Study protocol: a pragmatic, cluster-randomized controlled trial to evaluate the effect of implementation of the Truenat platform/MTB assays at primary health care clinics in Mozambique and Tanzania (TB-CAPT CORE)

BACKGROUND

In 2020, the WHO-approved Molbio Truenat platform and MTB assays to detect Mycobacterium tuberculosis complex (MTB) and resistance to rifampicin directly on sputum specimens. This primary health care center-based trial in Mozambique and Tanzania investigates the effect of Truenat platform/MTB assays (intervention arm) combined with rapid communication of results compared to standard of care on TB diagnosis and treatment initiation for microbiologically confirmed TB at 7 days from enrolment.

METHODS

The Tuberculosis Close the Gap, Increase Access, and Provide Adequate Therapy (TB-CAPT) CORE trial employs a pragmatic cluster randomized controlled design to evaluate the impact of a streamlined strategy for delivery of Truenat platform/MTB assays testing at primary health centers. Twenty-nine centers equipped with TB microscopy units were selected to participate in the trial. Among them, fifteen health centers were randomized to the intervention arm (which involves onsite molecular testing using Truenat platform/MTB assays, process process optimization to enable same-day TB diagnosis and treatment initiation, and feedback on Molbio platform performance) or the control arm (which follows routine care, including on-site sputum smear microscopy and the referral of sputum samples to off-site Xpert testing sites). The primary outcome of the study is the absolute number and proportion of participants with TB microbiological confirmation starting TB treatment within 7 days of their first visit. Secondary outcomes include time to bacteriological confirmation, health outcomes up to 60 days from first visit, as well as user preferences, direct cost, and productivity analyses.

ETHICS AND DISSEMINATION

TB-CAPT CORE trial has been approved by regulatory and ethical committees in Mozambique and Tanzania, as well as by each partner organization. Consent is informed and voluntary, and confidentiality of participants is maintained throughout. Study findings will be presented at scientific conferences and published in peer-reviewed international journals.

TRIAL REGISTRATION

US National Institutes of Health's ClinicalTrials.gov, NCT04568954. Registered 23 September 2020.

Alcohol use as a mediator of the effect of two alcohol reduction interventions on mental health symptoms of ART clients in Vietnam

We aimed to examine the mediating role of alcohol use in the pathway from the interventions to depression and anxiety symptoms using data from a randomized controlled trial among people living with HIV (PWH) with hazardous alcohol use (n = 440) in Thai Nguyen, Vietnam. Participants were randomized into either a combined intervention (CoI), a brief intervention (BI) and a standard of care arm. Both interventions were based on cognitive behavioral therapy and motivational enhancement therapy. Alcohol use was measured as the percentage of days abstinent from alcohol in the last 30 days. Symptoms of depression and anxiety were measured with the Patient Health Questionnaire-9 and Generalized Anxiety Disorder-7 scales. Alcohol use was a significant mediator of the effects of two alcohol interventions on depression symptoms, but not anxiety symptoms. There were significant indirect effects via alcohol use of both interventions on depression symptoms at 12 months (CoI: mean difference (MD) = -0.134; 95%CI: -0.251, -0.035); (BI: MD = -0.141; 95%CI: -0.261, -0.038). There were no significant direct or total effects of the interventions on either symptoms at 12 months. Interventions with a dual focus on mental health and alcohol disorders are needed to determine optimal ways to tackle these common comorbidities among PWH.

The impact of time at home on potential yield of home-based TB contact investigation

BACKGROUND: The yield of TB contact tracing is often limited by challenges in reaching individuals during the screening process. We investigated the times at which index patients and household contacts were typically at home and the potential effects of expanding the timing of home-based contact investigation.METHODS: Index patients and household contacts in Kampala, Uganda, were asked about their likely availability at different day/time combinations. We calculated the "participant identification gap" (defined as the proportion of participants who reported being home <50% of the time) during business hours only. We then estimated the incremental reduction in the participant identification gap if hours were expanded to include weekday evenings, Saturdays, and Sundays. Statistical significance was assessed using McNemar´s tests.RESULTS: Nearly half of eligible individuals (42% of index patients and 52% of contacts) were not likely to be home during contact investigation conducted only during business hours. Expanding to weekday evenings, Saturdays, and Sundays would reduce this participant identification gap to 15% among index patients and 18% among contacts - while also reducing differences by sex and employment.CONCLUSIONS: Expanding hours for conducting contact investigation or other home-based health interventions could substantially reduce the number of individuals missed and address disparities in access to care.

