Chagas disease in Japan and in developed countries
Tsutomu Takeuchi, Director of the Institute of Tropical Medicine at Nagasaki University warns public health authorities of the importance of improved treatment of those infected and the adoption of preventive measures
By Heitor Shimizu, in Tokyo
Agência FAPESP– The World Health Organization (WHO) estimates that at least 10 million people throughout the world are infected by Chagas disease, which in 2008 killed 10,000 people. Most of those infected or at risk for developing the disease live in Latin American countries, but the problem is already affecting other areas and has arrived in the developed countries.
In Japan, Chagas disease is a reality that challenges the health sector, according to Tsutomu Takeuchi, Director of the Institute of Tropical Medicine at Nagasaki University, one of the researchers invited to the Japan-Brazil Symposium on Research Collaboration, organized by FAPESP and the Japan Society for the Promotion of Science (JSPS) March 15-16 at Rikkyo University in Tokyo.
“Factors such as economic stagnation and political repression have resulted in the significant flow of people from 17 Latin American countries where Chagas disease is endemic, and is on its way to the developing world. Due to this migration, Chagas disease has become a health threat at the global level,” he said.
According to Takeuchi, it is estimated that 3.8% if the nearly 150,000 immigrants that arrived in Australia in 2006, from countries endemic to Tripanossoma cruzi(the parasite that causes the disease), were infected with the protozoan.
“In 2008, Spain accommodated close to 1.68 million legal and illegal immigrants from Latin American countries Chagas disease is endemic. Among these immigrants, an estimated 5.2% were infected with T. Cruziand 17,400 developed symptoms of the disease,” he said.
According to Takeuchi, in Spain, most of these immigrants were in the city of Barcelona. “From 2007 to 2009, out of 766 patients at one of the city’s health centers, 22 were diagnosed with T. Cruziinfection, with a prevalence rate of 2.87%. Among those infected, 21 were from Bolivia, which has a 16.5% prevalence rate for its immigrants,” he said.
The problem has also reached the United States, a country that receives large contingents of Latin Americans every year. “In 2005, the number of Latin American immigrants living in the United States was 22.8 million and an estimated 300,000 were infected by T. Cruzi. The highest prevalence was reported in immigrants from Bolivia, whose rate was 6.75%, followed by Argentina at 4.13%,” Takeuchi explained.
“In 2010, there were nearly 300,000 immigrants to Japan from Latin American countries, the largest majority, 76.6% of them, from Brazil. Unfortunately, tests on blood donations and serological verification of infection by T. Cruzihave not been extensively adopted to the same extent as in western countries,” he said.
The researcher reported that the Department of Tropical Medicine and Parasitology at the Keio University School of Medicine had been the primary center for serological testing and surveillance for Chagas disease.
“The numbers are still small, but significant. That department analyzed 42 suspected cases and confirmed that 16 of them were positive for the disease. Five developed cardiac symptoms associated with Chagas,” he added.
Takeuchi noted that, in addition to the lack of knowledge about the disease, another important problem related to the presence of Chagas in Japan is the limited availability of medicines to treat those infected, because they are not produced in the country.
“Chagas disease has been ignored in Japan as well as in other developed countries, which has led to a series of stigmas and misunderstandings against Latin American immigrants. Due to the large number of people in this population who do not have health insurance, the communication difficulties and the absence of preventive measures against infection by T. Cruzi, a number of prejudices have arisen in Japanese communities against carriers of the disease, leading to the possibility of social discrimination,” he explained
“Because of this, urgent measures must be taken to improve understanding and medical treatment of Chagas disease and other neglected diseases in Japan as well as in other developed countries,” concluded Takeuchi.