In a prospective autopsy study published in The Lancet of patients who died at a hospital in Lusaka, Zambia, researchers found a large percentage of patients were infected with tuberculosis but had gone undiagnosed and untreated, and 17 percent of patients infected with tuberculosis were indeed infected with multidrug-resistant TB but also remained undiagnosed.
Aiming to assess the burden of pulmonary TB, extrapulmonary TB, undiagnosed subclinical TB, and multidrug-resistant TB, researchers performed autopsies on 125 adults who died in the inpatient general medical wards of the tertiary care referral center. Researchers first performed histopathological examinations to detect rifampicin-resistant TB, and then used the Xpert MTB/RIF assay on tissue samples from patients with detected TB to confirm drug resistance.
Researchers found that of 125 patients, 101 were infected with HIV. They also found 78 patients had TB but only 47 had TB listed as cause of death, which meant 20 patients were infected with TB but had not been diagnosed, and subsequently had not received treatment. Of the 78 patients with TB, 13 had undiagnosed multidrug-resistant TB, and 35 patients had extrapulmonary TB. The risk of extrapulmonary TB was greater among those infected with HIV compared to uninfected patients. Only half of patients infected with HIV had access to antiretroviral therapy at time of death.
Study authors note “the neglected burden of tuberculosis among hospital inpatients might be greater” than in Zambia’s prison population which sees a TB prevalence of 7.6 percent.
“The fact that patients continue to die of tuberculosis at a tertiary care referral center reveals several shortcomings in clinical awareness, recognition, and diagnosis of tuberculosis, coupled with poor laboratory services and an inadequate cascade of tuberculosis health care, from peripheral clinics up to the tertiary care level,” authors wrote.
Study authors call for “more proactive screening for tuberculosis and MDR-TB” worldwide, suggesting screening for TB “on admission for all inpatients, irrespective of admission diagnosis, with the rapid GeneXpert MTB/RIF assay on sputum.”
“Additional screening would go some way to detecting a proportion of the 3 million missed cases of tuberculosis and undiagnosed multidrug-resistant tuberculosis,” authors wrote.