Effects of Two Alcohol Reduction Interventions on Depression and Anxiety Symptoms of ART Clients in Vietnam

Little is known about the potential mental health impacts of cognitive behavioral therapy and motivational interviewing interventions that focus on alcohol reduction among people with HIV (PWH). Our study aimed to assess the impact of two evidence-based alcohol reduction interventions on depression and anxiety symptoms of antiretroviral therapy (ART) clients with hazardous alcohol use. We conducted a secondary data analysis of data from a three-arm randomized controlled trial among ART clients in Thai Nguyen, Vietnam that evaluated the impacts of two alcohol reduction interventions in Vietnam. ART clients 18 years old or more with hazardous alcohol use (based on the Alcohol Use Disorders Identification Test-Consumption) were enrolled and randomized into one of three arms: Combined intervention, Brief intervention, and Standard of care (SOC). Symptoms of depression, measured with the Patient Health Questionnaire-9, and anxiety, measured with the Generalized Anxiety Disorder-7 scale, were assessed at baseline and 3, 6, and 12 months post-intervention. Generalized estimating equations were used to evaluate the effects of the interventions on depression and anxiety symptoms. The prevalence of depression and anxiety symptoms at baseline was 25.1% and 16.1%, respectively. Decreases in depression and anxiety symptoms were observed in all three arms from baseline to 12-month follow-up. There were no significant differences in depression and anxiety symptoms among participants receiving either intervention, relative to the SOC. Interventions with a dual focus on alcohol and mental health are needed to achieve more pronounced and sustainable improvements in depression and anxiety symptoms for PWH with hazardous alcohol use.

"I refused to drink but they still forced me": A mixed-methods approach to understanding the pathways to reduce alcohol use among Vietnamese people with HIV

AIMS

This study explores the effects of two evidence-based alcohol reduction counseling interventions on readiness to change, alcohol abstinence self-efficacy, social support, and alcohol abstinence stigma among people with HIV (PWH) who have hazardous alcohol use in Vietnam.

METHODS

PWH receiving antiretroviral therapy (ART) were screened for hazardous drinking and randomized to one of three study arms: combined intervention (CoI), brief intervention (BI), and standard of care (SOC). A quantitative survey was conducted at baseline (N = 440) and 3-month post-intervention (N = 405), while in-depth interviews were conducted with a subset of BI and CoI participants at baseline (N = 14) and 3 months (N = 14). Data was collected from March 2016 to August 2017. A concurrent mixed-methods model was used to triangulate quantitative and qualitative data to cross-validate findings.

RESULTS

At 3 months, receiving the BI and CoI arms was associated with 2.64 and 3.50 points higher in mean readiness to change scores, respectively, compared to the SOC group (BI: β = 2.64, 95% CI: 1.17-4.12; CoI: β = 3.50, 95% CI 2.02-4.98). Mean alcohol abstinence self-efficacy scores were 4.03 and 3.93 points higher among the BI and CoI arm at 3 months, compared to SOC (BI: β = 4.03, 95% CI: 0.17-7.89; CoI: β = 3.93, 95% CI: 0.05-7.81). The impacts of the interventions on social support and alcohol abstinence stigma were not significant. Perceived challenges to refusing drinks at social events remained due to strong alcohol abstinence stigma and perceived negative support from family and friends who encouraged participants to drink posed additional barriers to reducing alcohol use.

CONCLUSIONS

Both the CoI and BI were effective in improving readiness to change and alcohol abstinence self-efficacy among PWH. Yet, participants still faced significant barriers to reducing their drinking due to social influences and pressure to drink. Interventions at different levels addressing social support and alcohol abstinence stigma are warranted.

