Improving the laboratory diagnosis of TB in Ghana: the impact of a quality assurance system.

SETTING: Greater Accra region, Ghana. OBJECTIVE: To establish a pilot quality assurance (QA) system in sputum smear microscopy and to evaluate its impact. DESIGN: Quarterly supporting visits were paid to participating laboratories between 2000 and 2002. Fifteen examined slides were selected randomly from each laboratory during the visits and blindly re-assessed. Feedback was given promptly to the various laboratories. Training and stakeholder workshops were organised whenever necessary. RESULTS: General improvements in smear preparation and staining as well as the reading ability of the laboratory personnel included in the study were observed. The average marks for specimen quality, staining ability, smear cleanness, thickness, size and evenness increased from 64%, 79%, 69%, 46%, 67% and 60% in the last quarter of 2000 to 81%, 90%, 86%, 79%, 80% and 74%, respectively, 24 months after the establishment of the QA system. Within the same period, the rate of false-positives and -negatives decreased from respectively 14.8% and 20.5% to 0%, and agreements in positivity grade increased from 74% to 95%. The performance of the participating laboratories in keeping the laboratory registers up to date also improved. CONCLUSION: The QA system needs to be extended to the rest of the country.

Situation analysis of TB microscopy centres in Ghana.

SETTING: Public health laboratories in Ghana performing tuberculosis (TB) microscopy. OBJECTIVE: To assess the situation of the laboratories in terms of staff strength, technical skills, documentation, biosafety practices, equipment, supplies and disposal systems. DESIGN: Methods used for data collection were interviews using a structured questionnaire, informal observation of laboratory registers, disposal systems and safety measures for sputum handling. RESULTS: Of 114 laboratories visited between 2000 and 2001, 102 (89.5%) were performing TB microscopy. Of the staff working in the laboratories, 9% were medical technologists, 24% laboratory technicians, 37% laboratory assistants and 30% orderlies. Average false-negative and -positive rates were respectively 13% and 14%. Although most of the centres (85.3%) were using the recommended TB laboratory register for recording, in most cases they were not filled in accurately or completely. The majority of the available microscopes had mechanical or optical faults. Availability of other materials for smear preparation and staining ranged from 44% to 82%. The main methods employed for disposal of laboratory waste were burning and burying, but conditions were poor in most of the facilities visited. CONCLUSION: Training of laboratory personnel in TB microscopy and establishment of a quality assurance system are needed in Ghana.

Evaluation of two novel Ziehl-Neelsen methods for tuberculosis diagnosis.

BACKGROUND: Currently, the diagnosis of tuberculosis (TB) in Ghana relies on direct sputum smear, Ziehl- Neelsen (ZN) staining method. This method has low sensitivity and poses some health risks. The study was to compare the, direct sputum smear, (ZN) staining method against two newer ZN methods; 1% Sodium hypochlorite (NaOCL)-xylene floatation and 1% NaOCL sedimentation methods, to determine the most sensitive and the safest STUDY DESIGN: A prospective descriptive study involving 150 adult patients attending Komfo Anokye Teaching Hospital, Kumasi, Ghana suspected of pulmonary tuberculosis, using the three ZN microscopy methods: direct sputum smear, 1% NaOCL sedimentation, and 1% NaOCL-xylene floatation, for the detection of acid fast bacilli (AFB). Sputum culture on Lowenstein-Jensen (LJ) slopes was used as the gold standard for determining the sensitivity and specificity rates. RESULTS: The sensitivity rates of NaOCL sedimentation, NaOCL-xylene floatation and direct smear methods were 77.2%, 71.8% and 66.3% respectively. The specificity rate was 95.9 % for all three methods. Whereas the difference between the NaOCL sedimentation and the direct smear methods was statistically significant (P= 0.0446), that between the NaOCL-xylene floatation and direct smear was not (P=0.1788). CONCLUSION: In spite of the cost of chemicals, the hypochlorite sedimentation method was found to be the most accurate and the safest.

Diagnosis of tuberculosis in ghana: the role of laboratory training.

