Martin P. Grobusch

The Diarylquinoline TMC207 for Multidrug-Resistant Tuberculosis

BACKGROUND The diarylquinoline TMC207 offers a new mechanism of antituberculosis action by inhibiting mycobacterial ATP synthase. TMC207 potently inhibits drug-sensitive and drug-resistant Mycobacterium tuberculosis in vitro and shows bactericidal activity in patients who have drug-susceptible pulmonary tuberculosis. METHODS In the first stage of a two-stage, phase 2, randomized, controlled trial, we randomly assigned 47 patients who had newly diagnosed multidrug-resistant pulmonary tuberculosis to receive either TMC207 (400 mg daily for 2 weeks, followed by 200 mg three times a week for 6 weeks) (23 patients) or placebo (24 patients) in combination with a standard five-drug, second-line antituberculosis regimen. The primary efficacy end point was the conversion of sputum cultures, in liquid broth, from positive to negative. RESULTS The addition of TMC207 to standard therapy for multidrug-resistant tuberculosis reduced the time to conversion to a negative sputum culture, as compared with placebo (hazard ratio, 11.8; 95% confidence interval, 2.3 to 61.3; P=0.003 by Cox regression analysis) and increased the proportion of patients with conversion of sputum culture (48% vs. 9%). The mean log(10) count of colony-forming units in the sputum declined more rapidly in the TMC207 group than in the placebo group. No significant differences in average plasma TMC207 concentrations were noted between patients with and those without culture conversion. Most adverse events were mild to moderate, and only nausea occurred significantly more frequently among patients in the TMC207 group than among patients in the placebo group (26% vs. 4%, P=0.04). CONCLUSIONS The clinical activity of TMC207 validates ATP synthase as a viable target for the treatment of tuberculosis. (ClinicalTrials.gov number, NCT00449644.)

Imported Falciparum Malaria in Europe: Sentinel Surveillance Data from the European Network on Surveillance of Imported Infectious Diseases

Malaria continues to have a high morbidity rate associated among European travelers. Thorough recording of epidemiological and clinical aspects of imported malaria has been helpful in the detection of new outbreaks and areas of developing drug resistance. Sentinel surveillance of data collected prospectively since 1999 has begun within TropNetEurop, a European network focusing on imported infectious diseases. TropNetEurop appears to cover approximately 10% of all patients with malaria seen in Europe. Reports of 1659 immigrants and European patients with Plasmodium falciparum malaria were analyzed for epidemiological information and data on clinical features. Regional data were quite diverse, reflecting local patterns of immigration and international travel. By far, the most infections were imported from West Africa. Europeans had more clinical complications; consequently, all deaths occurred in this group. Compared with European standards, the mortality rate was low (0.6% in Europeans). Data from TropNetEurop member sites can contribute to our understanding of the epidemiological and clinical findings regarding imported falciparum malaria.

Randomized Pilot Trial of Eight Weeks of Bedaquiline (TMC207) Treatment for Multidrug-Resistant Tuberculosis: Long-Term Outcome, Tolerability, and Effect on Emergence of Drug Resistance

ABSTRACT The 2-year follow-up results for a randomized placebo-controlled study of 47 patients with multidrug-resistant pulmonary tuberculosis treated with either the new diarylquinoline TMC207, recently renamed bedaquiline, or placebo, added to the first 8 weeks of a background regimen, are presented. Bedaquiline significantly reduced the time to culture conversion over 24 weeks (hazard ratio, 2.253; 95% confidence interval, 1.08 to 4.71; P = 0.031). With the exception of nausea reported in 26% of patients receiving bedaquiline and none receiving placebo, adverse events occurred at similar frequencies in both groups of patients: bilateral hearing impairment, extremity pain, acne, and noncardiac chest pain occurred in 13 and 21%, 17 and 13%, 9 and 17%, and 4 and 17% of patients, respectively, receiving bedaquiline or placebo. Excluding resistance to ethambutol and ethionamide, only one patient receiving bedaquiline acquired resistance to companion drugs, but five patients receiving placebo (4.8% versus 21.7%; P = 0.18) acquired resistance to companion drugs, and resistance to ofloxacin was acquired in four patients receiving placebo and none receiving bedaquiline (0% versus 22%; 0 = 0.066). In all, 23 patients (49%), including 13 receiving placebo (54%) and 10 receiving bedaquiline (44%), discontinued the study prior to its completion, 12 during the first 24 weeks of treatment. Eight subjects were withdrawn for noncompliance or default, and seven withdrew consent, citing the rigorous program of investigations for safety and pharmacokinetic monitoring. Bedaquiline may contribute to the management of multidrug-resistant tuberculosis by effecting more rapid sputum culture negativity and by preventing acquired resistance to companion drugs.

Early treatment outcomes and HIV status of patients with extensively drug-resistant tuberculosis in South Africa: a retrospective cohort study

BACKGROUND Data from Kwazulu Natal, South Africa, suggest that almost all patients with extensively drug-resistant (XDR) tuberculosis are HIV-positive, with a fatal outcome. Since, there are few data for the treatment-related outcomes of XDR tuberculosis in settings with a high HIV prevalence, we investigated the associations of these diseases in such settings to formulate recommendations for control programmes. METHODS In a retrospective cohort study, we analysed the case records of patients (>16 years old) with XDR tuberculosis (culture-proven at diagnosis) between August, 2002, and February, 2008, at four designated provincial treatment facilities in South Africa. We used Cox proportional hazards regression models to assess risk factors associated with the outcomes-mortality and culture conversion. FINDINGS 195 of 227 patients were analysed. 21 died before initiation of any treatment, and 174 patients (82 with HIV infection) were treated. 62 (36%) of these patients died during follow-up. The number of deaths was not significantly different in patients with or without HIV infection: 34 (41%) of 82 versus 28 (30%) of 92 (p=0.13). Treatment with moxifloxacin (hazard ratio 0.11, 95% CI 0.01-0.82; p=0.03), previous culture-proven multidrug-resistant tuberculosis (5.21, 1.93-14.1; p=0.001), and number of drugs used in a regimen (0.59, 0.45-0.78, p<0.0001) were independent predictors of death. Fewer deaths occurred in patients with HIV infection given highly active antiretroviral therapy than in those who were not (0.38, 0.18-0.80; p=0.01). 33 (19%) of 174 patients showed culture conversion, of which 23 (70%) converted within 6 months of initiation of treatment. INTERPRETATION In South Africa, patients with XDR tuberculosis, a substantial proportion of whom are not infected with HIV, have poor management outcomes. Nevertheless, survival in patients with HIV infection is better than previously reported. The priorities for the country are still prevention of XDR tuberculosis, and early detection and management of multidrug-resistant and XDR tuberculosis through strengthened programmes and laboratory capacity. FUNDING South African Medical Research Council, European Union Framework 7 program, and European Developing Countries Clinical Trials Partnership.

Efficacy and safety of intermittent preventive treatment with sulfadoxine-pyrimethamine for malaria in African infants: a pooled analysis of six randomised, placebo-controlled trials

BACKGROUND Intermittent preventive treatment (IPT) is a promising strategy for malaria control in infants. We undertook a pooled analysis of the safety and efficacy of IPT in infants (IPTi) with sulfadoxine-pyrimethamine in Africa. METHODS We pooled data from six double-blind, randomised, placebo-controlled trials (undertaken one each in Tanzania, Mozambique, and Gabon, and three in Ghana) that assessed the efficacy of IPTi with sulfadoxine-pyrimethamine. In all trials, IPTi or placebo was given to infants at the time of routine vaccinations delivered by WHOs Expanded Program on Immunization. Data from the trials for incidence of clinical malaria, risk of anaemia (packed-cell volume <25% or haemoglobin <80 g/L), and incidence of hospital admissions and adverse events in infants up to 12 months of age were reanalysed by use of standard outcome definitions and time periods. Analysis was by modified intention to treat, including all infants who received at least one dose of IPTi or placebo. FINDINGS The six trials provided data for 7930 infants (IPTi, n=3958; placebo, n=3972). IPTi had a protective efficacy of 30.3% (95% CI 19.8-39.4, p<0.0001) against clinical malaria, 21.3% (8.2-32.5, p=0.002) against the risk of anaemia, 38.1% (12.5-56.2, p=0.007) against hospital admissions associated with malaria parasitaemia, and 22.9% (10.0-34.0, p=0.001) against all-cause hospital admissions. There were 56 deaths in the IPTi group compared with 53 in the placebo group (rate ratio 1.05, 95% CI 0.72-1.54, p=0.79). One death, judged as possibly related to IPTi because it occurred 19 days after a treatment dose, was subsequently attributed to probable sepsis. Four of 676 non-fatal hospital admissions in the IPTi group were deemed related to study treatment compared with five of 860 in the placebo group. None of three serious dermatological adverse events in the IPTi group were judged related to study treatment compared with one of 13 in the placebo group. INTERPRETATION IPTi with sulfadoxine-pyrimethamine was safe and efficacious across a range of malaria transmission settings, suggesting that this intervention is a useful contribution to malaria control. FUNDING Bill & Melinda Gates Foundation.

Epidemiology and Clinical Features of Imported Dengue Fever in Europe: Sentinel Surveillance Data from TropNetEurop

Travelers have the potential both to acquire and to spread dengue virus infection. The incidence of dengue fever (DF) among European travelers certainly is underestimated, because few centers use standardized diagnostic procedures for febrile patients. In addition, DF is currently not reported in most European public health systems. Surveillance has commenced within the framework of a European Network on Imported Infectious Disease Surveillance (TropNetEurop) to gain information on the quantity and severity of cases of dengue imported into Europe. Descriptions of 294 patients with DF were analyzed for epidemiological information and clinical features. By far the most infections were imported from Asia, which suggests a high risk of DF for travelers to that region. Dengue hemorrhagic fever occurred in 7 patients (2.4%) all of whom recovered. Data reported by member sites of the TropNetEurop can contribute to understanding the epidemiology and clinical characteristics of imported DF.

How useful is PCR in the diagnosis of malaria

Polymerase chain reaction (PCR) assays are the most sensitive and specific method to detect malaria parasites, and have acknowledged value in research settings. However, the time lag between sample collection, transportation and processing, and dissemination of results back to the physician limits the usefulness of PCR in routine clinical practice. Furthermore, in most areas with malaria transmission, factors such as limited financial resources, persistent subclinical parasitaemia, inadequate laboratory infrastructures in the poorer, remote rural areas preclude PCR as a diagnostic method. Even in affluent, non-endemic countries, PCR is not a suitable method for routine use. Nonetheless, PCR could be clinically useful in selected situations.

Tuberculosis Diagnostics and Biomarkers: Needs, Challenges, Recent Advances, and Opportunities

Tuberculosis is unique among the major infectious diseases in that it lacks accurate rapid point-of-care diagnostic tests. Failure to control the spread of tuberculosis is largely due to our inability to detect and treat all infectious cases of pulmonary tuberculosis in a timely fashion, allowing continued Mycobacterium tuberculosis transmission within communities. Currently recommended gold-standard diagnostic tests for tuberculosis are laboratory based, and multiple investigations may be necessary over a period of weeks or months before a diagnosis is made. Several new diagnostic tests have recently become available for detecting active tuberculosis disease, screening for latent M. tuberculosis infection, and identifying drug-resistant strains of M. tuberculosis. However, progress toward a robust point-of-care test has been limited, and novel biomarker discovery remains challenging. In the absence of effective prevention strategies, high rates of early case detection and subsequent cure are required for global tuberculosis control. Early case detection is dependent on test accuracy, accessibility, cost, and complexity, but also depends on the political will and funder investment to deliver optimal, sustainable care to those worst affected by the tuberculosis and human immunodeficiency virus epidemics. This review highlights unanswered questions, challenges, recent advances, unresolved operational and technical issues, needs, and opportunities related to tuberculosis diagnostics.

Multiple Origins and Regional Dispersal of Resistant dhps in African Plasmodium falciparum Malaria.

Cally Roper and colleagues analyze the distribution of sulfadoxine resistance mutations and flanking microsatellite loci to trace the emergence and dispersal of drug-resistant Plasmodium falciparum malaria in Africa.

Drug-Resistant Tuberculosis--Current dilemmas, unanswered questions, challenges, and priority needs

Tuberculosis was declared a global emergency by the World Health Organization (WHO) in 1993. Following the declaration and the promotion in 1995 of directly observed treatment short course (DOTS), a cost-effective strategy to contain the tuberculosis epidemic, nearly 7 million lives have been saved compared with the pre-DOTS era, high cure rates have been achieved in most countries worldwide, and the global incidence of tuberculosis has been in a slow decline since the early 2000s. However, the emergence and spread of multidrug-resistant (MDR) tuberculosis, extensively drug-resistant (XDR) tuberculosis, and more recently, totally drug-resistant tuberculosis pose a threat to global tuberculosis control. Multidrug-resistant tuberculosis is a man-made problem. Laboratory facilities for drug susceptibility testing are inadequate in most tuberculosis-endemic countries, especially in Africa; thus diagnosis is missed, routine surveillance is not implemented, and the actual numbers of global drug-resistant tuberculosis cases have yet to be estimated. This exposes an ominous situation and reveals an urgent need for commitment by national programs to health system improvement because the response to MDR tuberculosis requires strong health services in general. Multidrug-resistant tuberculosis and XDR tuberculosis greatly complicate patient management within resource-poor national tuberculosis programs, reducing treatment efficacy and increasing the cost of treatment to the extent that it could bankrupt healthcare financing in tuberculosis-endemic areas. Why, despite nearly 20 years of WHO-promoted activity and >12 years of MDR tuberculosis-specific activity, has the country response to the drug-resistant tuberculosis epidemic been so ineffectual? The current dilemmas, unanswered questions, operational issues, challenges, and priority needs for global drug resistance screening and surveillance, improved treatment regimens, and management of outcomes and prevention of DR tuberculosis are discussed.