Knowledge About Syphilis and Its Oral Manifestations Among Dental Students: Cross- sectional Study

Antonio Carlos Pacheco Filho Universidade Estadual Paulista Julio de Mesquita Filho Artênio José Isper Garbin Universidade Estadual Paulista Julio de Mesquita Filho Natália Cupertino Pires Universidade Federal do Espirito Santo Karina Tonini dos Santos Pacheco (  kktonini@yahoo.com.br ) Universidade Federal do Espirito Santo https://orcid.org/0000-0002-4687-6062 Cléa Adas Saliba Garbin Universidade Estadual Paulista Julio de Mesquita Filho


Background
Syphilis represents a chronic worldwide infection on the rise. This infection affects more than 10 million people worldwide per year [1], with 60% or more of cases occurring in men who have sex with men, being strongly associated with HIV co-infection and high-risk sexual behavior [2].
The disease presents four distinct stages that are characterized by particular symptoms, clinical manifestations, and infectivity levels: primary, secondary, tertiary, and latent syphilis. Clinical manifestations can occur in the mouth and in the perioral region and primary and secondary lesions are highly contagious. For this reason, in many cases, the dentist is the professional who makes the diagnosis of this pathology, and therefore plays an extremely important role in contributing to the effectiveness of diagnosis, control and treatment, through the identi cation of its signs and symptoms, guiding the patient in relation to procedures, treatment support and follow-up [3].
In addition, the possibility of non-sexual transmission makes the dentist to be among health professionals most at risk of contamination, as accidental contact with saliva and blood may occur during clinical practice. In addition, the risk is greater when considering that 9 out of 10 patients with syphilis do not present any clinical manifestations, although they remain infectious and that in most cases lesions are painless [4].
Considering the importance of academic formation that allows the insertion of dentists in multiprofessional teams for diagnosis and treatment of sexually transmitted infections (STIs) [5] and that the knowledge may in uence attitudes and behaviors [6], the aim of this study was to investigate the knowledge about syphilis and oral manifestations among dental students and to discuss the role of the dentist in prevention and control of this disease. Methods This is a cross-sectional study conducted with dental students from a Brazilian Public University. The sample universe was composed of students enrolled in the second, third, fourth and fth years in the rst semester of 2019. Students in the rst year and rst semester of the second year (third period) were excluded for not having taken the Stomatology discipline, which o cially addresses the content discussed in this study. A pilot study was carried out with rst-year students.
Data collection was performed by a semi-structured questionnaire, which was answered by students in   (Table 2).
Of the total number of students, 84 (50.0%) reported to know the clinical manifestations of syphilis, of those, 66 (78.8%) reported that one of the most common syphilis lesions is hard chancre. Only 40 (46.4%) students correctly answered the question about disease stages. Almost all participants answered that syphilis has oral manifestations; however, only 44 (25.7%) answered the question correctly, that is, they reported that the appearance of chancre is common in the primary disease stages (Table 2).
Regarding the different diagnoses with other oral lesions, only 63 (37.3%) claimed to know them, while 110 (63.3%) knew that the main form of treatment is penicillin ( Table 2). There was a statistically signi cant association between student's educational level in the Dentistry course and knowledge about etiologic agent (p = 0.000), clinical manifestations (p = 0.000), disease stages (p = 0.000), oral manifestations (p = 0.000) and drugs (p = 0.005) related to syphilis. Students enrolled in the early years had better knowledge about the disease than students in the nal years (Table 3).

