Resistance patterns of multidrug-resistant tuberculosis in Western Province, Papua New Guinea

Adverse treatment outcomes in multidrug resistant tuberculosis go beyond the microbe-drug interaction: Results of a multiple correspondence analysis

INTRODUCTION

Multidrug-resistant tuberculosis treatment is effective in 50% of patients due to several factors including antibiotic susceptibility of the microorganism, adverse treatment reactions, social factors, and associated comorbidities.

OBJECTIVES

In this study, we describe the demographics, clinical characteristics, and factors associated with treatment outcomes in multidrug-resistant tuberculosis (MDR-TB) patients in Medellín, Colombia.

MATERIALS AND METHODS

We conducted a retrospective analysis using data from patients diagnosed with MDR-TB attending Hospital La María in Medellín, Colombia, for treatment between 2010 and 2015. Patients were categorized as having successful (cured) or poor (failure, lost to follow-up, and death) treatment outcomes. Associations between demographic, clinical factors, laboratory results, treatment outcomes, and follow-up information were evaluated by univariate, multivariate, and multiple correspondence analyses.

RESULTS

Of the 128 patients with MDR-TB, 77 (60%) had successful outcomes. Of those with poor outcomes, 26 were lost to follow-up, 15 died, and 10 were treatment failures. Irregular treatment, the presence of comorbidities, and positive cultures after more than two months of treatment were associated with poor outcomes compared to successful ones (p<0.05 for all). The multiple correspondence analyses grouped patients who were lost to follow-up, had HIV, and drug addiction, as well as patients with treatment failure, irregular treatment, and chronic obstructive pulmonary disease.

CONCLUSION

The recognition of factors affecting treatment is essential and was associated with treatment outcomes in this series of patients. Early identification of these factors should increase the rates of treatment success and contribute to MDR-TB control.

Retrospective analysis of multidrug-resistant tuberculosis case notifications in Australia (1999-2018)

This study describes the epidemiology and treatment outcomes of multidrug-resistant tuberculosis (MDR-TB) cases notified in Australia between 1999 and 2018, and investigates whether current data fields in the national tuberculosis (TB) dataset allow description and measurement of surveillance information pertaining to the diagnosis and clinical management of MDR-TB. In May 2019, de-identified demographic, clinical, laboratory, drug susceptibility, treatment, risk factor and outcome data for all MDR-TB case notifications were extracted from the Australian National Notifiable Disease Surveillance System. The dataset included ten treatment outcome categories, which were aggregated to four categorical outcomes for descriptive and inferential analyses. The majority of cases were overseas-born (91%). Absolute case numbers increased over time; however, the MDR-TB notification rate remained fairly stable during the study period. Treatment success was achieved in nearly two-thirds of cases (62.1%). Whilst timeframes between initial presentation, specimen collection, case notification and treatment commencement were calculated, current data fields in the national dataset precluded measurement and description of other parameters deemed important for MDR-TB surveillance. This study demonstrates that while Australia's MDR-TB burden is low, cases will continue to occur until TB control improves in countries with which Australia shares cultural and migration links. Australia should continue to support national and regional TB control programmes to sustain progress towards national elimination of TB. This study's findings support a review of data fields in the national TB dataset with potential expansion or adjustment to improve national data reporting, including the monitoring of evidence-based recommendations for the prevention and management of MDR-TB.

Drug-resistant tuberculosis diagnosis since Xpert® MTB/RIF introduction in Papua New Guinea, 2012-2017

SETTING

Xpert® MTB/RIF was introduced in Papua New Guinea in 2012 for the diagnosis of tuberculosis (TB) and of rifampicin-resistant TB (RR-TB), a marker of multi-drug-resistant TB (MDR-TB).

OBJECTIVE

To assess the concordance of Xpert with phenotypic drug susceptibility testing (DST) performed at the supranational reference laboratory and to describe the patterns of drug-resistant TB observed.

DESIGN

This was a retrospective descriptive study of laboratory data collected from April 2012 to December 2017.

