Optimizing Moxifloxacin Dose in MDR-TB Participants with or without Efavirenz Coadministration Using Population Pharmacokinetic Modeling

Moxifloxacin is included in some treatment regimens for drug-sensitive tuberculosis (TB) and multidrug-resistant TB (MDR-TB). Aiming to optimize dosing, we described moxifloxacin pharmacokinetic and MIC distribution in participants with MDR-TB. Participants enrolled at two TB hospitals in South Africa underwent intensive pharmacokinetic sampling approximately 1 to 6 weeks after treatment initiation. Plasma drug concentrations and clinical data were analyzed using nonlinear mixed-effects modeling with simulations to evaluate doses for different scenarios. We enrolled 131 participants (54 females), with median age of 35.7 (interquartile range, 28.5 to 43.5) years, median weight of 47 (42.0 to 54.0) kg, and median fat-free mass of 40.1 (32.3 to 44.7) kg; 79 were HIV positive, 29 of whom were on efavirenz-based antiretroviral therapy. Moxifloxacin pharmacokinetics were described with a 2-compartment model, transit absorption, and elimination via a liver compartment. We included allometry based on fat-free mass to estimate disposition parameters. We estimated an oral clearance for a typical patient to be 17.6 L/h. Participants treated with efavirenz had increased clearance, resulting in a 44% reduction in moxifloxacin exposure. Simulations predicted that, even at a median MIC of 0.25 (0.06 to 16) mg/L, the standard daily dose of 400 mg has a low probability of attaining the ratio of the area under the unbound concentration-time curve from 0 to 24 h to the MIC (fAUC_0-24)/MIC target of >53, particularly in heavier participants. The high-dose WHO regimen (600 to 800 mg) yielded higher, more balanced exposures across the weight ranges, with better target attainment. When coadministered with efavirenz, moxifloxacin doses of up to 1,000 mg are needed to match these exposures. The safety of higher moxifloxacin doses in clinical settings should be confirmed.

The treatment gap for mental disorders in adults enrolled in HIV treatment programmes in South Africa: a cohort study using linked electronic health records

AIMS

Mental disorders are common in people living with HIV (PLWH) but often remain untreated. This study aimed to explore the treatment gap for mental disorders in adults followed-up in antiretroviral therapy (ART) programmes in South Africa and disparities between ART programmes regarding the provision of mental health services.

METHODS

We conducted a cohort study using ART programme data and linked pharmacy and hospitalisation data to examine the 12-month prevalence of treatment for mental disorders and factors associated with the rate of treatment for mental disorders among adults, aged 15-49 years, followed-up from 1 January 2012 to 31 December 2017 at one private care, one public tertiary care and two pubic primary care ART programmes in South Africa. We calculated the treatment gap for mental disorders as the discrepancy between the 12-month prevalence of mental disorders in PLWH (aged 15-49 years) in South Africa (estimated based on data from the Global Burden of Disease study) and the 12-month prevalence of treatment for mental disorders in ART programmes. We calculated adjusted rate ratios (aRRs) for factors associated with the treatment rate of mental disorders using Poisson regression.

RESULTS

In total, 182 285 ART patients were followed-up over 405 153 person-years. In 2017, the estimated treatment gap for mental disorders was 40.5% (95% confidence interval [CI] 19.5-52.9) for patients followed-up in private care, 96.5% (95% CI 95.0-97.5) for patients followed-up in public primary care and 65.0% (95% CI 36.5-85.1) for patients followed-up in public tertiary care ART programmes. Rates of treatment with antidepressants, anxiolytics and antipsychotics were 17 (aRR 0.06, 95% CI 0.06-0.07), 50 (aRR 0.02, 95% CI 0.01-0.03) and 2.6 (aRR 0.39, 95% CI 0.35-0.43) times lower in public primary care programmes than in the private sector programmes.

CONCLUSIONS

There is a large treatment gap for mental disorders in PLWH in South Africa and substantial disparities in access to mental health services between patients receiving ART in the public vs the private sector. In the public sector and especially in public primary care, PLWH with common mental disorders remain mostly untreated.

Implementing novel regimens for drug-resistant TB in South Africa: what can the world learn?

Worldwide uptake of new drugs in the treatment of rifampicin-resistant tuberculosis (RR-TB) has been extremely low. In June 2018, ahead of the release of the updated WHO guidelines for the management of RR-TB, South Africa announced that bedaquiline (BDQ) would be provided to virtually all RR-TB patients on shorter or longer regimens. South Africa has been the global leader in accessing BDQ for patients with RR-TB, who now represent 60% of the global BDQ cohort. The use of BDQ within a shorter modified regimen has generated the programmatic data underpinning the most recent change in WHO guidelines endorsing a shorter, injectable-free regimen. Progressive policies on access to new drugs have resulted in improved favourable outcomes and a reduction in mortality among RR-TB patients in South Africa. This supported global policy change. The strategies underpinning these bold actions include close collaboration between the South African National TB Programme and partners, introduction of new TB diagnostic tools in closely monitored conditions and the use of locally generated programmatic evidence to inform country policy changes. In this paper, we summarise a decade´s work that led to the bold decision to use a modified, short, injectable-free regimen with BDQ and linezolid under carefully monitored programmatic conditions.

Essential medicine selection during the COVID-19 pandemic: Enabling access in uncharted territory

The COVID-19 pandemic requires urgent decisions regarding treatment policy in the face of rapidly evolving evidence. In response, the South African Essential Medicines List Committee established a subcommittee to systematically review and appraise emerging evidence, within very short timelines, in order to inform the National Department of Health COVID-19 treatment guidelines. To date, the subcommittee has reviewed 14 potential treatments, and made recommendations based on local context, feasibility, resource requirements and equity. Here we describe the rapid review and evidence-to-decision process, using remdesivir and dexamethasone as examples. Our experience is that conducting rapid reviews is a practical and efficient way to address medicine policy questions under pandemic conditions.

