Behavioural and serological human immunodeficiency virus risk factors among female commercial sex workers in Cambodia

BACKGROUND: The spread of human immunodeficiency virus (HIV) in Cambodia is mainly caused by sexual transmission and the high-risk group in this country are female commercial sex workers (CSW). There are two types of CSW, direct CSW (DCSW) and indirect CSW (IDCSW), who are different from each other in sexual activities. This study was conducted in order to describe the risk factors on HIV for each type of CSW, and to establish effective preventive strategies against the HIV epidemic among CSW. METHODS: The participants, 143 DCSW and 94 IDCSW, were interviewed using a questionnaire to determine their demographic characteristics and behaviour. Blood samples were taken for serological tests on HIV, Chlamydia trachomatis and syphilis. The association between their behavioural pattern and their serological results was analysed. RESULTS: The questionnaire study showed that IDCSW had a riskier behavioural pattern than DCSW. The HIV seroprevalence rates of the DCSW and the IDCSW were 52.4% and 22.3%, respectively. Univariate logistic analyses showed a significant association between HIV antibody (HIV-Ab) and current age, age at commencement of commercial sex work, duration of commercial sex work, and the seropositivity of Chlamydia trachomatis-IgG antibody (CT-IgG-Ab) among the DCSW. The analyses also showed a significant relationship between HIV-Ab and CT-IgG-Ab among the IDCSW. CONCLUSIONS: Improving condom use rate is very important in order to prevent an HIV epidemic among the two types of CSW. This study also suggests it is important to prevent sexually transmitted disease (STD) such as Chlamydia trachomatis infection. The STD control programme could be efficient for HIV prevention, especially among DCSW.     

Chronic progressive myelopathy associated with elevated antibodies to human T-lymphotropic virus type I and adult T-cell leukemialike cells

Six adult patients had a chronic progressive myelopathy that possessed the following features: high antibody titers to human T-lymphotropic virus type I (HTLV-I) in serum and cerebrospinal fluid (CSF); predominantly upper motor neuron disorder, symmetrical, with mild sensory and bladder disturbances; and presence of adult T-cell leukemia-like cells in both peripheral blood and CSF. We refer to this entity as HTLV-I-associated myelopathy (HAM). Electrophoretic studies of immunoglobulin G in CSF using Western blot analysis characteristically demonstrated p24 and p32 bands. Rates of intra-blood-brain barrier synthesis were determined and found increased in the patients with HAM. Corticosteroid treatment produced clinical improvement in all of 4 patients. A retrospective survey of CSF samples was carried out in 287 patients with neurological disorders, and 6 additional patients with HAM were identified.     

Autoproliferative and self-reactive T-cell lines from patients with HTLV-I-associated myelopathy

In two patients with human T lymphotropic virus type 1 (HTLV-I)-associated myelopathy (HAM) and a non-HAM HTLV-I carrier, T-cell lines were generated and characterized from cerebrospinal fluid (CSF) lymphocytes and peripheral blood lymphocytes (PBL). In total, 62 T-cell lines were established using direct plating technique for expanding human T lymphocytes. Sixty three percent of the T-cell lines were CD4+, CDw29+ and HTLV-I gag+. CD8+T-cell lines were also established and they were gag-. Proliferation in the absence of additional antigens and exogenous interleukin 2 ("autoproliferation") was observed in 61% of the T-cell lines and significantly correlated with HTLV-I antigen (gag) expression. In addition, some T-cell lines from HAM patients exhibited proliferative response to self PBL, and the magnitude of their responses was diverse according to the phenotypes of stimulating cells. Therefore, the spontaneous lymphoproliferation observed in patients with HAM is generated by three components; HTLV-I-infected T cells and T cells reactive against HTLV-I and against self antigens. Since most gag+ T-cell lines produced lymphotoxin (LT)/tumor necrosis factor alpha (TNF alpha), it is suggested that those T cells are playing important roles in the pathogenesis of HAM.     

Type VI collagen in healing rabbit corneal wounds

A type-specific monoclonal antibody was used to examine the localization of type VI collagen in healing full-thickness corneal wounds (3 mm in diameter) in rabbits. By immunofluorescence, in 1-week-old wounds, type VI collagen was found only at the wound periphery. Subsequently, type VI collagen showed a rapid increase throughout the wounded area. In 3-week-old wounds, type VI collagen immunofluorescence had a laminar pattern as seen in normal corneal stroma, although it was irregular in arrangement. By electron-microscopic immunohistochemistry, type VI collagen was found in the pericellular region of fibroblastic cells possibly derived from keratocytes. These results suggest that type VI collagen might originate from the fibroblastic cells and play an important role in the regeneration of the corneal lamellar structure.     

Distribution of type VI collagen in the bovine cornea

Using a specific polyclonal antibody against type VI collagen, the distribution of type VI collagen in the bovine cornea was investigated by indirect immunofluorescence microscopy and immunoelectron microscopy. By immunofluorescence, type VI collagen was detectable throughout the stroma. In addition to the uniform but relatively weak signals, a laminar pattern similar to the arrangement of stromal lamellae was clearly seen. Consistent with the immunofluorescent pattern, immunoelectron micrographs showed strong linear reactions located in the interlamellar spaces. The reactions were also observed in the pericellular region of the keratocytes. Epithelium, Descemet's membrane and endothelium were negative.     

Cross-sectional study on risk factors of HIV among female commercial sex workers in Cambodia

To describe epidemiological features on HIV prevalence among female commercial sex workers (CSWs), a cross-sectional study on sexual behaviour and serological prevalence was carried out in Cambodia. The CSWs were interviewed on their demographic characters and behaviour and their blood samples were taken for testing on sexually transmitted diseases, including HIV, Chlamydia trachomatis, syphilis, and hepatitis B. Associations between risk factors and HIV seropositivity were analysed. High seroprevalence of HIV and Chlamydia trachomatis IgG antibody (CT-IgG-Ab) was shown among the CSWs (54 and 81.7%, respectively). Univariate logistic regression analyses showed an association between HIV seropositivity and age, duration of prostitution, the number of clients per day and CT-IgG-Ab. Especially, high-titre chlamydial seropositivity showed a strong significant association with HIV prevalence. In multiple logistic regression analyses, CT-IgG-Ab with higher titre was significantly independently related to HIV infection. These suggest that existence of Chlamydia trachomatis is highly related to HIV prevalence.