Alkadi Hussien O, Al-Maktari Mohamed T, Nooman Majed A
Department of Pharmacology and Therapeutics, Faculty of Medicine, Sana'a University, Sana'a, Yemen.
Chemotherapy. 2006;52(4):166-70. doi: 10.1159/000093592. Epub 2006 May 24.
The emergence of Plasmodium falciparum resistance to widely used antimalarial drugs such as chloroquine has made malaria control and treatment much more difficult. In Yemen, 60% of the total population live in malarious areas. The problem of chloroquine resistance in Yemen is gradually worsening since the detection of first indigenous cases of P. falciparum resistance to chloroquine in 1989.
In a cross-sectional malariometric parasitic survey, 447 Yemeni children were enrolled from two selected districts (Hethran and Al-mafatch) representing Taiz Governorate. Duplicate thin and thick blood smears were prepared, stained with Giemsa stain and examined microscopically. Fifty-six students satisfied all criteria of the WHO for the assessment of P. falciparum response to chloroquine using a 7-day in vivo test.
Out of 447 examined slides, 83 cases (100%) were found with falciparum malaria. The overall malaria parasite rate in Taiz Governorate was 18.6%, a prevalently mesoendemic condition. The obtained results of the 7-day in vivo study revealed that out of 83 P. falciparum cases who completed the study period, 56 cases did not respond to the standard dose of chloroquine, i.e. the overall resistance rate was 16.1%. The prevalence of chloroquine resistance was higher in the Hethran district (19.4%) compared with 10.0% in the Al-mafatch district. The majority had an RI resistance level.
Chloroquine resistance of the local strain of P. falciparum was recorded in all studied districts in Taiz Governorate. This calls for an urgent revision of the current malaria treatment policy which still considers chloroquine as the first-line drug for treatment of uncomplicated P. falciparum malaria. To assess the magnitude of the problem, these districts could be the basis of future sentinel posts for continuous monitoring of chloroquine resistance in the whole country.
恶性疟原虫对氯喹等广泛使用的抗疟药物产生耐药性，使得疟疾的控制和治疗变得更加困难。在也门，60%的总人口生活在疟疾流行地区。自1989年首次检测到本地恶性疟原虫对氯喹耐药病例以来，也门的氯喹耐药问题正逐渐恶化。
在一项横断面疟疾寄生虫调查中，从代表塔伊兹省的两个选定地区（赫斯兰和迈法奇）招募了447名也门儿童。制备了重复的厚薄血涂片，用吉姆萨染色并进行显微镜检查。56名学生符合世界卫生组织使用7天体内试验评估恶性疟原虫对氯喹反应的所有标准。
在447份检查的载玻片中，发现83例（100%）为恶性疟。塔伊兹省的总体疟原虫率为18.6%，普遍处于中度流行状态。7天体内研究的结果显示，在完成研究期的83例恶性疟病例中，56例对标准剂量氯喹无反应，即总体耐药率为16.1%。赫斯兰地区的氯喹耐药率（19.4%）高于迈法奇地区（10.0%）。大多数为RI耐药水平。
在塔伊兹省所有研究地区均记录到本地恶性疟原虫株对氯喹耐药。这就要求紧急修订现行的疟疾治疗政策，该政策仍将氯喹视为治疗非复杂性恶性疟的一线药物。为评估问题的严重程度，这些地区可作为未来全国持续监测氯喹耐药性的哨点基础。
