Characteristics of Hearing Impairment in Patients with Suspected Congenital Rubella Syndrome at the ENT Clinic of Prof. Dr. I.G.N.G Ngoerah Hospital Denpasar, Indonesia

Asymptomatic rubella virus infection can cause delays in the diagnosis of rubella in pregnant women, leading to the development of congenital rubella syndrome (CRS). The clinical manifestations of congenital rubella syndrome are called the rubella triad, which includes heart problems, eye problems, and hearing disorders. Sensorineural hearing loss is the most common type of hearing loss in children with rubella infection. This study aimed to determine the characteristics of hearing loss in CRS patients. This study used a retrospective descriptive research design, utilizing secondary data from the medical records of patients with CRS who underwent hearing examinations at the Ear, Nose, Throat (ENT) Polyclinic of Prof. dr. I.G.N.G. Ngoerah Hospital Denpasar, Indonesia. The study found that the most common age group among suspected CRS patients was 6 - 12 months (51.42%), the majority of these patients were male (62.86%), the most frequent clinical signs and symptoms in suspected CRS patients were congenital heart disease (CHD) as a major criterion (60%), and microcephaly as a minor criterion (77.14%). Based on the CRS case criteria, none of the suspected CRS patients were diagnosed with confirmed CRS, with most cases being classified as clinical CRS (65.71%). The hearing loss in suspected CRS patients was entirely sensorineural type with the majority of cases being bilaterally and to a very severe degree (53.57%)

1. INTRODUCTION

Rubella is a contagious RNA virus infection and there is no specific treatment for this infection. In 2016, there were 22,361 cases reported worldwide¹¹. A survey conducted in Indonesia from 2010 to 2015 estimated that there were 30,436 cases of rubella. Surveillance data over the last five years shows that 70% of rubella cases occurred in the <15-year age group. Additionally, a study on the estimated burden of congenital rubella syndrome (CRS) in Indonesia in 2013 estimated 2,767 cases of CRS, with an incidence of 82 per 100,000 among mothers aged 15-19 years and decreasing to 47 per 100,000 among mothers aged 40-44 years¹¹. Rubella infection during pregnancy can lead to miscarriage, stillbirth, and CRS in neonates, especially during the first trimester of pregnancy¹¹.

Asymptomatic rubella virus infection can delay the detection of the virus in pregnant women, which may lead to CRS. The clinical manifestations of CRS known as the rubella triad, include heart defects, eye problems, and hearing disorders²². Sensorineural deafness is the most common type of hearing loss in children with rubella infection³³. Parents often realize that their child has congenital deafness when the child is older, typically between 2-5 years of age, as growth and development, particularly speech and language abilities, may seem normal in the early years⁴⁴. Children with congenital deafness may experience speech delays, language disorders, social behavior deviations, and decreased cognitive abilities⁵⁵.

The incidence of congenital bilateral sensorineural hearing loss in Indonesia is 1–3 per 1,000 births in the normal baby care population and 2–4 per 100 babies in intensive care. In West Java, with a population of approximately 37 million and a population growth rate of 1.8% per year, it is estimated that at least 600 babies will be born with severe bilateral sensorineural hearing loss each year⁶⁶.

In developing countries, early detection of hearing loss is not yet fully optimized^7-9789. Early detection is crucial, particularly in children with risk factors for hearing loss, as 50% of newborns with these risk factors experience hearing loss from birth. Hearing disorders in children can be detected through subjective audiological examination, which involves observing the child's behavioral response to sounds, or through objective examinations such as Brainstem Evoked Response Audiometry (BERA) and Otoacoustic Emission (OAE)⁴⁴. Given the high number of CRS cases and the public's limited awareness of hearing loss associated with CRS, the authors conducted a study on the characteristics of hearing loss in patients with suspected congenital rubella syndrome at the ENT clinic at Prof. dr. I.G.N.G. Ngoerah Hospital in Denpasar.

2. MATERIALS AND METHOD

This study used a retrospective descriptive research design, utilizing secondary data from medical records of patients with suspected CRS who underwent hearing examinations at the ENT clinic of Prof. dr. I.G.N.G. Ngoerah Hospital, Denpasar, during the period January to December 2018. The research samples consisted of patients with suspected CRS who underwent hearing examinations at the ENT clinic, Prof. dr. I.G.N.G. Ngoerah Hospital, Denpasar in January – December 2018. Ethical clearance for this research was obtained from the Research Ethics Commission No. 1119/UN14.2.2.VII.14/LT/2020 of the Prof. dr. I.G.N.G. Ngoerah Hospital.

Sampling was conducted using the total sampling method, where all data from medical records that met the study's criteria were included in the analysis. The inclusion criteria for this study were all patients with suspected CRS who underwent hearing examination, while the exclusion criteria included patients with suspected CRS who had incomplete medical record data, patients with external and middle ear abnormalities, and patients who had not completed all CRS surveillance examinations.

3. RESULTS

Sample selection was conducted using the total sampling method, resulting in 35 samples. Based on age, the majority of patients with suspected CRS were examined at 6 - 12 months of age, accounting for 18 patients (51.42%), followed by 12 - 18 months with 11 patients (31.42%) and 18 - 24 months with 6 patients (17.16%). Among the 35 research samples, 22 patients (62.86%) were male and 13 patients (37.14%) were female. The sample characteristics are presented in Table 1.

Table 1.General characteristics of the study sample based on age at the time of hearing examination

Variables	Total	Percentage (%)
Age
<6	0	0
6 – 12	18	51.42
>12 – 18	11	31.42
>18 – 24	6	17.16
>24	0	0
Sex
Male	22	62.86
Female	13	37.14

Based on the clinical signs and symptoms of CRS, the samples were grouped according to the presence or absence of symptoms and signs. Major criteria included cataracts, congenital glaucoma, congenital heart disease, and retinal pigmentation. Minor criteria included purpura, splenomegaly, jaundice, microcephaly, mental retardation, meningoencephalitis, and radiolucent bone disease. As shown in Table 2, congenital heart disease (CHD) was the most common clinical sign and symptom according to the major criteria, found in 21 samples (60%). In terms of minor criteria, microcephaly was the most frequently observed present in 27 (77.14%) samples.

Clinical signs and symptoms	Yes	No	Total
Major Criteria Congenital Cataract Congenital Glaucoma Congenital heart Disease Retinal Pigmentation	11 (31.42%) 0 (0%) 21 (60%) 0 (0%)	24 (68.57%) 35 (100%) 14 (40%) 35 (100%)	35 (100%) 35 (100%) 35 (100%) 35 (100%)
Minor criteria Microcephaly Jaundice<24 jam Purpura Splenomegaly Mental retardation Meningoencephalitis Radioluscent Bone Disease	27 (77.14%)