Early surgery determines prognosis in patients with infective endocarditis: outcome in patients managed by an Endocarditis Team-a prospective cohort study.

Background: Infective endocarditis (IE) in South Africa is associated with significant morbidity and mortality, despite occurring in younger patients with fewer co-morbidities. Possible contributors include the high rates of blood culture negative endocarditis, high rates of mechanical valve replacement and the lack of inter-disciplinary coordination during management. Methods: The Tygerberg Endocarditis Cohort (TEC) study prospectively enrolled patients with IE between November 2019 and April 2021. All patients were managed by an Endocarditis Team with a set protocol for organism detection and a strategy of early surgery limiting the use of prosthetic material. Results: Seventy-two consecutive patients with IE were included, with a causative organism identified in 86.1% of patients. The majority of patients had a guideline indication for surgery (n=58; 80.6%). The in-hospital mortality rate was 18%, with a 6-month mortality rate of 25.7%. Surgery was performed in 42 patients (58.3%), with prosthetic valve (PVE) replacement in 32 (76.2%), conventional repair surgery in 8 (19.1%) and mitral valve reconstruction in 2 (4.8%) of patients. Patients who underwent surgery had a significantly lower in-hospital (4.8% vs. 56.3%; P<0.01) and 6-month (4.9% vs. 75.0%; P<0.01) mortality rate as compared with patients with an indication for surgery who did not undergo surgery. Conclusions: We have observed a reduction in the 6-month mortality rate in patients with IE following the establishment of an Endocarditis Team, adhering to a set protocol for organism detection and favouring early repair or reconstruction surgery. Patients who underwent surgery had a significantly lower mortality rate than patients with an indication for surgery who did not undergo surgery. Preventable residual mortality was driven by surgical delay.

Clinical features and outcomes of COVID-19 admissions in a population with a high prevalence of HIV and tuberculosis: a multicentre cohort study.

BACKGROUND: There is still a paucity of evidence on the outcomes of coronavirus disease 2019 (COVID-19) among people living with human immunodeficiency virus (PWH) and those co-infected with tuberculosis (TB), particularly in areas where these conditions are common. We describe the clinical features, laboratory findings and outcome of hospitalised PWH and human immunodeficiency virus (HIV)-uninfected COVID-19 patients as well as those co-infected with tuberculosis (TB). METHODS: We conducted a multicentre cohort study across three hospitals in Cape Town, South Africa. All adults requiring hospitalisation with confirmed COVID-19 pneumonia from March to July 2020 were analysed. RESULTS: PWH comprised 270 (19%) of 1434 admissions. There were 47 patients with active tuberculosis (3.3%), of whom 29 (62%) were PWH. Three-hundred and seventy-three patients (26%) died. The mortality in PWH (n = 71, 26%) and HIV-uninfected patients (n = 296, 25%) was comparable. In patients with TB, PWH had a higher mortality than HIV-uninfected patients (n = 11, 38% vs n = 3, 20%; p = 0.001). In multivariable survival analysis a higher risk of death was associated with older age (Adjusted Hazard Ratio (AHR) 1.03 95%CI 1.02-1.03, p < 0.001), male sex (AHR1.38 (95%CI 1.12-1.72, p = 0.003) and being "overweight or obese" (AHR 1.30 95%CI 1.03-1.61 p = 0.024). HIV (AHR 1.28 95%CI 0.95-1.72, p 0.11) and active TB (AHR 1.50 95%CI 0.84-2.67, p = 0.17) were not independently associated with increased risk of COVID-19 death. Risk factors for inpatient mortality in PWH included CD4 cell count < 200 cells/mm3, higher admission oxygen requirements, absolute white cell counts, neutrophil/lymphocyte ratios, C-reactive protein, and creatinine levels. CONCLUSION: In a population with high prevalence of HIV and TB, being overweight/obese was associated with increased risk of mortality in COVID-19 hospital admissions, emphasising the need for public health interventions in this patient population.

Pharmacogenetics of the Late-Onset Efavirenz Neurotoxicity Syndrome (LENS).

