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Although H5N1 has been reported for years in sub-Saharan Africa – in countries like Ghana, Nigeria & Burkina Faso – only one human infection with the virus has ever been confirmed there by the WHO (see 2007’s Nigeria Confirms Human Bird Flu Case).
There were three other suspected cases at the time - including the mother of the confirmed case in Lagos – but testing was `inconclusive’.
According to local media reports at the time (see The Nigerian Paradox), the only reason we have the one confirmed case is because the husband/father of the two related victims paid for a private autopsy and lab testing when his daughter died two weeks after his wife.
As to how many other cases there might be . . .
With a population of 175 million, and an average life expectancy of about 53 years, roughly 6,000 people die each day in Nigeria. According to the CDC, the top 10 causes of death in Nigeria are:
Deaths from Lower respiratory infections, which can cover a lot of territory – including influenza – are second only to malaria. The story is much the same in other nations reporting H5N1, with lower respiratory infections claiming 11% of the lives in Côte d’Ivoire, 9% in Ghana, and 13% in Burkina Faso.
These numbers are approximations, of course, as many people die and are buried without ever seeing a doctor. Cause of death is often determined using verbal autopsies, based on interviews with family members, friends and neighbors. Helpful, but imprecise.
The burden of influenza – both from seasonal strains, and potentially from novel flu strains like H5N1 – is largely unknown in Africa.
While we think of Asia as the most probable launching site for novel flu viruses (see EID Journal: Predicting Hotspots for Influenza Virus Reassortment), the African continent represents a huge blind spot with significant potential. And we aren’t just talking H5N1, for other avian and swine strains are undoubtedly present as well.
Although they still have a long ways to go, the following WHO new release details their work in improving influenza surveillance across the African continent.
WHO scales up efforts to detect and control the spread of influenza viruses in Africa
Brazzaville, 19 October 2015 – Highly infectious and unpredictable seasonal and avian influenza viruses are emerging threats in Africa triggering WHO to guide implementation of national influenza preparedness, surveillance and control strategies to protect individuals and populations.
Influenza viruses are deadly in their own right but they are also an important cause of respiratory disease such as pneumonia, which is a major cause of death in Africa, particularly among children.
In Africa, the impact of influenza infection is not very well documented. However, the information we do have shows that influenza viruses circulating in animals (zoonotic influenza viruses, including avian influenza) pose the greatest threat to human health.
This threat is due to people not having immunity against these viruses. The concern is that influenza viruses circulating in animals could develop traits in the future which could permit them to be spread easily from person to person – possibly triggering a new influenza pandemic.
With this, there is an urgent need to better understand trends, risk factors and burdens of seasonal and zoonotic influenza viruses. These significant gaps have sparked the rapid expansion of influenza preparedness, surveillance and reporting to better protect against both seasonal and zoonotic influenza viruses.
“Population vulnerabilities and weak national health systems, combined with the highly contagious and unpredictable nature of influenza viruses, mean we must enhance local and regional preparedness, surveillance and rapid response capacity now to improve health security in the African Region,” said Dr Ibrahima-Socé Fall, Director of the Health Security and Emergencies Cluster at the WHO Regional Office for Africa (WHO/AFRO).
To fill these gaps, WHO/AFRO has been working with partners in supporting the establishment and functioning of influenza sentinel surveillance systems. Influenza laboratories have been organized to form a regional network of laboratories, some of which are national influenza centres (NICs).
As of October 2015, over 64% (30/47) of countries in the African Region have developed laboratory capacity for influenza diagnosis using the minimum standards as recommended by WHO and are implementing virological surveillance for influenza and 45% (21/47) contributing to weekly influenza surveillance in the Region.
“In line with the Integrated Disease and Response strategy, surveillance provides us with data to better understand the burden and impact of influenza viruses and facilitates the sharing of best practices in the African Region. This will help to improve the detection and reporting of new strains of influenza viruses with pandemic potential,” said Dr Yahaya Ali Ahmed, Programme Manager, Integrated Disease Surveillance at WHO/AFRO.
WHO/AFRO continues to support Ministries of Health, in collaboration with Ministries of Agriculture and other governmental bodies, to protect communities and further strengthen national influenza capacities in line with the International Health Regulations (2005), Pandemic Influenza Preparedness (PIP) Framework and within the context of the Integrated Disease Surveillance and Response (IDSR) strategy.
To enhance influenza surveillance in the African Region, a newly published and disseminated standard operating procedure can be found at this link: Protocol for National Influenza Sentinel Surveillance [pdf - 1.06MB]