RESULTS

In 69 months, 1408 specimens with Xpert results were sent for mycobacterial culture and DST; Mycobacterium tuberculosis was cultured from 63% (884/1408) and DST was completed in 99.4%. The concordance between Xpert and culture for M. tuberculosis detection was 98.6%. Of 760 RR-TB cases, 98.7% were detected using Xpert; 98.5% of 620 MDR-TB cases were identified using phenotypic DST. Phenotypic resistance to second-line drugs was detected in 59.4% (522/879) of specimens tested, including 29 with fluoroquinolone resistance; the majority were from the National Capital District and Daru Island.

CONCLUSION

The high concordance between phenotypic DST and Xpert in identifying RR-TB cases supports the scale-up of initial Xpert testing in settings with high rates of drug resistance. However, rapid DST in addition to the detection of RR-TB is required.

Molecular Evidence of Drug-Resistant Tuberculosis in the Balimo Region of Papua New Guinea

Papua New Guinea (PNG) has a high burden of tuberculosis (TB), including drug-resistant TB (DR-TB). DR-TB has been identified in patients in Western Province, although there has been limited study outside the provincial capital of Daru. This study focuses on the Balimo region of Western Province, aiming to identify the proportion of DR-TB, and characterise Mycobacterium tuberculosis (MTB) drug resistance-associated gene mutations. Sputum samples were investigated for MTB infection using published molecular methods. DNA from MTB-positive samples was amplified and sequenced, targeting the rpoB and katG genes to identify mutations associated with rifampicin and isoniazid resistance respectively. A total of 240 sputum samples were collected at Balimo District Hospital (BDH). Of these, 86 were classified as positive based on the results of the molecular assays. For samples where rpoB sequencing was successful, 10.0% (5/50, 95% CI 4.4–21.4%) were considered rifampicin-resistant through detection of drug resistance-associated mutations. We have identified high rates of presumptive DR-TB in the Balimo region of Western Province, PNG. These results emphasise the importance of further surveillance, and strengthening of diagnostic and treatment services at BDH and throughout Western Province, to facilitate detection and treatment of DR-TB, and limit transmission in this setting.

Characterization of pncA mutations in multi-drug and pyrazinamide resistant Mycobacterium tuberculosis isolates cultured from Queensland migrants and Papua New Guinea residents

Outbreak of drug resistant tuberculosis in the Western province, Papua New Guinea is a concern to Queensland, Australia due to migration. We performed pncA mutation analysis and genotyping of multi-drug/pyrazinamide (MDR/PZA) resistant isolates from 18 Queensland (Qld) migrants and 81 Papua New Guinea (PNG) residents, to compare with phenotypic evidence of PZA resistance and to evaluate the genotypes obtained from the two countries. Seven different mutations were seen from Qld isolates of which 2 have not been described previously. A cluster of mutations were found between amino acids L35 and S65. Amongst the PNG isolates, 10 mutations were identified, of which 6 were unique and have not been described previously. Majority of the mutations formed 2 clusters, between amino acids Q10 to A20 and W68 to W119. Mutations identified at nucleotide (nt) position 202 and 307 were found to be the most common types, occurring in 25% and 51% of the PNG isolates respectively. The majority of the mutations were seen in MDR/PZA resistant isolates. These mutations could be utilized for direct screening of PZA resistance from PNG patient samples. Genotypic analysis of the isolates showed strong clustering amongst the PNG isolates as opposed to Qld isolates. A diversity of mutations and genotypes were seen amongst the Qld migrant isolates. Majority of PNG isolates had one genotype with two distinct pncA mutation patterns (T202C and T307G) which highlight on-going transmission. pncA mutation analysis provided a satisfactory alternative to PZA culture DST with high positive predictive value and an improved result turnaround time.

Isolation of anti-mycobacterial compounds from Curtisia dentata (Burm.f.) C.A.Sm (Curtisiaceae)

BACKGROUND

Tuberculosis is counted amongst the most infectious and lethal illnesses worldwide and remains one of the major threats to human health. The aim of the current study was to isolate and characterize anti-mycobacterial compounds present in Curtisia dentata (Burm.f.) C.A.Sm , a medicinal plant reportedly used in the treatment of tuberculosis, stomach ailments and sexually transmitted infections.