Time to care-seeking for TB symptoms

BACKGROUND: Early presentation to healthcare facilities is critical for early diagnosis and treatment of TB. We studied self-reported time to care-seeking from the onset of TB symptoms among primary healthcare clinic (PHC) attendees in Limpopo Province, South Africa.METHODS: We used data from participants enrolled in a cluster-randomized trial of TB case finding in 56 PHC clinics across two health districts. We fitted log-normal accelerated failure time regression models and we present time ratios (TRs) for potential risk factors.RESULTS: We included 2,160 participants. Among the 1,757 (81%) diagnosed with active TB, the median time to care-seeking was 30 days (IQR 14-60); adults sought care later than children/adolescents (adjusted TR aTR 1.47, 95% CI 1.10-1.96). Among those not diagnosed with TB, the median was 14 days (IQR 7-60); being HIV-positive (aTR 1.57, 95% CI 1.03-2.40); having less than grade 8 education and currently smoking were associated with longer time to care-seeking. In the combined analysis, living with HIV and having underlying active TB was associated with faster care-seeking (TB status x HIV interaction: TR 0.68, 95% CI 0.48-0.96).CONCLUSION: Delay in care-seeking was associated with age, lower education and being a current smoker. TB awareness campaigns targeting these population groups may improve care-seeking behavior and reduce community TB transmission.

Social support modifies the association between hazardous drinking and depression symptoms among ART clients in Vietnam

INTRODUCTION

Hazardous drinking is widespread among people with HIV (PWH). PWH are also vulnerable to depression due to HIV-related social stigma, and social support can play an important role in improving mental health for this population. No studies have explored whether social support modifies the association of hazardous drinking and depressive symptoms among PWH.

METHODS

We used baseline data from a randomized controlled trial of two evidence-based alcohol reduction interventions among antiretroviral therapy clients in Vietnam. Hazardous alcohol use was defined as having a score ≥8 for men and ≥ 7 for women on the Alcohol Use Disorders Identification Test. The presence of depression symptoms was defined as a score ≥ 5 on the Patient Health Questionnaire-9. Social support was measured with a 5-question modified version of the Medical Outcomes Study Social Support Instrument. Crude (CPRs) and adjusted prevalence ratios (aPRs) of the association were presented.

RESULTS

Hazardous drinking was significantly associated with increased likelihood of having depressive symptoms (aPR = 1.26;95%CI 1.04-1.52). Hazardous drinking and depression symptoms were not associated among those with high social support (aPR = 1.01;95%CI 0.76-1.35), but were associated among those with medium (aPR = 1.24;95%CI 0.92-1.69) and low social support (aPR = 1.71;95%CI 1.25-2.34).

CONCLUSIONS

Social support significantly modified the association between hazardous drinking and depression symptoms among ART clients in Vietnam. Interventions to decrease hazardous alcohol use are broadly indicated for PWH in Vietnam and other low-resource settings, but special attention or modifications may be needed to support mental health among those with lower levels of social support.

Risk factors for catastrophic costs associated with tuberculosis in rural South Africa

<sec> <title>SETTING</title> Fifty-five public clinics in northern South Africa. </sec> <sec> <title>OBJECTIVE</title> To estimate patient costs and identify the factors associated with catastrophic costs among individuals treated for tuberculosis (TB). </sec> <sec> <title>DESIGN</title> We performed cross-sectional interviews of consecutive patients at public clinics from October 2017 to January 2018. 'Catastrophic costs' were defined as costs totalling ≥20% of annual household income. For participants with no reported income, we considered scenarios where costs were considered non-catastrophic if 1) costs totalled <US$7.70 (ZAR100) or 2) a multidimensional poverty index was above a certain threshold. </sec> <sec> <title>RESULTS</title> Among 327 participants, the estimated mean TB episode costs were US$365 (95%CI 233-498): out-of-pocket costs comprised 58% of costs, wages lost due to health care-seeking represented 26%, and income reduction accounted for 16% of costs. Ninety (28%) participants experienced catastrophic costs, which were associated with clinic travel times of 60-90 min (adjusted prevalence ratio [aPR] 1.7, 95%CI 0.9-3.1), unemployment (aPR 2.0, 95%CI 1.0-4.0) and having fewer household members (aPR 0.6, 95%CI 0.3-1.0). </sec> <sec> <title>CONCLUSIONS</title> In rural South Africa, catastrophic costs from TB are common and associated with distance to clinics, unemployment, and household size. These findings can help tailor social protection programs and enhance service delivery to patients at greatest risk of experiencing financial hardship. </sec>.