Steady state pharmacokinetics of cycloserine in patients on terizidone for multidrug-resistant tuberculosis

SETTING

Terizidone/cycloserine (TRD/CS) is included in standard treatment regimens for multidrug-resistant tuberculosis (MDR-TB) in many countries. The steady state pharmacokinetics (PKs) of CS after TRD administration are not known.

OBJECTIVES AND DESIGN

We recruited in-patients treated with 250-750 mg oral TRD daily as part of standard treatment regimens for pulmonary MDR-TB in Cape Town, South Africa. Plasma CS assays were performed in samples taken pre-dose and at 2, 4, 6, 8 and 10 h post-dose. CS concentrations were measured using a validated liquid chromatography-tandem mass spectrometry method. Non-compartmental PK analyses were performed.

RESULTS

Of 35 participants enrolled, 22 were males, and 20 (57%) were infected with the human immunodeficiency virus; the median age was 37 years. The median duration on TRD at the time of sampling was 33 days (interquartile range [IQR] 28-39). The area under the concentration-time curve at 0-10 h (AUC0-10) was 319 μg.h/ml (IQR 267.5-378.7), and peak concentration was 38.1 μg/ml (IQR 32.6-47.2). On multiple regression, dose (mg/kg) was the only factor independently associated with AUC0-10.

CONCLUSION

Steady state concentrations of CS in patients treated with TRD for MDR-TB were higher than those reported with CS formulations. Our findings support once-daily dosing.

Effect of tablet crushing on drug exposure in the treatment of multidrug-resistant tuberculosis

SETTING: Treatment outcomes in multidrug-resistant tuberculosis (MDR-TB) are poor. Due to drug toxicity and a long treatment duration, approximately half of patients are treated successfully. Medication is often crushed for patients who have difficulty swallowing whole tablets. Whether crushing tablets affects drug exposure in MDR-TB treatment is not known.OBJECTIVE AND DESIGN: We performed a sequential pharmacokinetic study in patients aged >18 years on MDR-TB treatment at two hospitals in Cape Town, South Africa. We compared the bioavailability of pyrazinamide, moxifloxacin, isoniazid (INH), ethambutol and terizidone when the tablets were crushed and mixed with water before administration vs. swallowed whole. We sampled blood at six time points over 10 h under each condition separated by 2 weeks. Non-compartmental analysis was used to derive the key pharmacokinetic measurements.RESULTS: Twenty participants completed the study: 15 were men, and the median age was 31.5 years. There was a 42% reduction in the area under the curve AUC0-10 of INH when the tablets were crushed compared with whole tablets (geometric mean ratio 58%; 90%CI 47-73). Crushing tablets of pyrazinamide, moxifloxacin, ethambutol and terizidone did not affect the bioavailability significantly.CONCLUSION: We recommend that crushing of INH tablets in the MDR-TB treatment regimen be avoided. Paediatric INH formulations may be a viable alternative if the crushing of INH tablets is indicated.

Effect of lidocaine on kanamycin injection-site pain in patients with multidrug-resistant tuberculosis

SETTING

Reducing pain from intramuscular injection of kanamycin (KM) could improve the tolerability of multidrug-resistant tuberculosis (MDR-TB) treatment. Lidocaine has been shown to be an effective anaesthetic diluent for some intramuscular injections, but has not been investigated with KM in the treatment of adult patients with MDR-TB.

OBJECTIVE AND DESIGN

We performed a randomised single-blinded crossover study to determine if lidocaine reduces KM injection-site pain. We recruited patients aged 18 years on MDR-TB treatment at two TB hospitals in Cape Town, South Africa. KM pharmacokinetic parameters and a validated numeric pain scale were used at intervals over 10 h following the injection of KM with and without lidocaine on two separate occasions.

RESULTS

Twenty participants completed the study: 11 were males, the median age was 36 years, 11 were HIV-infected, and the median body mass index was 17.5 kg/m2. The highest pain scores occurred early, and the median pain score was 0 by 30 min. The use of lidocaine with KM significantly reduced pain at the time of injection and 15 min post-dose. On multiple regression analysis, lidocaine halved pain scores (adjusted OR 0.5, 95%CI 0.3-0.9). The area under the curve at 0-10 h of KM with and without lidocaine was respectively 147.7 and 143.6 μg·h/ml.

CONCLUSION

Lidocaine significantly reduces early injection-site pain and has no effect on KM pharmacokinetics.

Bioavailability of two licensed paediatric rifampicin suspensions: implications for quality control programmes

SETTING

To assess the revised World Health Organization-recommended dose of 10-20 mg/kg rifampicin (RMP), we studied the steady state pharmacokinetics of RMP in South African children who received standard treatment for drug-susceptible tuberculosis (TB).

OBJECTIVE

To determine the formulation effect on the pharmacokinetics of RMP.

DESIGN

RMP plasma concentrations were characterised in 146 children (median age 1.4 years, range 0.2-10.2). The morning dose on the day of the pharmacokinetic evaluation was administered as one of two RMP single-drug oral suspensions.

RESULTS

While one formulation achieved 2 h concentrations in the range of those observed in adults (median 6.54 mg/l, interquartile range [IQR] 4.47-8.84), the other attained a median bioavailability of only 25% of this, with a median 2 h concentration of 1.59 mg/l (IQR 0.89-2.38).

CONCLUSION

RMP is a key drug for the treatment of TB. It is critical that the quality of RMP suspensions used to treat childhood TB is ensured.

