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The bloodborne scourge

Transatlantic slavery: The Africans had inherited immunity to Plasmodium vivax because of their lack of a protein called Duffy antigen. Photo: Wiki Commons  

Earlier last week, the World Health Organization announced that the southeastern African country of Malawi would begin vaccinating children under the age of two against malaria. While trial runs conducted between 2009 and 2014 reveal that the efficacy of the vaccine is expected to be 40% — “the vaccine prevented four in 10 cases of clinical malaria” — it is still expected to substantively aid other anti-malarial efforts like mosquito nets, sanitation etc. For much of history, the female anopheles mosquito has been the greatest of human enemies and the Plasmodium it injects into the bloodstream among the deadliest weapons in its arsenal. Perhaps this can be seen most starkly at the Battle of Guadalcanal in the South Pacific during World War II where, while 1,700 Americans died from injuries inflicted by the Japanese, over 4-5,000 died due to malaria.

Amidst all these stories of malaria and yellow fever, there is a tendency to think about these diseases as stand-alone phenomena, affecting the here-and-now. What is often forgotten is the mosquito’s extraordinary influence on how societies have evolved, how institutions have emerged, and the history of colonisation itself. That historians have occasionally tipped their hats to the prowess of disease in shaping human history is not surprising. Thucydides in The History of the Peloponnesian War is one of the earliest examples, when he writes about the impact of the ‘plague’ of Athens in 430 B.C.E — was it bubonic plague, typhoid, typhus fever, or Ebola; we can’t be sure — that decimated the city-state during its war against Sparta.

Historical narratives

The Romans, ever so scrupulously colourful in documenting their travails, even had names for the great waves of disease that ravaged their cities — the Antonine Plague, the Plague of Cyprian, the Plague of Justinian. In ancient India, the great physician-scholar Sushruta wrote about ‘vishama jwara’ (intermittent fevers), which subsequent generations of commentators claimed were caused by ‘bhutabhishanga’ (spectral bodies); the latter were diagnosed as poisonous insects by even later commentators such as Chakrapani. Modern students of Ayurveda often interpret this as among the earliest evidence of malarial fevers in India. Yet, for most historical narratives, diseases and disease vectors (like mosquitos) have rarely made for exciting protagonists or even causal agents. A few rare historians such J.R. McNeill have, however, upended conventional wisdom when they frame historical events as a consequence of biological factors. Using a concept he calls “differential resistance” — those who have earned immunity thanks to malarial or yellow fever attacks as a child versus those who succumb to it on first exposure — McNeill’s narrative of the colonisation of Central America relies on mosquitoes as its protagonists. The Spanish Empire of the 17th and 18th centuries, which raised armies from native-born South Americans (who had immunity to yellow fever) defended its territories against the English, whose soldiers came from the home country and succumbed due to lack of immunity. He writes: “without [female of the species of aedes aegypti, which causes yellow fever], Spain might well have lost much of her American empire in the 18th century.”

The contrast

More provocatively, in Charles Mann’s fantastic survey of the post-Columbus world, titled 1493, he builds a careful case that the institution of transatlantic slavery of Africans from the 17th century onwards over-flourished because the Africans had inherited immunity to Plasmodium vivax because of their lack of a protein called Duffy antigen. In contrast, white servants from Europe (cheaper to import than African slaves) fell systematically ill and succumbed in the Americas. As Mann writes, “their [African] immunity became a wellspring for their enslavement.”

Malaria in modern India is an arms race story, between the State’s schemes to annihilate mosquitoes and newer generations of mosquito resistance. As of 1947, there were an estimated 7.5 crore malarial cases among a population of 33 crore. In the decades that followed independence — from the 1950s and 1960s — cases declined dramatically, with 1964 figures estimated at 1,00,000. This was largely achieved by “indoor residual spraying” of the chemical DDT under the auspices of the National Malaria Control Programme (NMCP). Then, by the mid-1970s, an explosion of cases was reported with figures ranging up to 64 lakh. By 2009, government figures estimated 1.5 million cases.

What a careful tracking of pathogens and vectors like mosquitoes teaches us is not just how fragile human bodies are, but that the elaborate, self-satisfying stories of conquest and freedoms that humans tell each other may be more complicated. Behind the visible world of heroes and villains, ideologies and conceits, there is another unseen world of microbes, viruses, and bacteria that works its way into human societies and ultimately governs how we find our place in this world. No different from the unseen strings of politics and religion that make marionettes of us.

Keerthik Sasidharan is a writer and lives in New York City.

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Printable version | Jul 23, 2021 5:14:30 AM |

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