LATENT TUBERCULOSIS INFECTION IN CHILDREN: A CALL FOR REVISED TREATMENT GUIDELINES

ABSTRACT

BACKGROUND:  Worldwide surveillance data demonstrate an increased rate of anti-tuberculosis drug resistance.  Guidelines for latent tuberculosis infection (LTBI) do not consider drug resistance patterns when recommending treatment for immigrant children.

OBJECTIVES:  The purpose of this research was to decide at what rate of isoniazid (INH) resistance a different regimen than the currently recommended INH for 9 months should be considered. 

METHODS:  We constructed a decision tree using data from the published literature on latent TB.  We studied three regimens considered to be effective for susceptible organisms: a) INH for 9 months, b) rifampin for 6 months, c) INH for 9 months plus rifampin for 6 months.  We included a no treatment option.  Our base case was a two-year-old child from Russia with a tuberculin skin test reaction of 12mm.  We assumed a societal perspective and expressed results as cost and cost per case of TB prevented. 

We conducted sensitivity analyses to test the stability of our model.  

RESULTS:  Rifampin was the least costly treatment regimen for any child arriving from an area with an INH resistance rate of 11% or higher.  Combined treatment with INH plus rifampin was the most effective treatment, but would cost >$1M per reactivation case prevented.  INH would become the least costly regimen if any of the following thresholds were met: rifampin resistance given INH resistance >82%, rifampin resistance given no INH resistance >9%, cost of rifampin > $47/month, effectiveness of rifampin <63%, effectiveness of INH > 74% and cost of pulmonary TB <$7,661.  Other variables did not affect the decision.

CONCLUSION:

Because of high prevalence of INH resistance, a rifampin-containing regimen should be considered for children with LTBI originating from Andorra, Armenia, Azerbaijan, China, C™te d'Ivoire, Ecuador, Estonia, Georgia, India, Kazakstan, Latvia, Lebanon, Lithuania, Republic of Moldova, Mozambique, Perœ, Russia, Ukraine, Uzbekistan and Vietnam.

COST-EFFECTIVENESS OF EXAMINED TB-TREATMENT REGIMENS

Regimen	Average Cost	Incremental cost	Average Effectiveness	Incremental Effectiveness	Average Cost Effectiveness	Incremental Cost Effectiveness
Rifampin	$1,173		0.94489		$1,241
INH	$1,235	$62	0.93503	-0.00986	$1,321	Dominated
INH + Rifampin	$1,364	$191	0.94504	0.000145	$1,443	$1,313,917
No treatment	$1,413	$49	0.87	-0.075037	$1,624	Dominated

 ADDIN