ArticlesInduced sputum versus gastric lavage for microbiological confirmation of pulmonary tuberculosis in infants and young children: a prospective study
Introduction
Diagnosis of pulmonary tuberculosis is difficult in infants and young children in whom clinical and radiological signs can be non-specific and variable.1 This difficulty has been compounded by the HIV epidemic, because other HIV-associated lung diseases mimic the clinical and radiological picture of tuberculosis, the development of anergy has reduced the sensitivity of skin testing for tuberculin, and clinical scoring systems have not been developed specifically for HIV-infected children.2, 3
Microbiological confirmation of tuberculosis is desirable for definitive diagnosis, for best use of antituberculous medication, and for epidemiological tracing of isolates. In infants and young children, culture confirmation has relied on specimens from sequential gastric lavages.3 Although sputum induction has been successfully used in adults,4, 5, 6 this technique is not regarded as feasible in young children since they swallow their sputum and do not expectorate. Limitations of gastric lavage, however, include the need for an overnight fast, repeated specimens, and admission of children. Moreover, the procedure is time consuming and unpleasant for both child and health worker. By contrast, sputum induction is less invasive than lavage, quicker to do, and can be done in resource-poor settings or outpatients.
Studies comparing gastric lavage with sputum induction in adults with suspected tuberculosis have reported that the diagnostic yield from sputum is higher.7, 8, 9, 10 However, few studies of sputum induction in young children are available. A study of 30 Malawian children with suspected tuberculosis reported that diagnosis could be confirmed by staining or culture of induced sputum in eight individuals (28%); however, most children were older than 5 years, and the yield from gastric lavage was not measured.11 In a previous study of young children (median age 9 months) admitted for acute pneumonia,12 we reported that sputum induction could be safely and effectively done. We also reported that in 16 children with tuberculosis confirmed by culture, the yield from induced sputum was equivalent to that from gastric lavage.13 However, few children had tuberculosis, only one sample from induced sputum was compared with one to three from lavage, and clinical suspicion of tuberculosis was low since children were admitted for acute pneumonia.13 The aim of the present study was to compare repeated specimens from induced sputum with repeated gastric lavages for yield of Mycobacterium tuberculosis in infants and young children with suspected pulmonary tuberculosis.
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Patients
The 2-year study was done from June, 2000, to June, 2002, in the general paediatric wards of two hospitals in Cape Town, South Africa—Red Cross War Memorial Children's Hospital and Somerset Hospital. Children were enrolled if they had been admitted for suspected pulmonary tuberculosis on the basis of a chronic cough (more than 28 days) and one of the following criteria: household contact known to be infected with tuberculosis within the previous 3 months; loss of weight or failure to gain
Results
250 children underwent sputum induction and gastric lavage; 141 (56%) were male and the median age was 13 months (IQR 6–24). Baseline median respiratory rate of children was 56 (40–64) breaths per minute, and median arterial oxygen saturation was 96% (95–98%). 68 (27%) children were receiving supplemental oxygen at the time of sputum induction; 65 via nasal prongs or cannulae and three via headbox oxygen. 30 children (12%) were known to be HIV-infected at enrolment; of the children whose HIV
Discussion
We have shown that the diagnostic yield from sputum induction was better than that from gastric lavage in infants and young children admitted for suspected pulmonary tuberculosis. One sample from induced sputum yielded twice the number of positive cases than did a single specimen from gastric lavage. The yield from one sample from induced sputum was equivalent to that from three sequential gastric lavages, the recommended clinical practice for microbiological confirmation in infants and young
References (24)
- et al.
Diagnosis and treatment of tuberculosis in children
Lancet Infect Dis
(2003) The relative efficacy of spontaneous sputa, aerosol-induced sputa and gastric aspirates in the bacteriologic diagnosis of pulmonary tuberculosis
Dis Chest
(1966)- et al.
The use of sputum induction for establishing a diagnosis in patients with suspected pulmonary tuberculosis in Malawi
Tuber Lung Dis
(1995) - et al.
Clinical diagnosis of smear-negative pulmonary tuberculosis in low-income countries: the current evidence
Lancet Infect Dis
(2003) - et al.
A critical review of diagnostic approaches used in the diagnosis of childhood tuberculosis
Int J Tuberc Lung Dis
(2002 Dec) Diagnosis of tuberculosis in children
Pediatr Infect Dis J
(2000)- et al.
Sputum induction to improve the diagnostic yield in patients with suspected pulmonary tuberculosis
Int J Tuberc Lung Dis
(1999) - et al.
Yield of sputum induction in the diagnosis of pleural tuberculosis
Am J Respir Crit Care Med
(2003) Sputum induction: simpler, cheaper, and safer: but is it better?
Am J Respir Crit Care Med
(2003)Sputum induction with heated aerosol inhalations for the diagnosis of tuberculosis
Am Rev Resp Dis
(1961)
A comparison of cultures of induced sputum and gastric washings in the diagnosis of tuberculosis
Mayo Clin Proc
The usefulness of induced sputum in the diagnosis of pulmonary tuberculosis
Kekkaku
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