METHODS

The bioassay guided principle was followed to isolate the anti-mycobacterial compounds. The crude ethanol extracts of the leaves was partitioned with various solvents four compounds such as β-sitosterol, betulinic acid, ursolic acid and lupeol were successfully isolated. The compounds and their derivatives were evaluated for anti-mycobacterial activity using Microplate Alamar Blue Assay (MABA) against Mycobacterium tuberculosis H37RV (ATCC 27294). Furthermore, the derivatives were investigated for their toxicity against HepG2 and HEK293 using the MTT assay.

RESULTS

The methanol fraction had the lowest minimum inhibitory concentration (MIC) of 22.2 μg/ml against the selected Mycobacterium strain when compared to other fractions. Ursolic acid acetate (UAA) was the most active compound with MIC value of 3.4 μg/ml. The derivatives had varying degrees of toxicity, but were generally non-toxic to the selected cell lines. Derivatives also exhibited highest selectivity index and offers a higher safety margin.

CONCLUSIONS

The derivatives had better antimicrobial activity and low cytotoxic effects compared to isolated compounds. These increased their selectivity. It appears that acetylation of both betulinic acid and ursolic acid increased their activity against the selected Mycobacterium species. The results obtained in this study gives a clear indication that Curtisia dentata may serve as major source of new alternative medicines that may be used to treat TB. Furthermore, there is a need to explore the activity of these tested plant against other pathogenic Mycobacterium species.

The social determinants of tuberculosis treatment adherence in a remote region of Papua New Guinea

Background

Papua New Guinea (PNG) is a diverse and culturally-rich country with severe infrastructural and health problems. Tuberculosis (TB) is widespread, and the number of cases with drug resistance is rising. Treatment adherence is known to be important for both effective treatment and limiting the emergence of drug resistance. The aim of this study was to construct a matrix of the factors that act as facilitators or barriers to TB treatment adherence in a remote region of PNG.

Methods

The study was based in the Balimo region of the Western Province. People known to have undergone TB treatment, as well as staff involved in managing people with TB, were asked to participate in an in-depth interview about their experiences. Purposive sampling was used to identify a diverse range of participants, from different geographic locations, social backgrounds, and with successful and unsuccessful treatment outcomes. The interview data was analysed based on grounded theory methodology.

Results

The study identified a range of factors that influence TB treatment adherence, with these being classified as personal, systems, and sociocultural. These factors are presented along with suggested recommendations for adaptations to DOTS-based treatment in this region. Barriers included the challenges associated with travel to treatment sites, and the difficulties of undertaking treatment alongside the daily need to maintain subsistence food production. However, facilitators were also identified, including the positive influence of religious beliefs, and high confidence in the ability of DOTS-based treatment to cure TB.

Conclusions

Documenting the wide range of factors that influence treatment adherence in a severely affected remote population will assist in improving TB control. These results provide impetus for further community-based efforts aimed at improving access to TB diagnosis and treatment, and maintaining successful treatment outcomes in the face of emerging drug resistance.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3935-7) contains supplementary material, which is available to authorized users.

Scenario Analysis for Programmatic Tuberculosis Control in Western Province, Papua New Guinea

