Understanding, Preventing, the Outbreak of Diphtheria

In this report, Sunday Ehigiator reflects on the recent outbreak of the deadly diphtheria disease in Nigeria, and precautions to take to prevent its recurrence

On July 6, 2023, the Nigeria Centre for Disease Control (NCDC) confirmed an outbreak of the deadly diphtheria disease in the capital Abuja, following the death of a four-year-old patient.

Nearly 800 cases of the disease have been confirmed through a statement by NCDC as of June 30, with most of the patients being children aged between 2 and 14 years.

According to the Director General (DG) of NCDC, Ifedayo Adetifa, “As of June 30, 2023, there have been 798 confirmed diphtheria cases, from 33 Local Government Areas (LGAs) in eight states, including the FCT.

“Most of the cases were recorded in Kano. Other States with cases are Lagos, Yobe, Katsina, Cross River, Kaduna, and Osun.

“The majority (71.7 per cent) of the 798 confirmed cases occurred among children aged 2 to 14. So far, a total of 80 deaths have been recorded among all confirmed cases (case fatality rate of 10.0).”

About diphtheria

Speaking to THISDAY about the diphtheria disease, Hospitals and Specialty Clinic Specialist, with Regions Healthcare, Dr Malachi Ezegbogu, said, “Diphtheria, coined from the Greek word ‘diphtheria’ – meaning leather, is so named because of the tough ‘pseudomembrane’ that forms in the patient’s throat.

“Diphtheria is known to be a severe infection caused by strains of the aerobic gram-positive bacteria called Corynebacterium diphtheriae that make an exotoxin (a toxin). It is the toxin that primarily causes people to get very sick.

“The three isolated strains of C diphtheria include gravis, intermedium, and mitis. Diphtheria manifests commonly as a localised upper respiratory tract (parts of the body involved in breathing) infection and sometimes as a localised cutaneous (skin) infection.

“Reports of epidemics of ‘throat distemper’ began to appear in the 1500s, but before the 19th century, diphtheria was known around the world by many different names, such as Syrian ulcer, membranous angina, malignant croup, and Boulogne sore throat.

“Diphtheria bacteria spread from person to person, usually through respiratory droplets and nasopharyngeal secretions after an infected person has coughed or sneezed.

“Occasionally, transmission occurs from skin sores and rarely through fomites (articles soiled with discharge from the sores of infected persons). Human carriers are the main reservoir of the infection; however, case reports have linked diphtheria to livestock.”

Signs and Symptoms

Speaking on the symptoms, Dr Ezegbogu noted that initially, its symptoms are general and nonspecific, often resembling a typical viral upper respiratory tract infection.

“The Diphtheria bacteria adhere to the mucosal epithelial membrane of the infected individual from where exotoxins are released after localized tissue destruction. The toxins are carried via the lymph and blood to other parts of the body where their effects can be seen, such as in the myocardium (heart muscles), kidneys and nervous system.

“People who are exposed to diphtheria usually start having symptoms in 2–5 days (incubation period) if they get sick. Within this period, the dead tissue forms a thick, grey coating that can build up in the throat or nose; this thick grey coating is medically known as a pseudomembrane.”

He, therefore, concluded that diphtheria can infect the respiratory tract (respiratory diphtheria) and skin (cutaneous diphtheria), as its symptoms depend on the body part that is affected.

Respiratory and cutaneous diphtheria

According to Dr Ezegbogu, “The bacteria most commonly infect the respiratory system, which includes parts of the body involved in breathing.

“When the bacteria get into and attach to the lining of the respiratory system, it may cause low-grade (mild) fever and chills, weakness, malaise, headaches, discharges from the nose (serosanguinous or seropurulent), sore throat, cervical lymphadenopathy (swollen glands in the neck), difficulty with swallowing, difficulty with breathing, wheezing and cough.

“The bacteria can also infect the skin, causing open sores or ulcers. However, diphtheria skin infections rarely result in severe disease.”

Diagnosis and treatment

Speaking on diagnosis, Dr Ezegbogu said, “Diagnosis depends on the type of diphtheria someone has, either respiratory or cutaneous. Doctors usually decide if a person has diphtheria by looking for common signs and symptoms. They can swab the back of the throat or nose and test it for the bacteria that cause diphtheria.

“A doctor can also take a sample from an open sore or ulcer and try and grow the bacteria. If the bacteria grow and make the diphtheria toxin, the doctor can be sure a patient has diphtheria. However, it takes time to grow the bacteria, so it is important to start treatment right away if a doctor highly suspects respiratory diphtheria.”

On treatment, he said, “management of diphtheria involves a multidisciplinary approach which may include consultations to CDC/NCDC (for surveillance and antitoxin medication), infectious disease services and neurology, cardiology (for assistance in managing cardiac complications), critical care services (for possible ICU admission), ENT/anaesthesia (for airway control), and CTU (for bronchoscopy for pseudomembrane removal or obstruction).

“It involves using diphtheria antitoxin to stop the bacteria toxin from damaging the body. This treatment is very important for respiratory diphtheria infections, but it is rarely used for diphtheria skin infections.

