LSTM Home > LSTM Research > LSTM Online Archive

Effect of malaria transmission reduction by insecticide-treated bed nets (ITNs) on the genetic diversity of Plasmodium falciparum merozoite surface protein (MSP-1) and circumsporozoite (CSP) in western Kenya

Downloads

Downloads per month over past year

Kariuki, Simon K, Njung'e, James, Muia, Ann, Muluvi, Geofrey, Gatei, Wangeci, terKuile, Feiko ORCID: https://orcid.org/0000-0003-3663-5617, Terlouw, Anja, Hawley, William A, Phillips-Howard, Penelope ORCID: https://orcid.org/0000-0003-1018-116X, Nahlen, Bernard L, Lindblade, Kim A, Hamel, Mary J, Slutsker, Laurence and Shi, Ya Ping (2013) 'Effect of malaria transmission reduction by insecticide-treated bed nets (ITNs) on the genetic diversity of Plasmodium falciparum merozoite surface protein (MSP-1) and circumsporozoite (CSP) in western Kenya'. Malaria Journal, Vol 12, Issue 295.

[img]
Preview
Text
1475-2875-12-295.pdf - Published Version
Available under License Creative Commons Attribution.

Download (489kB)

Abstract

Background
Although several studies have investigated the impact of reduced malaria transmission due to insecticide-treated bed nets (ITNs) on the patterns of morbidity and mortality, there is limited information on their effect on parasite diversity.
Methods
Sequencing was used to investigate the effect of ITNs on polymorphisms in two genes encoding leading Plasmodium falciparum vaccine candidate antigens, the 19 kilodalton blood stage merozoite surface protein-1 (MSP-119kDa) and the Th2R and Th3R T-cell epitopes of the pre-erythrocytic stage circumsporozoite protein (CSP) in a large community-based ITN trial site in western Kenya. The number and frequency of haplotypes as well as nucleotide and haplotype diversity were compared among parasites obtained from children <5 years old prior to the introduction of ITNs (1996) and after 5 years of high coverage ITN use (2001).
Results
A total of 12 MSP-119kDa haplotypes were detected in 1996 and 2001. The Q-KSNG-L and E-KSNG-L haplotypes corresponding to the FVO and FUP strains of P. falciparum were the most prevalent (range 32–37%), with an overall haplotype diversity of > 0.7. No MSP-119kDa 3D7 sequence-types were detected in 1996 and the frequency was less than 4% in 2001. The CSP Th2R and Th3R domains were highly polymorphic with a total of 26 and 14 haplotypes, respectively detected in 1996 and 34 and 13 haplotypes in 2001, with an overall haplotype diversity of > 0.9 and 0.75 respectively. The frequency of the most predominant Th2R and Th3R haplotypes was 14 and 36%, respectively. The frequency of Th2R and Th3R haplotypes corresponding to the 3D7 parasite strain was less than 4% at both time points. There was no significant difference in nucleotide and haplotype diversity in parasite isolates collected at both time points.
Conclusion
High diversity in these two genes has been maintained overtime despite marked reductions in malaria transmission due to ITNs use. The frequency of 3D7 sequence-types was very low in this area. These findings provide information that could be useful in the design of future malaria vaccines for deployment in endemic areas with high ITN coverage and in interpretation of efficacy data for malaria vaccines based on 3D7 parasite strains.

Item Type: Article
Additional Information: The electronic version of this article is the complete one and can be found online at: http://www.malariajournal.com/content/12/1/295
Uncontrolled Keywords: Malaria; Parasite diversity; MSP-1; CSP; Transmission; Bed nets
Subjects: QU Biochemistry > Genetics > QU 460 Genomics. Proteomics
QU Biochemistry > Genetics > QU 470 Genetic structures
QU Biochemistry > Genetics > QU 500 Genetic phenomena
QU Biochemistry > Proteins. Amino Acids. Peptides > QU 58.5 DNA.
QX Parasitology > Protozoa > QX 135 Plasmodia
WA Public Health > Preventive Medicine > WA 110 Prevention and control of communicable diseases. Transmission of infectious diseases
WA Public Health > Preventive Medicine > WA 240 Disinfection. Disinfestation. Pesticides (including diseases caused by)
WC Communicable Diseases > Tropical and Parasitic Diseases > WC 750 Malaria
WC Communicable Diseases > Tropical and Parasitic Diseases > WC 765 Prevention and control
Faculty: Department: Clinical Sciences & International Health > Clinical Sciences Department
Digital Object Identifer (DOI): https://doi.org/10.1186/1475-2875-12-295
Depositing User: Helen Wong
Date Deposited: 10 Sep 2013 14:53
Last Modified: 31 May 2018 14:04
URI: http://archive.lstmed.ac.uk/id/eprint/3473

Statistics

View details

Actions (login required)

Edit Item Edit Item