Tuberculosis (TB) and multidrug-resistant TB (MDR-TB) are major health problems in Western Province, Papua New Guinea. While comprehensive expansion of TB control programs is desirable, logistical challenges are considerable, and there is substantial uncertainty regarding the true disease burden. We parameterized our previously described mathematical model of Mycobacterium tuberculosis dynamics in Western Province, following an epidemiologic assessment. Five hypothetical scenarios representing alternative programmatic approaches during the period from 2013 to 2023 were developed with local staff. Bayesian uncertainty analyses were undertaken to explicitly acknowledge the uncertainty around key epidemiologic parameters, and an economic evaluation was performed. With continuation of existing programmatic strategies, overall TB incidence remained stable at 555 cases per 100,000 population per year (95% simulation interval (SI): 420, 807), but the proportion of incident cases attributable to MDR-TB increased from 16% to 35%. Comprehensive, provincewide strengthening of existing programs reduced incidence to 353 cases per 100,000 population per year (95% SI: 246, 558), with 46% being cases of MDR-TB, while incorporating programmatic management of MDR-TB into these programs reduced incidence to 233 cases per 100,000 population per year (95% SI: 198, 269) with 14% MDR-TB. Most economic costs were due to hospitalization during the intensive treatment phase. Broad scale-up of TB control activities in Western Province with incorporation of programmatic management of MDR-TB is vital if control is to be achieved. Community-based treatment approaches are important to reduce the associated economic costs.

Bleach processed smear for Acid fast bacilli staining in Papua New Guinea

The conventional method of processing sputum for acid fast bacilli microscopy has been a primary tool for laboratory diagnosis of pulmonary tuberculosis in Papua New Guinea. In routine preparation, untreated sputum is directly smeared on a glass slide without undergoing any stage of processing. Mounting evidence suggests that direct smearing is less sensitive and, to a certain degree, compromises infection control. A few alternatives for processing sputum have been recommended in the literature; however, their consumables are not easily accessible and are expensive for wide use in rural laboratories. The bleach concentration and processing method appears to be the most preferable choice because bleach is inexpensive, readily available, and has bactericidal properties.

The Burden of Drug-Resistant Tuberculosis in Papua New Guinea: Results of a Large Population-Based Survey

Background

Reliable estimates of the burden of multidrug-resistant tuberculosis (MDR-TB) are crucial for effective control and prevention of tuberculosis (TB). Papua New Guinea (PNG) is a high TB burden country with limited information on the magnitude of the MDR-TB problem.

Methods

A cross-sectional study was conducted in four PNG provinces: Madang, Morobe, National Capital District and Western Province. Patient sputum samples were tested for rifampicin resistance by the Xpert MTB/RIF assay and those showing the presence of resistance underwent phenotypic susceptibility testing to first- and second-line anti-TB drugs including streptomycin, isoniazid, rifampicin, ethambutol, pyrazinamide, ofloxacin, amikacin, kanamycin and capreomycin.

Results

Among 1,182 TB patients enrolled in the study, MDR-TB was detected in 20 new (2.7%; 95% confidence intervals [CI] 1.1–4.3%) and 24 previously treated (19.1%; 95%CI: 8.5–29.8%) TB cases. No case of extensively drug-resistant TB (XDR-TB) was detected. Thirty percent (6/20) of new and 33.3% (8/24) of previously treated cases with MDR-TB were detected in a single cluster in Western Province.

Conclusion

In PNG the proportion of MDR-TB in new cases is slightly lower than the regional average of 4.4% (95%CI: 2.6–6.3%). A large proportion of MDR-TB cases were identified from a single hospital in Western Province, suggesting that the prevalence of MDR-TB across the country is heterogeneous. Future surveys should further explore this finding. The survey also helped strengthening the use of smear microscopy and Xpert MTB/RIF testing as diagnostic tools for TB in the country.

Linezolid in the Starter Combination for Multidrug-Resistant Tuberculosis: Time to Move on to Group Four?

Linezolid (LNZ), a group 5 antituberculous drug (unclear efficacy), was used in the starter regimens of 23 adults with multidrug-resistant tuberculosis. The LNZ-containing regimens were effective in achieving culture conversions and relapse-free outcomes. The most frequent LNZ-related side effect was neuropathy. We propose that LNZ should be reclassified among bactericidal second-line drugs.

A Global Perspective on Pyrazinamide Resistance: Systematic Review and Meta-Analysis

BACKGROUND

Pyrazinamide (PZA) is crucial for tuberculosis (TB) treatment, given its unique ability to eradicate persister bacilli. The worldwide burden of PZA resistance remains poorly described.

