Blood pressure and lifestyle on Saba, Netherlands Antilles.

During the 20th century, infectious disease morbidity and mortality generally waned whereas chronic degenerative diseases posed a growing burden at the global level. The population on Saba, Netherlands Antilles has recently experienced such an epidemiologic transition, and hypertension was reported to be extraordinarily high, although no prevalences have been reported and relationships with lifestyle factors associated with rapid modernization have not been explored. In this study, a medical and demographic questionnaires, as well as body composition and blood pressure measures were collected from 278 Saban men and women aged 18-91 years. When age and sex adjusted, 48% of the population was hypertensive. Age, BMI, and Afro-Caribbean descent were all associated with higher blood pressures. In a second phase, 124 individuals of the 278 were invited to receive a longer questionnaire on individual exposure to modernizing influences such as travel and education. Higher blood pressure was associated with having lived in fewer different places in the past; those who stayed only on Saba or Statia had higher blood pressures than those who had also lived in more modernized areas. However, this was no longer statistically significant after adjustment for age and BMI. Lifestyle incongruity was positively associated with higher blood pressure in that those with more discord between material wealth and income were more likely to be hypertensive, and this remained statistically significant after adjustment for age and adiposity. In summary, hypertension is highly prevalent on Saba and tended to be associated with greater age, adiposity, Afro-Caribbean ancestry, and lifestyle incongruity.

Human T-lymphotropic virus type 1: a retrovirus causing chronic myeloneuropathies in tropical and temperate climates

Human T-cell lymphotropic virus type I (HTLV-I), the first human retrovirus to be isolated, is the cause of endemic tropical spastic paraparesis (TSP). Originally, this chronic neurological disorder was described as a disease seen among blacks of low socioeconomic status living in tropical countries, and thus for many decades TSP remained a little known curiousty outside the endemic regions. The link between HTLV-I infection and TSP was made fortuitously, when antibodies to HTLV-I were found in serum and cerebrospinal fluid of TSP patients in Jamaica, Colombia, and Martinique. Soon thereafter a similar disorder, designated HTLV-I associated myelopathy (HAM), was reported from southern Japan. This broadened the geographic and ethnic boundaries of this chronic myelopathy and the disease has now been reported in multiple ethnic groups from more than 40 countries, in both tropical and temperate regions. The name TSP/HAM is now used to include all patients (regardless of race or country of origin) who have HTLV-I-positive endemic TSP or HAM. (AU)

Tropical myeloneuropathies: a new aetiology

Tropical myeloneuropathies are a group of neurological disorders known to occur in subtropical and tropical regions. Many aetiologies have been postulated and investigated over the past 100 years, but no single cause has been found. Recent studies suggest that human T-cell lymphotropic virus HTLV-I is the causative agent of one of these tropical myeloneuropathies, endemic tropical spastic paraparesis, and of a related disorder in southern Japan called HTLV-I-associated myelopathy. Endemic tropical spastic paraparesis is now being reported from geographical and climatic regions that were previously thought to be free of these disorders. (AU)

The role of HTLV-I in tropical spastic paraparesis in Jamaica

We report clinical and laboratory investigations of 47 native-born Jamaican patients with endemic tropical spastic paraparesis and of 1 patient with tropical ataxic neuropathy. Mean age at onset was 40 years, with a female-male preponderance (2.7:1). Neurological features of endemic tropical spastic paraparesis are predominantly those of a spastic paraparesis with variable degrees of proprioceptive and/or superficial sensory impairment. Using enzyme-linked immunoabsorbent assay (ELISA), IgG antibodies to human T-lymphotropic virus type I (HTLV-I) were present in 82 percent of sera and 77 percent of cerebrospinal fluids. On Westren blot analysis, IgG antibodies detected the p19 and p24 gag-encoded core proteins in both serum and cerebrospinal fluid. Titers were tenfold higher by ELISA in serum than in cerebrospinal fluid, and some oligoclonal bands present in fluid were not seen in serum . Serum-cerebrospinal fluid albumin ratios wer normal, and IgG indexes indicated intrathecal IgG synthesis. Histopathological changes showed a chronic inflammatry reaction with mononuclear cell infiltration, perivascular cuffing, and demyelination that was predominant in the lateral colmns. In 1 patient, a retrovirus morphologically similar to HTLV-I on electron microscopy was isolated from spinal fluid. Our investgations show that endemic tropical spastic paraparesis in Jamaica is a retrovirus-assiciated myelopathy and that HTLV-I or an antigenically similar retrovirus is the causal agent. (AU)