Dynamics of Plasmodium vivax sporogony in wild Anopheles stephensi in a malaria-endemic region of Western India

Malaria Journal

Research

Laura Chery¹  Pradipsinh K. Rathod¹  Praveen Balabaskaran Nina¹  Suresh Kumar Manoharan²  Anjali Mascarenhas²  Jayashree Walke²  Edwin Gomes³  Neena Valecha⁴  Smita Vernekar⁵  Ajeet Kumar Mohanty⁵  Shuvankar Ballav⁵  Maria D’souza⁵  Ashwani Kumar⁵  Sushma Bhinge⁵ 

[1] Departments of Chemistry and of Global Health, University of Washington, 98195, Seattle, WA, USA;Departments of Chemistry and of Global Health, University of Washington, 98195, Seattle, WA, USA;Goa Medical College and Hospital, 403202, Bambolim, Goa, India;Goa Medical College and Hospital, 403202, Bambolim, Goa, India;National Institute of Malaria Research (ICMR), Sector 8, 110077, Dwarka, New Delhi, India;National Institute of Malaria Research, Field Unit, 403001, Campal, Goa, India;

关键词: MESA-ICEMR;    Goa;    Vector infection;    Anopheles stephensi;    Plasmodium vivax;    Oocysts;    Sporozoites;    Infection rate;   

DOI  :  10.1186/s12936-017-1931-8

 received in 2017-04-28, accepted in 2017-07-04,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundIn global efforts to track mosquito infectivity and parasite elimination, controlled mosquito-feeding experiments can help in understanding the dynamics of parasite development in vectors. Anopheles stephensi is often accepted as the major urban malaria vector that transmits Plasmodium in Goa and elsewhere in South Asia. However, much needs to be learned about the interactions of Plasmodium vivax with An. stephensi. As a component of the US NIH International Center of Excellence for Malaria Research (ICEMR) for Malaria Evolution in South Asia (MESA), a series of membrane-feeding experiments with wild An. stephensi and P. vivax were carried out to better understand this vector-parasite interaction.MethodsWild An. stephensi larvae and pupae were collected from curing water in construction sites in the city of Ponda, Goa, India. The larvae and pupae were reared at the MESA ICEMR insectary within the National Institute of Malaria Research (NIMR) field unit in Goa until they emerged into adult mosquitoes. Blood for membrane-feeding experiments was obtained from malaria patients at the local Goa Medical College and Hospital who volunteered for the study. Parasites were counted by Miller reticule technique and correlation between gametocytaemia/parasitaemia and successful mosquito infection was studied.ResultsA weak but significant correlation was found between patient blood gametocytaemia/parasitaemia and mosquito oocyst load. No correlation was observed between gametocytaemia/parasitaemia and oocyst infection rates, and between gametocyte sex ratio and oocyst load. When it came to development of the parasite in the mosquito, a strong positive correlation was observed between oocyst midgut levels and sporozoite infection rates, and between oocyst levels and salivary gland sporozoite loads. Kinetic studies showed that sporozoites appeared in the salivary gland as early as day 7, post-infection.ConclusionsThis is the first study in India to carry out membrane-feeding experiments with wild An. stephensi and P. vivax. A wide range of mosquito infection loads and infection rates were observed, pointing to a strong interplay between parasite, vector and human factors. Most of the present observations are in agreement with feeding experiments conducted with P. vivax elsewhere in the world.

【 授权许可】

CC BY   
© The Author(s) 2017