METHODS

Systematic PubMed, Science Direct and Scopus searches for articles reporting phenotypic (liquid culture drug susceptibility testing or pyrazinamidase activity assays) and/or genotypic (polymerase chain reaction or DNA sequencing) PZA resistance. Global and regional summary estimates were obtained from random-effects meta-analysis, stratified by presence or risk of multidrug resistant TB (MDR-TB). Regional summary estimates were combined with regional WHO TB incidence estimates to determine the annual burden of PZA resistance. Information on single nucleotide polymorphisms (SNPs) in the pncA gene was aggregated to obtain a global summary.

RESULTS

Pooled PZA resistance prevalence estimate was 16.2% (95% CI 11.2-21.2) among all TB cases, 41.3% (29.0-53.7) among patients at high MDR-TB risk, and 60.5% (52.3-68.6) among MDR-TB cases. The estimated global burden is 1.4 million new PZA resistant TB cases annually, about 270,000 in MDR-TB patients. Among 1,815 phenotypically resistant isolates, 608 unique SNPs occurred at 397 distinct positions throughout the pncA gene.

INTERPRETATION

PZA resistance is ubiquitous, with an estimated one in six incident TB cases and more than half of all MDR-TB cases resistant to PZA globally. The diversity of SNPs across the pncA gene complicates the development of rapid molecular diagnostics. These findings caution against relying on PZA in current and future TB drug regimens, especially in MDR-TB patients.

Maintenance of a reliable laboratory service for tuberculosis intervention in Papua New Guinea

The reemergence of tuberculosis, including multidrug-resistant strains, in Papua New Guinea highlights the never ending nature of the antituberculosis (anti-TB) campaign in that country and warrants the need for constant vigilance against the condition. Through surveillance, early detection, and management, the spread and incidence of TB can be kept in check. To maintain successful TB control programs, the government and partners committed to this campaign need to overhaul essential aspects of laboratory services. Clinical laboratories play a critical role in diagnostics; their functions cannot be substituted nor relegated. It is time to end neglect of these services in Papua New Guinea and to arm the laboratories in that country with full financial and logistical support so that they can lead the campaign against TB.

A prospective study of tuberculosis drug susceptibility in sabah, malaysia, and an algorithm for management of isoniazid resistance

Introduction. The burden of tuberculosis is high in eastern Malaysia, and rates of Mycobacterium tuberculosis drug resistance are poorly defined. Our objectives were to determine M. tuberculosis susceptibility and document management after receipt of susceptibility results. Methods. Prospective study of adult outpatients with smear-positive pulmonary tuberculosis (PTB) in Sabah, Malaysia. Additionally, hospital clinicians accessed the reference laboratory for clinical purposes during the study. Results. 176 outpatients were enrolled; 173 provided sputum samples. Mycobacterial culture yielded M. tuberculosis in 159 (91.9%) and nontuberculous Mycobacterium (NTM) in three (1.7%). Among outpatients there were no instances of multidrug resistant M. tuberculosis (MDR-TB). Seven people (4.5%) had isoniazid resistance (INH-R); all were switched to an appropriate second-line regimen for varying durations (4.5-9 months). Median delay to commencement of the second-line regimen was 13 weeks. Among 15 inpatients with suspected TB, 2 had multidrug resistant TB (one extensively drug resistant), 2 had INH-R, and 4 had NTM. Conclusions. Current community rates of MDR-TB in Sabah are low. However, INH-resistance poses challenges, and NTM is an important differential diagnosis in this setting, where smear microscopy is the usual diagnostic modality. To address INH-R management issues in our setting, we propose an algorithm for the treatment of isoniazid-resistant PTB.

Diversity of Mycobacterium tuberculosis and drug resistance in different provinces of Papua New Guinea

Background

Papua New Guinea (PNG) is a high tuberculosis (TB) burden country of the WHO Western Pacific Region, but so far research on drug resistance (DR) and genotypes of Mycobacterium tuberculosis (M. tuberculosis) was only conducted in few provinces in the country. The aim of the present study was to obtain baseline data on the level of drug resistance and the genotypic diversity of circulating M. tuberculosis in additional provinces and to investigate the differences between three selected sites across PNG.

