Genetic and nongenetic drivers of platelet reactivity in healthy Tanzanian individuals

BACKGROUND

Platelets play a key role in hemostasis, inflammation, and cardiovascular diseases. Platelet reactivity is highly variable between individuals. The drivers of this variability in populations from Sub-Saharan Africa remain largely unknown.

OBJECTIVES

We aimed to investigate the nongenetic and genetic determinants of platelet reactivity in healthy adults living in a rapidly urbanizing area in Northern Tanzania.

METHODS

Platelet activation and reactivity were measured by platelet P-selectin expression and the binding of fibrinogen in unstimulated blood and after ex vivo stimulation with adenosine diphosphate and PAR-1 and PAR-4 ligands. We then analyzed the associations of platelet parameters with host genetic and nongenetic factors, environmental factors, plasma inflammatory markers, and plasma metabolites.

RESULTS

Only a few associations were found between platelet reactivity parameters and plasma inflammatory markers and nongenetic host and environmental factors. In contrast, untargeted plasma metabolomics revealed a large number of associations with food-derived metabolites, including phytochemicals that were previously reported to inhibit platelet reactivity. Genome-wide single-nucleotide polymorphism genotyping identified 2 novel single-nucleotide polymorphisms (rs903650 and rs4789332) that were associated with platelet reactivity at the genome-wide level (P < 5 × 10-8) as well as a number of variants in the PAR4 gene (F2RL3) that were associated with PAR4-induced reactivity.

CONCLUSION

Our study uncovered factors that determine variation in platelet reactivity in a population in East Africa that is rapidly transitioning to an urban lifestyle, including the importance of genetic ancestry and the gradual abandoning of the traditional East African diet.

Chronic purulent pericarditis: case report

Purulent pericarditis is an infection of the pericardial space that produces pus that is found on gross examination of the pericardial sac or on the tissue microscopy. In this case report, we will discuss a 31-year-old male who presented with a chief complaint of low-grade fevers, dry cough and difficulty breathing for about two weeks which preceded after removing of dental also two weeks prior. He was admitted and treated as COVID-19 in the isolation ward, he later developed cardiac tamponade and during pericardiocentesis thick pus was discharged. Pus culture and Gene Xpert tests were all negative. After his condition improved, the patient was transferred to the general ward with the pericardial window still discharging pus. Pericardiectomy was chosen as definitive management. The key takeaway in this report is that Empirical treatment with RHZE (rifampin, isoniazid, pyrazinamide, and ethambutol) in resource-limited settings is recommended due to difficulty in identifying the exact cause at a required moment.

Performance Assessment of the Universal Vital Assessment Score vs Other Illness Severity Scores for Predicting Risk of In-Hospital Death Among Adult Febrile Inpatients in Northern Tanzania, 2016-2019

IMPORTANCE

Severity scores are used to improve triage of hospitalized patients in high-income settings, but the scores may not translate well to low- and middle-income settings such as sub-Saharan Africa.

OBJECTIVE

To assess the performance of the Universal Vital Assessment (UVA) score, derived in 2017, compared with other illness severity scores for predicting in-hospital mortality among adults with febrile illness in northern Tanzania.

DESIGN, SETTING, AND PARTICIPANTS

This prognostic study used clinical data collected for the duration of hospitalization among patients with febrile illness admitted to Kilimanjaro Christian Medical Centre or Mawenzi Regional Referral Hospital in Moshi, Tanzania, from September 2016 through May 2019. All adult and pediatric patients with a history of fever within 72 hours or a tympanic temperature of 38.0 °C or higher at screening were eligible for enrollment. Of 3761 eligible participants, 1132 (30.1%) were enrolled in the parent study; of those, 597 adults 18 years or older were included in this analysis. Data were analyzed from December 2019 to September 2021.

