Malaria elimination challenges in Mesoamerica: evidence of submicroscopic malaria reservoirs in Guatemala

Malaria Journal

Research

Myriam Arévalo-Herrera¹  Adolfo Miranda²  Shirley Evelyn Lennon³  Alvaro Alvarez³  Andres F. Vallejo³  Julianh Perez³  Juliana Henao³  Sócrates Herrera⁴ 

[1] Caucaseco Scientific Research Center (CSRC)/Centro Latino Americano de Investigación en Malaria (CLAIM), Cali, Colombia;Facultad de Salud, Universidad del Valle, Cali, Colombia;Centro Nacional de Epidemiología (CNE), Guatemala City, Guatemala;Malaria Vaccine and Drug Development Center (MVDC), Cali, Colombia;Malaria Vaccine and Drug Development Center (MVDC), Cali, Colombia;Caucaseco Scientific Research Center (CSRC)/Centro Latino Americano de Investigación en Malaria (CLAIM), Cali, Colombia;

关键词: Malaria;    Plasmodium vivax;    Prevalence;    Asymptomatic;    Submicroscopic;    Gametocytes;    Guatemala;    Mesoamerica;   

DOI  :  10.1186/s12936-016-1500-6

 received in 2016-05-19, accepted in 2016-08-20,  发布年份 2016

来源: Springer

【 摘 要 】

BackgroundEven though malaria incidence has decreased substantially in Guatemala since 2000, Guatemala remains one of the countries with the highest malaria transmission in Mesoamerica. Guatemala is committed to eliminating malaria as part of the initiative ‘Elimination of Malaria in Mesoamerica and the Island of Hispaniola’ (EMMIE); however, it is still in the control phase. During the past decade, the government strengthened malaria control activities including mass distribution of long-lasting insecticide-impregnated bed nets, early diagnosis and prompt treatment. This study aimed to determine the prevalence of malaria, including gametocytes, in three areas of Guatemala using active case detection (ACD) and quantitative polymerase chain reaction (qPCR).MethodsCross-sectional surveys were conducted in three departments with varying transmission intensities: Escuintla, Alta Verapaz and Zacapa. Blood samples from 706 volunteers were screened for malaria using microscopy and qPCR which was also used to determine the prevalence of gametocytes among infected individuals. Results were collected and analysed using REDCap and R Project, respectively.ResultsMalaria was diagnosed by microscopy in only 2.8 % (4/141) of the volunteers from Escuintla. By contrast, qPCR detected a prevalence of 7.1 % (10/141) in the same volunteers, 8.4 % (36/429) in Alta Verapaz, and 5.9 % (8/136) in Zacapa. Overall, 7.6 % (54/706) of the screened individuals were positive, with an average parasitaemia level of 40.2 parasites/μL (range 1–1133 parasites/μL) and 27.8 % carried mature gametocytes. Fifty-seven percent (31/54) of qPCR positive volunteers were asymptomatic and out of the 42.6 % of symptomatic individuals, only one had a positive microscopy result.ConclusionsThis study found a considerable number of asymptomatic P. vivax infections that were mostly submicroscopic, of which, approximately one-quarter harboured mature gametocytes. This pattern is likely to contribute to maintaining transmission across the region. Robust surveillance systems, molecular diagnostic tests and tailored malaria detection activities for each endemic site may prove to be imperative in accelerating malaria elimination in Guatemala and possibly across all of Mesoamerica.

【 授权许可】

CC BY   
© The Author(s) 2016