Dr. Babatunde Ogunbosi is an infectious disease expert in children. In this interview by SADE OGUNTOLA, he addresses issues surrounding cases of diphtheria in Nigeria and what individuals, communities and the government needs to do to stem the spike in cases of this vaccine-preventable infection in the country.
WE are recording cases of diphtheria in teenagers, and adults aside from children, what exactly is this disease?
Diphtheria is typically seen more in children, however, when you see cases in teenagers or adults, it will be in those not immunised or whose immunity has waned over time. They then get exposed to the germ that causes diphtheria. Also, when there is suboptimal immunisation coverage, there can be an outbreak in children when there is a large population of at-risk children.
What type of disease is diphtheria? Why are cases now recorded in many countries in the world, Nigeria inclusive, even though it is a vaccine-preventable problem in children?
Diphtheria is caused by strains of a gram-positive bacteria called Corynebacterium diphtheriae and it is typically transmitted via droplet infection. So people can come in contact with its droplets through coughing, sneezing, singing and so on. The droplet infects the mucosa covering the nose, throat, larynx (voice box) causing nasal, tonsillar/pharyngeal or laryngeal diphtheria.
A second type of diphtheria can affect the skin, causing pain, redness and ulcers similar to other bacterial skin infections. It occurs when people come into contact with the wounds or lesions of an infected person. Other parts of the body that it can affect include the legs, ears and vulva area. The symptoms of diphtheria depend upon the part of the body affected by the bacteria.
However, diphtheria usually affects the respiratory tract and the tiny tissue covering the surfaces of the tonsils and pharynx. As such, affected individuals will come down with nonspecific symptoms like weakness, cough, catarrh, sore throat, fever, hoarse voice and swollen jaw.
Now, the bacteria make a toxin that kills healthy tissues in the respiratory system. Within two to three days, the dead tissue forms a thick, grey coating that can build up in the throat or nose. This thick, grey coating is called a “pseudomembrane.” It can cover tissues in the nose, tonsils, voice box, and throat, making it very hard to breathe and swallow. So in the younger age groups due to the narrowing of the airway from the swelling, it could portend poor outcomes.
If the toxin gets into the bloodstream, it can cause heart, nerve and kidney damage. It can damage the heart and affect its ability to pump blood; nerve damage, eventually leading to paralysis; and it can affect the kidneys and cause shock with trouble pumping blood to organs of the body, and that is why it can be fatal.
Why the upsurge in cases all over the world?
There have been a lot of disruptions and displacements of people and poor access to basic health services due to security issues, including COVID-19 lockdown across the world. These have compromised immunisation and disrupted health services in general. Even in Africa, almost all of sub-Saharan Africa has been plaque by all sorts of disruptions by terrorists and militant groups. So, there is a lot of interruption in immunisation programmes across the world. Maybe this is the aftermath of the COVID-19 pandemic.
In general, when talking about diphtheria and other vaccine-preventable diseases, evidence in literature often speaks to poor education and empowerment of the girl-child. If a girl-child is well educated, enlightened and empowered, she will make sure that her household gets proper immunisation coverage. So in settings where you have outbreaks, often that factor is at play. This is aside from the possibility of a poor routine immunisation background either due to poor service provision or poor uptake of these vaccines. In some climes, the anti-vaccine groups promote poor uptake of immunisations.
Experts always talk about mutations and antibiotic resistance in instances of disease outbreaks, could this be the case in Nigeria?
In science, you don’t say never. I have not seen the data coming out from NCDC on these cases in Nigeria. Also, many diphtheria bacteria still remain susceptible to the traditional antibiotics we use in treating them. Antibiotic resistance has to do with poor response to treatment; it might not affect outbreaks like this. Outbreaks are likely due to a background incomplete immune coverage. There is a possibility that mutation in the bacteria has contributed to cases in the world. Even when there are new mutations, this will probably affect the virulence of the disease, the way it manifests and the groups of people it possibly affects.
Now that we have cases of diphtheria in teenagers and adults, what protective measures can be taken?
Currently, Nigeria’s national immunisation programmes stop in infancy, but the idea is that people should have booster doses of the TDaP and a couple of other vaccines when they are between 15 and 18 months and also in the preschool years, which is age 4 to 6 years. We don’t have booster doses of DTaP in our immunisation programme. Particularly now, it is something that calls for revision.
With schools opened for another academic session, what should teachers, parents and school proprietors do to ensure that the disease does not spread among children in their care?
It is a droplet infection, so they must ensure good ventilation and avoid crowded environments. If anybody has symptoms, no matter how mild, they should understand the risk they pose to others. Such should either use a face mask to cover their cough or maintain proper cough etiquette to prevent its spread. If ill, they should seek care and get treatment early.
Where there has been an outbreak, depending on the setting, there should be a good contact investigation on those they had close contact with, tests samples from the throat taken to know whether they have been exposed and given prophylactic therapy if necessary. For those with suboptimal immunisation, this is the time to up their immunisation status. They need to check their immunisation history to be sure that they have received all specified vaccinations and if they don’t complete that. Even those that have might need to get booster doses of the vaccine for diphtheria. Tdap is safe for adults and available in Nigeria.
You have been involved in the care of children for a while, is diphtheria something that you are also seeing in our environment too?
Well, in the last four years, we have had suspected cases of diphtheria in our setting. The challenge with diphtheria in many settings is testing and the lack of a special medium to transport the sample for testing. Tests for diphtheria are not routinely done in many hospitals because most health facilities don’t have the resources to do so. Ideally, one needs to identify the organism and grow it in the laboratory to see if it is the variant that produces toxins or has the potential to produce toxins. But we don’t have those facilities in most of our hospitals.
Can it be presumed therefore that before now we have been missing cases of diphtheria in our hospitals?
First, you need a high level of suspicion to suspect a case, take a sample from the throat region and send for tests. In general routine care, they often don’t have the resources to test and make a proper diagnosis. Even when they suspect it, they might have challenges diagnosing it except maybe in a few reference laboratories.
But of course, in settings of outbreaks, you wouldn’t be pushing to make a proper diagnosis. We have what we call an epidemiology case definition and based on that you will use that to treat so that you don’t miss cases of diphtheria and incur high mortalities.
How true is it that one can contract diphtheria from kissing or sharing foods and drinks?
It is possible because its mode of transmission is through droplets. If someone is coughing while on the table or preparing food, if the person is infected and coughs, it can easily spread to the food items and whosoever eats such contaminated food can contract the infection this way. Also, through kissing and saliva of an infected individual, the disease can be contracted.
Cases of diphtheria have been reported in Lagos, Ogun and Osun states, how do you see this?
I imagine a lot of these things have been there but when there is a lot of enlightenment and awareness, then you have increased reporting. But in the case of Kano, we have an obvious outbreak of cases. But like I said earlier, in the last 4 years, we have seen cases come through our system even though we have not been able to confirm the diagnosis, but the presentations are typical of diphtheria.
Any way forward for individuals, community and government?
Everybody should get immunised, we need to make sure that our children get immunised. I will also recommend that they get booster doses and then have a high index of suspicion. Also, those that might have a potential infection should take precautions and avoid crowded places where they can easily spread it. If they must go out, they must wear face masks. Health workers need to have a high index of suspicion and where there is no resource for testing, use an epidemiology case definition in the treatment of suspected cases and of course notify the appropriate health authorities. This will ensure that resources are made available to support diagnosis and treatment.