In depth analysis of patients with severe SARS-CoV-2 in sub-Saharan Africa demonstrates distinct clinical and immunological profiles.

Although the COVID-19 pandemic has left no country untouched there has been limited research to understand clinical and immunological responses in African populations. Here we comprehensively characterise patients hospitalised with suspected or confirmed COVID-19, and healthy community controls. PCR-confirmed COVID-19 participants were more likely to receive dexamethasone and a beta-lactam antibiotic, and survive to hospital discharge than PCR-/IgG+ and PCR-/IgG-participants. PCR-/IgG+ participants exhibited a nasal and systemic cytokine signature analogous to PCR-confirmed COVID-19 participants, but increased propensity for Staphylococcus aureus and Streptococcus pneumoniae colonisation. We did not find evidence that HIV co-infection in COVID-19 participants was associated with mortality or altered cytokine responses. The nasal immune signature in PCR-/IgG+ and PCR-confirmed COVID-19 participants was distinct and predominated by chemokines and neutrophils. In addition, PCR-/IgG+ individuals with high COVID-19 clinical suspicion had inflammatory profiles analogous to PCR-confirmed disease and potentially represent a target population for COVID-19 treatment strategies.

High mortality and prevalence of HIV and tuberculosis in adults with chronic cough in Malawi: a cohort study.

BACKGROUND: Adults with suspected tuberculosis (TB) in health facilities in Africa have a high risk of death. The risk of death for adults with suspected TB at community-level is not known but may also be high. METHODS: Adults reporting cough of ⩾ 2 weeks (coughers) during a household census of 19,936 adults in a poor urban setting in Malawi were randomly sampled and age-frequency matched with adults without cough ⩾ 2 weeks (controls). At 12 months, participants were traced to establish vital status, offered human immunodeficiency virus (HIV) testing and investigated for TB if symptomatic (sputum for Xpert(®) MTB/RIF, smear microscopy and culture). RESULTS: Of 345 individuals with cough, 245 (71%) were traced, as were 243/345 (70.4%) controls. TB was diagnosed in 8.9% (16/178) of the coughers and 3.7% (7/187) of the controls (P = 0.039). HIV prevalence among coughers was 34.6% (56/162) and 18.8% (32/170) in controls (P = 0.005); of those who were HIV-positive, respectively 26.8% and 18.8% were newly diagnosed. The 12-month risk of death was 4.1% (10/245) in coughers and 2.5% (6/243) in controls (P = 0.317). CONCLUSION: Undiagnosed HIV and TB are common among adults with chronic cough, and mortality is high in this urban setting. Interventions that promote timely seeking of HIV and TB care are needed.

Vitamin D deficiency in Malawian adults with pulmonary tuberculosis: risk factors and treatment outcomes.

SETTING: Vitamin D deficiency is common in African adults with tuberculosis (TB), and may be exacerbated by the metabolic effects of anti-tuberculosis drugs and antiretroviral therapy (ART). It is unclear whether vitamin D deficiency influences response to anti-tuberculosis treatment. OBJECTIVES: To describe risk factors for baseline vitamin D deficiency in Malawian adults with pulmonary TB, assess the relationship between serum 25-hydroxy vitamin D (25[OH]D) concentration and treatment response, and evaluate whether the administration of anti-tuberculosis drugs and ART is deleterious to vitamin D status during treatment. DESIGN: A prospective longitudinal cohort study. RESULTS: The median baseline 25(OH)D concentration of the 169 patients (58% human immunodeficiency virus [HIV] infected) recruited was 57 nmol/l; 47 (28%) had vitamin D deficiency (<50 nmol/l). Baseline 25(OH)D concentrations were lower during the cold season (P < 0.001), with food insecurity (P = 0.034) or in patients who consumed alcohol (P = 0.019). No relationship between vitamin D status and anti-tuberculosis treatment response was found. 25(OH)D concentrations increased during anti-tuberculosis treatment, irrespective of HIV status or use of ART. CONCLUSIONS: Vitamin D deficiency is common among TB patients in Malawi, but this does not influence treatment response. Adverse metabolic effects of drug treatment may be compensated by the positive impact of clinical recovery preventing exacerbation of vitamin D deficiency during anti-tuberculosis treatment.

Small alveolar macrophages are infected preferentially by HIV and exhibit impaired phagocytic function.

