Averting another outbreak of yellow fever
The recent alarm raised by the World Health Organisation concerning an imminent outbreak of yellow fever in urban areas of Africa calls for serious attention and urgent actions by all stakeholders in the Nigerian health sector. This is especially as the global health body has emphasised that except prompt actions are taken, the current outbreak in Angola which has killed hundreds of people could be “a threat to the entire world.”
Dr Margaret Chan, the director-general of WHO, who was in Angola’s capital, Luanda, in the first week of April for a two-day visit to assess the extent of the epidemic noted that this is the most serious outbreak of yellow fever that Angola has faced in 30 years, stressing that yellow fever outbreak is more likely than ever in other urban areas in Africa.
According to the WHO, the progression of the situation in Angola is concerning and needs to be closely monitored, warning that 12 African countries with large non-immune populations are presently at high risk and adding that immunisation needs to be intensified in these countries.
Particularly for Nigeria, the WHO has stated that even though the last yellow fever outbreak in the country was about 12 years ago, the fact that it took about 10 years to control the transmission of the virus makes prevention of a fresh outbreak a very important task. The WHO further warned that given the low vaccine coverage, children at risk in urban areas in Nigeria alone have been estimated at 23 million.
What makes the situation more demanding of prompt, preventative measures is that media reports have indicated that travellers from Angola have already exported the yellow fever virus to China, Kenya and the Democratic Republic of Congo where about 21 people are reported to have died. This should be of particular concern to Nigeria because Mr Patrick Sawyer who brought the Ebola virus to the country came into Nigeria with an ECOWAS delegation.
It is our view that the Nigerian nation must heed the warning of WHO and take timely steps to avert yellow fever outbreak in Nigeria. Yellow fever is an acute viral haemorrhagic disease transmitted to humans by the bites of infected aedes and haemogogus mosquitoes found in tropical and subtropical areas of South America and Africa, and which the WHO has estimated to cause about 200,000 illnesses and 30,000 deaths every year, especially in unvaccinated populations.
Ordinarily, considering how endemic the vector mosquitoes are in this clime, yellow fever should be one of the health conditions targeted by our mass immunisation programmes. This, however, is not the case as the last vaccination campaign against yellow fever in Nigeria was done way back in 1995 after an outbreak that affected about 20,000 people had resulted in the death of over 5,000 people within an eight or ten year period.
The implication of this poor vaccination coverage is that millions of Nigeria presently have no protection against yellow fever, therefore, herd immunity for the condition is currently low across the country. Nigeria must therefore, embrace the WHO’s recommendation of combining routine immunisation with mass vaccination campaign. Moreover, considering the fact that there is no clear therapy option for yellow fever, it is imperative for the nation to have a definite, comprehensive vaccination programme against the disease.
The WHO and its partners have established a Yellow Fever International Coordinating Group to oversee the management of an emergency vaccine stockpile of six million doses yearly and the world health body is willing to support countries in preparing and responding effectively to yellow fever outbreaks, as well help link outbreak response level with long-term efforts to control the condition at regional and global levels.
The Nigerian government and stakeholders at all levels must embrace this initiative. This will be far more effective in preventing another fatal outbreak of the disease, rather than the typically frenzied and reactive measures that we often adopt in dealing with disease outbreaks.
We also recommend that the long-term strategies towards keeping yellow fever away from our borders should include an integrated sanitation and waste management system, as poor public sanitation services in many large cities in Africa have been identified as a major factor promoting the growth and spread of the vector mosquitoes causing both malaria and yellow fever. Mosquito control, through involvement of communities in cleaning of drainages and the entire environment is crucial as prevention of bites and reduction of the transmitting mosquito population will go a long way in helping to halt frequent infections and outbreaks of yellow fever, as well as other diseases.