‘Infections in homeless people can lead to community infections and are associated with malnutrition, long periods of homelessness and high use of medical services,’ says Dr Seena Fazel of the Department of Psychiatry at the University of Oxford, who led the work. ‘Improvements in care of homeless people could have pronounced effects on public health.’
The prevalence of tuberculosis is at least 34 times greater in the homeless population than the general population in the UK. The prevalence of hepatitis C is nearly 50 times greater.
In the US, the prevalence of tuberculosis is at least 46 times greater among homeless people than the general population, and the prevalence of hepatitis C viral infection is increased more than four times.
HIV infection was typically one to twentyfold higher in US homeless people than the general population. No similar data was available for analysis for the UK.
The study by researchers from Oxford University and the Karolinska Institutet in Sweden was funded by the Wellcome Trust. Their findings are published in the journal Lancet Infectious Diseases.
The researchers looked at data from more than 40 studies which assessed the levels of HIV, hepatitis C and tuberculosis among homeless people from 1984 to 2012.
Improvements in care of homeless people could have pronounced effects on public health.
Dr Seena Fazel
They found that although there is considerable variation between countries and regions, homeless people have an overall much higher likelihood of suffering from one of these potentially fatal and debilitating diseases. There are thought to be more than 650,000 homeless people in the US and around 100,000 in the UK, with rates of family homelessness increasing in the US.
The researchers focused on the global prevalence of HIV, hepatitis C and tuberculosis, because these are the most heavily studied infectious diseases among homeless populations. However, high rates of other infectious diseases – such as hepatitis A and B, diphtheria, foot problems and skin infections – have been reported in some studies, suggesting that further research is urgently needed to assess the scale of the problem and allow public health efforts to be appropriately targeted.
The researchers also call for a more active approach to identifying tuberculosis patients in particular.
Dr Fazel adds: ‘Screening for tuberculosis needs to be done by active case-finding. It can’t just be restricted to people with the symptoms of tuberculosis presenting to health services, which happens less and later in marginalised groups, such as homeless people and prisoners, than in the general population.’
More effective treatment and management should be considered including syringe and needle exchange programmes, first-aid centres in large cities, and annual snapshot interventions of homeless populations.
Dr Didier Raoult of the University of Aix-Marseille in France, who was not involved in the work, comments in a related article in the same journal that: ‘Targeted actions are needed to address the susceptibility of homeless people to infection. The risks of epidemics of infectious diseases in homeless populations remain significantly higher than those in the general population in the same country. These increased risks are a public health challenge for the population as a whole. Implementation of specific strategies to reduce these risks is crucial.’