RESUMEN
OBJECTIVE: To document the prevalence of multidrug resistance among people newly diagnosed with - and those retreated for - tuberculosis in Malawi. METHODS: We conducted a nationally representative survey of people with sputum-smear-positive tuberculosis between 2010 and 2011. For all consenting participants, we collected demographic and clinical data, two sputum samples and tested for human immunodeficiency virus (HIV).The samples underwent resistance testing at the Central Reference Laboratory in Lilongwe, Malawi. All Mycobacterium tuberculosis isolates found to be multidrug-resistant were retested for resistance to first-line drugs - and tested for resistance to second-line drugs - at a Supranational Tuberculosis Reference Laboratory in South Africa. FINDINGS: Overall, M. tuberculosis was isolated from 1777 (83.8%) of the 2120 smear-positive tuberculosis patients. Multidrug resistance was identified in five (0.4%) of 1196 isolates from new cases and 28 (4.8%) of 581 isolates from people undergoing retreatment. Of the 31 isolates from retreatment cases who had previously failed treatment, nine (29.0%) showed multidrug resistance. Although resistance to second-line drugs was found, no cases of extensive drug-resistant tuberculosis were detected. HIV testing of people from whom M. tuberculosis isolates were obtained showed that 577 (48.2%) of people newly diagnosed and 386 (66.4%) of people undergoing retreatment were positive. CONCLUSION: The prevalence of multidrug resistance among people with smear-positive tuberculosis was low for sub-Saharan Africa - probably reflecting the strength of Malawi's tuberculosis control programme. The relatively high prevalence of such resistance observed among those with previous treatment failure may highlight a need for a change in the national policy for retreating this subgroup of people with tuberculosis.
Asunto(s)
Antituberculosos/uso terapéutico , Farmacorresistencia Bacteriana Múltiple , Mycobacterium tuberculosis/efectos de los fármacos , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Tuberculosis Resistente a Múltiples Medicamentos/epidemiología , Tuberculosis/tratamiento farmacológico , Tuberculosis/epidemiología , Adulto , Estudios Transversales , Femenino , Humanos , Malaui/epidemiología , Masculino , Mycobacterium tuberculosis/aislamiento & purificación , Prevalencia , Estudios ProspectivosRESUMEN
BACKGROUND: To quantify the likely impact of recent WHO policy recommendations regarding smear microscopy and the introduction of appropriate low-cost fluorescence microscopy on a) case detection and b) laboratory workload. METHODOLOGY/PRINCIPAL FINDINGS: An audit of the laboratory register in an urban hospital, Lilongwe, Malawi, and the application of a simple modelling framework. The adoption of the new definition of a smear-positive case could directly increase case detection by up to 28%. Examining Ziehl-Neelsen (ZN) sputum smears for up to 10 minutes before declaring them negative has previously been shown to increase case detection (over and above that gained by the adoption of the new case definition) by 70% compared with examination times in routine practice. Three times the number of staff would be required to adequately examine the current workload of smears using ZN microscopy. Through implementing new policy recommendations and LED-based fluorescence microscopy the current laboratory staff complement could investigate the same number of patients, examining auramine-stained smears to an extent that is equivalent to a 10 minutes ZN smear examination. CONCLUSIONS/SIGNIFICANCE: Combined implementation of the new WHO recommendations on smear microscopy and LED-based fluorescence microscopy could result in substantial increases in smear positive case-detection using existing human resources and minimal additional equipment.
Asunto(s)
Química Clínica/métodos , Microscopía Fluorescente/métodos , Microscopía Fluorescente/normas , Esputo/microbiología , Femenino , Humanos , Laboratorios de Hospital/organización & administración , Luz , Malaui , Masculino , Factores de Tiempo , Tuberculosis/diagnóstico , Tuberculosis/microbiología , Recursos HumanosRESUMEN
BACKGROUND: Despite policies advocating centralised transfusion services based on voluntary donors, the hospital-based replacement donor system is widespread in sub-Saharan Africa. AIMS: To evaluate the cost of all laboratory resources needed to provide a unit of safe blood in rural Malawi using the family replacement donor system METHODS: Full economic costs of all laboratory tests used to screen potential donors and to perform cross-matching were documented in a prospective, observational study in Ntcheu district hospital laboratory. RESULTS: 1729 potential donors were screened and 11,008 tests were performed to ensure that 1104 units of safe blood were available for transfusion. The annual cost of all transfusion-related tests (in 2005 USdollars) was USdollars 17,976, equivalent to USdollars 16.28 per unit of transfusion-ready blood. Transfusion-related tests used 53% of the laboratory's total annual expenditure of USdollars 33,608. CONCLUSIONS: This is the first study to provide prospective economic costs of all laboratory tests associated with the family replacement donor system in a district hospital in Africa. Results show that despite potential economies of scale, a unit of blood from the centralised system costs about three times as much as one from the hospital-based "replacement" system. Factors affecting these relative costs are complex but are in part due to the cost of donor recruitment in centralised systems. In the replacement system the cost of donor recruitment is entirely borne by families of patients needing a blood transfusion.