Conference Material > Abstract
Taremwa IM
TB Research Dissemination Workshop, Epicentre Uganda. 2022 June 29
BACKGROUND
People with immunosuppression may be particularly vulnerable to SARS-CoV-2 and some symptoms of infection by SARS-CoV-2 and TB are similar. Dual infection with both TB and COVID-19 may also lead to poorer treatment outcomes. This study was nested into the FujiLAM study and assessed the prevalence of exposure and infection by SARS-CoV-2 among HIV patients investigated for TB.
METHODS
A prospective observational study including HIV-positive patients with symptoms of TB (group 1) and patients with advanced HIV disease and no symptoms of TB (group 2) in Uganda, Kenya, and South Africa. All patients were investigated for TB and were proposed SARS-CoV-2 antibody testing at the first and the 6-month consultation. SARS-CoV-2 PCR was proposed to patients with symptoms of TB at the first consultation and patients with symptoms of Covid-19 at any time during follow-up. Exposure to SARS-CoV-2 was defined by the detection of antibodies, while the infection was determined by PCR.
FINDINGS
In total, 1466 HIV-positive patients included in the FujiLAM study were investigated for SARS-CoV-2 (985 patients in group 1 and, 481 patients in group 2). Of these, 1254 (85.5%) patients consented to SARS-CoV-2 antibody testing (829 in group 1 and 425 in group 2), and 1188 (94.7%) of them had results. Overall, 27.9% (331/1188) of patients had a positive serology result. According to the CD4 count, a positive serology result was found in 22.3% (110/443) of patients with CD4<200, and 31.7% (213/671) of those with CD4>200, p<0.001. Among patients with symptoms of TB who accepted PCR testing, 8.3% (40/483) had PCR positive results, of whom, 12.5% (5/40) had confirmed TB. Finally, among the 40 patients that were PCR positive, 15 (35.7%) were started on TB treatment.
INTERPRETATIONS
This study reports moderate to high exposure to Covid-19 among patients investigated for TB. Also, it reveals that HIV-positive with CD4<200 have lower Covid-19 serology positivity than those with CD4≥200. This finding may have implications regarding the level of protection for immunosuppressed HIV-positive patients who have passed the disease or for vaccination strategy. Indeed, people living with HIV and with a low levels of CD4 should be prioritized for COVID-19 vaccination. Moreover, a considerable proportion of Covid-19 infected patients were also diagnosed with TB.
These abstracts are not to be quoted for publication
People with immunosuppression may be particularly vulnerable to SARS-CoV-2 and some symptoms of infection by SARS-CoV-2 and TB are similar. Dual infection with both TB and COVID-19 may also lead to poorer treatment outcomes. This study was nested into the FujiLAM study and assessed the prevalence of exposure and infection by SARS-CoV-2 among HIV patients investigated for TB.
METHODS
A prospective observational study including HIV-positive patients with symptoms of TB (group 1) and patients with advanced HIV disease and no symptoms of TB (group 2) in Uganda, Kenya, and South Africa. All patients were investigated for TB and were proposed SARS-CoV-2 antibody testing at the first and the 6-month consultation. SARS-CoV-2 PCR was proposed to patients with symptoms of TB at the first consultation and patients with symptoms of Covid-19 at any time during follow-up. Exposure to SARS-CoV-2 was defined by the detection of antibodies, while the infection was determined by PCR.
FINDINGS
In total, 1466 HIV-positive patients included in the FujiLAM study were investigated for SARS-CoV-2 (985 patients in group 1 and, 481 patients in group 2). Of these, 1254 (85.5%) patients consented to SARS-CoV-2 antibody testing (829 in group 1 and 425 in group 2), and 1188 (94.7%) of them had results. Overall, 27.9% (331/1188) of patients had a positive serology result. According to the CD4 count, a positive serology result was found in 22.3% (110/443) of patients with CD4<200, and 31.7% (213/671) of those with CD4>200, p<0.001. Among patients with symptoms of TB who accepted PCR testing, 8.3% (40/483) had PCR positive results, of whom, 12.5% (5/40) had confirmed TB. Finally, among the 40 patients that were PCR positive, 15 (35.7%) were started on TB treatment.
