SHE sits before me, a frail woman of 28, pregnant for the fourth time. Her chest X-ray before treatment shows severe lung disease, and further testing reveals she harbours drug-resistant tuberculosis. She tells me she lives in a three-room house with 28 persons, and is the sixth occupant to contract TB. She will now receive daily injections for eight months, and continue with 26 pills a day for a total of 20 months.

She may lose her hearing, vomit, have abdominal pain from side effects, but if she stops treatment, she will have spread the same TB to many others before she dies. She had been cautioned against pregnancy, but her unemployed husband cannot be convinced that the potent drugs would hurt the unborn child. An almost daily encounter with this class of patients at the Indus Hospital in Karachi has taught us the realities of life in the underworld of infectious diseases.

Pakistan has the dubious distinction of being the country with the fifth highest burden of TB in the world, following India, China, Indonesia and the Philippines — all resulting from poverty, overcrowding and malnutrition. According to WHO, 50,000 new cases are added each year to the existing pool of 550,000 cases in Pakistan, of which 15,000 are drug-resistant. Thirty-five thousand die annually. In most countries more men have TB, but in Pakistan more women of childbearing age are affected, often with severe and advanced disease as a result of multiple pregnancies, poor nutrition and restricted approach to healthcare.

Some 35,000 people die annually of tuberculosis in Pakistan.

The wily bacterium called Mycobacterium tuberculosis (MTb) has existed since prehistoric times. Identified in Egyptian mummies over 5,000 years ago, it has survived through centuries. A cough or sneeze from an infected person aerosolises the bacteria-containing droplets. Dried droplets float in confined spaces and remain infectious for several hours. Persons sharing the same air space at close range for several hours and inhaling large doses of MTb are likely to get infected. Despite close exposure, 70 per cent will never acquire the disease. Of the 30pc who acquire the bacteria, 5-10pc will develop active disease in the next few months to two years, while the rest will remain latently infected.

Of those harbouring these dormant bacteria, 5-10pc may reactivate MTb several years to decades later, if their immunity wanes, while the remaining 80-90pc will contain the bacteria indefinitely. Overall percentages may appear low, but given our large population, the absolute number of diseased persons escalates into the hundreds of thousands. Exposed children are more likely to get TB earlier and in severe forms, and are less likely to be diagnosed easily.

It surprises laypersons to know that TB may not be confined to the lungs alone. MTb can crawl like termites to any organ — glands, intestine, reproductive system, bones, joints, skin or the nervous system. The deep-seated disease is understandably more difficult to diagnose and treat. Untrained doctors may not recognise TB or treat it incorrectly, and poor communication with patients may lead to poor drug adherence. ‘Teasing’ MTb with irregular doses causes it to mutate and become resistant to conventional drugs. Resorting to second-line drugs entails toxic injections and pills for up to two years, after which only 60pc may be cured permanently. Many patients relapse, causing lungs to become irreparably damaged.

WHO is seriously concerned about TB control in developing countries. With support from the Global Fund, Pakistan operates a large network of TB diagnostics and clinics through the National TB Con­trol Programme (NTP), which provides comprehensive training to doctors, establishes national reference laboratories and arranges quality drug distribution through provincial TB programmes. The task before NTP is enormous, as illiteracy, stigma and overcrowding are challenges beyond its scope. Patients who opt to take medicines through private care often consume substandard drugs or suffer from drug stock-outs, thus perpetuating drug resistance.

Control of any disease is best achieved through awareness building to erase myths and stigmas. Information-flows at the grass roots about disease source, transmission, early diagnosis, treatment and outcome are essential for cure. Patients should be counselled about healthy nutrition and completion of the prescribed course of treatment. Coupled with professional counselling and liaison with the treating doctor, this will achieve complete cure in a majority of patients. Prevention of spread to others will ultimately lead to TB control.

On World TB Day, it is underscored that this ancient disease is the biggest killer among all infectious diseases in Pakistan. TB programmes must find, treat and prevent TB, along with the government’s earnest pitch for population control which is seminal to poverty, overcrowding and malnutrition. Let us resolve to end TB now.

The writer is an infectious diseases specialist.

Published in Dawn, March 24th, 2019