AIDS - Origin and the Path to the West

As we saw, AIDS hit the West in the 1980’s. In his awesome book, Spillover, David Quammen gets into how it came out of Africa. That story starts off with a heated debate between two theories on the origin of HIV in humans: (1) the cut-hunter theory that said assumed a hunter killed an African primate, and got infected due to a wound/cut in his body; v/s (2) the polio-vaccine theory that blamed contaminated vaccines which had been tested on Africans in 1957-60.

 

To test the polio-vaccine theory, Dirk Teuwen went to the Congo to test one of the earliest HIV-1 samples from 1960. It was improbable anything would have survived that long, but as luck would have it, those samples had been preserved in just the right way. That strain was given the name DRC60. It was compared against another strain named ZR59. The two strains were very different:

“Every virus has its own rate (of mutation)… The amount of difference between two viral strains can therefore reveal how much time has passed since they diverged from a common ancestor.”

So how far back did DRC60 and ZR59 diverge from a common ancestor? The answer, was, take a deep breath: the year 1908 (approx.). In other words, the first HIV virus had entered humans way back in 1908 (give or take)! (It also proved that AIDS did not enter humans via the polio-vaccine route).

 

So why didn’t HIV go, er, viral for so long after that? Well, it had started in Africa. Imagine how Africa was in 1908. Exactly, not too many big cities. No aeroplanes in the world either. Besides, the rate of dispersion via sex between (infected) humans alone was very slow. Bottomline, the virus spread very slowly in Africa.

 

Between 1940-60, the population of Kinshasa, the capital of Congo, exploded:

“A virus was at the right place at the right time.”

And then the stars started to line up for the HIV virus.

 

Between 1921 and 1959, well-intended colonialists “aimed at treating certain tropical diseases with injectable medicines” in Congo. These were massive efforts. And this was long before the age of disposable syringes. On the contrary, only 2 million syringes were produced globally in 1930. No wonder then:

“(Syringes were) more available (than before) but not more expendable.”

Inevitably, syringes were reused across patients as part of those well-intended treatments. Obviously, sterilizing the needles between use on different patients was not practical either (far too many patients). And thus:

“All those injections… might account for boosting the incidence of HIV infection beyond a critical threshold.”

 

Around 1966, the HIV virus reach Haiti. How did it cross the Atlantic? In 1960, Belgium finally gave Congo its independence. As the Belgian exodus followed, it created a vacuum as:

“The Belgian regime had pointedly avoided educating its colonial subjects.”

A newly independent country was starting with no doctors and few teachers! The UN helped a bit. But how could one get bureaucrats, teachers, lawyers etc? Congo turned to a country with African roots that spoke French: Haiti, a poor country with no prospects. Thousands came over from Haiti to take up those roles that the Congo folks didn’t have the skills for. Many of those Haitians were single:

“We can assume few remained celibate.”

In 1965, a new dictator seized power in Congo and wanted the Haitians out:

“Someone brought back to Haiti, along with Congolese memories, a dose of HIV-1 group.”

 

Like in Congo, sex alone was too slow a way to spread the virus in Haiti. This time the accelerant wasn’t syringes though. Instead, it was the blood plasma trade of Haiti. Plasma is the liquid component of blood: the cells are removed, leaving valuable antibodies and clotting factors behind. Those extracted cells were put back into the donors (sellers) via plasmapheresis machines. Why? That way, the blood donor (seller) wouldn’t feel anaemic, in turn resulting in his return sooner to donate again. But those plasmapheresis machines were “gargling” the blood of different donors, thereby infecting more and more people with the HIV virus.

 

Some of that frozen blood plasma was regularly exported to the U.S. And since Haiti was poor with no prospects, and the U.S. wasn’t too far, Haitians were immigrating to the U.S. And of course, once HIV reached the U.S., it was trivially easy for it to global.

 

This is a fascinating tale indeed. Sure, it includes some conjectures, but much of it is scientific fact (and samples). The gratifying thing is that so many things had to go just right for the virus to go global. On the other hand, it’s scary that time (indeed, decades) wasn’t a deterrent.

 

What’s ominous about this tale is that it means the Next Big One could be out there already, slowly making its way a la HIV. Then again, it could come with breath-taking speed a la COVID-19.