Human T lymphotropic virus type I (HTLV-I) infection in neurological patients in Salvador, Bahia, Brazil

Spasticity distribution and severity in individuals with HTLV-1-associated myelopathy/tropical spastic paraparesis

In individuals with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), spasticity is one of the main symptoms. The neurological signs of the disease are well defined, but details of how spasticity appears in these individuals have not been well explored. To describe spasticity location and severity of HAM/TSP individuals. Cross-sectional study with individuals older than 18 years, diagnosed with HAM/TSP and with lower limb spasticity. Pregnant women, individuals with other associated neurological diseases, and those using antispastic drugs were not included. Spasticity was assessed by the Modified Ashworth Scale (MAS), applied to the abductor, adductor, flexor, and extensor muscles of the hips, flexors, and extensors of the knees, dorsiflexors, plantiflexors, evertors, and inverters of the foot. Thirty participants were included. The plantiflexor muscles (90%), knee extensors (80%), knee flexors (63,3%), and adductors (50%) were most frequently affected by spasticity. Twenty-three (76.7%) individuals had mixed spasticity, 5 (16.7%) with distal spasticity and 2 (6.7%) with proximal spasticity. MAS was similar between the lower limbs in at least 6 of the 10 muscle groups of each individual. Spasticity was mostly mixed in the lower limbs, with more frequently mild severity. The individuals were partially symmetrical between the lower limbs. The most affected muscle groups were the plantiflexors, knee extensors and flexors and the hip adductors, consecutively, being predominantly symmetrical.

Lymphotropic Viruses EBV, KSHV and HTLV in Latin America: Epidemiology and Associated Malignancies. A Literature-Based Study by the RIAL-CYTED

The Epstein-Barr virus (EBV), Kaposi sarcoma herpesvirus (KSHV) and human T-lymphotropic virus (HTLV-1) are lymphomagenic viruses with region-specific induced morbidity. The RIAL-CYTED aims to increase the knowledge of lymphoma in Latin America (LA), and, as such, we systematically analyzed the literature to better understand our risk for virus-induced lymphoma. We observed that high endemicity regions for certain lymphomas, e.g., Mexico and Peru, have a high incidence of EBV-positive lymphomas of T/NK cell origin. Peru also carries the highest frequency of EBV-positive classical Hodgkin lymphoma (HL) and EBV-positive diffuse large B cell lymphoma, not otherwise specified (NOS), than any other LA country. Adult T cell lymphoma is endemic to the North of Brazil and Chile. While only few cases of KSHV-positive lymphomas were found, in spite of the close correlation of Kaposi sarcoma and the prevalence of pathogenic types of KSHV. Both EBV-associated HL and Burkitt lymphoma mainly affect young children, unlike in developed countries, in which adolescents and young adults are the most affected, correlating with an early EBV seroconversion for LA population despite of lack of infectious mononucleosis symptoms. High endemicity of KSHV and HTLV infection was observed among Amerindian populations, with differences between Amazonian and Andean populations.

Ocular lesions in HTLV-1 infected patients from Salvador, State of Bahia: the city with the highest prevalence of this infection in Brazil

In order to determine the prevalence of ocular lesions in HTLV-1 infected patients in Salvador Bahia, a transversal study was conducted on 140 HTLV-1 infected patients (90 asymptomatic and 50 tropical spastic paraparesis/HTLV-1-associated myelopathy) between June 2004 and November 2005. The ophthalmological examination included visual acuity measurement, ocular motility, biomicroscopy of the anterior and posterior chambers, intraocular pressure and evaluation of lachrymal secretion. Observation verified 4 (2.8%) out of 140 patients with uveitis (two patients had intermediate uveitis and two had pan-uveitis) and 39 (36.4%) out of 107 patients with keratoconjunctivitis sicca. The prevalence of Keratoconjunctivitis sicca was significantly higher among the TSP/HAM patients (OR age adjusted=3.64; 95%CI 1.59-8.32). Uveitis and corneal opacities were also important findings, indicating the strong need for periodic ophthalmological follow-up in all HTLV-1 subjects.

