TY - JOUR
T1 - Impact of genetic complexity on longevity and gametocytogenesis of Plasmodium falciparum during the dry and transmission-free season of eastern Sudan
AU - Nassir, Elkhansaa
AU - Abdel-Muhsin, Abdel Muhsin A.
AU - Suliaman, Suad
AU - Kenyon, Fiona
AU - Kheir, Amani
AU - Geha, Haider
AU - Ferguson, Heather M.
AU - Walliker, David
AU - Babiker, Hamza A.
PY - 2005/1
Y1 - 2005/1
N2 - Malaria in eastern Sudan is characterised by limited seasonal transmission, with the majority of the year remaining transmission-free. Some inhabitants who contract malaria during the transmission season retain long-lasting sub-patent infections, which probably initiate transmission the following year. Here we have monitored Plasmodium falciparum infection prevalence and gametocyte production during the dry season, and examined the impact of parasite genetic multiplicity on infection longevity. A cohort of 38 individuals who were infected with P. falciparum in November 2001 was monitored monthly by microscopy and PCR until December 2002. Reverse transcriptase polymerase chain reaction of the pfg377 gene was used to detect sub-patent gametocytes. In addition, all isolates were examined for msp-2 alleles and the mean number of parasite clones per infection was estimated. We found that a large proportion (40%) of the cohort retained gametocytes throughout the dry season. The majority of patients retained asexual infection for at least 7 months. Genetic multiplicity of P. falciparum significantly influenced longevity of asexual infection and its gametocyte production. Gametocytes from mixed genotype P. falciparum infections persisted three times longer than those from single genotype infections, suggesting that genetic diversity promotes persistence. These findings are discussed in the context of the parasite biology and malaria epidemiology in the study area.
AB - Malaria in eastern Sudan is characterised by limited seasonal transmission, with the majority of the year remaining transmission-free. Some inhabitants who contract malaria during the transmission season retain long-lasting sub-patent infections, which probably initiate transmission the following year. Here we have monitored Plasmodium falciparum infection prevalence and gametocyte production during the dry season, and examined the impact of parasite genetic multiplicity on infection longevity. A cohort of 38 individuals who were infected with P. falciparum in November 2001 was monitored monthly by microscopy and PCR until December 2002. Reverse transcriptase polymerase chain reaction of the pfg377 gene was used to detect sub-patent gametocytes. In addition, all isolates were examined for msp-2 alleles and the mean number of parasite clones per infection was estimated. We found that a large proportion (40%) of the cohort retained gametocytes throughout the dry season. The majority of patients retained asexual infection for at least 7 months. Genetic multiplicity of P. falciparum significantly influenced longevity of asexual infection and its gametocyte production. Gametocytes from mixed genotype P. falciparum infections persisted three times longer than those from single genotype infections, suggesting that genetic diversity promotes persistence. These findings are discussed in the context of the parasite biology and malaria epidemiology in the study area.
KW - Gametocytes
KW - Plasmodium falciparum
KW - RT-PCR
KW - Seasonal malaria
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U2 - 10.1016/j.ijpara.2004.10.014
DO - 10.1016/j.ijpara.2004.10.014
M3 - Article
C2 - 15619515
AN - SCOPUS:19344377284
SN - 0020-7519
VL - 35
SP - 49
EP - 55
JO - International Journal for Parasitology
JF - International Journal for Parasitology
IS - 1
ER -