Application of lot sampling of sputum AFB smears for the assessment of microscopy centres.

SETTING: Designated microscopy centres (DMC) and additional microscopy centres (AMC) performing sputum acid-fast bacilli (AFB) microscopy, the District TB Centre (DTC) and a reference laboratory (RL). OBJECTIVES: To ascertain the feasibility of adopting lot sampling of AFB smears and to assess the performance of MCs employing Senior Tuberculosis Laboratory Supervisors (STLS) with no knowledge about the principles of quality assurance of AFB microscopy and RL-based laboratory technicians with training on quality assurance for blinded checking of AFB smears. METHODS: Slides from MCs were transported to the DTC and the RL; 20 smears per month per MC were selected systematically; 1547 slides from DMCs and 726 from AMCs were checked, respectively, by STLSs at the DTC and by RL laboratory technicians. Discrepancies were resolved by referee. RESULTS: The discrepancy between MC laboratory technicians and STLSs at the DTC was 4.7%, compared to 1% at the RL. The STLSs and RL-based laboratory technicians had 70 and 2 errors, respectively. CONCLUSIONS: Lot sampling of AFB smears is feasible under field conditions. Assessment of MCs was more valid with RL-based technicians trained in principles of quality assurance of sputum AFB microscopy than with STLSs with no such training and working in the field.     

Storage of heat-fixed unstained sputum AFB smears for panel testing in a tuberculosis unit in South India.

To evaluate the suitability for panel testing of heat-fixed unstained sputum AFB smears stored for up to 10 months, panels of slides were prepared at the national laboratory and stored under ambient conditions. Every month, three slides were utilised for panel testing in each of 12 microscopy centres; 70 smears were checked in a blinded fashion after 10 months. Reading errors occurred in 15/360 slides used in panel testing and in 4/70 slides used in blinded checking. The quality and grading of heat-fixed unstained smears were unaffected for up to 10 months and were found suitable for panel testing.     

Lot quality assurance sampling of sputum acid-fast bacillus smears for assessing sputum smear microscopy centers

Assessment of 12 microscopy centers in a tuberculosis unit by blinded checking of eight sputum smears selected by using a lot quality assurance sampling (LQAS) method and by unblinded checking of all positive and five negative slides, among the slides examined in a month in a microscopy centre, revealed that the LQAS method can be implemented in the field to monitor the performance of acid-fast bacillus microscopy centers in national tuberculosis control programs.     

Correction to: Describing the Profile of Diagnostic Features in Autistic Adults Using an Abbreviated Version of the Diagnostic Interview for Social and Communication Disorders (DISCO-Abbreviated)

Journal of Autism and Developmental Disorders - The original version of this article unfortunately contained two labelling errors in Fig. 3 and Figure S4.     

A case of autism in a child with Apert's syndrome

We present the case of a 7-year-old child with Aspert's syndrome who was diagnosed as suffering from childhood autism. As far as we are aware this is the first described association between autism and acrocephalosyndactyly syndromes. We discuss issues regarding the diagnosis and co-morbidity of the autistic spectrum disorders. Accepted: 11 September 2002 Correspondence to Dr. Jaime Morey-Canellas     

应用痰抗酸杆菌涂片批量抽样对镜检中心进行评价

地点：进行痰抗酸菌镜检的指定镜检中心（DMC）和其他镜检中心（AMC），地区结核病中心（DTC）和参比实验室（RL）。 目的：使用盲法AFB痰涂片对不知晓AFB镜检质控的结核病实验室高级督导员（STLS）和经过培训知晓质控的参比实验室（RL）的技术员进行结果评估，确定批量抽样痰涂片的可行性。 方法：镜检中心（MC）的痰涂片送至地区结核病中心（DTC）和参比实验室；经过系统选择每个镜检中心每月送20个涂片；DMC的1547张涂片和AMC的726张涂片分别由DTC的STLS和RL的技术员进行检查，由第三者负责分析差别。 结果：和RL的1％相比，MC实验室技术员和DTC的STLSs之间的不符合率为4．7％。STLSs与RL实验室技术员各有70次和2次错误。 结论：AFB涂片的批量抽样在现场情况下是可行的。受过AFB涂片镜检质控培训的RL技术员对MC的评价比没有受过此训练的STLSS更有效。     

Contamination of stored sputum AFB smears with environmental mycobacteria.

To check the quality of stains and the acid-fast bacilli (AFB) staining procedure, a sample of 73 AFB-negative sputum smears selected systematically from a microscopy centre was rechecked before and after restaining with the same AFB staining method at a reference laboratory. Respectively 0 and 30 showed AFB before and after restaining. Detection of AFB after restaining in 30 of 73 negative smears triggered suspicion of contamination with environmental mycobacteria, which was confirmed by reexamination of these slides. Restaining before rechecking is a major limiting factor, and the results of external quality assessment should be ignored when contamination of slides is suspected.