INTERPRETATIONS
This study reports moderate to high exposure to Covid-19 among patients investigated for TB. Also, it reveals that HIV-positive with CD4<200 have lower Covid-19 serology positivity than those with CD4≥200. This finding may have implications regarding the level of protection for immunosuppressed HIV-positive patients who have passed the disease or for vaccination strategy. Indeed, people living with HIV and with a low levels of CD4 should be prioritized for COVID-19 vaccination. Moreover, a considerable proportion of Covid-19 infected patients were also diagnosed with TB.
These abstracts are not to be quoted for publication
Conference Material > Abstract
Ben-Farhat J
Epicentre Scientific Day Paris 2022. 2022 June 1
INTRODUCTION
The COVID-19 pandemic and the measures taken to limit its spread have severely disrupted health systems and medical care. People living with HIV (PLHIV) suffer from high levels of comorbidities and stigma, and often faced challenges in access to care prior to the pandemic. The aim of this study was to explore the extent to which the pandemic and the public health measures have affected medical care for PLHIV. The study took place in two different contexts in terms of care and experience of the pandemic where MSF operates, in Arua (Uganda) and Chiradzulu (Malawi).
METHODS
We conducted a multicentric mixed-methods study . The quantitative component explored patients’ retention in care and viral suppression using programmatic data routinely collected from January 2018 to April 2021 . The qualitative study investigated patient perspectives and perceptions of the impact of Covid-19 and the public health and social measures on their lives and ability to manage their health, and on HIV care. The interviews with patients were conducted from January to June 2021.
RESULTS
From 2020 to 2021, we observed a 15% decrease in active cohort among adults on any regimen and a 17% decrease among children and adolescents in Arua. During the same period in Chiradzulu, the first- and second-line cohorts decreased in size (10% drop and 12% drop, respectively). In addition, we observed a reduction in ART initiations and in clinical consultations at the start of pandemic (50% and 68% in Arua and 34% and 60% in Chiradzulu, respectively) and a gradual decrease in viral load coverage. In Uganda, the lockdown affected patients’ and caregivers’ livelihoods, education, access to food and psychosocial wellbeing negatively, which at times affected their ability to manage HIV condition at home and to adhere. Adolescents lost support, experienced increasing HIV stigma, and started to provide for themselves. In Malawi, patients and caregivers emphasized the impact of the pandemic and public health measures on livelihoods and food security and noted the reduction or absence of MSF social support activities during this time. Also, the fear of COVID at health facilities and the confusion and lack of communication about regarding day-to-day changes in activities was disturbing to both patients and staff.
CONCLUSION
The COVID-19 epidemic and public health measures had an important negative impact on HIV care in the health facilities and in the community in Arua and Chiradzulu. To ensure a conducive environment for patients’ access to essential HIV care and treatment during potential future outbreaks requires continued collaboration with the national authorities and advocacy for more non-violent and less authoritarian ways of implementing restrictions. In addition, innovative public health information campaigns about COVID-19 and care services, to reduce fear of disease and to dispel rumours and misinformation are recommended.
KEY MESSAGE
COVID-19 has severely disrupted access to health systems and treatment. The measures put in place to limit the spread of the epidemic have altered people's bearings. How has the pandemic in Arua and Chiradzulu affected PLHIV, who already suffer from higher levels of mental health problems, comorbidities and stigma?
This abstract is not to be quoted for publication.
The COVID-19 pandemic and the measures taken to limit its spread have severely disrupted health systems and medical care. People living with HIV (PLHIV) suffer from high levels of comorbidities and stigma, and often faced challenges in access to care prior to the pandemic. The aim of this study was to explore the extent to which the pandemic and the public health measures have affected medical care for PLHIV. The study took place in two different contexts in terms of care and experience of the pandemic where MSF operates, in Arua (Uganda) and Chiradzulu (Malawi).
METHODS
We conducted a multicentric mixed-methods study . The quantitative component explored patients’ retention in care and viral suppression using programmatic data routinely collected from January 2018 to April 2021 . The qualitative study investigated patient perspectives and perceptions of the impact of Covid-19 and the public health and social measures on their lives and ability to manage their health, and on HIV care. The interviews with patients were conducted from January to June 2021.
