More than 70 people are feared to have died of yellow fever in Nigeria since September, as health authorities warn of a resurgence of the disease. The country recorded 47 deaths from yellow fever throughout the whole of 2019. Health officials said progress in reducing and eradicating yellow fever, polio and other diseases through mass vaccinations and local surveillance networks had been put at risk as services are refocused on the fight against Covid-19. The Nigeria Centre for Disease Control (NCDC) said on Monday there had been a “sudden spike in cases and deaths in some communities” in Enugu and Delta states in the south of the country. The deaths followed reports of an undiagnosed “strange disease”, with patients coughing blood and becoming feverish. At least four samples have been confirmed as yellow fever, the agency said. It added that it had increased testing and was working to diagnose all suspected cases. State government health officials fear 72 people have died from the disease in the two states. There is no specific treatment for yellow fever, which is largely transmitted in urban settings by mosquitos, yet vaccinations are nearly 100% effective. Recent decades have seen the introduction of mass vaccination programmes to combat the disease. But in recent years, cases have begun to rise. Before 2017, there had not been an outbreak of yellow fever in Nigeria for more than 20 years, said Adesola Yinka-Ogunyele, a doctor and epidemiologist at the NCDC. The climate crisis, increased migration and fewer vaccination campaigns are among the reasons for the increase even before the coronavirus pandemic. “We’re still having issues of unvaccinated children. The more children are unvaccinated, the more likely there will be outbreaks,” she said. “There were a lot of demands on the health sector and surveillance systems to focus on Covid during this pandemic. Another issue is the fact that during Covid there was a reduction of health centres utilised because people are wary of contracting the virus, so then surveillance suffered. “However there is a lot of effort by health officials to make sure there is now a balance in disease response.” Last month, the World Health Organization announced that Nigeria would resume its yellow fever vaccination campaign, halted because of coronavirus. Like much of the continent, cases of coronavirus in Nigeria have been relatively low. Since January, the country has recorded 64,184 confirmed cases and 1,158 deaths. However, health officials fear a second wave, with a rise in cases in recent weeks. Last week, Unicef and the WHO called for the resumption of mass vaccinations against polio and measles, which have been disrupted by the Covid-19 pandemic.