EXPOSURES

Modified Early Warning Score (MEWS), National Early Warning Score (NEWS), quick Sequential Organ Failure Assessment (qSOFA), Systemic Inflammatory Response Syndrome (SIRS) assessment, and UVA.

MAIN OUTCOMES AND MEASURES

The main outcome was in-hospital mortality during the same hospitalization as the participant's enrollment. Crude risk ratios and 95% CIs for in-hospital death were calculated using log-binomial risk regression for proposed score cutoffs for each of the illness severity scores. The area under the receiver operating characteristic curve (AUROC) for estimating the risk of in-hospital death was calculated for each score.

RESULTS

Among 597 participants, the median age was 43 years (IQR, 31-56 years); 300 participants (50.3%) were female, 198 (33.2%) were HIV-infected, and in-hospital death occurred in 55 (9.2%). By higher risk score strata for each score, compared with lower risk strata, risk ratios for in-hospital death were 3.7 (95% CI, 2.2-6.2) for a MEWS of 5 or higher; 2.7 (95% CI, 0.9-7.8) for a NEWS of 5 or 6; 9.6 (95% CI, 4.2-22.2) for a NEWS of 7 or higher; 4.8 (95% CI, 1.2-20.2) for a qSOFA score of 1; 15.4 (95% CI, 3.8-63.1) for a qSOFA score of 2 or higher; 2.5 (95% CI, 1.2-5.2) for a SIRS score of 2 or higher; 9.1 (95% CI, 2.7-30.3) for a UVA score of 2 to 4; and 30.6 (95% CI, 9.6-97.8) for a UVA score of 5 or higher. The AUROCs, using all ordinal values, were 0.85 (95% CI, 0.80-0.90) for the UVA score, 0.81 (95% CI, 0.75-0.87) for the NEWS, 0.75 (95% CI, 0.69-0.82) for the MEWS, 0.73 (95% CI, 0.67-0.79) for the qSOFA score, and 0.63 (95% CI, 0.56-0.71) for the SIRS score. The AUROC for the UVA score was significantly greater than that for all other scores (P < .05 for all comparisons) except for NEWS (P = .08).

CONCLUSIONS AND RELEVANCE

This prognostic study found that the NEWS and the UVA score performed favorably compared with other illness severity scores in predicting in-hospital mortality among a hospitalized cohort of adults with febrile illness in northern Tanzania. Given its reliance on readily available clinical data, the UVA score may have utility in the triage and prognostication of patients admitted to the hospital with febrile illness in low- to middle-income settings such as sub-Saharan Africa.

Gut microbiome-mediated metabolism effects on immunity in rural and urban African populations

The human gut microbiota is increasingly recognized as an important factor in modulating innate and adaptive immunity through release of ligands and metabolites that translocate into circulation. Urbanizing African populations harbor large intestinal diversity due to a range of lifestyles, providing the necessary variation to gauge immunomodulatory factors. Here, we uncover a gradient of intestinal microbial compositions from rural through urban Tanzanian, towards European samples, manifested both in relative abundance and genomic variation observed in stool metagenomics. The rural population shows increased Bacteroidetes, led by Prevotella copri, but also presence of fungi. Measured ex vivo cytokine responses were significantly associated with 34 immunomodulatory microbes, which have a larger impact on circulating metabolites than non-significant microbes. Pathway effects on cytokines, notably TNF-α and IFN-γ, differential metabolome analysis and enzyme copy number enrichment converge on histidine and arginine metabolism as potential immunomodulatory pathways mediated by Bifidobacterium longum and Akkermansia muciniphila.

The authors profile stool metagenomics and plasma metabolomics in Tanzanian individuals and uncover a gradient of gut microbial profiles, from rural through urban Tanzania towards Western populations. Integration with ex vivo blood microbial stimulations reveals immune responses associated with histidine and arginine pathways, mediated by Bifidobacterium longum and Akkermansia muciniphila.