RESULTS
From 2020 to 2021, we observed a 15% decrease in active cohort among adults on any regimen and a 17% decrease among children and adolescents in Arua. During the same period in Chiradzulu, the first- and second-line cohorts decreased in size (10% drop and 12% drop, respectively). In addition, we observed a reduction in ART initiations and in clinical consultations at the start of pandemic (50% and 68% in Arua and 34% and 60% in Chiradzulu, respectively) and a gradual decrease in viral load coverage. In Uganda, the lockdown affected patients’ and caregivers’ livelihoods, education, access to food and psychosocial wellbeing negatively, which at times affected their ability to manage HIV condition at home and to adhere. Adolescents lost support, experienced increasing HIV stigma, and started to provide for themselves. In Malawi, patients and caregivers emphasized the impact of the pandemic and public health measures on livelihoods and food security and noted the reduction or absence of MSF social support activities during this time. Also, the fear of COVID at health facilities and the confusion and lack of communication about regarding day-to-day changes in activities was disturbing to both patients and staff.
CONCLUSION
The COVID-19 epidemic and public health measures had an important negative impact on HIV care in the health facilities and in the community in Arua and Chiradzulu. To ensure a conducive environment for patients’ access to essential HIV care and treatment during potential future outbreaks requires continued collaboration with the national authorities and advocacy for more non-violent and less authoritarian ways of implementing restrictions. In addition, innovative public health information campaigns about COVID-19 and care services, to reduce fear of disease and to dispel rumours and misinformation are recommended.
KEY MESSAGE
COVID-19 has severely disrupted access to health systems and treatment. The measures put in place to limit the spread of the epidemic have altered people's bearings. How has the pandemic in Arua and Chiradzulu affected PLHIV, who already suffer from higher levels of mental health problems, comorbidities and stigma?
This abstract is not to be quoted for publication.
Journal Article > ResearchFull Text
Soc. Sci. Med. 1993 August 1
Schopper D, Doussantousse S, Orav J
Soc. Sci. Med. 1993 August 1
KAP surveys have been proposed as a means to gather quantitative information on AIDS-related sexual behaviors, but the validity of survey results has not been tested. The validity of data gathered during a KAP survey in a rural district in Northern Uganda (N = 1486) was examined analyzing expected behavioral patterns, agreement of partner reports, and concordance of number of sexual contacts across gender. Patterns of sexual behavior and age trends are as expected. More men (50%) than women (18.5%) reported premarital sex. The likelihood of sexual intercourse before marriage increases with age at first marriage and with education. Women marry 5 years earlier than men, and the number of marriages increases with age. Peak incidence of casual sex occurs before age 25. The male/female ratio of casual sex is 4, as compared to about 3 in other African surveys. Single men are 2.5 times more likely to engage in casual sex than married males. Agreement of partner reports was examined for 392 couples selected by chance. 86% of the couples agreed on being polygamous or monogamous. On average men reported 1.3 (SD = 0.7) wives as compared to women reporting 1.5 (SD = 0.89) wives (P < 0.001). 16.8% of women declared more, and 2.8% less cowives than their husband (r = 0.65). Self-reports on frequency of sexual intercourse in the past month were examined for 256 monogamous couples. Mean frequencies differ (5.24 +/- 5.1 for men, 4.43 +/- 4.7 for women, P < 0.001). 42.8% of couples are in agreement within +/- 1 unit (r = 0.44). The total number of extra-marital and marital sex acts, as well as the total number of partners reported by each gender are similar. There is, however, a striking gender difference in reporting of casual partners in the past year. Data were found to be accurate at the aggregate level. However, accuracy of reporting at the individual level was found to be low. The gender difference in reporting of casual partners may be due to female underreporting, to not having captured prostitutes or to a different perception of the meaning of casual partnership. All KAP surveys should include a validity analysis, so as to provide a sense of the accuracy of the surveys and allow for comparison of the quality of different KAP surveys. There is an urgent need for a standardized approach to validating the findings from AIDS-related KAP surveys. Some of the indirect methods described here could be relevant for further use.
