MADAGASCAR - Genetic evidence and historical theories of the Asian and African origins of the present Malagasy population [Scholarly Article - Human Molecular Genetics, March 2021]

Title:

Genetic evidence and historical theories of the Asian and African origins of the present Malagasy population  

 

Authors:

Margit Heiske, Omar Alva, Veronica Pereda-Loth, Matthew Van Schalkwyk, Chantal Radimilahy, Thierry Letellier, Jean-Aimé Rakotarisoa & Denis Pierron 

 

Published:

Human Molecular Genetics, Volume 30, Issue R1, 1 March 2021, Pages R72–R78, 

https://doi.org/10.1093/hmg/ddab018 

 

Abstract: 

The origin of the Malagasy population has been a subject of speculation since the 16th century. Contributions of African, Asian, Indian, Melanesian, Arabic and Persian populations have been suggested based on physical and cultural anthropology, oral tradition, linguistics and later also by archaeology. In the mid-20th century, increased knowledge of heredity rules and technical progress enabled the identification of African and Asian populations as main contributors. Recent access to the genomic landscape of Madagascar demonstrated pronounced regional variability in the relative contributions of these two ancestries, yet with significant presence of both African and Asian components throughout Madagascar. This article reviews the extent to which genetic results have settled historical questions concerning the origin of the Malagasy population. After an overview of the early literature, the genetic results of the 20th and 21th centuries are discussed and then complemented by the latest results in genome-wide analyses. While there is still much uncertainty regarding when, how and the circumstances under which the ancestors of the modern Malagasy population arrived on the island, we propose a scenario based on historical texts and genomic results.

 

Ethnicity and clinical outcomes in COVID-19: A systematic review and meta-analysis [Scholarly Article - The Lancet, 12 November 2020]

Title:

Ethnicity and clinical outcomes in COVID-19: A systematic review and meta-analysis

Authors:

Shirley Sze, Daniel Pan, Clareece R. Nevill, Laura J. Gray, Christopher A. Martin, Joshua Nazareth, Jatinder S. Minhas, Pip Divall, Kamlesh Khunti, Keith R. Abrams, Laura B. Nellums & Manish Pareek

Published:

The Lancet, 12 November 2020

https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370(20)30374-6/fulltext

Abstract:

Background 

Patients from ethnic minority groups are disproportionately affected by Coronavirus disease (COVID-19). We performed a systematic review and meta-analysis to explore the relationship between ethnicity and clinical outcomes in COVID-19. 

 

Methods 

Databases (MEDLINE, EMBASE, PROSPERO, Cochrane library and MedRxiv) were searched up to 31st August 2020, for studies reporting COVID-19 data disaggregated by ethnicity. Outcomes were: risk of infection; intensive therapy unit (ITU) admission and death. PROSPERO ID: 180654. 

 

Findings 

18,728,893 patients from 50 studies were included; 26 were peer-reviewed; 42 were from the United States of America and 8 from the United Kingdom. Individuals from Black and Asian ethnicities had a higher risk of COVID-19 infection compared to White individuals. This was consistent in both the main analysis (pooled adjusted RR for Black: 2.02, 95% CI 1.67–2.44; pooled adjusted RR for Asian: 1.50, 95% CI 1.24–1.83) and sensitivity analyses examining peer-reviewed studies only (pooled adjusted RR for Black: 1.85, 95%CI: 1.46–2.35; pooled adjusted RR for Asian: 1.51, 95% CI 1.22–1.88). Individuals of Asian ethnicity may also be at higher risk of ITU admission (pooled adjusted RR 1.97 95% CI 1.34–2.89) (but no studies had yet been peer-reviewed) and death (pooled adjusted RR/HR 1.22 [0.99–1.50]). 

 

Interpretation 

Individuals of Black and Asian ethnicity are at increased risk of COVID-19 infection compared to White individuals; Asians may be at higher risk of ITU admission and death. These findings are of critical public health importance in informing interventions to reduce morbidity and mortality amongst ethnic minority groups.