BACKGROUND: The late-onset efavirenz neurotoxicity syndrome (LENS) presents as ataxia and/or encephalopathy with supratherapeutic efavirenz plasma concentrations (>4 µg/mL). Efavirenz is primarily metabolized by cytochrome P450 2B6 (CYP2B6), with CYP2A6 as an accessory pathway. We hypothesized that participants with LENS would predominantly be CYP2B6 slow metabolizers. The aim of our study was to determine the frequency of CYP2B6 slow metabolizers in participants with LENS. METHODS: Adult HIV-positive participants on efavirenz-based antiretroviral therapy presenting with LENS were prospectively enrolled. Genetic polymorphisms known to be associated with increased efavirenz plasma concentrations in CYP2B6 (rs3745274, rs28399499, rs4803419) and CYP2A6 (rs28399433) were selected and used to determine proportions of slow metabolizers. Pharmacokinetic analyses were performed using liquid chromatography-tandem mass spectrometry. Median (IQR) plasma efavirenz and 8-hydroxyefavirenz were described. RESULTS: Fifteen participants were enrolled. Thirteen (13/15) were Black-African and 13 were female. Median weight was 49.9kg with a median duration on efavirenz of 2.2 years. All 15 participants were successfully genotyped as slow CYP2B6 metabolizers, with 6 participants additionally having CYP2A6 heterozygous genotype. Thirteen were receiving the CYP2A6 enzyme inhibitor isoniazid, and all 15 were genotypic NAT2 slow or intermediate acetylators. Efavirenz plasma concentration was markedly increased at 50.5 (47.0-65.4) µg/mL; 8-hydroxyefavirenz concentration was markedly decreased at 0.10 (0.07-0.15) µg/mL. CONCLUSIONS: Our cohort provides definitive evidence that LENS is associated with the CYP2B6 slow metabolizer genotype, with a median efavirenz plasma concentration >12-fold higher than the defined upper limit of the therapeutic range. Isoniazid and low body weight are important contributors to LENS development.

The diagnostic challenge of pneumocystis pneumonia and COVID-19 co-infection in HIV.

Coronavirus disease 2019 (COVID-19) and pneumocystis pneumonia (PCP) share many overlapping features and may be clinically indistinguishable on initial presentation in people living with HIV. We present the case of co-infection with COVID-19 and PCP in a patient with progressive respiratory failure admitted to our intensive care unit where the dominant disease was uncertain. This case highlights the difficulty in differentiating between the two diseases, especially in a high HIV prevalence setting where PCP is frequently diagnosed using case definitions and clinical experience due to limited access to bronchoscopy, appropriate laboratory testing, and computed tomography scans. In addition, diagnostic testing may yield false-negative results in both diseases, and clinician awareness to the overlap and pitfalls is essential if COVID-19 becomes endemic in such settings.

The utility of high-flow nasal oxygen for severe COVID-19 pneumonia in a resource-constrained setting: A multi-centre prospective observational study.

BACKGROUND: The utility of heated and humidified high-flow nasal oxygen (HFNO) for severe COVID-19-related hypoxaemic respiratory failure (HRF), particularly in settings with limited access to intensive care unit (ICU) resources, remains unclear, and predictors of outcome have been poorly studied. METHODS: We included consecutive patients with COVID-19-related HRF treated with HFNO at two tertiary hospitals in Cape Town, South Africa. The primary outcome was the proportion of patients who were successfully weaned from HFNO, whilst failure comprised intubation or death on HFNO. FINDINGS: The median (IQR) arterial oxygen partial pressure to fraction inspired oxygen ratio (PaO2/FiO2) was 68 (54-92) in 293 enroled patients. Of these, 137/293 (47%) of patients [PaO2/FiO2 76 (63-93)] were successfully weaned from HFNO. The median duration of HFNO was 6 (3-9) in those successfully treated versus 2 (1-5) days in those who failed (p<0.001). A higher ratio of oxygen saturation/FiO2 to respiratory rate within 6 h (ROX-6 score) after HFNO commencement was associated with HFNO success (ROX-6; AHR 0.43, 0.31-0.60), as was use of steroids (AHR 0.35, 95%CI 0.19-0.64). A ROX-6 score of ≥3.7 was 80% predictive of successful weaning whilst ROX-6 ≤ 2.2 was 74% predictive of failure. In total, 139 patents (52%) survived to hospital discharge, whilst mortality amongst HFNO failures with outcomes was 129/140 (92%). INTERPRETATION: In a resource-constrained setting, HFNO for severe COVID-19 HRF is feasible and more almost half of those who receive it can be successfully weaned without the need for mechanical ventilation.

Incidence of stage 3 chronic kidney disease and progression on tenofovir-based regimens.