Journal Article > ResearchFull Text
Trans R Soc Trop Med Hyg. 2008 October 21; Volume 103 (Issue 3); DOI:10.1016/j.trstmh.2008.09.005
Balasegaram M, Young H, Chappuis F, Priotto G, Raguenaud ME, et al.
Trans R Soc Trop Med Hyg. 2008 October 21; Volume 103 (Issue 3); DOI:10.1016/j.trstmh.2008.09.005
This paper describes the effectiveness of first-line regimens for stage 2 human African trypanosomiasis (HAT) due to Trypanosoma brucei gambiense infection in nine Médecins Sans Frontières HAT treatment programmes in Angola, Republic of Congo, Sudan and Uganda. Regimens included eflornithine and standard- and short-course melarsoprol. Outcomes for 10461 naïve stage 2 patients fitting a standardised case definition and allocated to one of the above regimens were analysed by intention-to-treat analysis. Effectiveness was quantified by the case fatality rate (CFR) during treatment, the proportion probably and definitely cured and the Kaplan-Meier probability of relapse-free survival at 12 months and 24 months post admission. The CFR was similar for the standard- and short-course melarsoprol regimens (4.9% and 4.2%, respectively). The CFR for eflornithine was 1.2%. Kaplan-Meier survival probabilities varied from 71.4-91.8% at 1 year and 56.5-87.9% at 2 years for standard-course melarsoprol, to 73.0-91.1% at 1 year for short-course melarsoprol, and 79.9-97.4% at 1 year and 68.6-93.7% at 2 years for eflornithine. With the exception of one programme, survival at 12 months was >90% for eflornithine, whilst for melarsoprol it was <90% except in two sites. Eflornithine is recommended where feasible, especially in areas with low melarsoprol effectiveness.
Conference Material > Video (talk)
Namulwana ML
Epicentre Scientific Day Paris 2022. 2022 June 21
Journal Article > ResearchFull Text
CPT Pharmacometrics Syst Pharmacol. 2013 November 13; Volume 2 (Issue 11); e83.; DOI:10.1038/psp.2013.59
Kloprogge F, Piola P, Dhorda M, Muwanga S, Turyakira E, et al.
CPT Pharmacometrics Syst Pharmacol. 2013 November 13; Volume 2 (Issue 11); e83.; DOI:10.1038/psp.2013.59
Pregnancy alters the pharmacokinetic properties of many antimalarial compounds. The objective of this study was to evaluate the pharmacokinetic properties of lumefantrine in pregnant and nonpregnant women with uncomplicated Plasmodium falciparum malaria in Uganda after a standard fixed oral artemether-lumefantrine treatment. Dense venous (n = 26) and sparse capillary (n = 90) lumefantrine samples were drawn from pregnant patients. A total of 17 nonpregnant women contributed with dense venous lumefantrine samples. Lumefantrine pharmacokinetics was best described by a flexible absorption model with multiphasic disposition. Pregnancy and body temperature had a significant impact on the pharmacokinetic properties of lumefantrine. Simulations from the final model indicated 27% lower day 7 concentrations in pregnant women compared with nonpregnant women and a decreased median time of 0.92 and 0.42 days above previously defined critical concentration cutoff values (280 and 175 ng/ml, respectively). The standard artemether-lumefantrine dose regimen in P. falciparum malaria may need reevaluation in nonimmune pregnant women.
Journal Article > ResearchFull Text
Malar J. 2017 October 28; Volume 16 (Issue 1); 449.; DOI:10.1186/s12936-017-2094-3
Oyet C, Roh ME, Kiwanuka G, Orikiriza P, Wade M, et al.
Malar J. 2017 October 28; Volume 16 (Issue 1); 449.; DOI:10.1186/s12936-017-2094-3
BACKGROUND
Early diagnosis of suspected malaria cases with a rapid diagnostic test (RDT) has been shown to be an effective malaria control tool used in many resource-constrained settings. However, poor quality control and quality assurance hinder the accurate reporting of malaria diagnoses. Recent use of a portable, battery operated RDT reader (Deki Reader™, Fio Corporation) has shown to have high agreement with visual inspection across diverse health centre settings, however evidence of its feasibility and usability during cross sectional surveys are limited. This study aimed to evaluate the performance of the Deki Reader™ in a cross-sectional survey of children from southwestern Uganda.