Results

Genotyping of 147 M. tuberculosis clinical isolates collected in Goroka, Eastern Highlands Province, in Alotau, Milne Bay Province and in Madang, Madang Province revealed three main lineages of M. tuberculosis: Lineage 4 (European-American lineage), Lineage 2 (East-Asian lineage) and Lineage 1 (Indo-Oceanic lineage). All three lineages were detected in all three sites, but the individual lineage compositions varied significantly between sites. In Madang Lineage 4 was the most prevalent lineage (76.6%), whereas in Goroka and Alotau Lineage 2 was dominating (60.5% and 84.4%, respectively) (p < 0.001). Overall, phenotypic drug susceptibility testing showed 10.8% resistance to at least one of the first-line drugs tested. Of all resistant strains (23/212) 30.4% were Streptomycin mono-resistant, 17.4% were Isoniazid mono-resistant and 13% were Rifampicin mono-resistant. Multi-drug resistant (MDR) TB was found in 2.8% of all tested cases (6/212). The highest amount of MDR TB was found in Alotau in Milne Bay Province (4.6%).

Conclusion

A large number of drug resistant TB infections are present in the country and MDR TB has already been detected in all three surveyed regions of PNG, highlighting the importance of monitoring drug resistance and making it a high priority for the National Control Program. Due to the high prevalence of Lineage 2 in Milne Bay Province and given the frequent association of this lineage with drug resistance, monitoring of the latter should especially be scaled up in that province.

Tuberculosis in Papua New Guinea: from yesterday until today

Little is known about the situation of tuberculosis in Papua New Guinea despite its high TB burden, emerging drug resistance and rising HIV co-infection. This review gives an overview on the current situation of TB in PNG and identifies knowledge gaps that should urgently be addressed in the future.

Multidrug-resistant tuberculosis in Western Australia, 1998-2012

OBJECTIVE To describe the epidemiology, clinical features, health care resource use, treatment and outcomes of multidrug-resistant tuberculosis (MDR-TB) cases diagnosed in Western Australia, compared with matched controls with drug-susceptible TB.

DESIGN, SETTING AND PATIENTS

Retrospective case-control study of all MDR-TB cases notified in WA between 1 January 1998 and 31 December 2012, compared with matched controls. Cases were identified and managed through the Western Australia Tuberculosis Control Program, including specialist TB services, the Mycobacterium Reference Laboratory and affiliated secondary and tertiary outpatient and inpatient medical services in WA.

MAIN OUTCOME MEASURES

Demographic characteristics, clinical manifestations, treatment, outcomes and health care resource use.

RESULTS

Sixteen MDR-TB cases were notified during the study period (1.2% of all TB notifications). The median age of patients with MDR-TB was 26 years, and 15 were born outside Australia. Patients with MDR-TB were more likely to have received previous treatment (25% v 2%; P = 0.006) and had longer delays to effective therapy (median, 48 v 21 days; P = 0.002) than controls. MDR-TB patients more frequently required hospitalisation (100% v 35%; P < 0.001) and were treated for longer (mean, 597 v 229 days). Adverse effects were more commonly reported in MDR-TB patients than controls (81% v 33%; P < 0.001). Treatment success was not significantly different between patients with MDR-TB and controls (75% v 84%; P = 0.72). No treatment failures or deaths were identified in either group.

CONCLUSION

MDR-TB remains uncommon in WA but its challenges are increasingly recognised. Despite delays in commencing effective therapy, MDR-TB is usually associated with treatment success. Adverse effects of medications are common, and treatment courses are long and complex. Specialist TB services should continue to be involved in management and prevention of all cases of MDR-TB.

Diagnosis of tuberculous lymphadenitis using fine needle aspiration biopsy

BACKGROUND

Tuberculous lymphadenitis is the commonest form of extrapulmonary tuberculosis. However, the optimal approach to diagnosis, employing biopsy by either fine needle aspiration (FNA) or surgical excision, remains uncertain.