OBJECTIVE: To describe the incidence of rapid kidney function decline (RKFD), and stage 3 chronic kidney disease (CKD) in HIV-1-infected adults initiated on tenofovir-containing antiretroviral therapy. METHODS: A retrospective cohort study at the infectious diseases clinic of Tygerberg Academic Hospital in Cape Town, South Africa. Patients with more than 3 ml/min per year decline in estimated glomerular filtration were classified as having RKFD, and stage 3 CKD was defined as a value less than 60 ml/min per 1.73 m. We used logistic and Cox proportional hazards regression models to determine factors associated with RKFD and stage 3 CKD. RESULTS: Of 650 patients, 361 (55%) experienced RKFD and 15 (2%) developed stage 3 CKD during a median interquartile range follow-up time of 54 (46.6-98) weeks. For every 10-year increase in age and 10 ml/min lower baseline estimated glomerular filtration, the odds of RKFD increased by 70% [adjusted odds ratio = 1.70, 95% confidence interval (CI) 1.36-2.13] and 57% (adjusted odds ratio = 1.57, 95% CI 1.38-1.80), respectively. Each 10-year older age was associated with a 1.90-fold increased risk of developing stage 3 CKD (adjusted hazard ratio = 1.90, 95% CI: 1.10-3.29). Women had about four-fold greater risk of stage 3 CKD compared with men (adjusted hazard ratio = 3.96, 95% CI: 1.06-14.74). CONCLUSION: About half of our study population developed RKFD but only 2% progressed to stage 3 CKD. Approaches that provide balanced allocation of limited resources toward screening and monitoring for kidney dysfunction and HIV disease management are critically needed in this setting.

Validation of a severity-of-illness score in patients with tuberculosis requiring intensive care unit admission.

BACKGROUND: There is a paucity of data on the determinants of mortality due to tuberculosis (TB) in the intensive care unit (ICU). OBJECTIVE: To develop a simple severity-of-illness score for use in patients with TB admitted to an ICU. METHODS: A scoring system was generated by retrospectively identifying the four most significant and clinically unrelated predictors of mortality from an existing prospectively collected dataset (January 2012 - May 2013), and combining these with known predictors of poor outcome. RESULTS: Of 83 patients admitted with TB, 38 (45.8%) died in the ICU. The four parameters identified from the retrospective analysis were: (i) HIV co-infection with a CD4cell count <200/µL; (ii) a raised creatinine level: (iii) a chest radiograph showing diffuse parenchymal infiltrates/miliary pattern; and (iv) absence of TB treatment on admission. These were combined with septic shock and a low arterial partial pressure of oxygen/fractional inspired oxygen (P:F) ratio to generate a six-point severity-of-illness score (one point for each parameter). The scores for survivors were significantly lower than those for non-survivors (mean (standard deviation) 2.27 (1.47) v. 3.58 (1.08); p<0.01). A score of ≥2 was associated with significantly higher mortality than a score of <2 (7.1% v. 46.4%; odds ratio (OR) 15.03; 95% confidence interval (CI) 1.86 - 121.32; p<0.01), whereas a score of ≥3 was associated with a significantly higher mortality than a score of <3 (64.6% v. 20.0%; OR 7.29; 95% CI 2.64 - 20.18; p<0.01). CONCLUSION: The proposed scoring system identified patients at increased risk of dying from TB in the ICU. Further prospective studies are indicated to validate its use.

Sub-optimal CD4 T-lymphocyte responses among HIV infected patients who develop TB during the first year of ART.

STUDY BACKGROUND: Poor CD4 T-lymphocyte responses to anti-retroviral treatment (ART) are associated with increased HIV disease progression and mortality. In sub-Saharan Africa a substantial proportion of HIV infected patients are co-infected with TB. This study evaluated the effect of active TB presenting after ART initiation on immunological responses to ART. METHODS: A retrospective cohort study was conducted of patients initiated on ART in a South African academic hospital between 1 January 2004 and 15 May 2008. Changes in CD4 T-lymphocyte count, virological suppression and incident TB episodes occurring in the first year of ART were assessed. Sub-optimal CD4 responses were defined as 'failure to increase CD4 T-lymphocyte count by 50cells/µl at 6 month on ART'. RESULTS: The cohort for analysis included 691 patients. 141 (20.4%) had sub-optimal CD4 responses at 6 months on ART. 49 patients (7.1%) developed incident TB within the first 12 months of ART. After adjustment for age, sex, baseline CD4 count and detectable viral load, patients with incident TB were found to have a 2.20 times greater odds of a sub-optimal CD4 response at 6 month of ART as compared to those who were TB free (95%CI: 1.14-4.23). CONCLUSION: Incident TB was associated with a poor CD4 response during early ART in this cohort. Although the direction of causality cannot be determined from these data, these findings provide additional support for the initiation of ART at higher CD4 counts.

