Suchergebnisse

Characterization of the HIV epidemic in Thailand has benefited from the systematic testing of young men upon entry into the military. These data, which have shown that public health measures can reverse an HIV epidemic, have been reanalyzed with current geographic information systems methods. The resulting maps, thus far, are the best means of visualizing the geography of the dynamic HIV epidemic in Thailand.

In HIV-1-infected patients, variation at the HLA class I locus is associated with disease progression, but few studies have assessed the influence of HLA alleles on HIV-1 CRF01_AE infection, which is dominant in Thailand. We hypothesized that alleles predicted to confer more effective immune responses, such as HLA-B*46, would protect against disease progression. HLA typing was performed on HIV-1 incident cases surviving until 1998–1999 and HIV-1-negative matched controls from Thai army cohorts enrolled between 1991 and 1995. We assessed associations between class I alleles and disease progression subsequent to HLA typing. Ninety-nine HIV-1-incident cases were followed for a median of 3.7 years after HLA typing; during this time, 58 participants died. Two alleles were associated with mortality: HLA B*51 was protective (3-year survival B*51pos vs. B*51neg: 75% vs. 52%; p = 0.034) whereas Cw*04 was deleterious (3-year survival Cw*04pos vs. Cw*04neg: 39% vs. 60%; p = 0.027). HLA-B*46 was not associated with disease progression. Alleles present at different frequencies in HIV-1-incident compared with HIV-1-negative men included HLA-A*02:03, B*35, B*15, and C*08. 1. In conclusion in this Thai army cohort, HLA-B*51 was associated with lower mortality, confirming that this allele, which is protective in clade B HIV-1 infection, has a similar effect on HIV CRF01_AE infection. The deleterious effect of HLA-Cw*04 must be interpreted with caution because it may be in linkage disequilibrium with disease-susceptible HLA-B alleles. We did not find that HLA-B*46 was protective. These findings may inform vaccine development for areas of the world in which HIV-1 CRF01_AE infection is prevalent.

Malaria remains a public health problem in Thailand, especially along its borders where highly mobile populations can contribute to persistent transmission. This study aimed to determine resistant genotypes and phenotypes of 112 Plasmodium falciparum isolates from patients along the Thai-Cambodia border during 2013–2015. The majority of parasites harbored a pfmdr1-Y184F mutation. A single pfmdr1 copy number had CVIET haplotype of amino acids 72–76 of pfcrt and no pfcytb mutations. All isolates had a single pfk13 point mutation (R539T, R539I, or C580Y), and increased % survival in the ring-stage survival assay (except for R539I). Multiple copies of pfpm2 and pfcrt-F145I were detected in 2014 (12.8%) and increased to 30.4% in 2015. Parasites containing either multiple pfpm2 copies with and without pfcrt-F145I or a single pfpm2 copy with pfcrt-F145I exhibited elevated IC(90) values of piperaquine. Collectively, the emergence of these resistance patterns in Thailand near Cambodia border mirrored the reports of dihydroartemisinin-piperaquine treatment failures in the adjacent province of Cambodia, Oddar Meanchey, suggesting a migration of parasites across the border. As malaria elimination efforts ramp up in Southeast Asia, host nations militaries and other groups in border regions need to coordinate the proposed interventions.