Southern African guidelines on the safe use of pre-exposure prophylaxis in persons at risk of acquiring HIV-1 infection

The Southern African HIV Clinicians Society published its first set of oral pre-exposure prophylaxis (PrEP) guidelines in June 2012 for men who have sex with men (MSM) who are at risk of HIV infection. With the flurry of data that has been generated in PrEP clinical research since the first guideline, it became evident that there was a need to revise and expand the PrEP guidelines with new evidence of safety and efficacy of PrEP in several populations, including MSM, transgender persons, heterosexual men and women, HIV-serodiscordant couples and people who inject drugs. This need is particularly relevant following the World Health Organization (WHO) Consolidated Treatment Guidelines released in September 2015. These guidelines advise that PrEP is a highly effective, safe, biomedical option for HIV prevention that can be incorporated with other combination prevention strategies in Southern Africa, given the high prevalence of HIV in the region. PrEP should be tailored to populations at highest risk of HIV acquisition, whilst further data from studies in the region accrue to guide optimal deployment to realise the greatest impact regionally. PrEP may be used intermittently during periods of perceived HIV acquisition risk, rather than continually and lifelong, as is the case with antiretroviral treatment. Recognition and accurate measurement of potential risk in individuals and populations also warrants discussion, but are not extensively covered in these guidelines.

The pharmacokinetics of lopinavir/ritonavir when given with isoniazid in South African HIV-infected individuals

Isoniazid preventive therapy is recommended in patients on antiretroviral treatment (ART) with latent tuberculous infection to prevent progression to active tuberculosis disease. Isoniazid (INH) inhibits cytochrome (CY) P3A4, which metabolises lopinavir (LPV). The administration of INH may cause higher LPV concentrations, which may increase LPV toxicity. LPV bioavailability is increased by co-formulated ritonavir (r), which may enhance the interaction of INH on LPV. We studied the effect of INH on LPV concentrations by administering INH for 7 days and performing intensive pharmacokinetic sampling in 16 human immunodeficiency virus infected patients established on LPV/r-based ART. INH did not significantly increase steady-state LPV area under the plasma concentration-time curve calculated for the 12 h-dosing interval.

The interaction between artemether-lumefantrine and lopinavir/ritonavir-based antiretroviral therapy in HIV-1 infected patients

Background

Artemether-lumefantrine is currently the most widely recommended treatment of uncomplicated malaria. Lopinavir–based antiretroviral therapy is the commonly recommended second-line HIV treatment. Artemether and lumefantrine are metabolised by cytochrome P450 isoenzyme CYP3A4, which lopinavir/ritonavir inhibits, potentially causing clinically important drug-drug interactions.

Methods

An adaptive, parallel-design safety and pharmacokinetic study was conducted in HIV-infected (malaria-negative) patients: antiretroviral-naïve and those stable on lopinavir/ritonavir-based antiretrovirals. Both groups received the recommended six-dose artemether-lumefantrine treatment. The primary outcome was day-7 lumefantrine concentrations, as these correlate with antimalarial efficacy. Adverse events were solicited throughout the study, recording the onset, duration, severity, and relationship to artemether-lumefantrine.

Results

We enrolled 34 patients. Median day-7 lumefantrine concentrations were almost 10-fold higher in the lopinavir than the antiretroviral-naïve group [3170 versus 336 ng/mL; p = 0.0001], with AUC_(0-inf) and C_max increased five-fold [2478 versus 445 μg.h/mL; p = 0.0001], and three-fold [28.2 versus 8.8 μg/mL; p < 0.0001], respectively. Lumefantrine C_max, and AUC_(0-inf) increased significantly with mg/kg dose in the lopinavir, but not the antiretroviral-naïve group. While artemether exposure was similar between groups, C_max and AUC_(0-8h) of its active metabolite dihydroartemisinin were initially two-fold higher in the lopinavir group [p = 0.004 and p = 0.0013, respectively]. However, this difference was no longer apparent after the last artemether-lumefantrine dose. Within 21 days of starting artemether-lumefantrine there were similar numbers of treatment emergent adverse events (42 vs. 35) and adverse reactions (12 vs. 15, p = 0.21) in the lopinavir and antiretroviral-naïve groups, respectively. There were no serious adverse events and no difference in electrocardiographic QTcF- and PR-intervals, at the predicted lumefantrine T_max.

Conclusion

Despite substantially higher lumefantrine exposure, intensive monitoring in our relatively small study raised no safety concerns in HIV-infected patients stable on lopinavir-based antiretroviral therapy given the recommended artemether-lumefantrine dosage. Increased day-7 lumefantrine concentrations have been shown previously to reduce the risk of malaria treatment failure, but further evidence in adult patients co-infected with malaria and HIV is needed to assess the artemether-lumefantrine risk : benefit profile in this vulnerable population fully. Our antiretroviral-naïve patients confirmed previous findings that lumefantrine absorption is almost saturated at currently recommended doses, but this dose-limited absorption was overcome in the lopinavir group.

Trial registration

Clinical Trial Registration number NCT00869700. Registered on clinicaltrials.gov 25 March 2009

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1345-1) contains supplementary material, which is available to authorized users.

Diagnostic accuracy and clinical role of rapid C-reactive protein testing in HIV-infected individuals with presumed tuberculosis in South Africa

OBJECTIVE

To determine the accuracy and role of rapid C-reactive protein (CRP) testing in human immunodeficiency virus (HIV) infected individuals with presumed tuberculosis (TB).

DESIGN

We enrolled HIV-infected adults (≥18 years)with a cough of ≥2 weeks and negative sputum smears for acid-fast bacilli in KwaZulu-Natal, South Africa. Participants were evaluated for pulmonary TB (PTB) by a nurse with rapid CRP, and independently by a physician by chest radiograph. Rapid CRP test results were compared with laboratory CRP and sputum sent for confirmation of TB.

RESULTS

Among 93 participants, 55 (59%) were female, the mean age was 35 years, and the median CD4 count was 177/mm3. Forty-five (54%) participants were diagnosed with PTB. Diagnostic sensitivity and specificity were respectively 95% (95%CI 74–99) and 51%(95%CI 35–66) for rapid CRP >8 mg/l, 87% (95%CI 73–96) and 53% (95%CI 38–68) for nurse assessment, and 69% (95%CI 52–83) and 76% (95%CI 61–87) for physician examination. Combining a negative rapid CRP(≤8 mg/l) with nurse and physician assessments reduced the post-test probability of PTB from 22% to 6% and from 32% to 6%, respectively.

