Publications by Dr Patrick Howlett

Dear Editor We undertook an evaluation of former TB patients for pulmonary rehabilitation. Our diagnostic evaluation aimed to implement clinical standards for post-TB lung disease (PTLD) using operational research. 1 Nightingale et al. also issued a clinical statement, addressing diverse post-TB morbidities such as social, economic, neurological, cardiovascular, PTLD and psychiatric impairments. 2 In low-and middle-income African countries (such as Sudan, Ethiopia and Kenya), only 4 in 10 clinicians can diagnose PTLD, contributing to an underestimation of its burden.

Studies of the immune response at the site of disease in extra-pulmonary tuberculosis (EPTB) disease are scarce. In this study, we compared the cellular profile of Mycobacterium tuberculosis (Mtb)-specific T cells in pericardial fluid and peripheral blood in patients with pericardial TB (PCTB). Whole blood and pericardial fluid (PCF) samples were collected at the time of diagnostic sampling, with repeat blood sampling after completion of anti-tubercular treatment (ATT) in 16 PCTB patients, most of them being HIV-1 infected (n=14).

Background

Globally, the number of small-scale miners (SSM) is estimated to be more than 25 million, but it supports the livelihoods of around 100 million individuals. In Tanzania, the number of SSM has increased from an estimated 150,000 in 1987 to ~1.5 million in 2017. The miners are at a high risk of occupational-related health challenges. The study aimed to assess the concentrations of respirable crystalline silica (RCS) and radon among the tanzanite mining communities in Simanjiro District, Tanzania.

An estimated 49·5 million small-scale miners worldwide are exposed to high concentrations of silica during their work. The substantial morbidity and mortality of silicosis and tuberculosis among workers exposed to such intensities have been documented. This Viewpoint raises concern at the failure to respond to a growing epidemic of lung disease (predominantly silicosis and tuberculosis) among small-scale miners.

Occupational exposures are a common and preventable cause of lung disease. About one in six cases of chronic obstructive pulmonary disease (COPD) and asthma worldwide are related to work.

Limited data among miners in Tanzania suggests prevalence of silicosis, obstructive lung disease and restrictive lung disease to be around 1.6%, 1.9% and 8.8% respectively. Our study aimed to determine the prevalence and factors associated with silicosis and impaired lung function among tanzanite mining community in northern Tanzania. We conducted a cross-sectional study, involving 330 miners and 330 peri-mining community members in Mererani mines.

Our understanding of the immune response at the site of disease in extra-pulmonary tuberculosis (EPTB) is still limited. In this study, using flow cytometry, we defined the pericardial fluid (PCF) cellular composition and compared the phenotypic and functional profile of Mycobacterium tuberculosis (Mtb)-specific T cells between PCF and whole blood in 16 patients with pericardial TB (PCTB). We found that lymphocytes were the predominant cell type in PCF in PCTB, with a preferential influx of CD4 T cells.