Losses in the Sputum Specimen Referral Cascade in Mpulungu District, Zambia: A Cross-Sectional Study.

Sputum specimen referral cascades in resource-limited settings are characterized by losses of specimens, resulting in delays in tuberculosis (TB) diagnosis. Mpulungu District Health Office in Zambia conducted a quantitative based cross-sectional study using both primary and secondary data to identify points at which loss of specimens occurred in the sputum referral cascade. Primary data were collected through observations and interviews with 22 TB service providers. Secondary data were collected through examination of patient files and presumptive TB and laboratory registers to retrospectively track sputum specimens referred by ten health centers from April to September 2018. Proportions of specimens/laboratory results at every stage of the referral cascade were calculated using Epi Info v7. Only 49 (23%) out of 209 sputum specimens completed the referral cascade. The remaining 160 (76%) were lost at various stages of the referral cascade. The largest loss (51%) occurred between the release of laboratory results by the diagnostic facility and their receipt at referring facilities. Barriers included an inadequate number of staff oriented in sputum specimen referral, negative staff attitudes, and lack of specimen packaging material and specimen transportation. The district health office should strengthen the sputum specimen referral system by providing transport and specimen packaging material and by training staff in sputum collection transportation and tracking.

The Prevalence of Tuberculosis in Zambia: Results from the First National TB Prevalence Survey, 2013-2014.

BACKGROUND: Tuberculosis in Zambia is a major public health problem, however the country does not have reliable baseline data on the TB prevalence for impact measurement; therefore it was among the priority countries identified by the World Health Organization to conduct a national TB prevalence survey. OBJECTIVE: To estimate the prevalence of tuberculosis among the adult Zambian population aged 15 years and above, in 2013-2014. METHODS: A cross-sectional population-based survey was conducted in 66 clusters across all the 10 provinces of Zambia. Eligible participants aged 15 years and above were screened for TB symptoms, had a chest x-ray (CXR) performed and were offered an HIV test. Participants with TB symptoms and/or CXR abnormality underwent an in-depth interview and submitted one spot- and one morning sputum sample for smear microscopy and liquid culture. Digital data collection methods were used throughout the process. RESULTS: Of the 98,458 individuals who were enumerated, 54,830 (55.7%) were eligible to participate, and 46,099 (84.1%) participated. Of those who participated, 45,633/46,099 (99%) were screened by both symptom assessment and chest x-ray, while 466/46,099 (1.01%) were screened by interview only. 6,708 (14.6%) were eligible to submit sputum and 6,154/6,708 (91.7%) of them submitted at least one specimen for examination. MTB cases identified were 265/6,123 (4.3%). The estimated national adult prevalence of smear, culture and bacteriologically confirmed TB was 319/100,000 (232-406/100,000); 568/100,000 (440-697/100,000); and 638/100,000 (502-774/100,000) population, respectively. The risk of having TB was five times higher in the HIV positive than HIV negative individuals. The TB prevalence for all forms was estimated to be 455 /100,000 population for all age groups. CONCLUSION: The prevalence of tuberculosis in Zambia was higher than previously estimated. Innovative approaches are required to accelerate the control of TB.

Non-tuberculous mycobacteria (NTM) in Zambia: prevalence, clinical, radiological and microbiological characteristics.

BACKGROUND: Non-tuberculous mycobacteria (NTM) infection is an emerging health problem. We present here the Zambia-specific national level data of prevalence, symptomatic, radiological and microbiological characteristics of NTM, using results from a national Tuberculosis (TB) prevalence survey. METHODS: This was a cross-sectional study of the prevalence of NTM among adults aged 15 years and above, who were participants in a national TB prevalence survey. Participants who had either an abnormal chest x-ray or were symptomatic were considered presumptive TB cases and submitted sputum for smear and culture analysis. HIV testing was performed on an opt-out basis. Symptomatic NTM prevalence was estimated from individual level analysis. RESULTS: Of the 6,123 individuals with presumptive TB, 923 (15.1%) were found to have NTM, 13 (0.2%) were MTB/NTM co-infected and 338 (5.5%) were contaminated (indeterminate). The prevalence of symptomatic NTM was found to be 1,477/100,000 [95% CI 1010-1943]. Smear positivity, history of cough or chest pain and HIV positivity were risk factors for NTM. CONCLUSION: This first study to estimate the national prevalence of NTM in Zambia indicates that the burden is high. The NTM occurrence in Zambia constitutes both a public health and ethical issue requiring action from health managers.

The Second Zambian National Tuberculosis Drug Resistance survey - a comparison of conventional and molecular methods.

OBJECTIVE: The prevalence of MDR-TB in Zambia was estimated to be 1.8% in 2001. A second drug resistance survey was conducted in 2008 to determine trends; the use of the Genotype MTBDRplus assay was applied to compare results to the gold standard. METHOD: A two-stage cluster sampling, with health facilities as primary sampling units. Processed sputum specimens were inoculated on solid media for culture; heat-inactivated bacterial suspensions from sputum samples were tested on a commercial line probe assay for the identification of rifampicin and isoniazid resistance. RESULTS: A total of 917 patients with TB were enrolled and 883 (96.3%) analysed. A total of 574 (65%) had LJ results and 824 (93.3%) had results from MTBDRplus assay. The median age was 32, and 63.3% were males. MDR-TB according to LJ-based DST was 1.1% (CI 0.1-2.4) whereas according to MDTBDRplus assay was 1.6% (CI 0.6-2.6). Isoniazid monoresistance in new cases was 2.4% (CI 0.613-4.26) based on LJ results and 5.0% (CI 3.2-6.7) based on the MTBDRplus; in retreatment cases, it was 4.4% (CI 0.3-8.6) and 2.40% (CI <0.1-5.1) on LJ and MTBDRplus, respectively. Rifampicin monoresistance in new cases was 0.1% (CI <0.1-0.4) based on LJ and 0.6% (CI 0.01-1.1) based on the MTBDRplus; in retreatment cases, it was 0% (CI 0-3.8) and 1.8% (CI <0.1-4.0) on LJ and MTBDRplus, respectively. There were no XDR-TB cases found and no association between MDR-TB and HIV. CONCLUSION: There was no increase in MDR-TB prevalence in Zambia from 2001 to 2008; results from the two methods were similar. Molecular methods were quicker and simpler to use.