We developed two sets of a multiplex amplification refractory mutation system (M-ARMS) assay to identify specific beta-thalassemia (beta-thal) mutations that are common in Thailand. The first one was for the detection of mutants with codon 17 (A>T), IV S-I-1 (G >T)), codons 41/42 (-TCT T) and codons 71/72 (+A), while the second one was for the -87 (C>A), -28 (A>G) and IVS-II-654 (C>T). Application of the proposed assay to 282 persons with beta-thal trait revealed a positive result in 276 cases (97.8%). There were 258 cases (91.5%) positive for the set 1 M-ARMS assay and 18 cases (6.4%) were positive for set 2. Six cases (2.2%) were negative for both sets 1 and 2, and were further characterized by DNA sequencing. The mutations detected by the set 1 M-ARMS assay were 113 cases (40.1%) of codons 41/42, 95 (33.7%) of codon 17, 41 (14.5%) of IVS-I-1 and nine cases (3.2%) of codons 71/72, while by set 2 there were 12 cases (4.2%) of -28, four cases(1.4%) of -87 and two cases (0.7%) of IVS-II-654. Mutations undetectable by M-ARMS assay were two cases of codons 27/28 (+C), one case of codon 35 (C>A), one of codon 43 (G>T), one of -31 (A>G) and one of IVS-I-5 (C>G). The M-ARMS assay proved to be a valuable tool for the analysis of beta-thal mutations. The method is robust, accurate, simple, speedy and cost-effective. The application of this assay will facilitate genetic counseling and prenatal diagnosis for severe thalassemia in high-risk pregnancies.

The study was conducted to explore factors associated with condom use of young Thai men conscripts. Methods: A cross-sectional study was conducted. Participants were 159 conscripts in second year who served in the Royal Thai Army by lottery method. Demographic data, sexual history including condom use, HIV and STDs and knowledge were collected using a self-administered questionnaire. Logistic regression was used to analyze the data. Results: Condom use at the last sex was 41.18% of the conscripts aged 20 -27 years and secondary school education completed of 74.2%. 25.78% had experience with drugs used but injection was rare (6.9%). Age at the first sex was reported lowest at 11 years, 9.4% reported first sex with men and 21.38% were married. The participants have sexual history (last six months) with female only of 83.2%, male only of 4.1% and both of 14.6%. Among these only 12.6% reported every time of condom use and 19.5% never used condom. Older age, higher education, drinking alcohol, drugs use and higher knowledge were associated with condom use with statistical significance. Conclusions: Condom use among male Thai conscripts was low. Education and a condom use program are urgently needed to prevent future spread of HIV and STDs.

ABSTRACT. The lower northern part of Thailand contains various genetically diverse ethnic populations. The sequences of the mitochondrial DNA hypervariable region were studied in three ethnic populations inhabiting Phitsanulok Province. One hundred and nine nucleotide sequences -53, 29, and 27 from Hmongs (Hill tribe), Lao Songs, and Thai-Siams, respectively -were collected. The haplotypes were generated from 1130 nucleotides of the entire control region. Eighty-six haplotypes were found in the three ethnic populations, and no shared haplotypes were found between populations. Point heteroplasmy was noted at position 311 (C→Y). Haplotypes with ACAC-insertion at position 512 were observed in immigrant individuals from the Lao Song population. The Thai-Siam population showed higher genetic diversity than the other populations. The Hmong and Lao Song populations showed less genetic diversity than those living in their original area. The neutrality testing suggested that the result might be influenced by genetic drift.

The number of mutations underlining -thalassemia generate a wide variety of different clinical phenotypes. An understanding of the genotype is important for medical personnel in order to provide proper counseling to patients and their families. Characterization of these mutations should aid the planning of a prenatal diagnosis program for -thalassemia. The heterogeneity of the mutations makes it difficult and time consuming to identify the mutation in some individuals. We developed a single -tube multiplex amplification refractory mutation system (multiplex ARMS) to identify common ethnicspecific -thalassemia mutations. Confirmation of multiplex ARMS results was carried out using direct sequencing. Three thousand three hundred twenty two people from Phitsanulok province were screened for the -thalassemia trait by quantitation of HbA 2 with microcolumn chromatography and the genotypes of mutations were characterized using multiplex ARMS and direct sequencing. We found that the deletion at codons 41/42 (-TCTT) was the most frequent (48%), codon 17 (AT) (30%), -28 (AG) (6%) and IVS-I-1(GT) (6%) were the second and third in frequency respectively. A -87 (CA) mutation (4%), IVS II-654 (CT) (2%), codons 71/72 (+A) (2%) and codon 35 (CA) mutations (2%) were also found. These techniques were found to be a valuable tool for analysis of -thalassemia mutations because they are accurate, simple, and speedy in operation. The application for the diagnosis of severe thalassemia in high -risk pregnancies is promising.

Background: Men who have sex with men (MSM) are highly vulnerable to HIV infection, but this population can be particularly difficult to reach in Thailand. This study aimed to estimate the number of MSM in Chiang Mai Thailand, in order to plan HIV control and prevention. Methods: The total of 348 potential MSM were identified at eight contact locations, including two public parks, two bars, two massage parlors and two pubs in Chiang Mai. Trained 16 research enumerators and 16 enumerators were trained to extend a recruitment of brooches to MSM. The MSMs were captured one week apart. A record was kept of when, where and by whom the invitation was extended and received, and of refusals. The total estimate of MSM was derived from capture-recapture calculation. Results: The total MSM in Chiang Mai Thailand estimated by capture and recapture method was 733 (95%CI = 480 − 948) or the estimate was 7.3% (95%CI = 7.1%-14.1%). Conclusions: Capture and recapture method can be used to enumerate and provide accurate and reliable estimates of the MSM population in any area, provided that certain conditions are controlled. MSM who are engaged in personal community represent a sizeable population who urgently need to be targeted by HIV and STDs prevention strategies.