Barriers to implementing antimicrobial stewardship programs in three low- and middle-income country tertiary care settings: findings from a multi-site qualitative study

BACKGROUND

Antimicrobial resistance has been named as one of the top ten threats to public health in the world. Hospital-based antimicrobial stewardship programs (ASPs) can help reduce antimicrobial resistance. The purpose of this study was to determine perceived barriers to the development and implementation of ASPs in tertiary care centers in three low- and middle-income countries (LMICs).

METHODS

Interviews were conducted with 45 physicians at tertiary care hospitals in Sri Lanka (n = 22), Kenya (12), and Tanzania (11). Interviews assessed knowledge of antimicrobial resistance and ASPs, current antimicrobial prescribing practices, access to diagnostics that inform antimicrobial use, receptiveness to ASPs, and perceived barriers to implementing ASPs. Two independent reviewers coded the interviews using principles of applied thematic analysis, and comparisons of themes were made across the three sites.

RESULTS

Barriers to improving antimicrobial prescribing included prohibitively expensive antimicrobials, limited antimicrobial availability, resistance to changing current practices regarding antimicrobial prescribing, and limited diagnostic capabilities. The most frequent of these barriers in all three locations was limited drug availability. Many physicians in all three sites had not heard of ASPs before the interviews. Improved education was a suggested component of ASPs at all three sites. The creation of guidelines was also recommended, without prompting, by interviewees at all three sites. Although most participants felt microbiological results were helpful in tailoring antibiotic courses, some expressed distrust of laboratory culture results. Biomarkers like erythrocyte sedimentation rate and c-reactive protein were not felt to be specific enough to guide antimicrobial therapy. Despite limited or no prior knowledge of ASPs, most interviewees were receptive to implementing protocols that would include documentation and consultation with ASPs regarding antimicrobial prescribing.

CONCLUSIONS

Our study highlighted several important barriers to implementing ASPs that were shared between three tertiary care centers in LMICs. Improving drug availability, enhancing availability of and trust in microbiologic data, creating local guidelines, and providing education to physicians regarding antimicrobial prescribing are important steps that could be taken by ASPs in these facilities.

166. Barriers to implementing antimicrobial stewardship programs in low- or middle-income country settings: findings from a multi-site qualitative study

Background

Antimicrobial resistance has been named as one of the top ten threats to health in the world. The World Health Organization has endorsed the implementation of hosptial-based antimicrobial stewardship programs (ASPs) to reduce antimicrobial resistance. We conducted a qualitative study to determine perceived barriers to the development and implementation of ASPs in low- and middle-income countries (LMICs).

Methods

We conducted 46 interviews with medical doctors at tertiary care hospitals in Sri Lanka (22 doctors), Kenya (12), and Tanzania (12). Interviews assessed knowledge and receptiveness to ASPs and barriers to implementing ASP protocols. Interviews were conducted in English, audio recorded, and transcribed. The interviews discussed knowledge of antimicrobial resistance and ASPs, current antimicrobial prescribing practices, access to diagnostics, receptiveness to ASPs, and perceived barriers to implementing ASPs. Data analysis followed procedures of applied thematic analysis, and used NVivo software. A codebook included structural themes based on the interview questions and emerging inductive themes. Two independent reviewers coded the interviews, and the coding was combined and reviewed for consensus. Themes were synthesized, with comparisons made across the three sites.

Results

Medical doctors from all three sites discussed multiple barriers to improving antimicrobial prescribing: prohibitively expensive antimicrobials, limited antimicrobial availability, resistance to change current practices regarding antimicrobial prescribing, and limited diagnostic data. The most frequent of these barriers discussed in all three locations was limited drug availability, mentioned by 12/22 physicians in Sri Lanka, 5/12 in Tanzania and 8/12 in Kenya. Improved education was a suggested component of ASPs in all three sites: 7/22 in Sri Lanka, 6/12 in Tanzania, and 6/12 in Kenya.

