RAPID AFFORDABLE TB DRUG SUSCEPTIBILITY TESTING

描述(申请人提供)：世界卫生组织(WHO)估计，2004年发生了890万例结核病病例，其中390万例是传染性最强的涂阳病例。在估计的170万死亡病例中，超过26万发生在艾滋病毒感染者中；全世界结核病发病率的增加几乎完全是由于非洲艾滋病毒高流行地区的病例造成的。在2004年的病例中，超过424,000例是多药耐药，即对异烟肼和利福平耐药；大多数发生在中国、印度和俄罗斯联邦。在耐多药病例中，约有10%是广泛耐药(XDR)，即对六类二线药物中的三种或更多也具有耐药性。耐多药结核病和广泛耐多药结核病对上述资源贫乏地区的公共卫生构成最大威胁，世卫组织最近强调，需要适用于这些地区的廉价、快速和简单的结核病诊断和抗生素敏感性检测。在这一背景下，显微观察直接敏感性(MODS)试验引起了人们的极大关注。将净化后的痰接种到装有液体介质的多孔平板中，在一些孔中加入一线药物(通常是异烟肼和RIF)，并在一段时间内观察这些孔。结核分枝杆菌(MTB)的生长是通过低倍显微镜下菌落的索状外观来检测的。该检测方法使用廉价的耗材和简单的设备，确定培养阳性和抗生素敏感性的中位数为7天；现代自动化方法使用昂贵的设备和消耗品，以及传统的培养技术不那么敏感，需要更长的时间。该项目将研究使用一种小型、简单、极其廉价的荧光图像细胞仪来自动读出MODS检测结果，或开发一种功能相当的仪器，在这两种情况下都不需要训练有素的显微镜专家，预期的结果是一种准确、快速和灵敏的设备和方法，用于检测结核病和确定抗生素敏感性，适用于发达国家和发展中国家。与公共卫生相关：2004年估计有890万结核病病例；在估计的170万死亡病例中，超过26万发生在感染艾滋病毒的个人中。耐多药结核病和广泛耐药结核病是非洲、中国、印度和俄罗斯联邦等资源贫乏地区公共卫生的重大威胁，在这些地区，结核病和艾滋病毒/艾滋病的流行以负面方式相互作用。世界卫生组织最近强调，需要适用于这些地区的廉价、快速和简单的结核病诊断和药物敏感性测试。一种这样的测试，MODS检测，快速且便宜，但需要熟练的显微镜专家读取数据。该项目将尝试开发一种廉价的仪器，使用简单的光学元件、发光二极管和数码相机芯片，可用于MODS自动检测或功能相当的设备，满足资源匮乏和富裕国家的诊断需求。

DESCRIPTION (provided by applicant): The World Health Organization (WHO) estimates that 8.9 million cases of TB occurred in 2004, with 3.9 million of these representing the most infectious, smear-positive, form. Of the estimated 1.7 million deaths, over 260,000 occurred in HIV-infected individuals; the increasing incidence of TB worldwide is due almost entirely to cases in areas of Africa with a high prevalence of HIV. Over 424,000 of the 2004 cases were multidrug resistant (MDR), i.e., resistant to isoniazid (INH) and rifampin (RIF); most occurred in China, India, and the Russian Federation. Among MDR cases, approximately 10% are extensively drug resistant (XDR), i.e., also resistant to three or more of the six classes of second-line drugs. MDR- and XDR-TB pose the greatest threats to public health in the resource-poor areas mentioned above, and WHO has recently emphasized the need for inexpensive, rapid, and simple TB diagnostic and antimicrobial susceptibility tests suitable for use in such areas. The microscopic observation direct susceptibility (MODS) assay has attracted considerable attention in this context. Decontaminated sputum is inoculated into multiwell plates containing liquid medium, with first-line drugs (typically INH and RIF) in some wells, and the wells are observed over a period of days. Growth of Mycobacterium tuberculosis (MTB) is detected by the cordlike appearance of colonies under a low-power microscope. The assay, uses inexpensive consumables and simple equipment, and determines culture positivity and antibiotic susceptibility at a median of 7 days; modern automated methods, employing expensive equipment and consumables, and classical culture techniques are less sensitive and take longer. This project will investigate the use of a small, simple, extremely inexpensive fluorescence image cytometer to automate the readout of the MODS assay or develop a functional equivalent, in either case eliminating the need for a trained microscopist, with the anticipated result being an accurate, rapid, and sensitive apparatus and method for detecting TB and determining antibiotic susceptibility, suitable for use in developed as well as developing countries. PUBLIC HEALTH RELEVANCE: An estimated 8.9 million cases of tuberculosis (TB) occurred in 2004; of the estimated 1.7 million deaths, over 260,000 occurred in HIV-infected individuals. Multidrug-resistant (MDR-TB) and extensively drug-resistant (XDR-TB) TB are a significant threat to public health in resource- poor areas such as Africa, China, India, and the Russian Federation, where epidemics of TB and HIV-AIDS interact in a negative fashion. The World Health Organization has recently emphasized the need for inexpensive, rapid, and simple TB diagnostic and drug susceptibility tests suitable for use in such areas. One such test, the MODS assay, is rapid and inexpensive, but requires readout by a skilled microscopist. This project will attempt to develop an inexpensive apparatus, using simple optics, light-emitting diodes, and a digital camera chip, that could be used for an automated MODS assay or its functional equivalent, meeting diagnostic needs in both resource-poor and affluent countries.