CONCLUSION

Rapid CRP testing helped exclude PTB,and may be a valuable test in assisting nurses and physicians in TB-endemic regions.

Systematic review of the evidence for rational dosing of colistin

BACKGROUND

There is an alarming global increase in the incidence of nosocomial infections with multidrug-resistant Gram-negative bacteria, which are often only susceptible to colistin. Colistin was developed prior to current methods of establishing dosing using pharmacokinetic-pharmacodynamic relationships. Dosing regimens differ in package inserts from different manufacturers and in different guidelines. It is imperative to avoid under-dosing with colistin in order to limit the development of resistance, as it is the last line of defence.

METHODS

We conducted a systematic review of the literature to develop guidelines for rational dosing of intravenous colistin, with a particular focus on critically ill patients.

RESULTS

Colistin is administered as the inactive pro-drug colistimethate sodium. Colistin demonstrates concentration-dependent bacterial killing, suggesting that higher doses should be administered less frequently to achieve higher peak concentrations. Dose-related nephrotoxicity occurs, making it impossible to safely achieve concentrations that prevent the selection of resistant mutants or the effective eradication of bacteria with higher minimum inhibitory concentrations. Theoretically, combination therapy should be used to reduce the risk of selection of resistant bacteria. In critically ill patients, a loading dose should be given to rapidly achieve therapeutic concentrations, followed by maintenance doses of 4.5 MU 12-hourly. Maintenance dose adjustment is necessary with renal impairment.

CONCLUSION

Easier access to colistin is needed in South Africa, where it is not a registered medicine. Further research is needed to better characterise colistin's pharmacokinetic-pharmacodynamic relationships in humans and to establish whether combinations of colistin with other antimicrobials result in improved clinical outcomes or a reduction in selection of resistant bacteria.

The pharmacokinetics of nevirapine when given with isoniazid in South African HIV-infected individuals

Isoniazid preventive therapy (IPT) is recommended in patients on antiretroviral treatment. Isoniazid (INH) inhibits CYP3A4, which metabolises nevirapine (NVP). Administration of INH may cause higher NVP concentrations and toxicity. We studied the effect of INH on NVP concentrations in 21 patients randomised to either placebo (n = 13) or INH (n = 8) in an ongoing trial of IPT in patients on ART. INH was associated with a 24% increase in median NVP area under the plasma concentration-time curve for the 12 h dosing interval, which was not statistically significant (P = 0.66).

Guidelines for antiretroviral therapy in adults

These guidelines are intended as an update to those published in the Southern African Journal of HIV Medicine in January 2008. Since the release of the previous guidelines, the scale-up of antiretroviral therapy (ART) in Southern Africa has continued to grow. Cohort studies from the region show excellent clinical outcomes; however, ART is still being started late (in advanced disease), resulting in relatively high early mortality rates. New data on antiretroviral (ARV) tolerability in the region and several new ARV drugs have become available. Although currently few in number, some patients in the region are failing protease inhibitor (PI)-based second-line regimens. To address this, guidelines on third-line (or ‘salvage’) therapy have been expanded.

Interferon release does not add discriminatory value to smear-negative HIV-tuberculosis algorithms

Clinical algorithms for evaluating HIV-infected individuals for tuberculosis (TB) prior to isoniazid preventive therapy (IPT) perform poorly, and interferon-γ release assays (IGRAs) have moderate accuracy for active TB. It is unclear whether, when used as adjunct tests, IGRAs add any clinical discriminatory value for active TB diagnosis in the pre-IPT assessment. 779 sputum smear-negative HIV-infected persons, established on or about to commence combined antiretroviral therapy (ART), were screened for TB prior to IPT. Stepwise multivariable logistic regression was used to develop clinical prediction models. The discriminatory ability was assessed by receiver operator characteristic area under the curve (AUC). QuantiFERON-TB Gold in-tube (QFT-GIT) was evaluated. The prevalence of smear-negative TB by culture was 6.4% (95% CI 4.9-8.4%). Used alone, QFT-GIT and the tuberculin skin test (TST) had comparable performance; the post-test probability of disease based on single negative tests was 3-4%. In a multivariable model, the QFT-GIT test did not improve the ability of a clinical algorithm, which included not taking ART, weight <60 kg, no prior history of TB, any one positive TB symptom/sign (cough ≥ 2 weeks) and CD4+ count <250 cells per mm(3), to discriminate smear-negative culture-positive and -negative TB (72% to 74%; AUC comparison p=0.33). The TST marginally improved the discriminatory ability of the clinical model (to 77%, AUC comparison p=0.04). QFT-GIT does not improve the discriminatory ability of current TB screening clinical algorithms used to evaluate HIV-infected individuals for TB ahead of preventive therapy. Evaluation of new TB diagnostics for clinical relevance should follow a multivariable process that goes beyond test accuracy.

Hypercytokinaemia accompanies HIV-tuberculosis immune reconstitution inflammatory syndrome

Increased access to combination antiretroviral therapy in areas co-endemic for tuberculosis (TB) and HIV-1 infection is associated with an increased incidence of immune reconstitution inflammatory syndrome (TB-IRIS) whose cause is poorly understood. A case-control analysis of pro- and anti-inflammatory cytokines in TB-IRIS patients sampled at clinical presentation, and similar control patients with HIV-TB prescribed combined antiretroviral therapy who did not develop TB-IRIS. Peripheral blood mononuclear cells were cultured in the presence or absence of heat-killed Mycobacterium tuberculosis for 6 and 24 h. Stimulation with M. tuberculosis increased the abundance of many cytokine transcripts with interleukin (IL)-1β, IL-5, IL-6, IL-10, IL-13, IL-17A, interferon (IFN)-γ, granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumour necrosis factor (TNF) being greater in stimulated TB-IRIS cultures. Analysis of the corresponding proteins in culture supernatants, revealed increased IL-1β, IL-2, IL-6, IL-8, IL-10, IL-12p40, IFN-γ, GM-CSF and TNF in TB-IRIS cultures. In serum, higher concentrations of TNF, IL-6, and IFN-γ were observed in TB-IRIS patients. Serum IL-6 and TNF decreased during prednisone therapy in TB-IRIS patients. These data suggest that cytokine release contributes to pathology in TB-IRIS. IL-6 and TNF were consistently elevated and decreased in serum during corticosteroid therapy. Specific blockade of these cytokines may be rational approach to immunomodulation in TB-IRIS.

