TABLE 1.

Frequency of infection with parasites bearing cp26 to cp29 in 305 children in Mali

Parasite type(s)aNo. of children with parasites
ObservedExpected at PR ofb:
50%10%
cp26 only527090*
cp27 only152117*135
cp28 only101015
cp29 only338*52*
cp26, cp27730*6
cp26, cp28031
cp26, cp295910***2****
cp27, cp281041**
cp27, cp297163
cp28, cp29010
cp26, cp27, cp28110
cp26, cp27, cp29440*
cp26, cp28, cp29000
cp27, cp28, cp29010
cp26, cp27, cp28, cp29000
  • a Parasites were typed by PCR and oligonucleotide hybridization, as described previously (5). The expected frequencies of single and mixed infections with each of the strains, assuming random mixing, are shown for different parasite rates (PR) in the population.

  • b Analysis of the distribution showed cp26 and cp29 together significantly more often than expected at a PR of 10% or 50% (*, χ2 = 10 to 50; **, χ2 = 50 to 100; ***, χ2 = 100 to 1,000; ****, χ2 > 1,000.)