Files

waltmann2015_1896.pdf (1.59 MB)

Document type

Article

Version

Published version

Publication date

2015-05-21

Publication license

cc by (c) Waltmann et al., 2015
Please use this identifier to cite or link to this item: https://hdl.handle.net/2445/69261

High Rates of Asymptomatic, Sub-microscopic Plasmodium vivax Infection and Disappearing Plasmodium falciparum Malaria in an Area of Low Transmission in Solomon Islands

Journal Title

Authors

Director/Tutor

Journal ISSN

Volume Title

Related resource

http://dx.doi.org/10.1371/journal.pntd.0003758

Abstract

INTRODUCTION: Solomon Islands is intensifying national efforts to achieve malaria elimination. A long history of indoor spraying with residual insecticides, combined recently with distribution of long lasting insecticidal nets and artemether-lumefantrine therapy, has been implemented in Solomon Islands. The impact of these interventions on local endemicity of Plasmodium spp. is unknown. METHODS: In 2012, a cross-sectional survey of 3501 residents of all ages was conducted in Ngella, Central Islands Province, Solomon Islands. Prevalence of Plasmodium falciparum, P. vivax, P. ovale and P. malariae was assessed by quantitative PCR (qPCR) and light microscopy (LM). Presence of gametocytes was determined by reverse transcription quantitative PCR (RT-qPCR). RESULTS: By qPCR, 468 Plasmodium spp. infections were detected (prevalence = 13.4%; 463 P. vivax, five mixed P. falciparum/P. vivax, no P. ovale or P. malariae) versus 130 by LM (prevalence = 3.7%; 126 P. vivax, three P. falciparum and one P. falciparum/P. vivax). The prevalence of P. vivax infection varied significantly among villages (range 3.0-38.5%, p<0.001) and across age groups (5.3-25.9%, p<0.001). Of 468 P. vivax infections, 72.9% were sub-microscopic, 84.5% afebrile and 60.0% were both sub-microscopic and afebrile. Local residency, low education level of the household head and living in a household with at least one other P. vivax infected individual increased the risk of P. vivax infection. Overall, 23.5% of P. vivax infections had concurrent gametocytaemia. Of all P. vivax positive samples, 29.2% were polyclonal by MS16 and msp1F3 genotyping. All five P. falciparum infections were detected in residents of the same village, carried the same msp2 allele and four were positive for P. falciparum gametocytes. CONCLUSION: P. vivax infection remains endemic in Ngella, with the majority of cases afebrile and below the detection limit of LM. P. falciparum has nearly disappeared, but the risk of re-introductions and outbreaks due to travel to nearby islands with higher malaria endemicity remains.

Subject

Plasmodium falciparum, Plasmodium vivax, Malària, Epidemiologia

Subject (English)

Plasmodium falciparum, Plasmodium vivax, Malaria, Epidemiology

Citation

Collections

Articles publicats en revistes (ISGlobal)

Citation

WALTMANN, Andreea, et al. High Rates of Asymptomatic, Sub-microscopic Plasmodium vivax Infection and Disappearing Plasmodium falciparum Malaria in an Area of Low Transmission in Solomon Islands. PLoS Neglected Tropical Diseases. 2015. Vol. 9, num. 5, pags. e0003758. ISSN 1935-2727. [consulted: 12 of June of 2026]. Available at: https://hdl.handle.net/2445/69261

Export metadata

JSON - METS

Share record