By Joe Lowry

Most people understand the need to screen for TB when people are on the move: it ensures they are healthy to travel, that they will not carry disease with them and that they will be able to work when they get to their destination countries.

But here's the thing IOM also sets out to ensure the health rights of migrants, which means providing health services for people at all stages of the migration cycles. That could mean before they set off, when they are in transit, when the reach their destinations, and indeed when they return to their home countries.

Another strategic objective of the organisation is to avoid disparities in health status and access to health services between migrants and the host population. Simply put, to ensure everyone gets the same treatment.

So, in the course of preparing millions of people to become healthy to travel, and while setting up TB treatment systems for migrants, IOM has, over the years, become one of the leading organisations in TB management.

The Organization runs TB programmes in over 60 countries and is a member of the Stop TB partnership (www.stoptb.org) The process is broadly similar for would-be refugees, immigrants, migrants and all other cased being screened. First of all, clients  are checked for symptoms such as a cough for more than two weeks, fever or weight loss. Then they have a chest x-ray and a tuberculin skin test. If there are signs of TB their sputum samples are investigated in a laboratory.

The laboratory diagnosis of TB in IOM facilities can be broken down into four stages:

Smear microscopy

Sputum smear microscopy is the simplest and cheapest technique that can be used to rapidly screen specimens to diagnose infectious TB cases, and is an excellent tool for monitoring TB treatment progress. Microscopy is highly specific but the test has poor sensitivity, which means that the patient would need to have a large number of TB bacteria in the specimen, otherwise microscopy may miss them, especially for cases of co-infection with HIV, or for cases of extra-pulmonary TB. Furthermore, microscopy cannot distinguish between dead and live bacteria. Regardless of the limitations, all specimens submitted to the IOM laboratories for TB investigations are screened by this method.

Sputum culture

To demonstrate the presence of the active TB organisms in a patient’s specimen the bacterial growth outside of the body must be demonstrated. The sample must be chemically treated, applied to a special growth media, and then incubated for up to eight weeks. This methods allows to detect as little as 10 bacteria per millilitre.

Culture identification

Pathogen strains grown on primary isolation media require further investigation to confirm that the isolated organism is TB bacteria and not other bacteria that may look similar.

Drug Susceptibility Testing

It is very important that TB treatment regimens are appropriate for the individuals being treated. The laboratories provide physicians with important information regarding the susceptibility of the test strains to the drugs routinely used to treat this disease. Timely and accurate information allows the physicians to tailor the drug therapies that result in better outcomes for patients.

After an accurate laboratory diagnosis is made, the journey to cure begins. The disease is treated with a combination of several drugs for at least six months.

Joe Lowry is the Senior Media and Communication for IOM