ABSTRACT
A community-based seroprevalence survey for human T-cell lymphotropic virus type I (HTLV-I) was undertaken in the Ngwelezane district of Natal/KwaZulu. A total of 1,018 individuals was interviewed for risk factors and had blood drawn for serological examination. To exclude antibody cross-reactivity between anti-HTLV-I and anti-HTLV-II all Western blot HTLV-I-positive samples were further subjected to a Select HTLV test. For comparison, anonymous HIV testing was done. The areas of residence of patients with myelopathy associated with HTLV-I were also ascertained. The seroprevalence of HTLV-I was 2.6% (95% confidence interval (CI) 1.62-3.58). An age-related rise in HTLV-I seropositivity from 1.3% in the 15-24-year age group to 6.1% in the over 55-year-old group was noted. There was no significant association between HTLV-I antibody positivity and marital status, occupation, history of blood transfusion, scarification, age at first sexual experience and number of sexual partners. Anti-HIV-1 antibody testing revealed a positivity of 3.5% (95% CI 2.4-4.68) and the relative risk for co-infection with both HTLV-I and HIV-1 in the 15-24-year group was 1.16 (95% CI 1.08-1.24). The study also identified the first HTLV-II-seropositive case in the Natal/KwaZulu region. Up to December 1991, 90 cases of HTLV-I-associated myelopathy/tropical spastic paraparesis were seen at the Neurology Unit, Wentworth Hospital. The patients came from all parts of Natal, from Pongola in the north to Transkei in the south. The Natal/KwaZulu region is, therefore, an endemic HTLV-I area.
Subject(s)
HTLV-I Infections/epidemiology , Adolescent , Adult , Age Distribution , Aged , Aged, 80 and over , Female , HIV Seroprevalence , HTLV-I Infections/transmission , Humans , Male , Middle Aged , Seroepidemiologic Studies , South Africa/epidemiologyABSTRACT
An extensive poliomyelitis outbreak due to type 1 poliovirus took place in Natal/KwaZulu, South Africa, in 1987-1988, causing 412 paralytic cases. This epidemic differed from a previously described outbreak in Gazankulu, South Africa, in 1982 in that it occurred against a background of relatively good immunity. Thus, only 12% of patients lacked antibodies to types 2 and 3, indicating lack of previous immunization, and 76% of healthy children sampled in the epidemic area had serological immunity to all 3 types of poliovirus. The occurrence of extensive outbreaks in relatively well-immunized communities emphasizes the need to maximize herd immunity and reduce reservoirs of infection in the gut and in the environment, which can be achieved only with oral polio vaccine.
Subject(s)
Poliomyelitis/immunology , Antibodies, Viral/analysis , Child, Preschool , Disease Outbreaks , Humans , Poliomyelitis/epidemiology , Poliomyelitis/prevention & control , Poliovirus Vaccine, Oral/administration & dosage , South Africa/epidemiologyABSTRACT
An epidemic of type 1 poliomyelitis occurred in Natal/KwaZulu in the eastern part of South Africa between December 1987 and November 1988. 412 poliomyelitis cases were reported, of whom 74% were younger than 5 years. The case-fatality rate was 8%. It is suggested that massive floods, experienced in the area 2 months earlier, triggered the outbreak.
