The elimination of Chagas' disease from Brazil

Abstract

On 9 June 2006 the Pan American Health Organization (PAHO) presented the Minister of Health of Brazil with the International Elimination of Transmission of Chagas' Disease Certificate. This act was the culmination of an intensive process that began in 1991 with the Southern Cone Initiative, a joint agreement between the governments of Argentina, Bolivia, Brazil, Chile, Paraguay, Uruguay and Peru, to control Chagas' disease by the elimination of the main vector, Triatoma infestans. This initiative has been highly successful and the prevalence area of the vector diminished rapidly in the last years. As a consequence, the current seroprevalence in children aged between 0 and 5 years is of the order of 10(-5), a clear indication that transmission, if it is occurring, is only accidental. In this review I calculate the basic reproduction number, R0, for Chagas' disease and demonstrate that its relatively low value (1.25) explains why vectorial transmission was interrupted relatively easily. In addition, I used a mathematical model to forecast how long the remaining cases of the disease, as well as the additional vertically transmitted cases will last.

Efficacy of benznidazol treatment for asymptomatic chagasic patients from state of Rio Grande do Sul evaluated during a three years follow-up

“…In Brazil, the vector control program, established in 1975 and continuing with the South Cone Initiative, eliminated the main vector, Triatoma infestans, from the country (Massad 2007). The seroprevalence of T. cruzi infection in Brazil among children aged 7-14 years fell 99.8% from 1980-1999 and the absence of seropositivity among young children (aged 0-4 years) is evidence of the interruption of vectorial transmission (Massad 2007). In Brazil, the highest prevalence of T. cruzi infection was found in the states of Rio Grande do Sul, Minas Gerais, São Paulo, Paraná, Goiás and Bahia (Silveira & Rezende 1994, Dias 1997.…”

Cardiac Involvement with Parasitic Infections

“…As a result of these dynamic changes in the population and the coordinated efforts of countries where disease is endemic to interrupt vectorial and trans- Q-R-S and ST-T, Q-R-S and ST-T intervals of the ECG; Q-Tc, the Q-T interval of the ECG corrected for heart rate. (209,222). According to the most recent estimates, there are currently 7.6 million people infected with T. cruzi in Latin America (239).…”

Steady State Stability Analysis of a Chagas Disease Model

“…However, because of the lack of an effective vaccine and the toxicity and questionable efficacy of the current drug treatments during the chronic stages of the disease, controlling the transmission of Chagas disease remains largely based on controlling the vector population and on blood-bank screening [12], [25], [29], [31]. The spraying uses pyrethroid insecticides and has proven to be effective in retarding the spread of the disease and, in some cases, nearly eliminating the domestic insects [11], [22].…”