HIV-1-infected persons are at higher risk of lower respiratory tract infections than HIV-1-uninfected individuals. This suggests strongly that HIV-infected persons have specific impairment of pulmonary immune responses, but current understanding of how HIV alters pulmonary immunity is incomplete. Alveolar macrophages (AMs), comprising small and large macrophages, are major effectors of innate immunity in the lung. We postulated that HIV-1 impairs pulmonary innate immunity through impairment of AM physiological functions. AMs were obtained by bronchoalveolar lavage from healthy, asymptomatic, antiretroviral therapy-naive HIV-1-infected and HIV-1-uninfected adults. We used novel assays to detect in vivo HIV-infected AMs and to assess AM functions based on the HIV infection status of individual cells. We show that HIV has differential effects on key AM physiological functions, whereby small AMs are infected preferentially by the virus, resulting in selective impairment of phagocytic function. In contrast, HIV has a more generalized effect on AM proteolysis, which does not require direct viral infection. These findings provide new insights into how HIV alters pulmonary innate immunity and the phenotype of AMs that harbors the virus. They underscore the need to clear this HIV reservoir to improve pulmonary immunity and reduce the high incidence of lower respiratory tract infections in HIV-1-infected individuals.

Hypoadrenalism is not associated with early mortality during tuberculosis treatment in Malawi.

SETTING: In the developing world, early mortality within 1 month of commencing tuberculosis (TB) treatment is high, particularly with human immunodeficiency virus (HIV) co-infection. In Malawi, 40% of those who die do so in the first month of treatment. Reasons remain unclear and may include delayed diagnosis, opportunistic infections, immune restoration inflammatory syndrome (IRIS) or malnutrition. One possible contributing factor is underlying hypoadrenalism associated with TB-HIV, exacerbated by rifampicin (RMP) induction of P450 and glucocorticoid metabolism. OBJECTIVE: To assess the prevalence of hypoadrenalism in TB patients before and after commencement of TB treatment, and relationship with early mortality. DESIGN: Prospective descriptive study assessing hypoadrenalism before and after anti-tuberculosis treatment, HIV status and outcome up to 3 months post-treatment. RESULTS: Of 51 patients enrolled, 29 (56.9%) were female (median age 32 years, range 18-62). Of 43 patients HIV-tested, 38 (88.3%) were HIV-positive and 15.7% died within the first month. At 3 months, 11 (21.6%) were known to have died. Adequate cortisol levels were found in 49/51 (95.9%) before commencing RMP. Neither of the two with reduced response died. All 34 patients revealed adequate cortisol responses at 2 weeks. CONCLUSION: No evidence of hypoadrenalism was found in this first study to assess adrenal function and outcome of anti-tuberculosis treatment.

The clinical impact of nucleic acid amplification tests on the diagnosis and management of tuberculosis in a British hospital.

BACKGROUND: Nucleic acid amplification tests (NAAT) based on PCR provide rapid identification of Mycobacterium tuberculosis and the detection of rifampicin resistance. Indications for their use in clinical samples are now included in British tuberculosis guidelines. METHODS: A retrospective audit of patients with suspected mycobacterial infection in a Liverpool hospital between 2002 and 2006. Documentation of the impact of NAAT usage in acid fast bacillus (AFB) microscopy positive samples on clinical practice and the influence of a multidisciplinary group on their appropriate use, compared with British guidelines. RESULTS: Mycobacteria were seen or isolated from 282 patients and identified as M tuberculosis in 181 (64%). NAAT were indicated in 87/123 AFB positive samples and performed in 51 (59%). M tuberculosis was confirmed or excluded by this method in 86% of tested samples within 2 weeks, compared with 7% identified using standard methods. The appropriate use of NAAT increased significantly over the study period. The NAAT result had a clinical impact in 20/51 (39%) tested patients. Culture results suggest the potential for a direct clinical impact in 8/36 (22%) patients in which it was indicated but not sent and 5/36 (14%) patients for whom it was not indicated. Patients managed by the multidisciplinary group had a higher rate of HIV testing and appropriate use of NAAT. CONCLUSIONS: There were significant clinical benefits from the use of nucleic acid amplification tests in this low prevalence setting. Our data suggest that there would be additional benefit from their use with all AFB smear positive clinical samples.

Fully intermittent dosing with drugs for treating tuberculosis in adults.

BACKGROUND: The number of people infected with tuberculosis continues to rise worldwide. Rifampicin-containing treatment regimens can achieve high cure rates. Intermittent drug treatment delivered in the community has the potential to improve adherence to treatment. OBJECTIVES: The objective of this review was to compare the effectiveness of rifampicin-containing short-course chemotherapy regimens, given two or three times a week, with similar regimens given daily in adult patients with pulmonary tuberculosis. SEARCH STRATEGY: We searched the Cochrane Infectious Diseases Group specialized trials register, The Cochrane Controlled Trials Register, MEDLINE, and reference lists of articles. We contacted experts in the field. SELECTION CRITERIA: Randomized and quasi-randomized trials of any multiple drug regimen containing rifampicin in patients with confirmed pulmonary tuberculosis. Treatment had to be given up to three times a week for up to nine months, with any initial daily dosing period not more than one month, and was compared to daily dosing throughout for the same period. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial eligibility and quality. MAIN RESULTS: One trial involving 399 patients was included. The trial compared treatment three times per week with daily treatment for six months. There was no difference in cure rate (198 out of 199 people in the intermittent group compared to all 200 in the daily group), but 5 patients relapsed in the group receiving intermittent therapy compared to one in the group receiving the daily regimen. REVIEWER'S CONCLUSIONS: There is not enough evidence to assess the equivalence of effect between fully intermittent, rifampicin-containing short-course chemotherapy and similar daily therapy in patients with pulmonary tuberculosis. Larger randomized studies are required to establish the equivalence of fully intermittent, short-course chemotherapy, with daily regimens.