METHODS
A two-stage, stratified cluster sampling survey was conducted between July and October 2014 in three districts of southwestern Uganda, with varying malaria transmission intensities. A total of 566 children aged 6-59 months were included in the analysis. Blood samples were collected and tested for malaria using: the SD Bioline Malaria Ag Pf/Pan RDT and microscopy. Results were compared between visual inspection of the RDT and by the Deki Reader™. Diagnostic performance of both methods were compared to gold-standard microscopy.
RESULTS
The sensitivity and specificity of the Deki Reader™ was 94.1% (95% CI 69.2-99.6%) and 95.6% (95% CI 93.4-97.1%), respectively. The overall percent agreement between the Deki Reader™ and visual RDT inspection was 98.9% (95% CI 93.2-99.8), with kappa statistic of 0.92 (95% CI 0.85-0.98).
CONCLUSIONS
The findings from this study suggest that the Deki Reader™ is comparable to visual inspection and performs well in detecting microscopy-positive Plasmodium falciparum cases in a household survey setting. However, the reader's performance was highly dependent on ensuring adequate battery life and a work environment free of dirt particles.
Early diagnosis of suspected malaria cases with a rapid diagnostic test (RDT) has been shown to be an effective malaria control tool used in many resource-constrained settings. However, poor quality control and quality assurance hinder the accurate reporting of malaria diagnoses. Recent use of a portable, battery operated RDT reader (Deki Reader™, Fio Corporation) has shown to have high agreement with visual inspection across diverse health centre settings, however evidence of its feasibility and usability during cross sectional surveys are limited. This study aimed to evaluate the performance of the Deki Reader™ in a cross-sectional survey of children from southwestern Uganda.
METHODS
A two-stage, stratified cluster sampling survey was conducted between July and October 2014 in three districts of southwestern Uganda, with varying malaria transmission intensities. A total of 566 children aged 6-59 months were included in the analysis. Blood samples were collected and tested for malaria using: the SD Bioline Malaria Ag Pf/Pan RDT and microscopy. Results were compared between visual inspection of the RDT and by the Deki Reader™. Diagnostic performance of both methods were compared to gold-standard microscopy.
RESULTS
The sensitivity and specificity of the Deki Reader™ was 94.1% (95% CI 69.2-99.6%) and 95.6% (95% CI 93.4-97.1%), respectively. The overall percent agreement between the Deki Reader™ and visual RDT inspection was 98.9% (95% CI 93.2-99.8), with kappa statistic of 0.92 (95% CI 0.85-0.98).
CONCLUSIONS
The findings from this study suggest that the Deki Reader™ is comparable to visual inspection and performs well in detecting microscopy-positive Plasmodium falciparum cases in a household survey setting. However, the reader's performance was highly dependent on ensuring adequate battery life and a work environment free of dirt particles.
Conference Material > Abstract
Lissouba P, Huerga H, Rucker C
Epicentre Scientific Day Paris 2021. 2021 June 10
BACKGROUND
The novel point-of-care urine-based FujiLAM test is promising for diagnosis of tuberculosis. We assessed the diagnostic yield of FujiLAM in HIV patients and the feasibility of using the test.
METHODS
We conducted a prospective diagnostic study and a mixed-methods feasibility and acceptability study in 4 countries: Uganda, Kenya,
Mozambique and South Africa. The diagnostic study included 2 groups of ambulatory HIV-positive adults: 1) with TB symptoms, 2) with advanced HIV disease and no TB symptoms. Patients received FujiLAM and AlereLAM, Xpert MTB/RIF, culture and chest X-ray. The feasibility study included test’ users, key informants and patients who participated through standard questionnaires, individual interviews and group discussions.
