IL-10-producing T cells suppress immune responses in anergic tuberculosis patients.
(9/469)
The lethality of Mycobacterium tuberculosis remains the highest among infectious organisms and is linked to inadequate immune response of the host. Containment and cure of tuberculosis requires an effective cell-mediated immune response, and the absence, during active tuberculosis infection, of delayed-type hypersensitivity (DTH) responses to mycobacterial antigens, defined as anergy, is associated with poor clinical outcome. To investigate the biochemical events associated with this anergy, we screened 206 patients with pulmonary tuberculosis and identified anergic patients by their lack of dermal reactivity to tuberculin purified protein derivative (PPD). In vitro stimulation of T cells with PPD induced production of IL-10, IFN-gamma, and proliferation in PPD(+) patients, whereas cells from anergic patients produced IL-10 but not IFN-gamma and failed to proliferate in response to this treatment. Moreover, in anergic patients IL-10-producing T cells were constitutively present, and T-cell receptor-mediated (TCR-mediated) stimulation resulted in defective phosphorylation of TCRzeta and defective activation of ZAP-70 and MAPK. These results show that T-cell anergy can be induced by antigen in vivo in the intact human host and provide new insights into mechanisms by which M. tuberculosis escapes immune surveillance. (+info)
Behavioural and serological human immunodeficiency virus risk factors among female commercial sex workers in Cambodia.
(10/469)
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. (+info)
Fatigue in Cambodia veterans.
(11/469)
In 1992 and 1993, Dutch military personnel were deployed in the peace operation UNTAC in Cambodia. Since returning, Cambodia veterans have reported health complaints which they perceive to be related to their service. Their symptoms strikingly resemble health problems reported by Gulf War veterans. Four years post-return, a cross-sectional survey on health symptoms in Cambodia veterans was initiated. Questionnaires were sent to all Cambodia veterans and four comparison groups. Forgetfulness, difficulty concentrating and fatigue were the symptoms most commonly endorsed. An operational case definition was constructed using a validated fatigue severity questionnaire. Cases were not uniquely found in Cambodia veterans (17%). In Rwanda and Bosnia veterans, respectively, 28% and 11% also met our case definition. Fatigue severity level was predicted by pre-mission, during-mission and post-mission variables, of which retrospective recollection of side-effects of vaccines and causal attributions also have been shown to be relevant in studies on Gulf-related illness. (+info)
Seroprevalence of bovine immunodeficiency virus and bovine leukemia virus in draught animals in Cambodia.
(12/469)
Since bovine immunodeficiency virus (BIV), known as bovine lentivirus, has been detected in dairy and beef cattle in various countries around the world, a prevalence study of antibodies to BIV and bovine leukemia virus (BLV) was conducted in draught animals in five provinces in Cambodia, where protozoan parasite infections were suspected in some animals. To clarify the status of draught animals including Haryana, Brahman, mixed-breed, local breed cattle and muscle water buffaloes, a total of 544 cattle and 42 buffaloes were tested, and 26.3 and 16.7%, respectively, were found positive for anti-BIV p26 antibodies determined by Western blotting. There were 5.3% positive for anti-BLV antibodies detected by immunodiffusion test among the cattle, but no reactors among buffaloes and no dual infection for both BIV and BLV was determined in this study. Peripheral blood mononuclear cells from BIV-seropositive cattle were found to have BIV-provirus DNA, as detected by polymerase chain reaction and subsequent Southern blot hybridization. This is the first evidence for the presence of BIV and BLV infections in draught animals in tropical countries such as Cambodia. This wide distribution of BIV suggests its association with problems in animal health as reported worldwide, and that a primary BIV infection can predispose death of affected animals by other aggressive pathogens or stresses. (+info)
Hunger in legal immigrants in California, Texas, and Illinois.
