Dr Olukemi Adekanmbi , a consultant infectious disease physician at UCH and the HOD of Infectious Disease Department at the University College Hospital, Ibadan, in this interview by Sade Oguntola X-rays issues around diphtheria, its implication, peculiarities and how best to curb its spread in Nigeria.
Is diphtheria a threat to Nigeria’s health system and health of Nigerians in general?
So, far we have had a moderate-sized outbreak, but any disease that has the potential to affect many more people is a threat and should not be taken lightly. There have been a few cases over the years but now there is an sizeable outbreak which is why it is attracting national attention. When a preventable disease causes mortality, we must intervene quickly. Without vaccination, it can cause severe disease or death and that is why we should pay attention to it.
Studies suggest that the organism that causes diphtheria silently circulates in some communities. Any reason to worry that the circulating disease-causing germs can lead to an outbreak as it happened in Kano?
There could indeed be circulation of the bacteria that causes diphtheria in the community which hasn’t caused those carrying it to become ill. An interesting fact about diphtheria is that an immunised individual can still be a carrier of the bacteria. This means that if an individual is immunised against diphtheria, they can still acquire it from an infected individual but because of the vaccination that they have received, they are unlikely to become sick. However, they could potentially infect people who unvaccinated or partially vaccinated and those individuals could become ill with the disease.
Is it possible to have a particular germ in circulation causing any problems, take for instance, diphtheria?
It is possible and in infectious disease, we refer to this as colonisation, which is different from infection. An infected person has symptoms and signs due to the infectious pathogen whereas a colonised individual carries the organism on or in them without becoming ill.
Where do these circulating germs that cause diphtheria in the community come from?
They probably are passed from person to person; person-to-person transmission is well established in diphtheria. It is effectively transmitted through droplets that are released during coughing, speaking, singing and so on. A person that is immunised against diphtheria might be colonised for a long period and continue to spread the bacteria to other people. If there are a large number of people that are carriers, they could potentially infect many others. These people they infect might experience the mild form of diphtheria while some could have severe disease or even die from the infection.
How effective is the complete Diphtheria vaccine course?
It is considered to be a highly effective vaccine. The US CDC recommends diphtheria vaccination for a child soon after birth and again in the first few months of life. A booster around 12 to 18 months and another booster at 4-5 years when the child is entering school and another one for pre-teens (11 to 12 years). An adult is to take booster doses every 10 years. Over time, there is a possibility for the immunity from the vaccine to wane. It is not a foreign concept when it comes to vaccines. It is for this same fact that COVID-19 vaccine boosters are also given. For influenza, you have annual vaccination because there is a possibility that the immunity can wane as well as the fact that the strain of virus changes from year to year.
Do we have groups of people whose booster may be contraindicated like for instance pregnant women?
Pregnant women can safely take diphtheria vaccines. In Nigeria, we have the pentavalent vaccine which protects against diphtheria and 4 other infectious diseases. In general, people who have diseases which weaken their immune systems may not be able to take some vaccines and people who have ever had a serious or life-threatening adverse reaction after receiving a vaccine should not be given the same vaccine again.
Given the scenario we are facing with the diphtheria outbreak in Kano and the importance of keeping safe, are there vaccines you will want to recommend for adults who also take the diphtheria vaccine?
There are quite a few vaccinations that are recommended for adults to prevent diseases that are quite common but we haven’t really adopted the culture immunisations in adults in this part of the world. For instance, vaccines like that for Hepatitis B. Hepatitis B is very common here and chronic hepatitis B has a lot of long term complications including liver cirrhosis and cancer, but there is no real culture of taking this vaccine the general population in adults who were not immunised in childhood. Other vaccines like the Hepatitis A vaccine, pneumococcal vaccine, typhoid vaccine, which prevent conditions that are also quite common in this part of the world should be considered. These vaccines prevent people from getting infected with these pathogens even if they get exposed. And if they do get infected, the severity of the disease should be less. In general vaccinated individuals tend not to get infected which means they are also unable to transmit the infection to others. In essence, they are doing the public some good apart from benefiting themselves. So there is so much to gain from adult immunisation.
Do increasing cases of many vaccine-preventable diseases like measles and now diphtheria also pose risks to the adult population?
Vaccine preventable diseases could pose a risk to adults as well because not all adults were vaccinated as children and even those that were might have waning immnuity. In addition, the elderly and immunocompromised are also at high risk for severe forms of these diseases.
What will be your advice to individuals to protect themselves from diphtheria?
First of all, we should all have a primary or family doctor that we can go to at least once a year for a medical checkup. This person should have all our medical records. Such a doctor will be able to recommend the vaccinations that you need and hopefully detect an infection when it occurs. Hopefully, the physician is in tune with on-going disease outbreaks within the community and around the world and he should consider these when making a diagnosis. So, preventive medicine and also early diagnosis, followed by treatment are key to optimal health.
Does diphtheria have a cure and can individuals prevent coming down with this infection?
Diphtheria can be cured with antibiotics and antitoxins. Even though the disease could be severe or fatal, it can be cured. But before a cure can be pursued, a diagnosis must be made first by a healthcare provider.
In terms of prevention, vaccination is key and then also such things as basic hygiene, cough etiquette and workplace and school policies that prevent spread of infections at these places. For instance, if you are sick with a respiratory infection stay at home and go to the doctor. Even if it is the common cold, it can be spread to others, and if it is something more serious than the common cold, it can also be transmitted it to others.
How best can we stem the spread of diphtheria in Nigeria?
First and foremost there should be awareness creation to make people aware that there is an outbreak of this disease. The public should be informed about its symptoms so that if people have similar symptoms, they can seek medical attention. Even health workers need to be sensitised about the outbreak so that they can maintain a high index of suspicion of diphtheria while they are seeing patients because there are so many diseases and infections out there. The NCDC has raised the alarm about the outbreak, rightly so. So that people can be aware of the magnitude of the outbreak.
Also, creating awareness would ensure that laboratories that have throat swabs for tests consider testing for diphtheria if the circumstance suggest that it would be appropriate. There should also be support for the public health laboratories to perform enhanced surveillance for the disease. It should be possible for public health laboratories to test patients who cannot afford to pay for the tests and there should be treatment support for indigent patients. And of course, booster vaccination can be rolled out. In addition the public should educated on hygiene practices, cough etiquette, and respiratory hygiene, all those things must be done to try to stem the tide.
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