Proposal for diagnostic criteria of tropical spastic paraparesis/HTLV-I-associated myelopathy (TSP/HAM)

After the first description of TSP/HAM in 1985 and the elaboration of WHO's diagnostic criteria in 1988, the experience of the professionals in this field has increased so that a critical reappraisal of these diagnostic guidelines was considered timely. Brazilian neurologists and observers from other countries met recently to discuss and propose a modified model for diagnosing TSP/HAM with levels of ascertainment as definite, probable, and possible, according to myelopathic symptoms, serological findings, and/or detection of HTLV-I DNA and exclusion of other disorders.

HTLV-I in the general population of Salvador, Brazil: a city with African ethnic and sociodemographic characteristics

The city of Salvador has the highest prevalence of HTLV-I among blood donors in Brazil. To study the prevalence of HTLV-I among the general population of Salvador, 30 "sentinel surveillance areas" were selected for the investigation of various infectious diseases, and 1385 individuals within these areas were surveyed according to a simple random sample procedure. ELISA was used to screen plasma samples for antibodies to HTLV-I, and the positive samples were tested by a confirmatory assay (Western blotting). The overall prevalence of HTLV-I was 1.76% (23/1385). Infection rates were 1.2% for males and 2.0% for females. Specific prevalence demonstrated an increasing linear trend with age. No one younger than 13 years of age was infected. Multivariate analysis estimated adjusted odds ratios for the association of HTLV-I with age of 9.7 (3.3; 30.4) for females and 12.3 (1.47; 103.1) for males. Less education and income might be associated with HTLV-I infection in females. Phylogenetic analysis of the long terminal repeat fragments showed that most of the samples belonged to the Latin American cluster of the Transcontinental subgroup (Cosmopolitan subtype). For the entire city of Salvador, it is estimated that approximately 40000 individuals are infected with HTLV-I. Our results suggest multiple post-Colombian introductions of African HTLV-Ia strains in Salvador.

Brazilian HTLV type 2a strains from intravenous drug users (IDUs) appear to have originated from two sources: Brazilian Amerindians and European/North American IDUs

In Brazil, HTLV-2 has been detected in blood donors, in intravenous drug users (IDUs) from urban areas, and in Amerindians living in the Amazon basin. Of the three main HTLV-2 subtypes (2a, 2b, and 2d) only subtype 2a has been detected in Brazil. However, a molecular variant of subtype 2a (also called HTLV-2c) characterized by an extended Tax protein has been isolated from Brazilian blood donors, IDUs, and Indians. Here, we analyzed HTLV-2 isolates from 10 IDUs and a Chilean woman living in Salvador, Bahia, Brazil. Sequencing of env, pX, and long terminal repeat (LTR) genes demonstrated that 10 of the isolates are related to the Brazilian subtype 2a molecular variant described previously. We show that most HTLV-2a Brazilian strains comprise a phylogenetic group harboring a considerable degree of diversity within the env region but not within the LTR region. Interestingly, we demonstrated for the first time in Brazil the presence of a subtype 2a in IDUs that is closely related to the prototype Mo but distinct from the Brazilian 2a molecular variant.

Human immunodeficiency virus/acquired immunodeficiency syndrome and tropical diseases: a Brazilian perspective

The paper summarizes recent findings on the epidemiology and pathogenesis of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/Aids), highlighting the role of co-infections with major tropical diseases. Such co-infections have been studied in the Brazilian context since the beginning of the Aids epidemic and are expected to be more frequent and relevant as the Aids epidemic in Brazil proceeds towards smaller municipalities and the countryside, where tropical diseases are endemic. Unlike opportunistic diseases that affect basically the immunocompromised host, most tropical diseases, as well as tuberculosis, are pathogenic on their own, and can affect subjects with mild or no immunosuppression. In the era of highly active anti-retroviral therapies (HAART), opportunistic diseases seem to be on decrease in Brazil, where such medicines are fully available. Benefiting from HAART in terms of restoration of the immune function, putative milder clinical courses are expected in the future for most co-infections, including tropical diseases. On the other hand, from an ecological perspective, the progressive geographic diffusion of Aids makes tropical diseases and tuberculosis a renewed challenge for Brazilian researchers and practitioners dealing with HIV/Aids in the coming years.