Chagas diagnostics now "an urgent global issue"
This article was originally published in Clinica
World health experts agree there is an urgent need to develop a screening and diagnostic test for Chagas, the serious chronic infection that has long been endemic to the Americas but is now being recognised as a global threat.
Last month saw the creation of a Global Network for Chagas Elimination, to implement a new strategy to improve the control and treatment of this transmissible disease, which will be reliant on effective diagnostics. With a target to eliminate Chagas by 2010, the network of expert-led technical groups will focus on key elements of Chagas control, including: identifying a diagnostic test to support both screening and diagnosis of infection; extending measures to prevent secondary and congenital transmission; and strengthening epidemiological surveillance.
Efforts to tackle Chagas in Latin America, where the insect-borne Trypanosoma cruzi parasite is endemic, have reduced the number of cases in the region from an estimated 20 million in the 1980s to around 8 million, and in some countries it is considered under control. However, the emergence of the disease in non-endemic countries - including in the EU, Canada and the US - is a source of growing concern and "demonstrates the need to globalise our efforts", according to WHO director-general Dr Margaret Chan.
"Much-needed screening tool"
The biggest challenge posed by Chagas remains the diagnosis of this complex, often long latent, but chronically debilitating and potentially very serious disease, that can ultimately develop into acute cardiopathies and gastrointestinal complications that require complex surgery. The development of an effective test - which differentiates T cruzi from its related non-pathogenic T rangeli, for example - would provide a much-needed screening tool to avert congenital (transplacental) and non-congenital (notably through blood transfusion or organ transplant) transmission.
"Remarkable success has been achieved in the Americas in eliminating vectorial [ie insect-borne] transmission of Chagas. Much remains to be done, however, to reduce the risk of transmission to recipients of blood or blood products obtained from migrants from endemic areas, and to ensure screening and diagnosis of congenital disease," said Dr Mirta Roses, director of the Pan American Health Organization (PAHO) and WHO regional office.