| 研究実績の概要 |
Objectives: Although doxycycline is recommend as malaria prophylaxis, a French soldier fatal case of malaria prophylactic failure was reported in Africa, despite the patient’s collective doxycycline intake as malaria prophylaxis in 2014. In the same year, it was reported that pfTetQ gene of KYNNNN motif repeats of <3 was correlated to a resistant phenotype of doxycycline, with an odds ratio of 15 in the study from Kenya. Therefore we conducted surveillance for polymorphism in the Plasmodium falciparum pfTetQ gene of KYNNNN motif repeats in samples from Kenya previously collected in western Kenya.
Methods: Screening for pfTetQ gene of KYNNNN motif repeats was conducted by sequencing using previously reported method.
Results: A total of 747 samples were analyzed. In total, 321 samples (43.0%) were <3 pfTetQ KYNNNN motif repeats, which is predictive of in vitro parasites related to doxycycline resistance. Two-hundred and forty-two (32.4%) samples more than 3 repeats and the remaining 184 (24.6%) were mixed type caused by multiple isolates with different genotype infection.
Conclusions: pfTetQ gene of KYNNNN motif repeats of <3 in P. falciparum was widely distributed in malaria endemic Kenya. Precise evaluation of the efficacy of doxycycline as a malarial prophylaxis is urgently needed for travelers who visit this area.
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