Chronic suppurative otitis media in Tanzanian school children and its effects on hearing.

OBJECTIVES: To compare different treatment regimens of chronic suppurative otitis media (CSOM) in school children, in regard to their consequence in hearing and discharge from the ear drum perforation. DESIGN: Randomised controlled trial. SETTING: Randomly selected primary schools within Dar es Salaam. SUBJECTS: Three hundred and twenty eight children between 5-17 years of age with CSOM in one or both ears. RESULTS: Three to four months after the onset of treatment 31% of group 1, 54% of group 2, and 56% of group 3, had dry ears. Treatment with dry mopping and boric acid in alcohol ear drops was significantly better than dry mopping alone. Adding amoxicillin to the treatment did not improve the end results. Hearing test performed before and after treatment showed that the hearing thresholds were the same or better after the treatment. The possible risk that boric acid in alcohol ear drops should lead to sensorineural hearing loss has not been confirmed. CONCLUSION: Based on the above results, the treatment of choice for CSOM in children in Dar es Salaam should be dry mopping and boric acid in spirit ear drops.

Noise induced hearing loss among industrial workers in Dar es Salaam.

OBJECTIVES: To determine whether sound in the study areas was of sufficient intensity to cause hearing loss and if so whether those exposed have been affected and to determine whether workers/employees in the study areas were aware that sound can cause hearing loss and if so whether they knew that this can be prevented by ear protection. DESIGN: Cross-sectional study. SETTING: Industrial area A and B randomly selected from among industries in Dar es Salaam. SUBJECTS: One hundred and fifty workers from area A and fifty two employees from area B. RESULTS: In both study areas the noise levels were above the safe limit of 85dB(A). In area A 28 workers and in area B eight employees had noise induced hearing loss. In area A 81.1% of the workers and in area B 85% of the employees knew that noise causes hearing loss. All workers/employees from both study areas knew that noise induced hearing loss could be prevented by some form of ear protection. CONCLUSION: Workers/Employees exposed to noise above 85dB(A) will eventually develop hearing loss. Workers/employees are aware of this hazard. There is therefore a need to educate those exposed on how best to protect their ears from the hazard and provide them with protective gear.

Bacteriology of chronic otitis media in Dar es Salaam, Tanzania.

OBJECTIVES: To determine the aetiology of chronic otitis media (COM) in Dar es Salaam and to find out the shelf life of boric acid in spirit ear drops (BAISED). DESIGN: Cross-sectional study. SETTING: Muhimbili Medical Centre and selected primary schools within Dar es Salaam. MAIN OUTCOME MEASURES: Bacterial isolates and their sensitivity patterns and shelf life of BAISED. SUBJECTS AND METHODS: One hundred and seventy six pus swab specimens obtained from 150 patients with COM for more than three months were submitted for culture and antimicrobial sensitivity testing in 1997. RESULTS: The isolates included Pseudomonas aeruginosa (51.7%), Staphylococcus aureus (17.2%), Proteus mirabilis (13.2%), Klebsiella spp. (8.0%), Escherichia coli (5.8%) and unidentified coliforms in 4.0%. All isolates were sensitive to gentamicin. Sensitivity of Pseudomonas aeruginosa and Proteus mirabilis to kanamycin was 98.5% and 100%, respectively. P. aeruginosa was sensitive to chloramphenicol, ampicillin and tetracycline by 58.1%, 10.1% and 8.3%, respectively. Three per cent BAISED inhibited the growth of all Pseudomonas aeruginosa even after it has been stored at room temperature for six weeks. CONCLUSION: Based on these results, the drug of choice for management of COM in Dar es Salaam is gentamicin. However, given its ototoxicity effects and the fact that BAISED is effective and affordable, the later should be the treatment of choice.

Chronic cyanide poisoning in relation to blindness and tropical neuropathy.

Within a group of 20 patients showing optic atrophy and macula degeneration, 14 patients could be examined for neurological and audiometric defects. In 6 patients neurological signs and symptoms were observed. Nine patients reported loss of hearing and in 3 of them a severe perceptive deafness was seen in the audiogram. In 3 of the 14 patients a combination of severe neurologic and audiologic symptoms developed and in two of them a high thiocyanate concentration in serum was observed. The occurrence of perceptive deafness and posterior column sensory loss in the lower extremities in four of the patients made the diagnosis of polyneuropathy the most plausible. Although a similarity to chronic myelopathies caused by nutritional cyanide poisoning cannot be denied, the mean thiocyanate concentration in plasma 24 mumol/L (1.39 mg/L), and the cyanide levels in the blood 0.09 mumol/L (2.3 micrograms/L) were substantially lower than those found in other individuals during periods of extreme drought in which food only consisted of the bitter variety of cassava. The role of cyanide in the etiopathology of this polyneuropathy is unknown.