Monteiro provides a passionate and compelling commentary  on our systematic review and meta-analysis of substance use among street-involved children in resource-constrained settings . It is indeed extremely disheartening that 20 years after the World Health Organization (WHO) identified the issue as a public health priority and developed resources attempting to address the problem, little or nothing has changed except that the numbers of street children have grown.
Using a quantitative method of assessing and understanding substance use among this vulnerable group, we hoped this systematic review, in spite of its limitations, would bring street children's substance use and related issues back to the forefront of the public health agenda. Re-ignition of enthusiasm among researchers, policymakers, advocates and communities to collaborate internationally and move forward mechanisms to improve the health and welfare of these children through policy, research and programmatic initiatives is urgently needed.
Street children's fundamental human rights are being violated on a daily basis, including the right to an adequate standard of living, education, health, access to health-care, protection from all forms of physical or mental violence, injury, abuse, neglect or maltreatment, economic exploitation and substance use, as outlined in the United Nations Convention on the Rights of the Child (CRC) [3, 4]. With estimates indicating that tens of millions of children continue to live and work on the streets world-wide , it is appalling that these young people and their issues are not a priority concern for global public health policymakers, despite 192 countries signing and ratifying the CRC .
We applaud the WHO Program on Substance Abuse Street Children Project and training package initiatives, but believe that, to facilitate internationally comprehensive programming, advocacy and policy changes, more needs to be done. The reports and training documents cited by Dr Monteiro did not fall into the scope of our review. Although limited quantitative data are available in these publications [7, 8] they did not meet our inclusion criteria, as the methods were primarily qualitative and the quantitative measures reported were from organizations utilizing unknown methods and sample sizes for estimating prevalence of substance use. We acknowledge our restriction of English-language publications as a limitation, but suggest that a more appropriate title to Monteiro's commentary might have been simply ‘Lost’, rather than ‘Lost in Translation’ to describe the sad state of street children today.
There is clearly an opportunity for leadership among international organizations such as United Nations Children's Fund (UNICEF), Pan American Health Organization (PAHO) and the WHO to address the plethora of individual and public health issues of street children in resource-constrained settings. At a minimum, stakeholders from academic, government, non-governmental and community-based organizations including street youth leaders should be brought together to develop a research and action framework that will mitigate risks to street children, make recommendations to policymakers, and set a research agenda. It is clearly long overdue that the rights, health and welfare of this largely invisible and extremely vulnerable youth population be put back onto the international agenda.
Declaration of interests