Cervical shedding of human T cell lymphotropic virus type I is associated with cervicitis.

Human T cell lymphotropic virus type I (HTLV-I) is sexually transmitted. The purpose of this study was to determine the prevalence and risk factors for cervical shedding of HTLV-I DNA among Peruvian sex workers. HTLV tax DNA was detected in cervical specimens from 43 (68%) of 63 HTLV-I-infected sex workers and in samples obtained during 113 (52%) of 216 clinic visits between 1993 and 1997. Detection of HTLV DNA was associated with the presence of > or =30 polymorphonuclear cells (PMNs) within cervical mucus per 100x microscopic field (odds ratio [OR], 4.3, 95% confidence interval [CI], 1.8-10.1) and with the presence of cervical secretions (OR, 2.0; 95% CI 1.2-3.4). Hormonal contraceptive use (OR 1.7; 95% CI, 0.8-3.6) and concomitant cervical infection by Chlamydia trachomatis (OR, 1.5; 95% CI, 0.3-4.3) or Neisseria gonorrhoeae (OR, 1.1; 95% CI, 0.6-3.7) were not significantly associated with HTLV-I shedding. Our results suggest that cervicitis may increase cervical HTLV-I shedding and the sexual transmission of this virus.

Chemokine receptor gene polymorphisms and risk of human T lymphotropic virus type I infection in Jamaica.

Polymorphisms of some chemokine receptor genes and their ligands are associated with susceptibility and progression of human immunodeficiency virus infection. This study assessed whether these variants are also responsible for susceptibility to infection with human T lymphotropic virus (HTLV) type I. Frequencies of CCR5-Delta 32, CCR2-64I, and SDF-1-3'A genotype among 116 HTLV-I-positive and 126 HTLV-I-negative persons of African descent in Jamaica were 1.0%, 14.9%, and 5.4%, respectively. The association of HTLV-I infection with the most common variant, CCR2-64I, was examined in 532 subjects. Thirteen (5.4%) of 241 HTLV-I-negative subjects were homozygous for CCR2-64I, versus 3 (1.0%) of 291 HTLV-I-positive subjects (P=.005). Among HTLV-I carriers, provirus load and antibody titer were not significantly different in persons with CCR2-+/64I or CCR2-+/+. These findings suggest that CCR2-64I, or alleles in linkage disequilibrium with it, may affect the risk of HTLV-I infection in a recessive manner.

Estimating the time of HTLV-I infection following mother-to-child transmission in a breast-feeding population in Jamaica

Mother-to-child transmission of human T-cell lymphotrophic virus type 1 (HTLV-I) is primarily due to prolonged breast-feeding (>6 months) in the post-natal period. Most infant infections are not identifiable until 12-18 months of age by available whole virus Western blot serologic tests because of their inability to distinguish passively transferred maternal antibody from infant antibody. We investigated two methods to assess more accurately the time of infant infection. In prospectively collected serial biospecimens, HTLV-I-specific immunoglobulin (Ig) isotypes of IgM and IgA were determined by Western blot and HTLV-I proviral DNA was detected by polymerase chain reaction (PCR). IgA and IgG reactivity was assessed in periodic serum samples from 16 HTLV-I-seropositive children while IgM reactivity was observed in 100 percent of children at 24 months of age and 73 percent of children at 6-12 months of age; however, this could represent maternal and not infant antibody. Both IgA and IgM reactivity were insensitive indicators of infection, with only 50 percent of children showing reactivity at 24 months of age. PCR testing was performed in biospecimens obtained from 11 of these children. An estimated median time of infection of 11.9 months was determined by PCR, which was similar to the median time to infection determined by whole virus Western blot (12.4 months; P=0.72). PCR Tests support a median time to infection that is similar to that estimated by whole virus Western blot. (AU)

Low prevalence of HTLV-II in mayan indians in the Yucatan Peninsula, Mexico

Infection with HTLV-II endemic in Ameridians, with prevalence ranging from 0.89 percent - 33 percent. To determine the prevalence of HTLV-II among indigenous Mayans in the Yucatan Peninsula of Mexico, 440 indigenous Mayans were recruited, all native to and residents of one of six Mayan communities in the Yucatan Peninsula, (Xohuayan n=144, Yaxachen n=101, Kanxoc n=84, Xocen n=40, Nabalan N=46 and X'calot n=25) between May, 1992 and June, 1993. All of the above are pre-Hispanic settlements located in tropical forest with no immigrations for over 50 years. Of the 440 indigenous Mayans, only one woman from the X'calot tribe (0.23 percent) was shown to be infected with HTVL-II. A high precentage of indeterminate results was found (22/439, 5 percent), three of which were accounted for by the husband and two children of the positive female case. PCR analysis followed by specific restriction digestion demonstrated the virus to be of the HTVL-IIb subtype, similar to that described in the Guaymi Indians from Panama. The presence of HTVL-II in the Mayan ethnos, and in other Ameridian populatins supports the idea that HTVL-II is an ancestral virus in America and that it has been sustained in "closed" communities

Viral specific humoral immune responses following transfusion-related transmission of human T cell lymphotropic virus type-I infection

The immunoglobulin (Ig) isotypes of antibodies to specific proteins of the human T cell lymphotropic virus type I (HTLV-I) were determined by Western blot analysis of serial specimens from six individuals who experienced HTLV-I seroconversion following blood transfusion; five remained asymptomatic carriers, while one developed HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP) 32 weeks posttransfusion. Analysis of Ig isotypes demonstrated that while IgM was the most frequent early response to gag (p19, p24) and env (r21e) proteins within the first 3 months following transfusion, IgG and IgA responses could also be detected within this period. HTLV-I-specific antibody responses plateaued in all Ig isotypes, including IgM, wtihin the next 4- to 6-months period following transfusion and pesisted through the entire study period (> 4 years). Comparison of antibody profiles in Ig isotypes and IgG1 and IgG3 subclass among asymptomatic carriers and one individual who developed HAM/TSP demonstrated no evidence of isotypic prominence or IgG subclass restriction in either group. These results indicate the appearance of HTLV-I-specific IgM that persists even after the primary infection and suggest that such responses does not appear to provide an early marker of seroconversion. Further, we found no evidence of isotypic prominence or restriction of the antibody response in recipients who remained asymptomatic compared to one who developed HAM/TS.(AU)