A deadly diphtheria outbreak has claimed 98 lives across northern Nigeria, with health authorities warning that poor vaccination coverage is fuelling the continued spread of the highly infectious disease among children.

The Nigeria Centre for Disease Control and Prevention said the outbreak remains concentrated in several northern states, where low routine immunisation rates have left thousands of children vulnerable to infection.

According to the NCDC, more than 55 per cent of confirmed diphtheria cases involve children who had not received any dose of the diphtheria vaccine, highlighting what public health experts describe as one of the country’s most pressing immunisation gaps.

The outbreak has been driven largely by infections recorded in Kano, Borno, Katsina, Bauchi, Jigawa, Yobe, Plateau and Kaduna, which together account for the overwhelming majority of confirmed cases nationwide.

Diphtheria is a serious bacterial infection caused by Corynebacterium diphtheriae. It primarily affects the nose and throat, producing a thick grey membrane that can obstruct breathing and become fatal if not treated promptly. The disease is preventable through routine childhood vaccination.

Health officials said the current outbreak reflects longstanding challenges facing routine immunisation in parts of northern Nigeria, including vaccine hesitancy, poverty, insecurity, limited access to healthcare facilities and inadequate primary healthcare coverage.

Public health specialists have expressed concern that the large proportion of unvaccinated children demonstrates weaknesses in routine immunisation rather than vaccine availability alone.

The NCDC has intensified surveillance, laboratory testing, contact tracing and case management in the affected states, while emergency vaccination campaigns are being conducted in high-risk communities in collaboration with state governments, the World Health Organization and UNICEF.

Medical experts say early symptoms of diphtheria include fever, sore throat, swollen neck glands and difficulty swallowing. Without timely treatment using diphtheria antitoxin and antibiotics, the infection can lead to severe breathing complications, heart damage and death.

The resurgence also underscores Nigeria’s continuing battle against vaccine-preventable diseases. Since 2023, the country has experienced recurring diphtheria outbreaks, particularly in northern states, prompting repeated emergency immunisation responses and stronger disease surveillance measures.

Health authorities have urged parents and guardians to ensure their children complete the full routine immunisation schedule, stressing that vaccination remains the most effective protection against diphtheria.

The NCDC said efforts are continuing to contain the outbreak, improve vaccine uptake and prevent additional fatalities, particularly among children under the age of 15 who remain the most affected group.