Comparative Study of the Prevalence of Hearing Loss among Hepatitis B Virus Infected Patients and Uninfected Volunteers: A Case Study

Abstract

Background: Worldwide the hepatitis B virus (HBV) infection is considered a major public health concern, infecting about two billion people. Annually, the disease accounts for about one million deaths. The prevalence of the disease is considered high in Africa, affecting about 8% of the population in West Africa and between 5 to 7% in Southern, Eastern, and Central Africa. Ghana has a high prevalence rate of 12.3% with most infected persons seeking medical attention at the terminal stage of the disease. Studies have reported hearing loss among HBV infected persons. Though Ghana is considered a high endemic region, currently no such data exists. This necessitated the study to investigate the prevalence of hearing loss among persons with HBV infection. Aim: The study determined the prevalence of hearing loss among persons with HBV infection compared with uninfected volunteers. Methods: This case-control study recruited 57 persons diagnosed of HBV infection (case group) and 60 uninfected volunteers (control group) between the ages of 18 and 40 years. All the 117 participants undertook tympanometry (middle ear analysis), pure tone audiometry (hearing test), and transient evoked otoacoustic emission (TEOAE) test. Hearing threshold greater than 25 dB was considered a hearing loss. Data were statistically analyzed using student‟s t-test. Results: There were 31 (54%) males and 26 (46%) females in the case group. The control group included 31 (51.7%) males and 29 (48.3%) females. Among the case group, the mean age was 30 ± 5.6 years and 24.9 ± 4.6 years among the control group. The tympanometry results showed that all 117 participants presented normal middle ear function in both ears. The results of the pure tone audiometry showed a pure tone average (PTA) of 22.19 dB HL for the case group for the right ear and 21.92 dB HL for the left ear, whiles the control group recorded a PTA of 15.42 dB HL for the right ear and 15.89 for the left ear. The PTA of the two groups showed a significant difference (p<0.001). Mild sensorineural hearing loss (SNHL) was recorded among the case group at frequencies of 4000 Hz (25.88 dB HL) and 8000 Hz (28.33 dB HL) in the right ear, and 25.18 dB HL and 27.98 dB HL in the left ear at 4000 Hz and 8000 Hz respectively. The difference between the average hearing thresholds of both groups was statistically significant with a p<0.001. All 60 uninfected volunteers passed the TEOAE test. While 14 (25%) of the case group participants passed with 43 (75%) referred in the right ear, and 15 (26%) passed with 42 (74%) participants referred in the left ear. Out of the 43 persons diagnosed with mild SNHL, 42 had bilateral hearing loss and 1 had unilateral hearing loss in the left ear. Conclusion: The prevalence of hearing loss among persons infected with the HBV is 75% for the right ear and 74% for the left ear. Based on the findings of this study, persons with HBV infection are more likely to acquire SNHL.

Keywords: Hearing loss, hepatitis B virus, sensorineural hearing loss, viral infection.