I thought TB died out a long time ago - what's going on?

World Health Organisation (WHO) Source:

Tuberculosis (TB), a public health threat for thousands of years, remains a top killer worldwide despite the discovery 50 years ago of drugs that can cure this infectious disease. 8 million new TB cases developed in 2000 and an estimated 2 million men and women died, most 15-45 years old. 95% of cases and 98% of deaths occurred in the developing world.

Africa faces the highest TB rates (per population), but Asia carries the greatest absolute burden and the epidemic is worsening in other regions as well. As seen in the former Soviet republics, economic and social crises can quickly exacerbate the TB epidemic.

One third of the world's population is infected by Mycobacterium tuberculosis (M.TB. usually but not exclusively, by coughing and or sneezing, the infection being contained within the droplets expelled by these actions). Persons with infectious TB spread the infection through the air to people nearby, especially in crowded or poorly ventilated situations.

In general, approx. 90% of infected individuals harbors the bacteria but never develop the disease. Approximately 10% fall ill, either soon after infection, or later in life as their immune systems become impaired or when burdened by physical or emotional stress.

Without any treatment, at least half of those who fall ill will die. People with pulmonary TB can present a range of symptoms, the most frequent of which are a productive cough, fever and / or night sweats.

Due to cultural, access, knowledge, or even financial constraints, patients may delay seeking care and health care providers may fail to detect or treat the disease quickly or effectively, thereby increasing the likelihood of transmitting the disease to others, thereby increasing risk of developing complications and potentially, dying as a result.

As with HIV/AIDS and malaria, the social and economic burden of TB on ill people, and on their families and communities is enormous. Poor people are especially vulnerable to TB because of their underlying health status, adverse living conditions, and their limited access to treatment.

People who suffer from malnutrition or diseases such as HIV/AIDS or diabetes are at greater risk given their impaired ability to fight off infection and illness. Over 12 million people are dually infected with M.tb and HIV worldwide.

More HIV-infected persons die due to TB than to any other opportunistic infection. Up to 60% of TB patients are HIV-positive in some Sub-Saharan African countries and the proportion is rising in Asia.

Poor prescribing, inadequate drug supply, erratic pill taking and self-medication all have contributed to the emergence of Multi drug-resistant TB. Recent standardized national surveys have documented multi-drug resistant TB (MDR-TB) strains across the globe.

Patients with MDR-TB face more complex, higher-cost, and a more toxic treatment regime, and a higher risk of death. As TB crosses all borders and market failures reduce the probability of effective treatment, TB control must be considered a global public good. Increased international cooperation is urgently needed to reverse the epidemic, and move towards elimination of this ancient killer

Why is TB screening important, especially as a lab test is still required?