Course and complications of varicella zoster ophthalmicus in a high HIV seroprevalence population (Cape Town, South Africa)

AIM

To describe the course and complications of varicella zoster ophthalmicus (VZO) in patients attending an eye clinic in a community with a high HIV seroprevalence.

STUDY DESIGN

Prospective cohort study of consecutive patients presenting to a tertiary hospital eye clinic with VZO.

METHOD

Patients recruited in 2001 and 2002 received standardized initial topical and systemic management, which was then modified according to complications. Information on the course and complications of the disease was entered in a database prior to statistical analysis.

RESULTS

Information on 102 patients who had 250 visits to the eye clinic was collected. HIV serology was positive, negative, and unknown in 66, 22, and 14 patients, respectively. The most common complication was uveitis (40/102). Median delay from onset of rash to starting acyclovir was 5 days. Complications were present in 33 patients at the first visit. Complications were commoner in patients with positive Hutchinson's sign and were less common at CD4 counts <200. At CD4 counts, > or =200 HIV infection had little effect on the course and complications of VZO. Timing of commencement of Acyclovir therapy within or after 72 h had no demonstrable effect on the incidence of new complications.

CONCLUSION

In a resource-limited setting, patients with the following characteristics should have immediate ophthalmic assessment: symptoms suggesting ocular complications or the presence of Hutchinson's sign. All VZO patients should receive antiviral therapy at the first doctor's visit even if they present >72 h after onset of the rash.

Randomised controlled trial of isoniazid preventive therapy in South African adults with advanced HIV disease

BACKGROUND

Tuberculosis (TB) preventive therapy is not effective in human immunodeficiency virus (HIV) infected adults with negative tuberculin skin tests (TSTs). However, there are insufficient data on patients with advanced HIV disease from high TB incidence areas.

METHODS

We conducted a randomised, double-blind, controlled trial comparing isoniazid (INH) with placebo among TST-negative adults with World Health Organization Stage 3 or 4 HIV disease. INH/placebo was administered for 12 months by patient-nominated supervisors. TST-positive participants were given open-label INH. Participants, who did not have access to antiretroviral therapy (ART), were followed up for 24 months with 6-monthly sputum culture and chest radiography.

RESULTS

A total of 118 participants were enrolled: TST was negative in 98. In the randomised arms, the incidence of TB was 18/100 person-years (py) in the INH arm and 11.6/100 py in the placebo arm (hazard ratio 1.59, 95%CI 0.57-4.49). There were no significant differences in mortality, hospitalisation rate or CD4+ lymphocyte decline. INH/placebo adherence was 85%, and was significantly higher among participants with work-based treatment supervisors.

CONCLUSIONS

We did not find any association between INH preventive therapy and reductions in incident TB among TST-negative adults with advanced HIV disease, but the study had limited statistical power. High levels of adherence were observed with patient-nominated supervisors.

Outcome of AIDS-associated cryptococcal meningitis initially treated with 200 mg/day or 400 mg/day of fluconazole

Background

AIDS-associated cryptococcal meningitis has a high mortality. Fluconazole was the only systemic antifungal therapy available in our centre. From 1999–2001 we used low-dose fluconazole (200 mg daily initially), and did not offer therapy to patients perceived to have poor prognoses. In 2001 donated fluconazole became available, allowing us to use standard doses (400 mg daily initially). Antiretroviral therapy was not available during the study period.

Methods

Retrospective chart review of adult patients before and after the fluconazole donation.

Results

205 patients fulfilled the inclusion criteria, 77 before and 128 after the donation. Following the donation fewer patients received no antifungal treatment (5% vs 19%, p = 0.002), and more patients received standard-dose fluconazole (90% vs 6%, p < 0.001). In-hospital mortality was 25%. Impaired consciousness, no antifungal treatment received and cerebrospinal fluid antigen titre > 1,000 were independent predictors of in-hospital mortality. Concomitant rifampicin did not affect in-hospital survival. Thirteen patients were referred to the tertiary referral hospital and received initial treatment with amphotericin B for a mean of 6 days – their in-hospital survival was not different from patients who received only fluconazole (p = 0.9). Kaplan-Meier analysis showed no differences in length of survival by initial treatment with standard or low doses of fluconazole (p = 0.27 log rank test); median survival was 76 and 82 days respectively.

Conclusion

Outcome of AIDS-associated cryptococcal meningitis is similar with low or standard doses of fluconazole. The early mortality is high. Initial therapy with amphotericin B and other measures may be needed to improve outcome.

Diagnosing smear-negative tuberculosis using case definitions and treatment response in HIV-infected adults

OBJECTIVE

To assess the diagnostic utility of expanded case definitions for HIV-associated smear-negative pulmonary tuberculosis (PTB) and extra-pulmonary TB (EPTB), and to derive objective criteria for response to anti-tuberculosis treatment.

DESIGN

A prospective cohort study of HIV-infected adults who met expanded clinical case definitions for smear-negative PTB and EPTB.

METHODS

All participants were started on rifampicin-based anti-tuberculosis treatment after mycobacterial cultures from multiple sites. At weeks 2, 4 and 8, response to treatment (RTT) was assessed by measuring changes in weight, haemoglobin, C-reactive protein, Karnofsky performance score and symptom count ratio.