Lack of specificity of anticyclic citrullinated peptide antibodies in advanced human immunodeficiency virus infection.

OBJECTIVE: To determine the prevalence and specificity of anticyclic citrullinated peptide antibodies (anti-CCP) and rheumatoid factor (RF) for rheumatoid arthritis (RA) in human immunodeficiency virus (HIV) infection and to evaluate the effect of immune reconstitution on these markers. METHODS: Patients with advanced HIV infection without arthritis were enrolled. CD4+ T lymphocyte counts (CD4), anti-CCP, and RF were determined before initiating antiretroviral therapy (ART) and repeated after 6 months. Results were compared to those of healthy controls. Patients were followed for the development of RA for 1 year. RESULTS: Sixty patients and 26 controls were studied. Six-month followup results were available on 49 patients. Mean (SD) levels of anti-CCP were higher in patients with HIV compared to controls: respectively, 9.50 (11.41) versus 0.80 (1.32) units (p < 0.001). Mean (SD) levels decreased to 4.85 (8.12) units (p = 0.006) after 6 months of ART (HIV-infected group). Fifteen percent of patients initially tested positive for anti-CCP, 4% after 6 months versus no controls (p = 0.031). Forty-seven percent of patients initially tested positive for RF, 18% after 6 months versus 8% of controls (p < 0.001). Decreases in RF and anti-CCP after ART were accompanied by increased mean (SD) CD4: from 129 (56) to 278 (140) cells/mm(3) (p < 0.001). Anti-CCP and RF positivity was not associated with the development of RA. CONCLUSION: Increased titers of anti-CCP and RF occur in advanced HIV infection. Although more specific than RF, before immune reconstitution, anti-CCP is an unreliable diagnostic marker for RA and does not necessarily predict future RA. After immune reconstitution, the specificity of anti-CCP approaches that of a control group.

Potential for nosocomial transmission of multidrug-resistant (MDR) tuberculosis in a South African tertiary hospital.

BACKGROUND: Tuberculosis (TB) is a major health problem in the Western Cape, with an incidence exceeding 900 per 100 000 people. Nosocomial transmission of TB, and particularly drug-resistant TB, is a potential risk that may be undetected. Rapid diagnosis and rapid institution of effective anti-TB treatment, combined with appropriate infection control measures, are essential to prevent nosocomial transmission of TB. To estimate the potential for nosocomial transmission, we aimed to determine the in-hospital delays in diagnosis and treatment of patients with multidrug-resistant (MDR)-TB at a tertiary care hospital. METHODS: A descriptive study, based on retrospective review of patient records and laboratory data, including all adult patients (>13 years) where TB culture and susceptibility testing confirmed MDR- TB on specimens submitted to Tygerberg Hospital's National Health Laboratory Service (NHLS) laboratory in 2007. RESULTS: Thirty-one patients with MDR-TB were identified. The median laboratory turnaround time (TAT) from collection of specimen to confirmation of MDR-TB was 40 days, while the median time from the time of first presentation at Tygerberg Hospital to institution of MDR treatment was 44 days. Twenty patients were considered infectious during their hospital stay, generating 345 inpatient infectious days. CONCLUSIONS: The study suggests that there is an ongoing substantial risk for nosocomial transmission of MDR-TB at Tygerberg Hospital. We propose improvements, including the use of rapid drug susceptibility testing. The consistent application of infection control measures to prevent nosocomial spread of TB, including MDR-TB, remains vital.

Evaluation of paradoxical TB-associated IRIS with the use of standardized case definitions for resource-limited settings.

OBJECTIVE: Standardized case definitions have recently been proposed by the International Network for the Study of HIV-associated immune reconstitution inflammatory syndrome (INSHI; [IRIS]) for use in resource-limited settings. We evaluated paradoxical tuberculosis (TB)-associated IRIS in a large cohort from a TB endemic setting with the use of these case definitions. DESIGN: A retrospective cohort study. METHOD: We reviewed records from 1250 South African patients who initiated antiretroviral therapy (ART) over a 5-year period. RESULTS: A total of 333 (27%) of the patients in the cohort had prevalent TB at the initiation of ART. Of 54 possible paradoxical TB-associated IRIS cases, 35 fulfilled the INSHI case definitions (11% of TB cases). CONCLUSIONS: INSHI-standardized case definitions were used successfully in identifying paradoxical TB-associated IRIS in this cohort and resulted in a similar proportion of TB IRIS cases (11%) as that reported in previous studies from resource-limited settings (8%-13%). This case definition should be evaluated prospectively.