Genetic diversity of Anopheles stephensi in Ethiopia provides insight into patterns of spread

Parasites & Vectors

Cecilia Flately¹  Gedeon Yohannes¹  Meshesha Balkew¹  Dereje Dengela²  Karen Lopez³  Daniel Janies³  Tamar E. Carter⁴  Sae Hee Choi⁴  Joseph Spear⁴  Jeanne N. Samake⁴  Solomon Yared⁵  Dejene Getachew⁶  Sheleme Chibsa⁷  Gunawardena Dissanayake⁷  Sarah Zohdy⁸  Seth R. Irish⁸  Peter Mumba⁹  Matthew Murphy^1,10 

[1] Abt Associates, PMI VectorLink Ethiopia Project, Addis Ababa, Ethiopia;Abt Associates, PMI VectorLink Project, Rockville, MD, USA;Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC, USA;Department of Biology, Baylor University, Waco, TX, USA;Department of Biology, Jigjiga University, Jigjiga, Ethiopia;Dire Dawa University, Dire Dawa, Ethiopia;U.S President’s Malaria Initiative (PMI) Program, Addis Ababa, Ethiopia;U.S. President’s Malaria Initiative and Entomology Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA;USAID, Addis Ababa, Ethiopia;Abt Associates, PMI VectorLink Ethiopia Project, Addis Ababa, Ethiopia;USAID, Bureau for Global Health, Office of Infectious Disease, Malaria Division, 2100 Crystal Drive

[2]  10082B, 22202, Arlington, VA, USA;

关键词: Malaria;    Invasive species;    Horn of Africa;    Sequencing;    Phylogeography;    Vector-borne;   

DOI  :  10.1186/s13071-021-05097-3

来源: Springer

【 摘 要 】

BackgroundThe recent detection of the South Asian malaria vector Anopheles stephensi in the Horn of Africa (HOA) raises concerns about the impact of this mosquito on malaria transmission in the region. Analysis of An. stephensi genetic diversity and population structure can provide insight into the history of the mosquito in the HOA to improve predictions of future spread. We investigated the genetic diversity of An. stephensi in eastern Ethiopia, where detection suggests a range expansion into this region, in order to understand the history of this invasive population.MethodsWe sequenced the cytochrome oxidase subunit I (COI) and cytochrome B gene (CytB) in 187 An. stephensi collected from 10 sites in Ethiopia in 2018. Population genetic, phylogenetic, and minimum spanning network analyses were conducted for Ethiopian sequences. Molecular identification of blood meal sources was also performed using universal vertebrate CytB sequencing.ResultsSix An. stephensi COI-CytB haplotypes were observed, with the highest number of haplotypes in the northeastern sites (Semera, Bati, and Gewana towns) relative to the southeastern sites (Kebridehar, Godey, and Degehabur) in eastern Ethiopia. We observed population differentiation, with the highest differentiation between the northeastern sites compared to central sites (Erer Gota, Dire Dawa, and Awash Sebat Kilo) and the southeastern sites. Phylogenetic and network analysis revealed that the HOA An. stephensi are more genetically similar to An. stephensi from southern Asia than from the Arabian Peninsula. Finally, molecular blood meal analysis revealed evidence of feeding on cows, goats, dogs, and humans, as well as evidence of multiple (mixed) blood meals.ConclusionWe show that An. stephensi is genetically diverse in Ethiopia and with evidence of geographical structure. Variation in the level of diversity supports the hypothesis for a more recent introduction of An. stephensi into southeastern Ethiopia relative to the northeastern region. We also find evidence that supports the hypothesis that HOA An. stephensi populations originate from South Asia rather than the Arabian Peninsula. The evidence of both zoophagic and anthropophagic feeding support the need for additional investigation into the potential for livestock movement to play a role in vector spread in this region.Graphical Abstract

【 授权许可】

CC BY