“The health is not all,
but all without the health are no one.” Socrates.
Totally drug resistant; Are
we prepared for this?
Tuberculosis is one of
the most serious infectious diseases of the developing world and it remains the
leading cause of death from infectious disease globally. Tuberculosis (TB) is a contagious and potentially fatal
disease that can affect almost any part of the body but manifests mainly as an
infection of the lungs. It is caused by a bacterial microorganism, the tubercle
bacillus or Mycobacterium.
Totally
drug-resistant tuberculosis (TDR-TB) is a generic term for tuberculosis strains that
are resistant to a wider range of drugs than strains classified as extensively drug-resistant
tuberculosis. TDR-TB has been identified in three countries; India,
Iran, and Italy. The emergence of TDR-TB has been documented in four major
publications. TDR-TB has resulted from further mutations within the bacterial
genome to confer resistance, beyond those seen in XDR- and MDR-TB. Development
of resistance is associated with poor management of cases. Drug resistance
testing occurs in only 5% of TB cases worldwide. Without testing to determine
drug resistance profiles, MDR- or XDR-TB patients may develop resistance to
additional drugs. TDR-TB is
relatively poorly documented, as many countries do not test patient samples
against a broad enough range of drugs to diagnose such a comprehensive array of
resistance. The United
Nations' Special
Programme for Research and Training in Tropical Diseases has set up a TDR Tuberculosis Specimen Bank to archive
specimens of TDR-TB. Multi-drug-resistant
tuberculosis (MDR-TB) is defined as tuberculosis that is
resistant at least to isoniazid (INH) and rifampicin (RMP), the
two most powerful first-line anti-TB
drugs. Isolates that have multiple resistant to any
other combination of anti-TB drugs but not to INH and RMP are not classed as
MDR-TB. Extensively drug-resistant
tuberculosis (XDR-TB) is a form of tuberculosis caused by
bacteria that are resistant to some of the most effective anti-TB drugs. XDR-TB
strains have arisen after the mismanagement of individuals with multidrug-resistant TB (MDR-TB).
Though terms likes such as
“totally drug resistant” have not been clearly defined for tuberculosis by WHO.
While the concept of “total drug resistance” is easily understood in general
terms, in practice, in vitro drug susceptibility testing (DST) is technically
challenging and limitations on the use of results remain: conventional DST for
the drugs that define MDR and XDR-TB has been thoroughly studied and consensus
reached on appropriate methods, critical drug concentrations that define
resistance, and reliability and reproducibility of testing. Data on the
reproducibility and reliability of DST for the remaining SLDs are either much
more limited or have not been established, or the methodology for testing does
not exist.
To be remembered is the fact that the race by all medical
practitioners to find a cure started since the existence of TB down to all its
variants. Yet this mycobacterium seems to elude us as it keeps resisting each
of our solution? Hence, it begs the question will these devastating disease
take its leave? Will it be eradicated completely? Will our generation survive
it? And if yes, will another strain of this mycobacterium exist?
Finally, I ask you all if our medical society of
practitioners will survive these.