Nuno R. Faria, Andrew Rambaut, Marc A. Suchard, Guy Baele,Trevor Bedford,Melissa J. Ward, Andrew J. Tatem, João D. Sousa, Nimalan Arinaminpathy, Jacques Pépin, David Posada, Martine Peeters, Oliver G. Pybus, Philippe Lemey “The early spread and epidemic ignition of HIV-1 in human populations” Science Vol. 346 no. 6205 pp. 56-61, 3 October 2014 http://www.sciencemag.org/content/346/6205/56
これを伝えるIan Sample “HIV pandemic originated in Kinshasa in the 1920s, say scientists”*3から切り抜き；
Thirty years after the discovery of HIV-1, the early transmission, dissemination, and establishment of the virus in human populations remain unclear. Using statistical approaches applied to HIV-1 sequence data from central Africa, we show that from the 1920s Kinshasa (in what is now the Democratic Republic of Congo) was the focus of early transmission and the source of pre-1960 pandemic viruses elsewhere. Location and dating estimates were validated using the earliest HIV-1 archival sample, also from Kinshasa. The epidemic histories of HIV-1 group M and nonpandemic group O were similar until ~1960, after which group M underwent an epidemiological transition and outpaced regional population growth. Our results reconstruct the early dynamics of HIV-1 and emphasize the role of social changes and transport networks in the establishment of this virus in human populations.
An international team of scientists led by the universities of Oxford in Britain and Leuven in Belgium reconstructed the history of the HIV pandemic using historical records and DNA samples of the virus dating back to the late 1950s. The DNA allowed them to draw up a family tree of the virus that traced its ancestry through time and space. Using statistical models they could push farther back than the 1950s and locate the origin of the pandemic in 1920s Kinshasa.
The genetic data suggests that pandemic HIV spread rapidly through the Democratic Republic of the Congo, a country the size of western Europe. From the late 1930s to the early 1950s, the virus spread by rail and river to Mbuji-Mayi and Lubumbashi in the south and Kisangani in the north. There the virus took hold and formed secondary reservoirs from where it spread to countries in southern and eastern Africa.
From the 1920s until 1960, the pandemic HIV strain – there were others that fizzled out – spread from Kinshasa, crossed borders to other nations, and ultimately landed on distant continents. It has infected nearly 75 million people worldwide to date.
When the virus arrived, Kinshasa was bustling. It was the largest and fastest growing city in the region with transport links reaching up and down the country. The busy Congo river curved north and east to Kisangani more than 600 miles away. The railway carried scores of workers southeast to Katanga, a mining province reliant on immigrant labour, and on to Lubumbashi more than 900 miles away.
Records show that by the 1940s, more than a million people a year passed through Kinshasa on the railways alone. By 1960, the rate of new pandemic HIV infections outpaced the growth of the regional population, according to research published in Science.
While boats and trains spread the virus far, other factors played their part. Records suggest Kinshasa had a relatively high proportion of men and a consequent demand for sex workers. Some doctors may have unwittingly spread the virus further, through unsterilised jabs at sexual health clinics.
James Gallagher “Aids: Origin of pandemic 'was 1920s Kinshasa'” http://www.bbc.com/news/health-29442642
*2:See eg. http://ja.wikipedia.org/wiki/%E3%82%B3%E3%83%B3%E3%82%B4%E6%B0%91%E4%B8%BB%E5%85%B1%E5%92%8C%E5%9B%BD http://fr.wikipedia.org/wiki/R%C3%A9publique_d%C3%A9mocratique_du_Congo http://en.wikipedia.org/wiki/Democratic_Republic_of_the_Congo Mentioned in http://d.hatena.ne.jp/sumita-m/20100224/1267021071 http://d.hatena.ne.jp/sumita-m/20120113/1326474831