Microscopic Detection of Entamoeba gingivalis and Trichomonas tenax in Oral Specimens from Healthy Individuals and Patients with Periodontal Disease in Misurata, Libya: A Clinic-Based Cross-Sectional Study

Abstract

The oral cavity harbours a diverse microbial community that includes bacteria, fungi, viruses, and protozoa. Among the protozoa detected in the human oral cavity, Entamoeba gingivalis and Trichomonas tenax have been reported in saliva, dental plaque, gingival crevices, and periodontal pockets, although their precise clinical significance remains incompletely understood. This clinic-based cross-sectional laboratory study aimed to describe the occurrence of E. gingivalis and T. tenax according to periodontal status and to examine the distribution of periodontal categories by age and sex among individuals attending dental clinics in Misurata, Libya. One hundred participants aged 18–72 years were included, comprising 80 participants with periodontal disease and 20 participants with a clinically healthy periodontium. The periodontal-disease group included 53 participants with gingivitis and 27 with periodontitis. Four oral specimens were collected from each participant, yielding 400 specimens. The specimens comprised saliva; one paper-point specimen containing gingival crevicular fluid and periodontal-pocket material; dental plaque collected from tooth surfaces; and dental plaque collected from gingivitis-associated or periodontitis-associated sites. A sterile absorbent paper point (size 40) was placed for approximately 30 seconds. Samples were examined by direct light microscopy and Giemsa staining, and protozoa were identified according to their characteristic morphological features and motility. Data were analysed using SPSS version 25, and categorical variables were evaluated using the chi-square test, with statistical significance set at P<0.05. Among the 400 examined specimens, 89 (22.3%) showed detection of E. gingivalis alone, 16 (4.0%) showed detection of T. tenax alone, 82 (20.5%) showed co-detection of both protozoa, and 213 (53.3%) showed no protozoan detection. Of the 89 specimens showing E. gingivalis alone, 81 (91.0%) were associated with periodontal disease and 8 (9.0%) with a healthy periodontium. All 16 specimens showing T. tenax alone were associated with periodontal disease and specifically with periodontitis. Of the 82 specimens showing co-detection, 81 (98.8%) were associated with periodontal disease and 1 (1.2%) with a healthy periodontium. Within the periodontal-disease group, E. gingivalis alone was detected in 59 (72.8%) gingivitis-associated specimens and 22 (27.2%) periodontitis-associated specimens, whereas T. tenax alone was detected exclusively in periodontitis-associated specimens. Co-detection was observed in 31 (38.3%) gingivitis-associated and 50 (61.7%) periodontitis-associated specimens (P<0.001). Overall periodontal disease status did not differ significantly according to sex (P=0.060), although the distribution of gingivitis and periodontitis differed significantly between males and females (P=0.025). Age was significantly associated with periodontal disease status in both males and females (P<0.001). The findings support an epidemiological association between oral protozoan detection and periodontal status in this clinic-based sample from Misurata. However, because the analysis was performed at the specimen level and four specimens were obtained from each participant, the results should not be interpreted as participant-level prevalence estimates. Furthermore, the cross-sectional design does not establish a causal relationship between protozoan detection and periodontal disease. Larger participant-level studies using appropriate methods for clustered observations and molecular diagnostic techniques are warranted.