The role of macroscopic sputum quality assessments to optimise sputum testing for tuberculosis.

SETTING: Community-wide active case finding for tuberculosis (TB) using Xpert® MTB/RIF as the primary screening tool, Ca Mau Province, Viet Nam. OBJECTIVES: To determine whether macroscopic sputum quality characteristics (sputum colour and volume) can be used to predict Xpert MTB-negative sputum and hence exclude sputum samples from testing. DESIGN: Field staff conducted household visits to approximately 51,200 adults in 58 villages randomly selected from throughout the province. Sputum samples from all screened participants who were able to produce ⩾1 ml sputum underwent macroscopic sputum assessment and were tested with Xpert. RESULTS: Of the 21,624 sputum samples tested, 159 (0.74%) were Xpert MTB-positive; 93% of the samples were 1-2 ml and nearly all were mucoid (93%) or mucopurulent (5.7%). One salivary sample was Xpert MTB-positive (2.0% of all salivary samples). The lowest positive predictive value for any sputum volume or colour characteristic was 0.66%. This was not substantially different from the overall prevalence of positive sputum Xpert MTB (0.74%). CONCLUSION: Sputum colour and volume cannot be used to predict the presence or absence of M. tuberculosis in sputum detected using Xpert. These sputum quality parameters cannot therefore be used to exclude sputum samples from testing for TB.

Furosemide-induced natriuresis as a test to identify cirrhotic patients with refractory ascites.

The diagnosis of refractory ascites in cirrhotic patients carries a poor prognosis and liver transplantation should always be considered in this situation. Identification of patients who will not respond to diuretic therapy usually requires several weeks of observation during which a trial of diuretics is instituted using stepwise increases in dosage in order to classify ascites as refractory. In the present study we evaluated the effect of a single dose of 80 mg intravenous furosemide on urinary sodium excretion over 8 hours in cirrhotic patients with ascites responsive to diuretic treatment (group 1; n = 14) and patients with refractory ascites (group 2; n = 15). The test was performed after 3 days without diuretics and patients were on a 80 mEq sodium/day diet. Refractory ascites was defined by the absence of response after 3 months of high doses of diuretics (spironolactone 200 mg/d + furosemide 80 mg/d + metolazone 2.5 mg/d) and the need for repeated paracentesis. The two groups had similar degrees of liver and renal dysfunction as assessed by the Pugh score and creatinine clearance. The effects of furosemide on 8-hour natriuresis was much higher in patients with responsive ascites as compared with patients with refractory ascites (125 +/- 46 vs. 30 +/- 16 mEq; mean +/- SD; P <.0001). A natriuresis lower than 50 mEq/8 hours was observed in all group-2 patients as compared with none from group 1. The present study shows that patients with refractory ascites can be identified quickly and accurately by using this simple furosemide-induced natriuresis test, which could be very useful to select patients for liver transplantation.

Long-term evaluation of immune status in leprosy patients undergoing multiple drug therapy.

A long-term survey of leprosy patients of all clinical types, starting at the time of diagnosis, was carried out to monitor clinical, bacteriological and immunological parameters at regular intervals during multiple drug therapy (MDT). The patients were assigned to two groups for treatment following WHO guidelines: paucibacillary (PB) and multibacillary (MB). Immunoglobulin levels, specific antibodies, skin-test responses to different soluble mycobacterial antigens (new tuberculins), and in vitro proliferative responses to mitogens and to antigens were measured during treatment, as were clinical changes, the bacterial index, and clinical improvement. No exact relations between disease activity and IgM antibody levels, both IgM immunoglobulin and specific IgM antibody to a species-specific antigen (ND-O-BSA), could be seen for MB patients. Changes in in vitro cell-mediated immunity and skin-test response seemed to be more directly related to the bacterial load and could reflect the improvement of bacteriological and clinical parameters during MDT.