With the disturbing news today that a nurse has contracted Ebola from an infected patient in Spain, a new study that reveals the early spread of HIV can be explained by transport networks and social change is a chilling reminder that far greater vigilance and appropriate action based upon science rather than politics or misguided sentiment will be needed to ensure Ebola does not become a truly global pandemic.
The study by a multinational team led by the University of Oxford and the Rega Institute for Medical Research (Belgium), used molecular genetics to establish that HIV originated in Kinshasa during the 1920’s (in what is now D.R. Congo).
This area was the focus for early transmission up to the 1960’s, when major epidemiological transitions occurred that resulted in different forms of HIV.
The “M” type of HIV-1 is the variant that led to pandemic HIV and has caused over 75 million infections worldwide to date (the non-pandemic “O” variant remains relatively local).
Their estimate of the pandemic origin explains why Kinshasa supports the greatest contemporary diversity in HIV-1, and why several early cases of AIDS (the disease caused by HIV) were diagnosed in this area.
This is a major addition to our understanding, and arguably the most significant since earlier studies suggested that cross species transition from chimpanzees to humans originated in southeast Cameroon (which was connected to Kinshasa by a ferry route during German colonial rule at the time of its spread).
The study indicates genetic biogeography of contemporary HIV-1 in sub-Saharan Africa is strongly influenced by development of transport networks from the D.R. Congo, and also explains non-local infections in Haiti as a result of returning migrant workers who had previously flocked to Kinshasa in the newly independent D.R. Congo during the 1960’s.
Interestingly transport networks were not the only factor strongly correlated with the spread of HIV; social practices also emerged as a strong predictor.
Public health records suggested that use of unsterilized needles in sexual health clinics, coupled with changes to the organisation of commercial sex work that resulted in increased partner exchange are likely a strong contributor.
That this study was able to link the spread of HIV to transport networks should be a wake-up call that unless more globally responsible management of Ebola is forthcoming, there is a risk that the disease will become pandemic.
The latest response from the White House: The President is “considering” extra screening at airports for those people arriving from the worst-affected countries in west Africa – I hope for everyone’s sake this does not end up being a case of “too little too late”.
The HIV study is published in this week’s edition of Science: