A partially randomised trial of pretomanid, moxifloxacin and pyrazinamide for pulmonary TB

BACKGROUND: Treatment for TB is lengthy and toxic, and new regimens are needed.METHODS: Participants with pulmonary drug-susceptible TB (DS-TB) were randomised to receive: 200 mg pretomanid (Pa, PMD) daily, 400 mg moxifloxacin (M) and 1500 mg pyrazinamide (Z) for 6 months (6Pa200MZ) or 4 months (4Pa200MZ); 100 mg pretomanid daily for 4 months in the same combination (4Pa100MZ); or standard DS-TB treatment for 6 months. The primary outcome was treatment failure or relapse at 12 months post-randomisation. The non-inferiority margin for between-group differences was 12.0%. Recruitment was paused following three deaths and not resumed.RESULTS: Respectively 4/47 (8.5%), 11/57 (19.3%), 14/52 (26.9%) and 1/53 (1.9%) DS-TB outcomes were unfavourable in patients on 6Pa200MZ, 4Pa200MZ, 4Pa100MZ and controls. There was a 6.6% (95% CI -2.2% to 15.4%) difference per protocol and 9.9% (95%CI -4.1% to 23.9%) modified intention-to-treat difference in unfavourable responses between the control and 6Pa200MZ arms. Grade 3+ adverse events affected 68/203 (33.5%) receiving experimental regimens, and 19/68 (27.9%) on control. Ten of 203 (4.9%) participants on experimental arms and 2/68 (2.9%) controls died.CONCLUSION: PaMZ regimens did not achieve non-inferiority in this under-powered trial. An ongoing evaluation of PMD remains a priority.

South African Thoracic Society statement on obstructive airways disease and COVID-19

Asthmatics do not appear to have increased susceptibility to COVID-19.Uncontrolled severe asthma may be associated with worsened COVID-19 outcomes, especially in asthmatics managed with oral corticosteroids. Risk mitigation measures such as hand hygiene, social distancing and wearing of face masks must be observed at all times. Asthma should be managed as outlined in local and international guidelines.Ensure an adequate supply of medication, and inhaled corticosteroids should not be withdrawnChronic obstructive pulmonary disease (COPD) is associated with severe COVID-19 disease and poor outcomes. Maintenance of background medication is important to avoid exacerbations of COPD.Vaccination against influenza is strongly advised for all patients with asthma and COPDVaccination against pneumococcal infection is advisable for patients with COPD. Patients with obstructive airway disease on oral corticosteroids and/or with impaired lung function should take stringent safety precautions. This statement will be updated when more data become available Asthma and COPD occur commonly in South Africa. SARS-CoV-2 is a novel coronavirus, which can result in COVID-19-associated severe respiratory infection with respiratory failure and the need for mechanical ventilation. The South African Thoracic Society has prepared a guidance statement to assist clinicians and patients with asthma and COPD during the current epidemic.

Screening for pulmonary tuberculosis in HIV-infected individuals: AIDS Clinical Trials Group Protocol A5253

BACKGROUND

Improved tuberculosis (TB) screening is urgently needed for human immunodeficiency virus (HIV) infected patients.

METHODS

An observational, multi-country, cross-sectional study of HIV-infected patients to compare a standardized diagnostic evaluation (SDE) for TB with standard of care (SOC). SOC evaluations included TB symptom review (current cough, fever, night sweats and/or weight loss), sputum Ziehl-Neelsen staining and chest radiography. SDE screening added extended clinical signs and symptoms and fluorescent microscopy (FM). All participants underwent all evaluations. Mycobacterium tuberculosis on sputum culture was the primary outcome.

RESULTS

A total of 801 participants were enrolled from Botswana, Malawi, South Africa, Zimbabwe, India, Peru and Brazil. The median age was 33 years; 37% were male, and median CD4 count was 275 cells/mm(3). Thirty-one participants (4%) had a positive culture on Löwenstein-Jensen media and 54 (8%) on MGIT. All but one positive culture came from sub-Saharan Africa, where the prevalence of TB was 54/445 (12%). SOC screening had 54% sensitivity (95%CI 40-67) and 76% specificity (95%CI 72-80). Positive and negative predictive values were respectively 24% and 92%. No elements of the SDE improved the predictive values of SOC.

CONCLUSIONS

Symptom-based screening with smear microscopy was insufficiently sensitive. More sensitive diagnostic testing is required for HIV-infected patients.

Influenza guideline for South Africa--update 2008

OBJECTIVE

The South African Thoracic Society, in conjunction with interested stakeholders, published a Guideline for Influenza Management in Adults in 1999. This year the South African Thoracic Society (SATS) identified the need to revise that guideline for the following reasons: * To indicate the viral strains that are to be incorporated into the vaccine for the 2008 season * To add important new data regarding treatment of influenza * To add a section on influenza in children * To clarify issues in managing and preventing influenza in HIV-infected individuals.

INFLUENZA VIRUS

The influenza virus genus belongs to the family orthomyxoviridae. The haemagglutinin (HA) protein is the outermost protein, responsible for attachment to the host receptor, and is critical in determining the host's immune response to the virus. Changes in the antigenic epitopes of HA therefore allow the virus to escape the host's specific immune response. The genus is classified into three types, A, B and C, on the basis of the antigenic epitopes of the nucleoprotein (NP). Type A, which is widespread in nature in birds and mammals, is the most important type clinically and epidemiologically. It is further divided into subtypes on the basis of the antigenic epitopes of the HA and neuraminidase (NA) proteins. Each of the human subtypes H1N1, H2N2 and H3N2 are further subdivided into strains on the basis of more subtle antigenic properties of the HA protein.

INFLUENZA VACCINATION

Influenza vaccine is the mainstay of influenza prevention strategies. All persons who are at high risk of influenza and its complications because of underlying medical conditions or who are receiving regular medical care for conditions such as chronic pulmonary and cardiac disease, chronic renal diseases, neuromuscular diseases, diabetes mellitus and similar metabolic disorders, and individuals who are immunosuppressed (including HIV-infected persons with CD4 counts above 100 cells/microl and HIV-infected children with CD4 counts >15%), should be vaccinated. Vaccines should be given from at least 2 months prior to the onset of autumn (March in South Africa). The recommended vaccine formulation for 2008 is: * A/Solomon Islands/3/2006 (H1N1) (IVR-145) * A/Brisbane/10/2007 (H3N2) (IVR-147) * B/Florida/4/2006 or B/Brisbane/3/2007.

TREATMENT OF INFLUENZA

Influenza illness is characterised by the acute onset of systemic and respiratory signs occurring in autumn or winter. Recommendations for the Prevention and Control of Influenza have indicated that neither amantadine nor rimantadine should be used for the treatment or chemoprophylaxis of influenza A. NA inhibitors are an important adjunct to influenza vaccination, in both the prevention and treatment of influenza. Because of concerns about the possibility of the development of viral resistance with overuse of these agents, it is recommended that NA inhibitors in the treatment of influenza should be reserved for high-risk or sicker influenza patients.

Symbicort: controlling asthma in adults

Inhaled corticosteroids reduce airway inflammation and bronchial hyper-responsiveness in asthma. Their regular use is associated with a reduction in morbidity and mortality from asthma. International guidelines recommend their use as first-line treatment in asthma and the dose should be increased stepwise in accordance with asthma severity. Short-acting beta2-agonists are recommended for use as reliever medication for the acute relief of symptoms. Long-acting beta2-agonists have a sustained bronchodilator action but are not recommended for use as monotherapy in asthma, particularly because they lack clinically relevant anti-inflammatory action. The seminal observation in a controlled trial that the addition of salmeterol to low-dose inhaled beclomethasone dipropionate was superior to doubling the dose ofthe beclomethasone dipropionate was followed by several well-controlled studies that confirmed this observation. These included multinational and multicentre trials in large numbers of patients and the use of different inhaled corticosteroids and the two long-acting beta2-agonists, formoterol and salmeterol. Therefore level A evidence (randomized controlled trials with a rich body of evidence) is available for this recommendation. Based on this, updated asthma guidelines recommend the addition of long-acting beta2-agonists for chronic asthma that is at least moderately severe or mild asthmathat is not well controlled with low-dose inhaled corticosteroids. Attention was therefore focused on developing combination inhalers that included inhaled corticosteroids and long-acting beta2-agonists in order to simplify asthma treatment and improve adherence to prescribed medication. Symbicort Turbuhaler (budesonide/formoterol in a single inhaler) is one such development. Studies to date in over 800 adult patients have confirmed that budesonide/formoterol is superior to double the dose of budesonide monotherapy and at least as effective and safe as budesonide and formoterol in separate inhalers, These studies also demonstrate that there are no physico-chemical interactions when the two medications are combined in a single inhaler. Symbicort in its easy to use formulation and inhaler device represents a valuable addition to the pharmacological management of asthma.

The 'healthy smoker': a phenomenon of health selection?

The detrimental effects of smoking on lung function have been recognized for several decades. Evidence comes from cross-sectional studies which emphasize that damage, certainly at the level of the small airways, may be detectable after a relatively short smoking history, and from longitudinal studies which show that smoking is associated with an increased rate of function loss over time. Implicit in most published evaluations of the evidence has been the concept that smoking is a habit taken up at random by the general population, and that those who do and do not take up the habit start out with similar levels of lung function. Published material was reviewed for evidence to the contrary, consistent with a health selection process similar to that shown in relation to workplace exposures and labeled the 'healthy worker' effect. Despite the wealth of published data on the topic of lung function in relation to the smoking habit, much is presented in a way which does not permit the concept of the 'healthy smoker' to be addressed. Nevertheless, this review revealed sufficient evidence from cross-sectional studies, as well as evidence from one longitudinal study to support the concept of the 'healthy smoker' as an individual who takes up the habit because his/her lungs are relatively resistant to the effects of smoking. If correct, this means that previous studies, particularly those which were cross-sectional in design and focussed on younger persons, are likely to have underestimated the consequences of smoking on lung function. The concept of the 'healthy smoker' may also throw light on characteristics which identify the 'susceptible smoker'.