RESULTS

Of 147 participants enrolled, 105 (71%) were diagnosed with definite (culture-positive) or probable (histological features) TB and 25 (17%) with possible TB (treatment response). The positive predictive value for the most common case definitions ranged from 89% to 96%. Significant improvements in all the RTT parameters occurred in the subjects with confirmed TB (P < 0.001). Clinically relevant RTT criteria were derived, two or more of which were met at week 8 in 97.5% of subjects with confirmed TB, 91.3% of subjects with possible TB and none of the subjects without TB.

CONCLUSION

Expanded case definitions could enhance the diagnosis of PTB and EPTB in HIV-infected adults in resource-limited settings. Using objective criteria, RTT can be assessed within 8 weeks of initiating anti-tuberculosis treatment.

Diagnostic yield of peripheral lymph node needle-core biopsies in HIV-infected adults with suspected smear-negative tuberculosis

Significant lymphadenopathy in human immunodeficiency virus (HIV) infected adults in developing countries is usually caused by tuberculosis. We studied the safety and diagnostic yield of needle-core biopsies, under local anaesthetic, of enlarged lymph nodes in 26 HIV-infected adults presenting with suspected tuberculosis who were sputum smear-negative. Biopsy samples were sent for histology and mycobacterial culture. Induced sputum, urine and blood were also sent for mycobacterial culture. The procedure was well tolerated. A definitive diagnosis was made on initial needle-core biopsy in 22 subjects (85%) and in two of three subjects who underwent a second needle-core biopsy. Tuberculosis was the final diagnosis in 24 subjects (92%).

Quality of Life in Patients Treated with First-Line Antiretroviral Therapy Containing Nevirapine And/Or Efavirenz

Objective

To assess whether differences in safety profiles between nevirapine (NVP) and efavirenz (EFV), as observed in the 2NN study, translated into differences in ‘health related quality of life’ (HRQoL).

Design

A sub-study of the 2NN study, with antiretro-viral-naive patients randomly allocated to NVP (once or twice daily), EFV or NVP+EFV, in addition to stavudine and lamivudine.

Methods

Comparing differences in changes of HRQoL over 48 weeks as measured with the Medical Outcomes Study HIV Health Survey (MOS-HIV) questionnaire, using analysis of variance.

Results

The 2NN study enrolled 1216 patients. No validated questionnaires were available for 244 patients, and 55 patients had no HRQoL data at all, leaving 917 patients eligible for this sub-study. A total of 471 (51%) had HRQoL measurements both at baseline and week 48. The majority (69%) of patients without HRQoL measurements did, however, complete the study. The change in the physical health score (PHS) was 3.9 for NVP, 3.4 for EFV and 2.4 for NVP+EFV ( P=0.712). For the mental health score (MHS) these values were 6.1, 7.0 and 3.9, respectively ( P=0.098). A baseline plasma HIV-1 RNA concentration (pVL) ≥100 000 copies/ml and a decline in pVL (per log10) were independently associated with an increase of PHS. An increase of MHS was only associated with pVL decline. Patients experiencing an adverse event during follow-up had a comparable change in PHS but a significantly smaller change in MHS, compared with those without an adverse event.

Conclusions

First-line ART containing NVP and/or EFV leads to an improvement in HRQoL. The gain in HRQoL was similar for NVP and EFV, but slightly lower for the combination of these drugs.

Guideline for the management of upper respiratory tract infections

INTRODUCTION

Inappropriate use of antibiotics for upper respiratory tract infections (URTIs), many of which are viral, adds to the burden of antibiotic resistance. Antibiotic resistance is increasing in Streptococcus pneumoniae, responsible for most cases of acute otitis media (AOM) and acute bacterial sinusitis (ABS).

METHOD

The Infectious Diseases Society of Southern Africa held a multidisciplinary meeting to draw up a national guideline for the management of URTIs. Background information reviewed included randomised controlled trials, existing URTI guidelines and local antibiotic susceptibility patterns. The initial document was drafted at the meeting. Subsequent drafts were circulated to members of the working group for modification. The guideline is a consensus document based upon the opinions of the working group.

OUTPUT

Penicillin remains the drug of choice for tonsillopharyngitis. Single-dose parenteral administration of benzathine penicillin is effective, but many favour oral administration twice daily for 10 days. Amoxycillin remains the drug of choice for both AOM and ABS. A dose of 90 mg/ kg/day is recommended in general, which should be effective for pneumococci with high-level penicillin resistance (this is particularly likely in children < or = 2 years of age, in day-care attendees, in cases with prior AOM within the past 6 months, and in children who have received antibiotics within the last 3 months). Alternative antibiotic choices are given in the guideline with recommendations for their specific indications. These antibiotics include amoxycillin-clavulanate, some cephalosporins, the macrolide/azalide and ketolide groups of agents and the respiratory fluoroquinolones.

CONCLUSION

The guideline should assist rational antibiotic prescribing for URTIs. However, it should be updated when new information becomes available from randomised controlled trials and surveillance studies of local antibiotic susceptibility patterns.

Screening for tuberculosis in adults with advanced HIV infection prior to preventive therapy

It is important to exclude tuberculosis prior to preventive therapy, but this can be difficult in patients with symptomatic human immunodeficiency virus (HIV) disease. Patients with clinically advanced HIV disease were screened for active tuberculosis using a symptom questionnaire, measured weight loss, chest radiography, sputum microscopy and culture prior to receiving tuberculosis preventive therapy. Tuberculosis was diagnosed in 11 of 129 patients screened. A simple screening instrument of two or more of the symptoms measured weight loss, cough, night sweats or fever, had a sensitivity of 100% and specificity of 88.1%, and positive and negative predictive values of 44% and 100%, respectively.

