HTLV-1 in South America

Most people who are infected with HTLV-1 show no symptoms but some do develop serious disease.

The problems associated with HTLV-1 infection include:

• Tropical spastic paraparesia and bilateral neurological disease (1 - 4%). 
• Acute leukemia/lymphoma with poor prognosis (1 - 4%)

Also associated with HTLV-1 infection are :

• Norwegian scabies
• Recurrent uveitis

People infected with the roundworm, Strongyloides stercoralis,  and HTLV-1 seem to develop more severe disease

Infections are usually found among poor people and in certain South American (pre-Hispanic) indigenous groups. In North America, the virus is found among some Amerindians from British Columbia.   Also, in South America, predisposition to disease resulting from HTLV-1 infection seems to correlate with a Japanese ancestry and African ancestry. A large proportion of  some South American populations are descended from African immigrants. Here the infection rate is 2 - 5%. It was thought that the virus was introduced from Africa and was then spread to indigenous groups. However, this may not be the case, since HTLV-1 has been found in a Chilean pre-Columbian mummy. Japanese immigrants into South America show high HTLV-1 seropositivity. 17% of older Japanese immigrants in Bolivia exhibit evidence of infection while, in Peru, 15.8% of Japanese immigrants are seropositive. 4% of first generation Japanese born in Peru and none of the second generation were found to harbor the virus. The strain of the virus in the Japanese population is different from that in other South Americans.

Source:  Gotuzzo, E. HTLV-1: a new problem for Latin America ASM News, 67, 144, 2001