We first compared the sensitivity of the primer pairs in detecting diluted DNA samples from an infected chicken that had a known parasitemia (0.02%) and showed that both primer sets could detect parasite DNA diluted up to1,000–5,000 fold, with the cytb primers appearing to be slightly more sensitive (a faint band could be seen at 1:20,000 dilution) than the coxIII primers in detecting parasite DNA (Fig 1C). The gene discussed is MT-CO3; the disease is parasitic infectious disease.