Guillaume Lachenal

Variable epidemic histories of hepatitis C virus genotype 2 infection in West Africa and Cameroon.

It has recently been suggested that HCV genotype 2 (HCV-2) was more recently introduced to Cameroon (Middle Africa) than West African countries. In order to explore the relationships among HCV-2 strains from Cameroon and West Africa, and to estimate the epidemic history of each lineage, a recently-developed Bayesian evolutionary analysis approach was used. The estimated date of the most recent common ancestor (MRCA) of the Cameroon HCV-2 strains, 1630 (95% highest posterior density interval: 1470-1760) was slightly more recent than that of West Africa, 1540 (95% highest posterior density interval: 1380-1680). Estimates of epidemic history indicate significant differences between the two strains. HCV-2 appears to have spread relatively slowly within the West African population from 1630 to 1900, whilst the Cameroon lineages exhibit rapid, exponential spread from 1920 to 1960. This comparative genetic analysis indicates that Cameroon HCV-2 strains are derived from West African strains and that HCV-2 has undergone radically different epidemiological histories in the two regions.

The Two-Phase Emergence of Non Pandemic HIV-1 Group O in Cameroon

Unlike the pandemic form of HIV-1 (group M), group O viruses are endemic in west central Africa, especially in Cameroon. However, little is known about group O’s genetic evolution, and why this highly divergent lineage has not become pandemic. Using a unique and large set of group O sequences from samples collected from 1987 to 2012, we find that this lineage has evolved in successive slow and fast phases of diversification, with a most recent common ancestor estimated to have existed around 1930 (1914–1944). The most rapid periods of diversification occurred in the 1950s and in the 1980s, and could be linked to favourable epidemiological contexts in Cameroon. Group O genetic diversity reflects this two-phase evolution, with two distinct populations potentially having different viral properties. The currently predominant viral population emerged in the 1980s, from an ancient population which had first developed in the 1950s, and is characterized by higher growth and evolutionary rates, and the natural presence of the Y181C resistance mutation, thought to confer a phenotypic advantage. Our findings show that although this evolutionary pattern is specific to HIV-1 group O, it paralleled the early spread of HIV-1 group M in the Democratic Republic of Congo. Both viral lineages are likely to have benefited from similar epidemiological contexts. The relative role of virological and social factors in the distinct epidemic histories of HIV-1 group O and M needs to be reassessed.

SOCIAL HISTORY, BIOLOGY, AND THE EMERGENCE OF HIV IN COLONIAL AFRICA

This essay considers how historians of Africa can draw from and critically contribute to biomedical debates. Recent virological research has established that the HIV/AIDS pandemic began with the passage of simian immunodeficiency viruses into human populations in the first half of the twentieth century. Current debates on the emergence of HIV are an opportunity for historians to engage with biomedical research to rethink social political and environmental histories of Africa. While biomedical writings focus on HIV ‘origins’ the authors propose a broader look at the historical changes associated with the beginnings of the HIV/AIDS pandemic. KEY WORDS: health disease medicine Central Africa HIV/AIDS environment urban.

At home in the postcolony: Ecology, empire and domesticity at the Lamto field station, Ivory Coast

This article is a history of the field station Lamto, in Ivory Coast, which was created by French ecologists in 1962, after independence. It retraces the origins, the logics and the contradictions of an extraordinarily ambitious scientific project, which aimed at the systematic, holistic, quantitative and multi-disciplinary description of a unit of African nature – the savannah ecosystem. It explores how knowledge-making was articulated with work hierarchies and postcolonial politics, lifestyles, values and affects. It reconstitutes the political ecology of a research station in ecology, following in its residences, laboratories and open-air experiments the co-production of domesticity, nature, science and (post-)colonial situations.

Neglected Actors in Neglected Tropical Diseases Research: Historical Perspectives on Health Workers and Contemporary Buruli Ulcer Research in Ayos, Cameroon.

“We are neglected, just as Buruli ulcer is neglected” (WS1.KE). With these words, Kombang Ekodogo and Daniel Ze Bekolo, two nurses with long experience with Buruli ulcer disease (henceforth, BU) at the hospital of Ayos, Cameroon, expressed dissatisfaction about their involvement in international research projects. They felt that their contribution to crucial progress in the surgery, rehabilitative care, and epidemiology of BU was insufficiently recognized and rewarded. Although medical research projects meant considerable benefits for themselves and their communities, they insisted on their frustration with being, in the best cases, merely “acknowledged” in a footnote to the final publications. “When I tell my children that I participated in this and that project, they will ask: yes, dad, but where is your name [on the paper]?” (WS1.ZB). Collaborative research in Africa faces difficult ethical challenges. Inequalities between local and expatriate scientists constrain the functioning of research projects and contradict their official presentation as “partnerships” [1]. In spite of efforts to acknowledge and redress such inequalities among researchers, the “collaboration equation” remains hard to balance [2]. Debates over the ethics of transnational research rarely take into account the case of auxiliary staff such as nurses, laboratory technicians, research assistants, and fieldworkers. Although largely invisible in academic outputs of medical research, they play an essential role at the interface of community work, medical care, and scientific research [3]. Their pivotal contribution to disease control, including HIV, tuberculosis (TB), onchocerciasis, dracunculiasis, and BU [4– 9] is beginning to be acknowledged, as well as their crucial role as mediator of research ethics [10–14]. Their epistemological role as knowledge-producers has been less studied. In this research, we document the expertise of auxiliary health workers involved in BU research. We retrace historically how their knowledge about tropical diseases like leprosy, sleeping sickness, and BU has been transmitted across century-old genealogies of local nurses. This article aims to recognize and value this memory and expertise. The original idea for this paper emerged from repeated conversations between our team of historians and anthropologists and nurses working at Ayos Hospital. Our discussions focused