SAN DIEGO, Calif. – At one of the first sessions of this conference of infectious diseases physicians, scientists discussed an urgent need to scale up tuberculosis prevention efforts globally, especially in light of data expected from the World Health Organization showing that TB has surpassed HIV as a leading cause of death globally.
Dr. Henry Blumberg of Emory University recounted his time as chief epidemiologist at Grady Memorial Hospital in Atlanta in the early 1990s when an underfunded public health system and emerging HIV epidemic resulted in a resurgent TB epidemic in the United States. It was also a time when, before a major renovation, patients were kept together in large open wards – a practice that remains common in the developing world. Three months after an HIV-infected patient was found to be co-infected with tuberculosis, several patients and healthcare workers developed active TB while 35 hospital workers showed latent infection. After the hospital’s renovation and expanded TB control efforts, Grady Memorial now sees almost no cases of hospital-acquired tuberculosis — from an average of more than four patient exposures per month to about one a year.
Expanded tuberculosis control efforts, Blumberg said, include careful screening of patients, separation and isolation, and early diagnosis and treatment, along with environmental and engineering controls like improving air circulation to 12 air changes per hour.
Hospitals and clinics in the developing world, however, don’t have the resources to implement the same control efforts. Effecting infection control in the developing world is “very much back to the future,” Blumberg said.
Inadequate surveillance, health capacity, and environmental controls, along with comingling of HIV and tuberculosis patients drive transmission in resource limited settings, Blumberg said. Most importantly, however, a lack of political commitment inhibits progress against tuberculosis control, he said.
“We need advocacy, funding, and political commitments in the era of multidrug resistance,” he added.
Treating latent TB infection is also a critical part of TB control, said Dr. Carol Dukes Hamilton of FHI 360. In areas with large populations of people who are susceptible to developing active TB disease, including people living with HIV, infants and children under five years of age, people who are suffering from malnutrition or underweight and people living with diabetes, treating latent TB to reduce the TB reservoir and prevent future cases of active TB is critical, she said.
Treating active TB and mass treatment of tuberculosis infection are the most effective interventions, she said. But fears of drug resistance, expense, and difficulties in procuring isoniazid, often interfere with efforts to tackle tuberculosis that is latent, she said.
The current regimen for treating latent tuberculosis — or infection — is six-to-nine months of isoniazid — so long that few people will finish it while many won’t even start when hearing the duration, she said. Studies show that shorter regimens are better for completion but they’re not as effective as the standard, longer regimen. The exception is the alternative regimen of three months of rifapentine and isoniazid, which has been shown to be just as effective as the currently standard course of isoniazid, she said.