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Hearing impairment after childhood bacterial meningitis dependent on etiology in Luanda, Angola
Mariia Karppinen1, Tuula Pelkonen2, Irmeli Roine3
1Children's Hospital, Helsinki University Central Hospital, and Helsinki University, Haartmaninkatu 4 E, Helsinki, Finland.
Objective:
Childhood bacterial meningitis (BM) damages hearing, but the potential of different agents to cause impairment in developing countries is poorly understood. We compared the extent of hearing impairment in BM caused by Haemophilus influenzae type b (Hib), Streptococcus pneumoniae or Neisseria meningitidis among children aged 2 months to 13 years in Luanda, Angola.
Methods:
Hearing of 685 ears of 351 (78%) survivors among 723 enrolled patients was tested by brainstem-evoked response audiometry on day 7 of hospitalization. The causative agent was sought by cerebrospinal fluid culture, PCR or the latex-agglutination test.
Results:
Altogether, 45 (12%) of the survivors were deaf (threshold >80 dB), and 20 (6%) had a threshold of 80 dB. The incidence of any kind of hearing loss, with ≥60 dB, was 34% with Hib, 30% with S. pneumoniae, 19% with N. meningitidis and 33% with other bacteria. Examining all ears combined and using the ≥60 dB threshold, the agents showed dissimilar harm (P=0.005), Hib being the most frequent and N. meningitidis the most infrequent cause. Compared to other agents, S. pneumoniae more often caused deafness (P=0.025) and hearing impairment at ≥60 dB (P=0.017) in infants, whereas this level of hearing loss in older survivors was most commonly caused by Hib (P=0.031).
Conclusions:
BM among children in Angola is often followed by hearing impairment, but the risk depends on the agent. S. pneumoniae is a major problem among infants, whereas Hib is mainly a risk beyond 12 months. N. meningitidis impairs hearing less frequently.
Insights
Bacterial meningitis in children often causes hearing loss, with the risk varying by causative agent. Streptococcus pneumoniae is a significant threat to infants, while Haemophilus influenzae type b poses a greater risk to older children.
Area of Science:
- Pediatrics
- Infectious Diseases
- Audiology
Background:
- Childhood bacterial meningitis (BM) is a significant cause of acquired hearing loss.
- The specific impact of different bacterial agents on hearing in developing countries remains understudied.
Purpose of the Study:
- To compare the extent of hearing impairment in children with BM caused by Haemophilus influenzae type b (Hib), Streptococcus pneumoniae, and Neisseria meningitidis in Luanda, Angola.
Main Methods:
- Brainstem-evoked response audiometry was used to assess hearing in 351 survivors of BM.
- Causative agents were identified through cerebrospinal fluid culture, PCR, or latex-agglutination tests.
Main Results:
- Overall, 34% of survivors experienced hearing loss (≥60 dB), with Hib (34%) and other bacteria (33%) being the most frequent causes.
- Streptococcus pneumoniae was more likely to cause severe hearing impairment (≥60 dB) in infants, while Hib was more associated with hearing loss in children over 12 months.
- Neisseria meningitidis was the least frequent cause of hearing impairment.
Conclusions:
- Bacterial meningitis frequently leads to hearing impairment in Angolan children, with the risk stratified by the specific pathogen.
- Streptococcus pneumoniae poses a substantial risk for hearing loss in infants, whereas Haemophilus influenzae type b is a greater concern for older children.
- Neisseria meningitidis demonstrates a lower propensity for causing hearing impairment compared to other common BM pathogens.
