of transmission, although other factors may also be important (
1-
4).
This study was the first survey in Iran to identify the acceptance and compliance of hepatitis B vaccination among the tested group. In our study, the acceptance rate of 69.3% was relatively and acceptably high for the infectious clinic patients. In studies in other countries, lower rates of acceptance, ranging from 23% to 69% (
7,
10,
11) were reported. One possible explanation for the higher rates in our survey could be the opportunity of free vaccination offered by the healthcare provider, not by the research worker. People may be more receptive when a healthcare worker recommends for immunization. We referred patients to a clinic which offered the vaccine to all the consecutive patients, as well as all neonates and children as routine healthcare manner, while in other studies, hepatitis B vaccine was only offered to the patients who agreed to participate to their survey, possibly making the process appear outside the routine vaccination scope. Those who refused the vaccine had significantly more addiction rates (PV = 0.00), but considering other variables, those who accepted hepatitis B vaccination were not significantly different from those who refused it (for age group PV = 0.470, for marital status PV = 0.302, for educational status PV = 0.410, for condom usage status PV = 0.789).
The reason given by patients for vaccination rejection often involved lack of knowledge about hepatitis B infection and importance of vaccination, fear of side effects, worries about privacy, perceived low risk for infection, and time situations. Survey of hepatitis B vaccine acceptance among other groups reported similar findings regarding health beliefs (
12,
13). Some of these beliefs may be readily modified through brief group interventions, including providing accurate information about the risk for infection (
14,
15). Acceptance of hepatitis B vaccination among healthcare staff were compatible with health thoughts (
16,
17). Some of these beliefs were based on clarified information about the hazard of hepatitis B infection and the benefits of vaccination (
18,
19). Studies that explain the indices corresponding to fellow vaccination (2nd, 3rd) by patients in infection referral clinics are few (
20-
22), so we suggest to establish a study to determine the health belief parameters about hepatitis B vaccination acceptance in patients with STIs.