People who abuse drugs or alcohol have a greater risk of contracting tuberculosis. The use of drugs and excessive consumption of alcohol damage a person’s organs and weaken their defences (immune system) against illnesses such as TB.
Drug and alcohol abusers may not access a diet that provides all the nutrients needed to stay healthy; they may fail to adhere to their treatment, which may lead to drug-resistant TB, and they may also spend time in places where it’s easier for TB to spread, such as crowded or poorly ventilated homes or social venues.
TB patients with a substance abuse problem may not access health services in time and if they do, they may fail to take their medication as prescribed. Untreated TB is highly contagious and may be fatal, this means sufferers pose an increased risk of passing infectious TB to others and developing drug-resistant TB.
TB treatment can also be complicated for drug users and alcohol abusers because the combination of these and TB medication may lead to liver toxicity, which is particularly dangerous for people who drink too much alcohol. Injecting drug users are at risk of co-infection with viral hepatitis and HIV, which require careful monitoring and alternative drug regimens.
Drug use and injection drug use are essential factors in tuberculosis epidemiology in developed and developing countries. While the incidence of TB in most industrialised nations has declined over the past decade, the burden of disease is increasingly borne by urban sub-populations, including drug users.
Recognising the important relationship between TB and drug use, the World Health Organization, UNAIDS and the UN Office on Drugs and Crime issued a set of guidelines to better coordinate TB care among drug users.
Drug use has been associated with a higher prevalence of latent TB infection and incidence of TB disease. Several studies have characterised the LTBI prevalence (10-59 per cent) among various cohorts of drug users.
The most effective way to reduce TB incidence and mortality is to interrupt transmission. This requires finding and treating individuals with TB early, including those with subclinical disease.
Spatial clustering of individuals with higher rates of progression from infection to disease, such as those with HIV and malnourishment, can also form transmission hotspots.
Illicit drug users have higher TB infection prevalence and disease incidence compared to non-users, likely due to significant within-group transmission and clustered vulnerability.
Increased transmission among people who use illicit drugs could result from the creation of more efficient TB transmitters, increased close contact among transmitters, increased rates of primary progression from infection to disease among contacts, or a combination.
Therefore, the interrogation of illicit drug user networks for TB transmission holds great potential as a target for early case identification and linkage to treatment, with potential benefits of halting transmission to the broader population.
Mwangi is manager, corporate communications-Nacada, while Gikandi is manager, communications-CHS
