Title:
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Detection Of Very Low Level Pl4smodium Falciparum Infections Using The Nested Polymerase Chain Reaction And A Reassessment Of The Epidemiology Of Unstable Malaria In Sudan |
Author:
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Roper, Cally; Elhassan, Ibrahim M.; Hviid, Lars; Giha, Haider; Richardson, William; Babiker, Hamza; Sarfi, Gwiria M. H.; Theander, Thor G.; Arnot, @R@Diat Vid E.
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Abstract:
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We have used the nested polymerase chain reaction (PCR) to assay for low level Plasmodiumfalciparum
infections that were below the threshold of detection of blood film examination. This revealed a substantial group of
asymptomatic, submicroscopically patent infections within the population of a Sudanese village present throughout
the year although clinical malaria episodes were almost entirely confined to the transmission season. In our September,
January, April, and June surveys, the PCR-detected prevalences were 13%, 19%, 24%, and 19%, respectively. These
figures reveal a much higher prevalence of dry season infection than previous microscopic surveys have indicated.
Furthermore, 20% of a cohort of 79 individuals were healthy throughout the September to November transmission
season but were PCR-positive for P. falciparum in a least one of a series of samples taken in the ensuing months.
Levels of exposure to P. falciparum infection were therefore higher than was previously believed in this region,
highlighting the fact that many individuals were infected but healthy for most of the year. The reservoir parasite
population was thus larger and more stable than previously thought, a finding that is consistent with the high levels
of genetic variation at polymorphic loci reported from analysis of P. falciparum parasites in this area. |
URI:
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http://khartoumspace.uofk.edu/123456789/17121
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Date:
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2015-11-16 |