Symptom and digital chest X-ray TB screening in South African prisons: yield and cost-effectiveness

BACKGROUND: Correctional inmates are at a high risk of tuberculosis (TB). The optimal approach to screening this population is unclear.METHODS: We retrospectively reviewed records from TB screening in 64 correctional facilities in South Africa between January 2015 and July 2016. Inmates received symptom screening (any of cough, fever, weight loss, or night sweats) combined with digital chest X-ray (CXR), when available. CXRs were assessed as 'abnormal' or with no abnormalities. Inmates with either a symptom or an 'abnormal' CXR were asked to provide a single spot sputum for Xpert^® MTB/RIF testing. We estimated the incremental cost-effectiveness ratio (ICER) per additional TB case detected using CXR screening among asymptomatic inmates.RESULTS: Of 61 580 inmates, CXR screening was available for 41 852. Of these, 19 711 (47.1%) had TB symptoms. Among 22 141 inmates without symptoms, 1939/19 783 (9.8%) had an abnormal CXR, and 8 (1.2%) were Xpert-positive among those with Xpert tests done. Of 14 942 who received symptom screening only and had symptoms, 84% (12 616) had an Xpert result, and 105 (0.8%) were positive. The ICER for CXR screening was US$22 278.CONCLUSION: Having CXR in addition to symptom screening increased yield but added considerable cost. A major limitation of screening was the low specificity of the symptom screen.

Tuberculosis patients with higher levels of poverty face equal or greater costs of illness

SETTING: Fifty-six public clinics in Limpopo Province, South Africa.OBJECTIVE: To evaluate the association between tuberculosis (TB) patient costs and poverty as measured by a multidimensional poverty index.DESIGN: We performed cross-sectional interviews of consecutive patients with TB. TB episode costs were estimated from self-reported income, travel costs, and care-seeking time. Poverty was assessed using the South African Multidimensional Poverty Index (SAMPI) deprivation score (a 12-item household-level index), with higher scores indicating greater poverty. We used multivariable linear regression to adjust for age, sex, human immunodeficiency virus status and travel time.RESULTS: Among 323 participants, 108 (33%) were 'deprived' (deprivation score >0.33). For each 0.1-unit increase in deprivation score, absolute TB episode costs were 1.11 times greater (95%CI 0.97-1.26). TB episode costs were 1.19 times greater with each quintile of higher deprivation score (95%CI 1.00-1.40), but lower by a factor of 0.54 with each quintile of lower self-reported income (higher poverty, 95%CI 0.46-0.62).CONCLUSION: Individuals experiencing multidimensional poverty and the cost of tuberculosis illness in Limpopo, South Africa faced equal or higher costs of TB than non-impoverished patients. Individuals with lower self-reported income experienced higher costs as a proportion of household income but lower absolute costs. Targeted interventions are needed to reduce the economic burden of TB on patients with multidimensional poverty.

'Something so hard': a mixed-methods study of home sputum collection for tuberculosis contact investigation in Uganda

BACKGROUND

Home sputum collection could facilitate prompt evaluation and diagnosis of tuberculosis (TB) among contacts of patients with active TB. We analyzed barriers to home-based collection as part of an enhanced intervention for household TB contact investigation in Kampala, Uganda.

DESIGN

We conducted a convergent mixed-methods study to describe the outcomes of home sputum collection in 91 contacts and examine their context through 19 nested contact interviews and two focus group discussions with lay health workers (LHWs).

RESULTS

LHWs collected sputum from 35 (39%) contacts. Contacts reporting cough were more likely to provide sputum than those with other symptoms or risk factors (53% vs. 15%, RR 3.6, 95%CI 1.5-2.8, P < 0.001). Males were more likely than females to provide sputum (54% vs. 32%, RR 1.7, 95%CI 1.0-2.8, P = 0.05). Contacts said support from the index patient and the convenience of the home visit facilitated collection. Missing containers and difficulty producing sputum spontaneously impeded collection. Women identified stigma as a barrier. LHWs emphasized difficulty in procuring sputum and discomfort pressing contacts to produce sputum.

CONCLUSIONS

Home sputum collection by LHWs entails different challenges from sputum collection in clinical settings. More research is needed to develop interventions to mitigate stigma and increase success of home-based collection.

Patterns of usage and preferences of users for tuberculosis-related text messages and voice calls in Uganda

BACKGROUND

Little information exists about mobile phone usage or preferences for tuberculosis (TB) related health communications in Uganda.

METHODS

We surveyed household contacts of TB patients in urban Kampala, Uganda, and clinic patients in rural central Uganda. Questions addressed mobile phone access, usage, and preferences for TB-related communications. We collected qualitative data about messaging preferences.