Conclusion

The study highlighted several important issues in determining the next steps for the implementation of ASPs in these LMIC hospitals. Improving drug availability and improving education to change physicians’ antimicrobial prescribing practices are important targets that could be addressed by ASPs in these facilities.

Disclosures

All Authors: No reported disclosures

158. A multi-site, prospective study of antimicrobial prescribing practices in three low- or middle-income country hospitals

Background

Antimicrobial stewardship programs (ASPs) are being developed internationally to mitigate the misuse of antimicrobials. An understanding of current practices and prescribing patterns is necessary to determine targets to develop context-specific ASPs in low- and middle-income country (LMIC) hospitals.

Methods

We conducted a prospective study of patients admitted to the adult medical wards at three LMIC tertiary care centers in 2018- 2019: a 1,800-bed public hospital in Galle, Sri Lanka; a 991-bed public hospital in Eldoret, Kenya; and a 630-bed private hospital in Moshi, Tanzania. Information regarding antimicrobial therapy received during hospitalization, indications for antimicrobial therapy, and duration of antimicrobial use were extracted from the medical record.

Results

In total, 3150 patients were enrolled: 1297 in Sri Lanka, 750 in Kenya, and 1103 in Tanzania. Antimicrobial use prevalence varied between the three sites, with 56.0% of patients receiving antimicrobials during hospitalization in Sri Lanka, 56.5% in Kenya, and 35.4% in Tanzania. Third-generation cephalosporins were used most frequently in Kenya (70.0%) and Tanzania (73.1%), whereas amoxicillin/ clavulanic acid was used most frequently in Sri Lanka (48.4%). Lower respiratory tract infection was the most common indication for antimicrobial use in all three locations: 37.4% in Sri Lanka, 27.8% in Kenya, and 49.2% in Tanzania. No clear indication for antimicrobial use was documented among 11.6% patients receiving antimicrobials in Sri Lanka, 32.8% in Kenya, and 10.5% in Tanzania. In Tanzania, 8.6% of the patients had documentation of input from the microbiology or infectious diseases teams compared to less than 1% in either Sri Lanka or Kenya. Pertinent culture data related to the primary indication for antimicrobials was present in 16.1% (Sri Lanka), 6.1% (Kenya), and 7.4% (Tanzania).

Conclusion

Unclear documentation for antimicrobial use was common in all three sites and most patients on antimicrobial therapy did not have pertinent culture data. Improving documentation and the capacity of the local microbiology laboratories could be initial targets for ASPs in these LMIC hospitals.

Disclosures

All Authors: No reported disclosures

Returning of antiretroviral medication dispensed over a period of 8 months suggests non-adherence despite full adherence according to real time medication monitoring

Real-time medication monitoring (RTMM) may potentially enhance adherence to antiretroviral treatment (ART). We describe a participant in an ongoing trial who, shortly after completing trial participation, died of cryptococcal meningitis despite high levels of adherence according to self-report, pill-counts and RTMM (> 99%). However, she evidenced consistently high HIV viral load throughout the 48-week study follow-up. Subsequently, her relatives unsolicitedly returned eight months’ dispensed ART medication that she was supposed to have taken. This brief report illustrates the challenges of adherence measurements including RTMM, and reinforces the need to combine adherence assessments with viral load monitoring in HIV care.

Technical and Psychosocial Challenges of mHealth Usage for Antiretroviral Therapy Adherence Among People Living With HIV in a Resource-Limited Setting: Case Series

Background

Mobile communication has been found to improve antiretroviral therapy (ART) adherence among people living with HIV. In an ongoing randomized clinical trial, 2 mobile communication strategies (ie, sending SMS text messages and real-time medication monitoring [RTMM]) were used to improve adherence to ART among people living with HIV in Tanzania. We noticed remarkable discrepancies between self-reported adherence and adherence recorded by SMS text messaging or RTMM among some of the first trial participants.