(13/469)
OBJECTIVES: This study determined the prevalence of food insecurity and hunger in low-income legal immigrants. METHODS: We conducted a cross-sectional survey of Latino and Asian legal immigrants attending urban clinics and community centers in California, Texas, and Illinois with a food security questionnaire. RESULTS: Among 630 respondents, 40% of the households were food insecure without hunger and 41% were food insecure with hunger. Independent predictors of hunger were income below federal poverty level (odds ratio [OR] = 2.72, 95% confidence interval [CI] = 1.72, 4.30), receipt of food stamps (OR = 2.53, 95% CI = 1.57, 4.09), Latino ethnicity (OR = 2.39, 95% CI = 1.49, 3.82), and poor English (OR = 1.76, 95% CI = 1.10, 2.82). CONCLUSIONS: The prevalence of hunger among low-income legal immigrants is unacceptably high. Access to food assistance programs is important for the health and well-being of this population. (+info)
Panic disorder among Cambodian refugees attending a psychiatric clinic. Prevalence and subtypes.
(14/469)
This study surveys Khmer refugees attending two psychiatric clinics to determine both the prevalence of panic disorder as well as panic attack subtypes in those suffering panic disorder. A culturally valid adaptation of the SCID-panic module, the Cambodian Panic Disorder Survey (CPDS), was administered to 89 consecutive Cambodian refugees attending these psychiatric clinics. Utilizing culturally sensitive panic probes, the CPDS provides information regarding both the presence of panic disorder and panic-attack subtypes during the month prior to interview. Of 89 patients surveyed at two psychiatric clinics, 53 (60%) currently suffered panic disorder. Among the 53 patients suffering panic disorder, the most common panic attack subtypes during the previous month were the following: "sore neck" [51% of the 53 panic disorder patients (PDPs)], orthostatic dizziness (49% of PDPs), gastrointestinal distress (26% of PDPs), effort induced (21% of PDPs), olfactory induced (21% of PDPs), and "while-sitting dizziness" (16% of PDPs). (+info)
Evidence for recombination in natural populations of dengue virus type 1 based on the analysis of complete genome sequences.
(15/469)
Recombination events are known to occur in non-segmented RNA viruses like polioviruses or alphaviruses. Analysis of the subgenomic sequences of dengue virus type 1 (DENV-1) structural genes has recently allowed the identification of possible recombination breakpoints. Because DENV is a major human pathogen, this discovery might have important implications for virus pathogenicity, vaccine safety and efficiency, or diagnosis and, therefore, requires clear confirmation. We report the complete sequence determination of one Asian and two African strains of DENV-1 isolated from human patients. Rigorous sequence analysis provided strong evidence for the occurrence of intragenomic recombination events between DENV-1 strains belonging to different lineages. Singapore S275/90 strain appears to be the evolutionary product of a recombination event between viruses belonging to two distinct lineages: one lineage includes an African strain isolated in Abidjan (Ivory Coast) and the other includes isolates from Djibouti and Cambodia. The 'Recombination Detection Program', bootscanning and analysis of diversity plots provided congruent results concerning the existence of a two-switch recombination event and the localization of recombination breakpoints. Thus, the 5' and 3' genomic ends of the Singapore S275/90 strain were inherited from a Djibouti/Cambodia lineage ancestor and an internal fragment located in the envelope/NS1 region originated from an Abidjan lineage ancestor. (+info)
Changes in Expanded Program for Immunization coverage for mother and child in Krakor, Cambodia 1996--1998.
(16/469)
We evaluated a training intervention aimed at enhancing the roles of health centre staff, Village Health Volunteers (VHVs) and Traditional Birth Attendants (TBAs) within the Expanded Program for Immunization (EPI) in the district of Krakor, Cambodia. We conducted population-based surveys to determine the coverage of the EPI at baseline (1996) and after the intervention (1998), using data from health cards for mothers and their children and history data. Statistically significant changes over the 2-year period were apparent for tetanus, BCG, polio and DTP, supporting the positive impact the training intervention had on immunization coverage in the district. (+info)