The short-term effects of anti-tuberculosis therapy on plasma pyridoxine levels in patients with pulmonary tuberculosis

Plasma levels of pyridoxal phosphate (PLP) were determined in 20 patients with pulmonary tuberculosis before and after one week of drug therapy including isoniazid. At baseline, body mass index and PLP levels were reduced in 10 and 18 patients, respectively. After 7 days of therapy, PLP levels decreased (P < 0.001) in all but one subject who inadvertently received pyridoxine supplementation. The decreased PLP levels occurred despite a significant improvement in the acute phase response (increased albumin [P < 0.001] and reduced C-reactive protein levels [P < 0.01]). This study indicates the need for possible routine pyridoxine supplementation in patients with newly diagnosed tuberculosis.

Impact of HIV on admissions and deaths in a tuberculosis hospital--recommendations for admission and discharge criteria

Mortality and HIV prevalence rose concordantly at Brooklyn Chest Hospital from 1998 to 2001. Death and unconfirmed tuberculosis (TB) (15% of adult admissions in a sample from 2000) were associated with HIV seropositivity. Excluding unconfirmed TB and shortening length of stay would increase the number of patients able to benefit from hospitalisation.

Plasma vitamin A and zinc levels in HIV-infected adults in Cape Town, South Africa

A cross-sectional study of 132 adults attending an HIV clinic in Cape Town, South Africa, was conducted to determine predictors of low plasma vitamin A and Zn levels. No patients were on antiretroviral therapy. The possible confounding effect of the acute-phase response was controlled by including C-reactive protein levels in multivariate analysis and by excluding active opportunistic infections. Retinol levels were low (<1.05 micromol/l) in 39 % of patients with early disease (WHO clinical stages I and II) compared with 48 and 79 % of patients with WHO stage III and IV respectively (P<0.01). Plasma Zn levels were low (<10.7 micromol/l) in 20 % of patients with early disease v. 36 and 45 % with stage III and IV disease respectively (P<0.05). C-reactive protein levels were normal in 63 % of subjects. Weak, positive associations were found between CD4+ lymphocyte count and plasma levels of retinol (r 0.27; 95 % CI 0.1, 0.43) and Zn (r 0.31; 95 % CI 0.25, 0.46). Multivariate analysis showed the following independent predictors of low retinol levels: WHO stage IV (odds ratio 3.4; 95 % CI 2.1, 5.7) and body weight (odds ratio per 5 kg decrease 1.15; 95 % CI, 1.08, 1.25), while only body weight was significantly associated with low Zn levels (OR per 5 kg decrease 1.19; 95 % CI 1.09, 1.30). CD4+ lymphocyte count <200/microl was not significantly associated with either low retinol or Zn levels. In resource-poor settings, simple clinical features (advanced disease and/or weight loss) are associated with lowered blood concentrations of vitamin A and/or Zn. The clinical significance of low plasma retinol and/or Zn levels is unclear and more research is required to establish the role of multiple micronutrient intervention strategies in HIV disease.

Opportunistic infections associated with HIV infection in Africa

HIV-associated infections in sub-Saharan Africa differ markedly in their incidence from those in industrialized countries. Tuberculosis is the commonest cause of morbidity and mortality. Enteric pathogens such as microsporidiosis commonly cause disease as access to safe water is limited. Pneumocystis carinii pneumonia, which is the commonest opportunistic infection in industrialized countries, is uncommon in adults with HIV infection. This remains unexplained because P. carinii pneumonia is common in Black African HIV-infected children. Cytomegalovirus and Mycobacterium avium complex, which only occur in severely immune-suppressed individuals, are seldom found. One reason may be that survival after conversion to AIDS is relatively short in Africa. Patients often die before they develop severe immune suppression. Recently, prophylactic cotrimoxazole treatment was shown to be effective in symptomatic HIV-infected adults in Africa. Tuberculosis preventive therapy is also effective in Africa, at least in the medium term. It is hoped that these two affordable interventions will become available to large numbers of patients identified in voluntary counselling and testing centres.

The prevention and treatment of opportunistic infections in HIV-infected adults

No abstract available.

Tuberculosis should not be considered an AIDS-defining illness in areas with a high tuberculosis prevalence

OBJECTIVE

To assess the prognosis of human immunodeficiency virus (HIV) associated tuberculosis in a high tuberculosis prevalence setting.

METHODS

Survival and subsequent AIDS-defining illnesses (ADI) of patients with tuberculosis were compared with patients remaining tuberculosis-free in a prospective cohort study in two university-affiliated adult HIV clinics in Cape Town.

RESULTS

Tuberculosis without prior or simultaneous ADI was diagnosed in 141 patients. CD4+ T-lymphocyte count was >200 cells/microl in 67% of the incident tuberculosis cases. Survival in tuberculosis patients was comparable to that of patients with oral hairy leukoplakia and/or oral candidiasis (median = 23.6 vs. 27.8 months respectively; P = 0.59, adjusted hazard ratio [AHR] = 0.87; 95%CI 0.63-1.58), and better than in patients with AIDS (median = 11.5 months; P < 0.001, AHR = 2.37; 95% CI 1.93-4.66). Subsequent ADI were less frequent in tuberculosis than in AIDS patients (AHR = 0.36; 95%CI 0.23-0.58). Survival of patients with pulmonary or extra-pulmonary tuberculosis was similar (P = 0.32).

CONCLUSION

Tuberculosis in HIV-infected patients from areas endemic with tuberculosis occurs across a wide spectrum of immune suppression and has a considerably better prognosis than other ADI. Inclusion of tuberculosis in the clinical case definition of AIDS in such areas should be reconsidered.

Predictors and prognostic value of oral hairy leukoplakia and oral candidiasis in South African HIV-infected patients

BACKGROUND

Oral hairy leukoplakia and oral candidiasis diseases (OHL/OC) are common clinical manifestations of HIV/AIDS. Sparse literature exists from resource-limited countries on their incidence and impact on HIV-infected patients.

OBJECTIVE

To determine the predictors and prognosis of OHL/OC in HIV-infected patients.