Fully intermittent dosing with drugs for tuberculosis.

BACKGROUND: The number of people infected with tuberculosis continues to rise world-wide. Rifampicin-containing treatment regimens can achieve high cure rates. Intermittent drug treatment delivered in the community has the potential to improve adherence to treatment. OBJECTIVES: The objective of this review was to compare the effectiveness of rifampicin-containing short-course chemotherapy regimens, given two or three times a week, with similar regimens given daily in patients with pulmonary tuberculosis. SEARCH STRATEGY: We searched the Cochrane Infectious Diseases Group trials register, the Cochrane Controlled Trials Register, Medline, and reference lists of articles. We contacted experts in the field. SELECTION CRITERIA: Randomised and quasi-randomised trials of any multi-drug regimen containing rifampicin in patients with confirmed pulmonary tuberculosis. Treatment had to be given up to three times a week for up to nine months, with any initial daily dosing period not more than one month, and was compared to daily dosing throughout for the same period. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial eligibility and quality. MAIN RESULTS: One trial involving 399 patients was included. The trial compared treatment three times per week with daily treatment for six months. There was no difference in cure rate (198 out of 199 people in the intermittent group compared to all 200 in the daily group), but 5 patients relapsed in the group receiving intermittent therapy compared to one in the group receiving the daily regimen. REVIEWER'S CONCLUSIONS: There is not enough evidence to assess the equivalence of effect between fully intermittent, rifampicin-containing short-course chemotherapy and similar daily therapy in patients with pulmonary tuberculosis. Larger randomised studies are required to establish the equivalence of fully intermittent, short-course chemotherapy, with daily regimens.

Fully intermittent dosing with drugs for tuberculosis.

BACKGROUND: The number of people infected with tuberculosis continues to rise world-wide. Rifampicin-containing treatment regimens can achieve high cure rates. Intermittent drug treatment delivered in the community has the potential to improve adherence to treatment. OBJECTIVES: The objective of this review was to compare the effectiveness of rifampicin-containing short-course chemotherapy regimens, given two or three times a week, with similar regimens given daily in patients with pulmonary tuberculosis. SEARCH STRATEGY: We searched the Cochrane Infectious Diseases Group trials register, the Cochrane Controlled Trials Register, Medline, and reference lists of articles. We contacted experts in the field. SELECTION CRITERIA: Randomised and quasi-randomised trials of any multi-drug regimen containing rifampicin in patients with confirmed pulmonary tuberculosis. Treatment had to be given up to three times a week for up to nine months, with any initial daily dosing period not more than one month, and was compared to daily dosing throughout for the same period. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial eligibility and quality. MAIN RESULTS: One trial involving 399 patients was included. The trial compared treatment three times per week with daily treatment for six months. There was no difference in cure rate (198 out of 199 people in the intermittent group compared to all 200 in the daily group), but 5 patients relapsed in the group receiving intermittent therapy compared to one in the group receiving the daily regimen. REVIEWER'S CONCLUSIONS: There is not enough evidence to assess the equivalence of effect between fully intermittent, rifampicin-containing short-course chemotherapy and similar daily therapy in patients with pulmonary tuberculosis. Larger randomised studies are required to establish the effectiveness of fully intermittent, short-course chemotherapy.

Pyogenic lung infections: factors for predicting clinical outcome of lung abscess and thoracic empyema.

Lung abscess and thoracic empyema continue to cause significant morbidity and mortality despite appropriate antibiotic therapy and various options for drainage of empyema. Multiple factors, including the patient's general state of health, the presence of underlying disease, the virulence of the pathogen responsible, and the promptness of drainage of empyema, appear to dictate the clinical outcome. However, the available data are derived from uncontrolled, retrospective studies and the high morbidity and mortality rates underscore the need for large prospective studies to better evaluate factors that may predict the clinical outcome of these conditions.

Pyogenic lung infections.

Pyogenic lung infections still occur despite the availability of effective antibiotics for the treatment of patients with acute bacterial pneumonia. Our understanding of the pathogenesis and management of these conditions has steadily improved over the past few decades, although some areas remain obscure. The effect of HIV infection on the incidence of pyogenic lung infections remains largely unknown, and large studies are required to evaluate this. Burkholderia (formerly Pseudomonas) cepacia strains are now recognized as important respiratory pathogens in patients with cystic fibrosis, and the high transmissibility of some strains, combined with their inherent multiple antibiotic resistance, are continuing causes for concern.