AIMS

To evaluate the diagnostic value of biopsy using each of the component diagnostic modalities of FNA (microscopy, cytology and culture), and compare these with excision biopsy in the diagnosis of tuberculous lymphadenitis in a predominantly migrant population in Melbourne.

METHODS

A retrospective examination of tuberculous lymphadenitis cases presenting to Western Health over 12 years was conducted. Using a reference method of positive culture of Mycobacterium tuberculosis, the diagnostic sensitivities of each modality employed in FNA were determined.

RESULTS

Forty-two subjects having FNA and 30 having excision biopsy as the initial investigation were compared. Among specimens obtained by FNA, sensitivity of microscopy was 18% (95% confidence interval (CI): 5–40%) and sensitivity of cytology was 38% (95% CI: 20–59%). For specimens obtained by excision biopsies, sensitivities for microscopy and histology were 17% (95% CI: 2–32%) and 96% (95% CI: 88–100%) respectively. Sensitivity of culture performed on FNA specimens was 86% (95% CI: 65–97%).

CONCLUSIONS

Given the relatively high sensitivity of mycobacterial cultures from FNA, this study supports its routine use as the initial investigation in most patients with suspected tuberculous lymphadenitis. Microscopy and cytology add relatively little to the clinical utility of FNA

TB incidence and characteristics in the remote gulf province of Papua New Guinea: a prospective study

Background

The incidence and characteristics of tuberculosis (TB) in remote areas of Papua New Guinea (PNG) are largely unknown. The purpose of our study was to determine the incidence of TB in the Gulf Province of PNG and describe disease characteristics, co-morbidities and drug resistance profiles that could impact on disease outcomes and transmission.

Methods

Between March 2012 and June 2012, we prospectively collected data on 274 patients presenting to Kikori Hospital with a presumptive diagnosis of TB, and on hospital inpatients receiving TB treatment during the study period. Sputum was collected for microscopy, GeneXpert analysis, culture and genotyping of isolates.

Results

We estimate the incidence of TB in Kikori to be 1290 per 100,000 people (95% CI 1140 to 1460) in 2012. The proportion of TB patients co-infected with HIV was 1.9%. Three of 32 TB cases tested were rifampicin resistant. Typing of nine isolates demonstrated allelic diversity and most were related to Beijing strains.

Conclusions

The incidence of TB in Kikori is one of the highest in the world and it is not driven by HIV co-infection. The high incidence and the presence of rifampicin resistant warrant urgent attention to mitigate substantial morbidity in the region.

'Z(S)-MDR-TB' versus 'Z(R)-MDR-TB': improving treatment of MDR-TB by identifying pyrazinamide susceptibility

Indispensable for shortening treatment of drug-susceptible tuberculosis (TB), pyrazinamide (PZA, Z) is also essential in the treatment of multidrug-resistant (MDR)-TB. While resistance to PZA in MDR-TB is associated with poor treatment outcome, bacillary susceptibility to PZA along with the use of fluoroquinolone (FQ) and second-line injectable drugs (SLIDs) may predict improved treatment success in MDR-TB. Despite a high prevalence of PZA resistance among MDR-TB patients (10%–85%), PZA susceptibility testing is seldom performed because of technical challenges. To improve treatment of MDR-TB, we propose to: (i) classify MDR-TB into PZA-susceptible MDR-TB (Z^S-MDR-TB) and PZA-resistant MDR-TB (Z^R-MDR-TB); (ii) use molecular tests such as DNA sequencing (pncA, gyrA, rrs, etc.) to rapidly identify Z^S-MDR-TB versus Z^R-MDR-TB and susceptibility profile for FQ and SLID; (iii) refrain from using PZA in Z^R-MDR-TB; and (iv) explore the feasibility of shortening the treatment duration of Z^S-MDR-TB with a regimen comprising PZA plus at least two bactericidal agents especially new agents like TMC207 or PA-824 or delamanid which the bacilli are susceptible to, with one or two other agents. These measures may potentially shorten therapy, save costs, and reduce side effects of MDR-TB treatment.