OBJECTIVES: The laboratory is considered the cornerstone of tuberculosis (TB) control programme. International review of Ghana's programme in the late nineties identified the laboratory services as the weakest component. Sputum smear microscopy (SSM) being the main method of diagnosing pulmonary TB in Ghana, the training objectives were to: (i) strengthen the knowledge and skills of laboratory personnel on SSM (ii) impart necessary techniques in biosafety and (iii) introduce a Quality Assurance (QA) system in order to strengthen SSM services. METHODS: Personnel were selected for training during a nationwide situation analysis of SSM centres in 2000/2001. Four training sessions on SSM/QA were held between 2001/2004. RESULTS: A total of 80 personnel were trained: 10 regional TB coordinators and 70 laboratory personnel. The participants upon return to their respective regions also organized training within their districts. This approach resulted in another 100 district TB coordinators and 200 laboratory personnel being trained. Improvement in smear preparation, staining and reading ability of the participants were observed during the post-test and subsequent visit to their respective laboratories. The training has led to strengthening of TB laboratory services in the country and has contributed to increase in case detection from 10,745 in 2000 to 11,827 in 2004 and 14,022 in 2008. It was observed during the post-training follow-up and quarterly supervision visits that morale of the personnel was high. CONCLUSION: Continuous training and re-training of laboratory personnel on SSM and QA at regular intervals do play an important role for effective and efficient TB control programme.

Mycobacterial species causing pulmonary tuberculosis at the korle bu teaching hospital, accra, ghana.

SUMMARY OBJECTIVE: Characterize mycobacterial species causing pulmonary tuberculosis (PTB) at the Korle-Bu Teaching Hospital in Ghana. DESIGN: Sputum smear positive samples, two (2) from 70 patients diagnosed as having tuberculosis, after they had consented, were collected from the Korle-Bu Teaching Hospital Chest Clinic between January and July 2003. SETTING: Korle-Bu Teaching Hospital Chest Clinic, Accra. RESULTS: Sixty-four mycobacterial isolates were obtained and confirmed as members of Mycobacterium tuberculosis complex by colonial morphology and conventional biochemical assays. Forty-seven (73%) were M. tuberculosis, the human strain, 2 (3%) M. bovis, the bovine strain, 13 (20%) M. africanum I (West Africa type), and 2 (3%) M. africanum II (East Africa type). CONCLUSION: The results indicate that, there are various strains causing PTB at the Korle-Bu Teaching Hospital and of great concern is M. bovis, which mostly causes extra-PTB in humans but found to cause PTB in this study. This calls for the need to conduct a nationwide survey using both conventional and molecular techniques to characterize various mycobacterial species causing TB in Ghana. This will result in better understanding of the various strains circulating in the country and inform individual TB treatment regimen especially the inclusion or exclusion of pyrazinamide.

Microbiological quality of "khebab" consumed in the accra metropolis.

SummaryThe study was carried out in 2003 to evaluate the microbial load in "khebab", meat products from pork, and beef, which are vended in most of the streets and some public drinking places, either with alcoholic or non-alcoholic drinks.Osu (Alata), Nima-Kotobabi and Central Accra (Adabraka - very close to the main lorry station), all in the Accra Metropolis, were selected for the investigation. The main reason for the selection of these sites was based on the population density as well as patronage for the khebab. Our main interest for this investigation was to assess the microbial load in khebab as far as enteric pathogen and other pathogenic micro-organisms reported earlier in the raw meat are concerned. Thirty samples of khebab were bought from these sampling points. Results obtained from samples at Osu recorded mean total plate count (TPC) of 5.02, Accra Central samples had TPC of 4.08 and those from Nima had TPC of 4.80 log(10) colony-forming units (cfu) per gram of khebab. Samples from Accra Central recorded the highest mean coliform count (5.12) whist samples bought from Osu and Nima recorded 4.41 and 3.70 log(10) cfu/g respectively. Accra Central samples again recorded the highest faecal coliforms (4.4 log(10) cfu/g) as compared to 3.98 and 3.80 log10 cfu/g for samples bought from Osu and Nima respectively. Salmonella ssp were not isolated from the samples bought at the three sampling sites. Khebab samples from sites were contaminated with E. coli, other gram-negative bacteria and Staphylococcus species, whose virulence factor(s) are yet to be determined. The faecal coliforms enumerated could originate from either humans or the animals slaughtered for the khebab.Staphylococcus species could originate from the vendors. Vendors have to be educated on hygienic practices which could help reduce risks of food-borne infection. Skin disinfection can be done by a thorough wash. Vendors could also be educated to stop selling their products to customers once they have bouts of diarrhoea, vomiting and "fever". Washing of their hands with soap and water before serving their customers could also help reduce the risk of food-borne infection from eating their products.