Human T-lymphotropic virus type 1 infection is frequent in rural communities of the southern Andes of Peru.

OBJECTIVES: To evaluate the presence of human T-lymphotropic virus type 1 (HTLV-1) infection in isolated rural communities in the southern Andes of Peru. METHODS: We conducted a cross-sectional study in five communities located in three provinces in Ayacucho, Peru. The five communities are located at >3000 meters above sea level and are mainly rural, and more than 85% of the population speaks Quechua. Volunteers aged 12 years and older were included. Clinical and epidemiological data were collected, along with a blood sample for serological testing. RESULTS: We included 397 participants; their median age was 41 years (interquartile range 31-57 years) and 69% were women. According to our definitions, 98% were of Quechua origin. HTLV-1 was diagnosed in 11 people: 0/164 in Cangallo, 3/154 (2%) in Vilcashuaman, and 8/79 (10%) in Parinacochas. There were no cases of HTLV-2. All the HTLV-1-positive participants were born in Ayacucho and were of Quechua origin; they ranged in age from 29 to 87 years (median 56 years) and 10/11 were women. Ten were apparently healthy, and one woman was diagnosed with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Three out of 11 had a family member with a lower limb impairment compatible with HAM/TSP. CONCLUSION: The fact that HTLV-1 infection was present in two out of three provinces suggests that HTLV-1 could be highly endemic in the southern Andes in the Quechua population.

Association between onychodystrophy and human T-lymphotropic virus type 1 infection.

OBJECTIVE: To assess the association between human T-lymphotropic virus type 1 (HTLV-1) infection and onychodystrophy. METHODS: This was a cross-sectional study. At our institute, we provide HTLV-1 testing to relatives of HTLV-1-infected people and patients with suspected HTLV-1-associated diseases. The diagnosis of onychodystrophy was made clinically before testing for HTLV-1; the number and distribution of affected nails was registered. We assessed the association between onychodystrophy and HTLV-1 through bi- and multivariable analyses. Logistic regression was used to adjust for age, sex, and indication for HTLV-1 testing, using six affected nails (90(th) percentile) as the cut-off point. RESULTS: Between April 2006 and March 2008, we included 893 subjects; their mean age was 38 years (standard deviation 19 years), and 527 (59%) were women. Onychodystrophy of one or more nails was observed in 323 participants (36%), and 236 subjects (26%) were HTLV-1-positive. The median number of affected nails was higher in HTLV-1-positive than in HTLV-1-negative subjects (Mann-Whitney test, p < 0.001). Thirty-eight of 97 subjects with six or more affected nails (39%) were HTLV-1-infected, compared to 198 of 796 subjects with fewer than six affected nails (25%) (crude OR 1.9, 95% confidence interval (CI) 1.2-3.1; p = 0.003). This association remained significant in the multiple logistic regression model (adjusted OR 2.0, 95% CI 1.2-3.3; p = 0.005). CONCLUSIONS: There is an independent association between HTLV-1 infection and onychodystrophy. Patients with an HTLV-1 infection might have a higher risk for onychomycosis given the abnormal nail plate and a decreased T-cell-mediated immunologic response.