METHODS

Patients were drawn from a cohort established in 1992 and prospectively followed until 1997 in the adult HIV clinics, University of Cape Town. Cox hazards regression models were fitted to determine the predictors of OHL/OC, and the association between OHL/OC and progression to AIDS and death.

RESULTS

218 patients presenting with OHL/OC at their initial clinic visit were excluded. 205/772 patients developed OHL/OC (27.8 cases/100 years). White ethnicity (hazard ratio [HR] = 1.73, 95% CI 1.23-2.33), CD4+ count < 200 cells/(L (HR = 2.55, 95% CI 1.89-3.45), total lymphocyte count < 1250 cells/(L (HR = 1.72, 95% CI 1.28-2.31) and WHO stage 3 or 4 (HR = 2.61, 95% CI = 1.93-3.53) where variables predictive of increased hazard to developing OHL/OC. OHL/OC were independently associated with hazard of AIDS (HR = 3.65, 95% CI 1.89-6.69) and death (HR = 2.12, 95% CI 1.47-4.34).

CONCLUSIONS

The presence of OHL/OC in HIV-infected patients provides important prognostic information, and can be used as a cost-effective tool for screening patients in therapeutic interventions in resource-limited settings.

Tuberculosis preventive therapy in HIV infection

No abstract available.

AIDS in Africa--survival according to AIDS-defining illness

OBJECTIVE

Evaluation of prognostic significance of the type of AIDS-defining illness (ADI) and performance status in a cohort of AIDS patients.

DESIGN, SETTING, SUBJECTS, OUTCOME MEASURES

A retrospective analysis of 280 patients with AIDS, as defined by the proposed World Health Organisation (WHO) clinical staging system, who attended two Cape Town-based HIV clinics between 1984 and 1997. Patients were stratified according to the type of initial ADI. Survival associated with each opportunistic event was determined by Kaplan-Meier analysis. Cox proportional hazard analysis was used to determine relative risk for death associated with three strata of ADI.

RESULTS

Median survival associated with various initial ADIs varied from less than 3 months (encephalopathy and wasting), to over 2 years (extrapulmonary tuberculosis and herpes simplex virus infection). This effect of ADI on outcome was most striking in patients with relatively preserved CD4 counts (CD4 > 50/microliter). A performance status score 4 predicted 50% mortality at 1 month, irrespective of co-morbidity.

CONCLUSION

The type of ADI is an important determinant of survival, particularly in patients with preserved CD4 counts. The stratification of patients by type of ADI and performance status may be useful in the management of patients with advanced HIV infection in resource-limited environments.

Initiating co-trimoxazole prophylaxis in HIV-infected patients in Africa: an evaluation of the provisional WHO/UNAIDS recommendations

OBJECTIVE

To evaluate the proposed WHO/UNAIDS criteria for initiating co-trimoxazole prophylaxis in adult HIV-infected patients in Africa [WHO clinical stages 2--4 or CD4 count < 500 x 10(6) /l or total lymphocyte count (TLC) equivalent].

DESIGN

Observational cohort study of 5-year follow-up.

SETTING

Adult HIV clinics, University of Cape Town, South Africa.

METHODS

Effect of prophylactic low dose co-trimoxazole (480 mg per day or 960 mg three times per week) on survival and morbidity was assessed in patients stratified by WHO clinical stage, CD4 T-lymphocyte count or TLC. Patients receiving antiretroviral therapy were excluded.

RESULTS

Co-trimoxazole reduced mortality [adjusted hazard ratio (AHR), 0.56; 95% confidence interval (CI), 0.33--0.85; P > 0.001] and the incidence of severe HIV-related illnesses (AHR, 0.52; 95% CI, 0.38--0.68; P < 0.001) in patients with evidence of advanced immune suppression on clinical (WHO stages 3 and 4) or laboratory assessment (TLC < 1250 x 10(6)/l or CD4 count < 200 x 10(6)/l). No significant evidence of efficacy was found in patients with WHO stage 2 or CD4 count 200--500 x 10(6)/l/TLC 1250--2000 x 10(6)/l. If we had applied the WHO/UNAIDS recommendations 88.3% of our patients would have received co-trimoxazole prophylaxis at their initial clinic visit.

CONCLUSION

Co-trimoxazole in HIV-infected adults from an area in which Pneumocystis carinii pneumonia is uncommon demonstrated a survival benefit consistent with previous randomized trials. Further studies are needed to assess the optimal time of commencement of prophylaxis, as widespread co-trimoxazole use will lead to increasing antimicrobial resistance to other major pathogens in Africa.

Association between tuberculosis and HIV disease progression in a high tuberculosis prevalence area

SETTING

Adult human immunodeficiency virus (HIV) clinics affiliated to the University of Cape Town, South Africa.

OBJECTIVE

To assess the impact of tuberculosis on HIV-1 disease progression in an area with high tuberculosis prevalence and minimal antiretroviral therapy use.

DESIGN

Prospective patient cohort study.

METHODS

Age, race, risk status, CD4+ T-lymphocyte count, history of AIDS, prophylactic co-trimoxazole and antiretroviral therapy were controlled for in a time-dependent Cox proportional hazards regression model.

RESULTS

Tuberculosis fulfilling the case definition developed in 158/609 patients in the 5-year observation period. Tuberculosis was associated with an increased risk of AIDS (adjusted risk ratio [RR] = 1.60, 95% confidence interval [CI] 1.08-2.41; P = 0.02) and death (adjusted RR = 2.16, 95% CI 1.29-3.59; P = 0.003). In a stratified analysis, the increased mortality associated with tuberculosis was observed only in patients with CD4+ T-lymphocyte count > 200 cells/microliter and in those without AIDS at baseline.

CONCLUSION

The onset of tuberculosis in HIV-infected patients is associated with an increased risk of AIDS and death. Although a causal link cannot be established in an observational study, our findings support the view that prolonged immune activation induced by tuberculosis leads to prolonged increased HIV replication and consequent accelerated disease progression.