RESULTS
We included 1117 patients in the diagnostic study: 712 with TB symptoms (Group 1) and 405 with advanced HIV disease and no TB
symptoms (Group 2). TB was confirmed in 9.2% (63/685) and 4.1% (16/395) in Group 1 and 2, respectively. FujiLAM diagnostic yield among patients with confirmed TB was 63.2% and 43.8% in Group 1 and 2, respectively. FujiLAM diagnostic yield by CD4 count was: 75.0% in CD4<200, 77.8% in CD4 200-349, 31.3% in CD4≥350 (Group 1) and 46.7% in CD4<200 (Group 2). Most of the test users (including lay health workers) found FujiLAM easy to perform. The main concern was the multiple timed steps involved. Invalid results were obtained if test cartridges were dropped or performed on blood stained or cloudy urine. Most patients viewed urine sampling
positively and easier than sputum provision.
CONCLUSIONS
FujiLAM detects TB in a high proportion of the HIV patients with confirmed TB who have symptoms of TB and low CD4 counts, and in
a considerable proportion of those asymptomatic. The test is easy to perform at point-of-care. Urine sampling is well accepted by patients. These results encourage the future use of the FujiLAM assay.
KEY MESSAGES: The novel urine-based FujiLAM is a useful and easy to use point-of care test for TB diagnosis in HIV-positive patients. Urine sampling is well accepted.
This abstract is not to be quoted for publication.
The novel point-of-care urine-based FujiLAM test is promising for diagnosis of tuberculosis. We assessed the diagnostic yield of FujiLAM in HIV patients and the feasibility of using the test.
METHODS
We conducted a prospective diagnostic study and a mixed-methods feasibility and acceptability study in 4 countries: Uganda, Kenya,
Mozambique and South Africa. The diagnostic study included 2 groups of ambulatory HIV-positive adults: 1) with TB symptoms, 2) with advanced HIV disease and no TB symptoms. Patients received FujiLAM and AlereLAM, Xpert MTB/RIF, culture and chest X-ray. The feasibility study included test’ users, key informants and patients who participated through standard questionnaires, individual interviews and group discussions.
RESULTS
We included 1117 patients in the diagnostic study: 712 with TB symptoms (Group 1) and 405 with advanced HIV disease and no TB
symptoms (Group 2). TB was confirmed in 9.2% (63/685) and 4.1% (16/395) in Group 1 and 2, respectively. FujiLAM diagnostic yield among patients with confirmed TB was 63.2% and 43.8% in Group 1 and 2, respectively. FujiLAM diagnostic yield by CD4 count was: 75.0% in CD4<200, 77.8% in CD4 200-349, 31.3% in CD4≥350 (Group 1) and 46.7% in CD4<200 (Group 2). Most of the test users (including lay health workers) found FujiLAM easy to perform. The main concern was the multiple timed steps involved. Invalid results were obtained if test cartridges were dropped or performed on blood stained or cloudy urine. Most patients viewed urine sampling
positively and easier than sputum provision.
CONCLUSIONS
FujiLAM detects TB in a high proportion of the HIV patients with confirmed TB who have symptoms of TB and low CD4 counts, and in
a considerable proportion of those asymptomatic. The test is easy to perform at point-of-care. Urine sampling is well accepted by patients. These results encourage the future use of the FujiLAM assay.
KEY MESSAGES: The novel urine-based FujiLAM is a useful and easy to use point-of care test for TB diagnosis in HIV-positive patients. Urine sampling is well accepted.
This abstract is not to be quoted for publication.
Journal Article > ResearchFull Text
J Infect Dis. 2016 May 25; Volume 215 (Issue 1); 64–69.; DOI:10.1093/infdis/jiw206
Muehlenbachs A, de la Rosa Vazquez O, Bausch DG, Schafer IJ, Paddock C, et al.
J Infect Dis. 2016 May 25; Volume 215 (Issue 1); 64–69.; DOI:10.1093/infdis/jiw206
Here we describe clinicopathologic features of EVD in pregnancy. One woman infected with Sudan virus in Gulu, Uganda in 2000 had a stillbirth and survived, and another woman with Bundibugyo virus had a livebirth with maternal and infant death in Isiro, the Democratic Republic of the Congo in 2012. Ebolavirus antigen was seen in the syncytiotrophoblast and placental maternal mononuclear cells by immunohistochemistry, and no antigen was seen in fetal placental stromal cells or fetal organs. In the Gulu case, ebolavirus antigen localized to malaria pigment-laden macrophages. These data suggest trophoblast infection may be a mechanism of transplacental ebolavirus transmission.
