The resurgence of yellow fever in some states in the country is shameful and symptomatic of how Nigeria handles preventable diseases already subdued or contained by innovative countries. Though potentially deadly, the potency of the viral haemorrhagic disease is surmountable by vaccine. Rather than sustain the vaccination programme, the country slipped into a deep slumber after containing an outbreak in 2019.
About 76 persons have reportedly died since the recent outbreak of the virus in Bauchi, Delta and Enugu states. In a pitiable case, some residents of Delta State initially linked the deaths to a ‘strange disease’ before the Commissioner for Health, Mordi Ononye, identified yellow fever as the cause. In Enugu, three additional local government areas have been reportedly hit by ‘strange deaths’ presumably linked to yellow fever. Health Minister, Osagie Ehanire, said the Federal Government, through the Nigeria Centre for Disease Control, was responding to the outbreak. He said, “There was an outbreak that started in Delta State and was found in Enugu and then two other states, making it a total of four states. The analysis we have done so far shows it is yellow fever.”
Yellow fever, the International Journal of Infectious Diseases, says, is an endemic arboviral disease in African sub-Saharan and South American countries caused by yellow fever virus. YFV has complex jungle cycles of maintenance; it is transmitted by mosquito bites of Aedes sp in Africa and Haemagogus and Sabethes mosquitoes in South America. Experts say there is no cure for yellow fever, which took a big toll in Europe and the Americas in the 18th and 19th centuries, but there is a vaccine now. About 15 percent of people who get yellow fever progress to a severe form, which is characterised by jaundice, the condition that gave the disease its name. Between 20 percent and 50 percent of people who become very sick die.
Historically, the earliest outbreak of the virus in Nigeria occurred in Lagos in 1864, followed by more outbreaks in 1894, 1905, 1906, 1925 and 1926. The 1969 outbreak in Jos, Plateau State, spread to several parts of the country with many infected. According to the World Health Organisation, between 1987 and 1996, the virulence of the disease manifested dangerously in Plateau, Benue, Cross River and Oyo states. It resurfaced 21 years later in 2017 in Kwara State and elsewhere in the country in 2018 and 2019.
The Director, Disease Control and Immunisation at the National Primary Health Care Development Agency, Bassey Okposen, who linked Nigeria’s dilemma to its location within the tropical belt, said that public awareness campaign and immunisation had started in states with confirmed cases. This is a good step, but efforts should be largely geared towards containment to prevent the virus from spreading to other states. The WHO noted that 12 countries in Africa, including Nigeria, have large non-immune populations who are at high risk of yellow fever outbreaks, requiring intensification of routine immunisation, as well as preventive vaccination campaigns.
Yellow fever is an acute viral haemorrhagic disease that is transmitted by infected mosquitoes. Symptoms include fever, jaundice, headaches, muscle pain, fatigue, nausea and vomiting. Experts say that a small proportion of those infected with virus develop severe symptoms; half of those die within seven to 10 days.
State governments have a lot to do in curtailing the spread of yellow fever beyond the expected collaborative efforts of the Federal Government. They should massively equip state hospitals and primary health centres to engender prompt detection, prevention and rapid vaccination campaigns. With the wretched state of health facilities in many states, a slipshod approach to the development would horribly sustain the yearly resurgence of the disease. States, including those currently unaffected by the disease, must imbibe strong control strategies to keep inhabitants safe from the virus.
Essentially, the WHO identified control strategies to include effective and timely yellow fever surveillance, strengthening laboratory services; high-coverage yellow fever routine immunisation; fast rapid diagnosis and availability of global vaccine stockpiles. The NCDC said its multi-agency yellow fever technical working group had been coordinating the prevention, preparedness and response activities of the disease. The centre’s rapid response team should quickly conduct vaccination coverage of children between one and 10 years, conduct yellow fever surveillance, partner states in supporting risk communication and social mobilisation activities for yellow fever. The WHO noted, “The virus is endemic in tropical areas of Africa and Central and South America. Twenty-seven countries are at highest risk for yellow fever epidemics in Africa. The burden of yellow fever in Africa is estimated at 84,000-170,000 severe cases and 29,000-60,000 deaths annually.”
The organisation’s disclosures should propel Nigeria to action to realise that since infected mosquitoes and other urban vectors are known to transmit the virus, increased vaccination of those in affected areas is needed to stimulate immunity. Scientists’ findings that changing climate and rainfall across Africa are likely to increase yellow fever deaths by 25 percent by 2050 ought to also nudge Nigeria to find ways of implementing more sustainable actions in the country to tackle the challenges.
States should not go to sleep upon ending the current outbreak, as it is often the standard approach to every critical matter. There must be consistency in preventive measures to keep the virus at bay. The relevant authorities must enforce the WHO recommendation stipulating vaccination against yellow fever for all international travellers more than nine months old to Nigeria. Also, they should require a yellow fever vaccination certificate for travellers older than one year from countries with risk of the virus transmission.
Considered as a high-risk country by the Eliminate Yellow Fever Epidemics strategy, it is expected that Nigeria would work assiduously to ensure that as EYE envisaged, by 2024, all states in Nigeria would have undergone campaign activities to protect at-risk populations against the virus.
Nigeria can also take its cue from Brazil, which announced vaccination for all citizens during its battle three years ago against the largest yellow fever outbreak in the country since the 1940s. All the 27 states in Brazil were engaged in a vaccination campaign targeting 78 million people by 2019. For a country at the forefront of production of yellow fever vaccine, it intensified efforts to stamp out the virus by building tropical diseases expertise and stepping up follow-up vaccinations. Nigerians should also show responsibility by protecting themselves against mosquitoes and promptly report anyone exhibiting symptoms of yellow fever for treatment.