RESULTS

We enrolled 145 contacts and 203 clinic attendees. Most contacts (58%) and clinic attendees (75%) owned a mobile phone, while 42% of contacts and 10% of clinic attendees shared one; 94% of contacts and clinic attendees knew how to receive a short messaging service (SMS) message, but only 59% of contacts aged 45 years (vs. 96% of contacts aged <45 years, P = 0.0001) did so. All contacts and 99% of clinic attendees were willing and capable of receiving personal-health communications by SMS. Among contacts, 55% preferred detailed messages disclosing test results, while 45% preferred simple messages requesting a clinic visit to disclose results.

CONCLUSIONS

Most urban household TB contacts and rural clinic attendees reported having access to a mobile phone and willingness to receive TB-related personal-health communications by voice call or SMS. However, frequent phone sharing and variable messaging abilities and preferences suggest a need to tailor the design and monitoring of mHealth interventions to target recipients.

Modelling the impact of social protection on tuberculosis: the S-PROTECT project

Background

Tackling the social determinants of Tuberculosis (TB) through social protection is a key element of the post-2015 End TB Strategy. However, evidence informing policies are still scarce. Mathematical modelling has the potential to contribute to fill this knowledge gap, but existing models are inadequate. The S-PROTECT consortium aimed to develop an innovative mathematical modelling approach to better understand the role of social protection to improve TB care, prevention and control.

Methods

S-PROTECT used a three-steps approach: 1) the development of a conceptual framework; 2) the extraction from this framework of three high-priority mechanistic pathways amenable for modelling; 3) the development of a revised version of a standard TB transmission model able to capture the structure of these pathways. As a test case we used the Bolsa Familia Programme (BFP), the Brazilian conditional cash transfer scheme.

Results

Assessing one of these pathways, we estimated that BFP can reduce TB prevalence by 4% by improving households income and thus their nutritional status. When looking at the direct impact via malnutrition (not income mediated) the impact was 33%. This variation was due to limited data availability, uncertainties on data transformation and the pathway approach taken. These results are preliminary and only aim to serve as illustrative example of the methodological challenges encountered in this first modelling attempt, nonetheless they suggest the potential added value of integrating TB standard of care with social protection strategies.

Conclusions

Results are to be confirmed with further analysis. However, by developing a generalizable modelling framework, S-PROTECT proved that the modelling of social protection is complex, but doable and allowed to draw the research road map for the future in this field.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5539-x) contains supplementary material, which is available to authorized users.

Incorporating social justice and stigma in cost-effectiveness analysis: drug-resistant tuberculosis treatment

Novel therapies for multidrug-resistant tuberculosis (MDR-TB) are likely to be expensive. The cost of novel drugs (e.g., bedaquiline, delamanid) may be so prohibitively high that a traditional cost-effectiveness analysis (CEA) would rate regimens containing these drugs as not cost-effective. Traditional CEA may not appropriately account for considerations of social justice, and may put the most disadvantaged populations at greater risk. Using the example of novel drug regimens for MDR-TB, we propose a novel methodology, 'justice-enhanced CEA', and demonstrate how such an approach can simultaneously assess social justice impacts alongside traditional cost-effectiveness ratios. Justice-enhanced CEA, as we envision it, is performed in three steps: 1) systematic data collection about patients' lived experiences, 2) use of empirical findings to inform social justice assessments, and 3) incorporation of data-informed social justice assessments into a decision analytic framework that includes traditional CEA. These components are organized around a core framework of social justice developed by Bailey et al. to compare impacts on disadvantage not otherwise captured by CEA. Formal social justice assessments can produce three composite levels: 'expected not to worsen…', 'may worsen…', and 'expected to worsen clustering of disadvantage'. Levels of social justice impact would be assessed for each major type of outcome under each policy scenario compared. Social justice assessments are then overlaid side-by-side with cost-effectiveness assessments corresponding to each branch pathway on the decision tree. In conclusion, we present a 'justice-enhanced' framework that enables the incorporation of social justice concerns into traditional CEA for the evaluation of new regimens for MDR-TB.

Higher cost of implementing Xpert(®) MTB/RIF in Ugandan peripheral settings: implications for cost-effectiveness

SETTING

Initial cost-effectiveness evaluations of Xpert(®) MTB/RIF for tuberculosis (TB) diagnosis have not fully accounted for the realities of implementation in peripheral settings.

OBJECTIVE

To evaluate costs and diagnostic outcomes of Xpert testing implemented at various health care levels in Uganda.

