Technology

Introduction
Tuberculosis (TB) is an infectious bacterial disease that mainly spreads through contact. The World Health organization estimates that people with TB, on average, infect 10-15 people, although not all those who get infected with the bacteria become sick. Some of them end up being carriers of the disease, that is, they retain the bacteria in the body, infect others but never become seriously ill. To get infected, one has to inhale the minute particles causing the disease, which is usually let out by a person suffering from the disease through coughing, sneezing, spitting or shouting. However, mere contact with person such as shaking hands or mere touching does not bring about an infection.

Airlines and TB
From the transmission modes listed, it is clear that presence of a TB-infected person in an airplane does not necessarily mean an infection for the other passengers. Unlike other respiratory diseases such as Severe Acute Respiratory Syndrome (SARS), whose highly infectious nature justifies an automatic total quarantine for it sufferers, TB is different because its infection is not automatic. In addition, some strains or stages of TB are no longer infectious, yet, for such facts to be established one needs to do a number of tests.

W.H.O guidelines
As is the case when dealing with health matters organizations have to rely on the guidelines issued by W.H.O as a minimum, and thereafter set their own extra guidelines if it so desires. The W.H.O guidelines for the handling of TB patients are contained in its 2006-2015 strategy, also known as stop TB strategy. According to (W.H.O), transmission of TB during flights caught the attention of the W.H.O in the early 1990s when a few cases of people who had been infected with TB started to emerge causing anxiety to a number of travelers. Even of more concern was the infection of the then new strain known as Multi-Drug Resistant TB (MDR-TB). In an effort to restore public confidence in air travel, the organization decided to issue guidelines on the handling of TB patients. The guidelines recognize pulmonary or laryngeal TB as the infectious strain, while at the same time saying that there is no evidence of any bacteriological or clinical infection that has been attributed to air travel exposure.

Air travel is the preferred mode of transport for millions of people each day and with such a number it is near impossible to screen each one of them individually. Given this bottleneck, airlines have to take austerity measures even before they take steps to conform to the W.H.O measures. The risk of transmission of TB is dependent on the length of time one is exposed to the germ-carrying particles, closeness to the carrier and the conditions in the plane such as level of crowding and ventilation. For an airline, especially those engaged in long hour travel, their first focus should be in creating an environment that does not provide ambient conditions for the bacteria to spread. It can do so by ensuring good air quality and reasonable spacing between the passengers.

Some countries demand that all people immigrating to their countries undergo a mandatory testing for TB with those found infected not being allowed to immigrate to the countries. Such countries include the US, UK, Australia and Switzerland. Some require screening to be done in the country of origin others screen them at the entry point while others do the screening at both points.

However, these screenings do not mean much to the airline industry because of their criteria. To begin with, the screening demanded by these countries only affects the asylum seekers, refugees and other immigrants. They are by no means the only people capable of carrying TB, meaning that even if all immigrants are ascertained to be free from the TB, the disease could still come from other quarters. Moreover, a good majority of those using air travels do not fall into these categories. Secondly, TB is transmitted within a very short time hence there is no assurance that the person may not become infected immediately after being declared free of the bacteria.

The W.H.O guidelines focus on passengers whose flights take more than eight hours because these are the people who pose the most challenge in curbing the spread of the disease. In formulating its guidelines, W.H.O is guided by among other things, the need to comply with country-specific laws and to maintain any patient rights inherent in any medical procedure. In addition, W.H.O notes that there are no proven cases of active TB that have ever been linked to infections during air travel (W.H.O). For that reason, precautions taken to minimize risk of TB transmission should have minimal effects on travel and trade (W.H.O).

First among the measures recommended by the W.H.O is the maintenance of passenger records. The information contained in airline passenger documentation should be as thorough as possible to enable easy tracing of passengers. The basis of this is that the guidelines do not provide for screening of passengers before flight, meaning that discovery of people infected with the disease mostly takes place after the flight. That means that if one is suspected to have contacted the bacteria during the flight then he should be easily traceable.

With the exception of those with infectious TB, the guidelines do not provide for denial of travel to TB patients. Those with the infectious strain should be excluded for travel and in case the disease is noted midway then it is recommended that the patient be isolated if possible. Under certain conditions, passengers on board flights that have a TB-infected person on board should be informed. Some of these conditions include duration of exposure, degree of infectiousness of the disease and proximity of the passenger to the other passengers. Other guidelines from the organization cover areas such as ventilation and health of the cabin crew.

Evaluation of TB threat
From the guidelines, it is clear that TB infection is not considered a major threat. In fact, for a case to be of concern it has to meet three conditions, which are they have to be long flights (8 hours), the disease has to be infectious and the passenger has to sit in close proximity with the potentially affected passengers. Without meeting the set criteria then the case will not catch the attention of the authorities. Yet, even with all that slack, the guidelines are still under severe criticisms for being too stringent and time wasting.  According to (Fiore), 13 studies have not linked any active TB to airline infection, and in addtion, the UK government issued guidelines that termed tracing of passengers as unnecessary. Instead, the government wants the passengers under the potential risk to just be informed that they are at risk of contracting the disease. Similarly,  (AFP) cites a study in which 2,761 passengers were screened after they had potential contact with a TB-infected person. Of the 2,761, only 10 returned a positive result, but with a mild infection incapable of causing an active infection. Accordingly therefore, the author dismisses the process guidelines issued by W.H.O as a waste of time and resources.

Conclusion
From the foregoing, it is obvious that TB is of little concern to most travellers. The airplane does not provide the relevant conditions the bacteria needs to survive and infect. The guidelines issued by both countries and W.H.O should be sufficient to give anyone engaged in air travel the confidence to do so. Passengers should instead worry about the other highly infectious diseases such as SARS.