I return to Malawi today. Yesterday, in preparation for the trip, I got a haircut. Barbers in my town are frequently of Vietnamese origin. The woman who usually cuts my hair is chatty. We talk about our families and work. She is very interested, and knows a lot about malaria.
Yesterday she was not available. Needing to be shorn before boarding the long flight, I booked a haircut with the woman whose chair is right alongside. She was right on time. I sat down, greeted my substitute hair cutter, and immediately realized her English was less advanced than the woman who usually cuts my hair. Today’s visit would be quieter.
The barbershop that I use has chairs for clients that are back-to-back. When I look into the mirror in front of me, I can see the back of the head of the patron seated with his back to mine. Fifteen minutes into my haircut, another client sat down in the chair behind me. I noted a small black device above one of his ears. I overheard his barber asking him how he wanted his hair cut. He answered her questions and began a short conversation in completely normal speech. After a couple of minutes, he told his barber that the device on his ear was a cochlear implant. When he removed it to get his haircut, he would be deaf.
My fellow patron’s speech had normal rhythm, volume, and intonation. To me, this meant that when he learned to speak, he had normal hearing. I wondered how an otherwise normal looking American man could lose their ability to hear in late childhood, adolescence, or early adulthood.
I wondered how an otherwise normal looking American man could lose their ability to hear in late childhood, adolescence, or early adulthood.
In Malawi, acquired deafness is usually from infections. Some of the patients that we treat at Queen Elizabeth Central Hospital will survive their illness with cerebral malaria, but return home deaf. Bacterial meningitis or viral encephalitis can also lead to deafness in those who survive. Additionally, there are medicines used to treat these infections (particularly aminoglycosides, a class of antibiotics) that can lead to permanent hearing loss.
This American man likely had had none of these problems. Unless he grew up in Africa, he probably had not had cerebral malaria. Bacterial meningitis is uncommon in the USA due to vaccinations. Encephalitis is still possible. There are about 25,000 cases of encephalitis each year in the USA. The majority are in children. I have treated many children with encephalitis in the USA. In those who end up with neurological issues afterwards, their problems (epilepsy, cerebral palsy) are not subtle. It is likely possible to survive encephalitis and only have deafness, though. Perhaps it was that.
Prolonged exposure to loud noises, of course, can cause deafness. In neurology training I learned about genetic causes of congenital deafness, hearing loss one is born with. Interestingly, there are also genetic causes that are delayed, leading to hearing loss in late childhood or adolescence. The most common genetic cause of non-syndromic (meaning not associated with other physical or medical problems) acquired deafness is an abnormality in a gene called STRC, which stands for stereocilin. Inheritance is autosomal recessive, meaning that neither parent is affected, but both carry the gene. In people with STRC abnormalities, hearing loss may be present before someone learns to speak (pre-lingual) or after they learn language (post-lingual).
My haircut completed, I left the barbershop, continuing with my pre-trip preparations. Later in the day, I thought again about my fellow barbershop patron and the deaf children I have seen in Malawi. The man in the barbershop moved easily through the hearing world. It seems likely that the kids in Malawi are not as fortunate. They do not have access to cochlear implants. Malawi has a population of 19 million people. There are 4 schools for the deaf. None is in the country’s largest city, Lilongwe. All are boarding schools. I cannot imagine what it must be like to be a Malawian child and have my hearing disappear. In order to gain an education, I would be forced to move away from my family, learning to live in a newly silent world.