Journal Article > ResearchFull Text
East Afr Med J. 2017 March 31; Volume 6 (Issue 2); 383.; DOI:10.4102/ajlm.v6i2.383
Orikiriza P, Nyehangane D, Atwine D, Kisakye JJ, Kassaza K, et al.
East Afr Med J. 2017 March 31; Volume 6 (Issue 2); 383.; DOI:10.4102/ajlm.v6i2.383
BACKGROUND
To confirm presence of Mycobacterium tuberculosis complex, some tuberculosis culture laboratories still rely on para-nitrobenzoic acid (PNB), a traditional technique that requires sub-culturing of clinical isolates and two to three weeks to give results. Rapid identification tests have improved turnaround times for mycobacterial culture results. Considering the challenges of the PNB method, we assessed the performance of the SD Bioline TB Ag MPT64 assay by using PNB as gold standard to detect M. tuberculosis complex from acid-fast bacilli (AFB) positive cultures.
OBJECTIVES
The aim of this study was to determine the sensitivity, specificity and turnaround time of the SD MPT64 assay for identification of M. tuberculosis complex, in a setting with high prevalence of tuberculosis and HIV.
METHODS
A convenience sample of 690 patients, with tuberculosis symptoms, was enrolled at Epicentre Mbarara Research Centre between April 2010 and June 2011. The samples were decontaminated using NALC-NaOH and re-suspended sediments inoculated in Mycobacterium Growth Indicator Tubes (MGIT) media, then incubated at 37 °C for a maximum of eight weeks. A random sample of 50 known negative cultures and 50 non-tuberculous mycobacteria isolates were tested for specificity, while sensitivity was based on AFB positivity. The time required from positive culture to reporting of results was also assessed with PNB used as the gold standard.
RESULTS
Of the 138 cultures that were AFB-positive, the sensitivity of the SD MPT64 assay was 100.0% [95% CI: 97.3 - 100] and specificity was 100.0% (95% CI, 96.4 - 100). The median time from a specimen receipt to confirmation of strain was 10 days [IQR: 8-12] with SD MPT64 and 24 days [IQR: 22-26] with PNB.
CONCLUSION
The SD MPT64 assay is comparable to PNB for identification of M. tuberculosis complex and reduces the time to detection.
To confirm presence of Mycobacterium tuberculosis complex, some tuberculosis culture laboratories still rely on para-nitrobenzoic acid (PNB), a traditional technique that requires sub-culturing of clinical isolates and two to three weeks to give results. Rapid identification tests have improved turnaround times for mycobacterial culture results. Considering the challenges of the PNB method, we assessed the performance of the SD Bioline TB Ag MPT64 assay by using PNB as gold standard to detect M. tuberculosis complex from acid-fast bacilli (AFB) positive cultures.
OBJECTIVES
The aim of this study was to determine the sensitivity, specificity and turnaround time of the SD MPT64 assay for identification of M. tuberculosis complex, in a setting with high prevalence of tuberculosis and HIV.
METHODS
A convenience sample of 690 patients, with tuberculosis symptoms, was enrolled at Epicentre Mbarara Research Centre between April 2010 and June 2011. The samples were decontaminated using NALC-NaOH and re-suspended sediments inoculated in Mycobacterium Growth Indicator Tubes (MGIT) media, then incubated at 37 °C for a maximum of eight weeks. A random sample of 50 known negative cultures and 50 non-tuberculous mycobacteria isolates were tested for specificity, while sensitivity was based on AFB positivity. The time required from positive culture to reporting of results was also assessed with PNB used as the gold standard.
RESULTS
Of the 138 cultures that were AFB-positive, the sensitivity of the SD MPT64 assay was 100.0% [95% CI: 97.3 - 100] and specificity was 100.0% (95% CI, 96.4 - 100). The median time from a specimen receipt to confirmation of strain was 10 days [IQR: 8-12] with SD MPT64 and 24 days [IQR: 22-26] with PNB.
CONCLUSION
The SD MPT64 assay is comparable to PNB for identification of M. tuberculosis complex and reduces the time to detection.