Discussion
This study showed that dental students, in general, have inadequate knowledge about syphilis. Moleri et al. [5] reported that although many universities present their curricula aimed at general knowledge, they often have not adequately prepared students to recognize and diagnose complex clinical conditions, such as those presented by syphilis.
In this perspective, few students know the oral manifestations of syphilis. In agreement with our research, Wu et al. [6] investigated the knowledge about occupational blood-borne pathogen among Chinese dental students and found that less than half of participants were able to answer which are the main oral manifestations of syphilis.
The main oral manifestations are hard chancre, mucous plaques and gumma. Oral chancre in primary syphilis is characterized as a painless ulcer, measuring 1 to 2 centimeters, with rm and rolled border [7]. It manifests as a single ulcer, usually on the lip or, more rarely, on the tongue [8]. Secondary syphilis presents multiple and generally symptomatic ulceration [9]. In these cases, lesions are maculopapular, affecting the hard palate and, sometimes, the soft palate 8 . Gumma, associated with tertiary syphilis, initially manifests as one or more painless swelling, especially on the hard palate [10].
Recognizing the oral manifestations of syphilis is a crucial role of the dentist, because as oral lesions are highly contagious, the reliability of the correct diagnosis helps in the adequate management, reduces the infection chain and reduces the risk of transmission to health professional [11]. It is worth mentioning that the form of transmission least reported by participants was through the dental practice. This occurs when correct professional practice is not established [3,4].
In addition, a small percentage of students reported knowledge about the differential diagnoses of oral manifestations of the disease. Indeed, studies have shown that the diagnosis of oral manifestations of syphilis represents a challenge for professionals because they have a variety of clinical appearances [12,13]. The fact that some characteristics may be similar to other conditions is of concern, and if diagnosis is not performed in the primary and secondary stages, the patient is exposed to the risk of complications related to the tertiary stage [12].
Our study also showed that students enrolled in the early years of the Dentistry course had better knowledge about etiologic agents, clinical manifestations, disease stages, oral manifestations and drugs than students enrolled in the last two years. The only association that was not statistically signi cant was in relation to differential diagnosis, where knowledge was low for both groups.
Unlike this research, studies that investigated the knowledge of dental students about HIV / AIDS [14][15][16] and occupational of blood-borne pathogens [17,18] showed that knowledge about some aspects was greater among students with higher educational level. Keser et al. [14] justi ed this nding by the fact that the older group may have gained more experience over the years and was exposed to larger number of patients compared to the younger group. Brailo et al. [18] reported that this nding can be explained by the fact that in the clinical phase, at the beginning of the clinical practice in each department, students are introduced to this content again.
Usually, in the st years of the Dentistry course, students have the Stomatology discipline, which addresses the content about syphilis and it' s oral manifestations. However, we consider it essential that this content is addressed in other moments and disciplines throughout the undergraduate course, so that students are aware of all aspects that involve the disease, regardless of the educational level they are attending.
A fact that attracted attention was that studies on knowledge about the transmission of blood-borne pathogens among dental students conducted by Myers et al. [17] and Brailo et al. [18], published in 2012 and 2011, respectively, did not address syphilis. The study by Wu et al. [6], published in 2016, included the disease, probably due to its increasing prevalence worldwide. Syphilis started to become evident again a few years ago, so many clinicians do not consider syphilis in their differential diagnosis of oral lesions [19]. In Brazil, the disease has shown signi cant increase in incidence since 2010.
The number of participants who recognized penicillin as the drug of choice for treatment was less than expected. Penicillin became universal as an effective way of treating syphilis and was responsible for the signi cant decrease in the epidemiological numbers of the disease. This positive result in coping with the disease left a signi cant gap in medical and dental education [5].
The study has limitations due to its cross-sectional design. Another limitation was the limited number of articles published on the topic with dental students, which makes our research original. Our ndings, together with the increased number of new cases of the disease in the world, reinforce the need for training dental professional with knowledge about early diagnosis, effective treatment and follow-up of syphilis cases. As the main form of infection transmission is sexual, its diagnosis and treatment must consider socio-cultural and ethical scope. The disease has repercussions on the affected people's way of life, and this issue should also be addressed during the undergraduate courses [20].
It is necessary to raise the student's interest not only in the clinical aspect of the disease, but also in care issues. Improving students' knowledge can be an effective way to increase the willingness to treat patients [6]. However, it is necessary to seek educational methods that can improve student's experience and learning skills.