DESIGN

We collected empirical cost data from five health centers utilizing Xpert for TB diagnosis, using an ingredients approach. We reviewed laboratory and patient records to assess outcomes at these sites and10 sites without Xpert. We also estimated incremental cost-effectiveness of Xpert testing; our primary outcome was the incremental cost of Xpert testing per newly detected TB case.

RESULTS

The mean unit cost of an Xpert test was US$21 based on a mean monthly volume of 54 tests per site, although unit cost varied widely (US$16-58) and was primarily determined by testing volume. Total diagnostic costs were 2.4-fold higher in Xpert clinics than in non-Xpert clinics; however, Xpert only increased diagnoses by 12%. The diagnostic costs of Xpert averaged US$119 per newly detected TB case, but were as high as US$885 at the center with the lowest volume of tests.

CONCLUSION

Xpert testing can detect TB cases at reasonable cost, but may double diagnostic budgets for relatively small gains, with cost-effectiveness deteriorating with lower testing volumes.

Cost-effectiveness of Xpert® MTB/RIF for diagnosing pulmonary tuberculosis in the United States

SETTING

Conventional approaches to tuberculosis (TB) diagnosis and resistance testing are slow. The Xpert® MTB/RIF assay is an emerging molecular diagnostic assay for rapid TB diagnosis, offering results within 2 hours. However, the cost-effectiveness of implementing Xpert in settings with low TB prevalence, such as the United States, is unknown.

OBJECTIVE

We evaluated the cost-effectiveness of incorporating Xpert into TB diagnostic algorithms in the United States compared to existing diagnostics.

DESIGN

A decision-analysis model compared current TB diagnostic algorithms in the United States to algorithms incorporating Xpert. Primary outcomes were the costs and quality-adjusted life years (QALYs) accrued with each strategy; cost-effectiveness was represented using incremental cost-effectiveness ratios (ICER).

RESULTS

Xpert testing of a single sputum sample from TB suspects is expected to result in lower total health care costs per patient (US2673) compared to diagnostic algorithms using only sputum microscopy and culture (US2728) and improved health outcomes (6.32 QALYs gained per 1000 TB suspects). Compared to existing molecular assays, implementation of Xpert in the United States would be considered highly cost-effective (ICER US39992 per QALY gained).

CONCLUSION

TB diagnostic algorithms incorporating Xpert in the United States are highly cost-effective.

Potent urea and carbamate inhibitors of soluble epoxide hydrolases

The soluble epoxide hydrolase (sEH) plays a significant role in the biosynthesis of inflammation mediators as well as xenobiotic transformations. Herein, we report the discovery of substituted ureas and carbamates as potent inhibitors of sEH. Some of these selective, competitive tight-binding inhibitors with nanomolar K(i) values interacted stoichiometrically with the homogenous recombinant murine and human sEHs. These inhibitors enhance cytotoxicity of trans-stilbene oxide, which is active as the epoxide, but reduce cytotoxicity of leukotoxin, which is activated by epoxide hydrolase to its toxic diol. They also reduce toxicity of leukotoxin in vivo in mice and prevent symptoms suggestive of acute respiratory distress syndrome. These potent inhibitors may be valuable tools for testing hypotheses of involvement of diol and epoxide lipids in chemical mediation in vitro or in vivo systems.

The structural distribution of cooperative interactions in proteins: analysis of the native state ensemble

Cooperative interactions link the behavior of different amino acid residues within a protein molecule. As a result, the effects of chemical or physical perturbations to any given residue are propagated to other residues by an intricate network of interactions. Very often, amino acids "sense" the effects of perturbations occurring at very distant locations in the protein molecule. In these studies, we have investigated by computer simulation the structural distribution of those interactions. We show here that cooperative interactions are not intrinsically bi-directional and that different residues play different roles within the intricate network of interactions existing in a protein. The effect of a perturbation to residue j on residue k is not necessarily equal to the effect of the same perturbation to residue k on residue j. In this paper, we introduce a computer algorithm aimed at mapping the network of cooperative interactions within a protein. This algorithm exhaustively performs single site thermodynamic mutations to each residue in the protein and examines the effects of those mutations on the distribution of conformational states. The algorithm has been applied to three different proteins (lambda repressor fragment 6-85, chymotrypsin inhibitor 2, and barnase). This algorithm accounts well for the observed behavior of these proteins.