Objective

Our objective was to describe these cases and the observed discrepancies in more detail, to serve as a useful illustration of some of the challenges in using mobile health in resource-limited settings.

Methods

In an ongoing randomized trial, adults living with HIV from two HIV treatment centers in Tanzania who were suspected of low levels of adherence were randomly assigned in a 1:1:1 ratio to receive (1) SMS text message reminders, (2) an RTMM device, or (3) no additional intervention to standard HIV care. During bimonthly study visits, the participants self-reported their level of adherence, received feedback about their level of adherence based on SMS text messaging or RTMM, and discussed strategies to overcome adherence problems with nurses providing HIV care. For the purpose of this report, we selected people living with HIV who had completed 5 follow-up visits and consistently reported more than 95% adherence, while SMS text messaging or RTMM recorded lower than 75% adherence. The participants were invited for a short, face-to-face in-depth interview to explore reasons for this discrepancy.

Results

At the time of this analysis, 26 participants had completed follow-up. Six of these evidenced the above-mentioned discrepancies, with an average adherence of 46% based on SMS text messaging or RTMM, while self-reported adherence was 98%. Five of these 6 participants insisted that their adherence to ART was good, with 4 reporting that their adherence to properly using the monitoring device was low. Three participants mentioned concerns about involuntary disclosure of HIV status as a main reason for low adherence to using the device. Two participants were still depending on other reminder cues despite receiving SMS text message or RTMM reminders. Poor network coverage caused low adherence in 1 participant.

Conclusions

Psychosocial barriers were reported as importantly contributing to low adherence, both with respect to use of ART and proper use of the adherence-monitoring device. This case series illustrates that when introducing new digital adherence monitoring technology, researchers should consider psychosocial barriers and distinguish between adherence to device use and adherence to treatment.

Trial Registration

Pan African Clinical Trials Registry PACTR201712002844286; https://tinyurl.com/y98q4p3l

2029. Prevalence of Antibiotic Use and Administration among Hospitalized Adult Patients at a Tertiary Care Hospital in Kilimanjaro, Tanzania

Background

Antimicrobial stewardship programs (ASPs) have been shown to improve the appropriate use of antimicrobials, especially in high-income countries. However, ASPs are relatively less well implemented in low-or-middle income countries. To improve the effectiveness of ASPs in these settings, it is important to determine the core actions and targets for improving antimicrobial use. We sought to describe the prevalence and patterns of antibiotic use at a tertiary care hospital in Tanzania.

Methods

Consecutive patients admitted to an adult medical ward at a tertiary care hospital, Kilimanjaro Christian Medical Centre, in Moshi, Tanzania were enrolled from June 2018 to March 2019. The medical record was reviewed for data regarding the type of antibiotics prescribed, indications for use, and microbiologic testing ordered.

Results

A total of 1103 patients were enrolled during the study period. The majority of patients were males (663, 60.1%), with the median age being 54 years (IQR 39–70). About one-third (390, 35.4%) of the admitted patients received antimicrobials during hospitalization, with pneumonia being the leading indication for antimicrobial use (158, 40.5%). The most commonly used antibiotics included ceftriaxone in 285 (73.1%), metronidazole in 155 (39.7%), and amoxicillin/ ampicillin in 46 (11.8%) patients. The median duration of antimicrobial use was 5 days (IQR 3–7). Few patients on antimicrobials (27, 6.9%) had culture results, of which half (15, 55.6%) were positive for an organism and a minority (8, 29.6%) were susceptible to the antibiotics being used. Overall, mortality in the cohort was 22.7% and the median duration of hospitalization was 5 days (IQR 3–8).

Conclusion

Antibiotics were used in a substantial proportion of admitted patients. However, in most cases, treatment was empirical with limited use of culture results. Future ASP efforts can target the improved use of microbiologic cultures to target antimicrobial use.

Disclosures

All authors: No reported disclosures.