Khan A M, Dutta P, Das S, Pathak A K, Sarmah P, Hussain M E, Mahanta J
Regional Medical Research Centre (ICMR), Northeastern Region, Dibrugarh, India.
J Vector Borne Dis. 2015 Sep;52(3):208-12.
BACKGROUND & OBJECTIVES: Wuchereria bancrofti has shown nocturnal periodicity in India and other endemic countries of the world except pacific regions where non-periodic or diurnal sub-periodic forms have been reported. Presence of sub-periodic form of W. bancrofti in Andaman and Nicobar Islands, India and a case report of sub- periodic form of W. bancrofti from Mysore, India provide basis for exploring the periodicity pattern of microfilaria of W. bancrofti prevalent in Assam, Northeastern region of India. State of Assam has unique geographical location as its Northeastern region shares international boundaries with Nepal, China, Bhutan, Myanmar and Bangladesh. Evolutionary association of W. bancrofti found in Assam is not known and possibility of its link with W. bancrofti form, prevalent in neighbouring countries may not be ruled out. Hence, this study was undertaken to know the microfilarial periodicity of W. bancrofti in Assam.
Ten microfilaria positive adult male individuals having moderate to high microfilaraemia were selected. Informed written consent from each participant was obtained. The presence of microfilaria was observed at two hourly intervals over a period of 24 h using 50 μl of finger prick peripheral blood samples. Peripheral blood smears were processed, stained and examined under microscope and microfilaria counts were recorded.
Data collected were calculated and analyzed using modified statistical method, and the periodicity curve was prepared. Typical nocturnal periodicity was observed at a peak time of 0003 hrs with a periodicity index of 136.2.
INTERPRETATION & CONCLUSION: Analysis of the data revealed nocturnal periodicity of the W. bancrofti prevalent in the Assam with peak periodicity about one hour ahead of the other states in India. Findings will be helpful in evaluation and monitoring of ongoing MDA programme for elimination of LF in Assam.
除太平洋地区报告有非周期性或昼夜亚周期性形式外，班氏吴策线虫在印度及世界其他流行国家呈夜现周期性。印度安达曼和尼科巴群岛存在班氏吴策线虫的亚周期性形式，以及印度迈索尔的一例班氏吴策线虫亚周期性形式病例报告，为探索印度东北部阿萨姆邦流行的班氏吴策线虫微丝蚴的周期性模式提供了依据。阿萨姆邦地理位置独特，其东北地区与尼泊尔、中国、不丹、缅甸和孟加拉国接壤。尚不清楚在阿萨姆邦发现的班氏吴策线虫的进化关联，也不能排除其与邻国流行的班氏吴策线虫形式存在联系的可能性。因此，开展本研究以了解阿萨姆邦班氏吴策线虫的微丝蚴周期性。
选择10名微丝蚴阳性的成年男性个体，其微丝蚴血症为中度至高度。获得每位参与者的知情书面同意。使用50μl手指针刺外周血样本，在24小时内每隔两小时观察微丝蚴的存在情况。对外周血涂片进行处理、染色并在显微镜下检查，记录微丝蚴计数。
使用改良统计方法对收集的数据进行计算和分析，并绘制周期性曲线。观察到典型的夜现周期性，高峰时间为00:03时，周期性指数为136.2。
数据分析显示，阿萨姆邦流行的班氏吴策线虫呈夜现周期性，其高峰周期性比印度其他邦提前约一小时。研究结果将有助于评估和监测阿萨姆邦正在进行的消除淋巴丝虫病的大规模药物治疗计划。