“Using antibiotics to kill and get rid of the bacteria is also another option. This is important for diphtheria infections in the respiratory system and on the skin and other parts of the body.

“People with diphtheria are usually no longer able to infect others 48 hours after they begin taking antibiotics. However, it is essential to finish taking the full course of antibiotics to make sure the bacteria are completely removed from the body. After the patient finishes the full treatment, the doctor will run tests to make sure the bacteria are not in the patient’s body anymore.

“For some people, respiratory diphtheria can lead to death. Even with treatment, about 1 in 10 patients with respiratory diphtheria die. Without treatment, up to half of patients can die from the disease.”

Similarly while speaking on treatment, the NCDC boss, Adetifa, said, “Diphtheria infection is caused by a toxin produced by the bacteria Corynebacterium diphtheria. It is a vaccine-preventable disease covered by one of the vaccines provided routinely through Nigeria’s childhood immunisation schedule.

“Despite the availability of a safe and cost-effective vaccine in the country, the majority i.e., 654 (82 per cent) of 798 confirmed diphtheria cases in the ongoing outbreak were unvaccinated. Unfortunately, this also included the recently announced FCT case.”

Adetifa concluded by saying, “So far, a total of 80 deaths have been recorded among all confirmed cases.”

Prevention

Speaking on prevention, Dr Ezegbogu noted that keeping up to date with recommended vaccines is the best protection against diphtheria.

“With the widespread vaccination (immunization) of children, diphtheria is now rare in many parts of the world. However, childhood immunity wanes, requiring an updated booster vaccine.

“The NCDC recommends either Tdap or Td at least every 10 years to maintain immunity.

“There are four vaccines used to prevent diphtheria, DTaP, Tdap, DT, and Td. Each of these vaccines prevents diphtheria and tetanus. DTaP and Tdap also help prevent pertussis (whooping cough).

“The NCDC diphtheria vaccination recommendations are DTap for young children between 2, 4 and 6 months; 15 through 18 months; and 4 through 6 years.

“It recommends Tdap for pre-teens, that is, 11 through 12 years. Td or Tdap for adults every 10 years.

“The NCDC also recommends that anyone who had close contact with someone infected by diphtheria should receive antibiotics to prevent them from getting sick.

“In addition to getting antibiotics, close contacts of someone with diphtheria should be monitored for possible illness for 7 to 10 days from the time they were last exposed, tested for diphtheria with a sample collected from the nose and throat, and given a diphtheria booster shot if they are not up to date with their vaccines.”

Epidemic Preparedness in Nigeria

Nigeria has made tremendous progress in strengthening its epidemic preparedness and response capabilities, going beyond just responding to outbreaks, especially in the area of governance, capacity and resources.

The country has taken significant steps to enhance its public health infrastructure and build capacity to detect, respond to, and prevent future epidemics effectively, even down to the states.

For instance, the Lagos State government developed a policy on emergency preparedness and biosecurity, providing oversight and coordination of emergency preparedness strategies.

A key milestone in this journey was the establishment of the Nigeria Centre for Disease Control (NCDC) in 2011. As the National Public Health Institute, NCDC has played a crucial role in coordinating surveillance, detection, and response to infectious disease outbreaks through its network of state-level epidemiologists and laboratories. This has enabled rapid response to disease outbreaks and prevention of spread.

In addition, Nigeria has invested in training healthcare workers, strengthening its healthcare system, and establishing emergency response teams and contingency plans for various potential epidemics.

The country has also improved its disease surveillance and reporting systems, enabling more timely and accurate detection of outbreaks. Electronic reporting systems and a national database for tracking disease trends have been implemented, allowing public health officials to quickly identify and respond to potential threats.

While there are still challenges to overcome, including funding constraints, inadequate healthcare infrastructure, and security concerns, Nigeria’s progress in epidemic preparedness is a testament to its commitment to protecting the health and well-being of its citizens.

Funding for Epidemic Preparedness in Nigeria

It is great to note that, Nigeria has doubled funding for its Center for Disease Control over the last two years. The Nigeria Centre for Disease Control (NCDC) received $4.7 million in fiscal year 2019, and $9.4 million in fiscal year 2022.

Kano state created the Epidemic Preparedness and Response (EPR) budget line in 2020 for the fiscal year 2021, with funding increased by 33 per cent for the fiscal year 2022 totalling $960,000.

Kano state also secured commitments for EPR budget allocations in each of the 44 local government areas (LGAs) in fiscal year 2021, with funding commitments increasing by 50 per cent in fiscal year 2022, for a commitment of N3 million ($6,600) in 2022, up from N2 million ($4,400) in 2021, a total allocation of N132 million ($290,000) for EPR.

Similarly, Lagos state created the Public Health Epidemics and Emergencies budget line with $12.2 million allocated for fiscal year 2022.

Despite environmental changes and global factors that contribute to the unpredictable nature of emerging diseases, Nigeria continues to work towards enhancing its capacity to respond effectively to epidemics.

Notwithstanding, more states need to take the initiative from Kano and Lagos states in terms of strengthening epidemic preparedness in their states, and citizens need to make this a top priority demand when electing the leadership, as it not only improves the level of epidemic preparedness in the states but likewise improve on the life expectancy of the citizenry.