Naowarat Kanchanakhan

Genetic diversity and population structure of Plasmodium falciparum in Thailand, a low transmission country

BackgroundThe population structure of the causative agents of human malaria, Plasmodium sp., including the most serious agent Plasmodium falciparum, depends on the local epidemiological and demographic situations, such as the incidence of infected people, the vector transmission intensity and migration of inhabitants (i.e. exchange between sites). Analysing the structure of P. falciparum populations at a large scale, such as continents, or with markers that are subject to non-neutral selection, can lead to a masking and misunderstanding of the effective process of transmission. Thus, knowledge of the genetic structure and organization of P. falciparum populations in a particular area with neutral genetic markers is needed to understand which epidemiological factors should be targeted for disease control. Limited reports are available on the population genetic diversity and structure of P. falciparum in Thailand, and this is of particular concern at the Thai-Myanmar and Thai-Cambodian borders, where there is a reported high resistance to anti-malarial drugs, for example mefloquine, with little understanding of its potential gene flow.MethodsThe diversity and genetic differentiation of P. falciparum populations were analysed using 12 polymorphic apparently neutral microsatellite loci distributed on eight of the 14 different chromosomes. Samples were collected from seven provinces in the western, eastern and southern parts of Thailand.ResultsA strong difference in the nuclear genetic structure was observed between most of the assayed populations. The genetic diversity was comparable to the intermediate level observed in low P. falciparum transmission areas (average HS = 0.65 ± 0.17), where the lowest is observed in South America and the highest in Africa. However, uniquely the Yala province, had only a single multilocus genotype present in all samples, leading to a strong geographic differentiation when compared to the other Thai populations during this study. Comparison of the genetic structure of P. falciparum populations in Thailand with those in the French Guyana, Congo and Cameroon revealed a significant genetic differentiation between all of them, except the two African countries, whilst the genetic variability of P. falciparum amongst countries showed overlapping distributions.ConclusionPlasmodium falciparum shows genetically structured populations across local areas of Thailand. Although Thailand is considered to be a low transmission area, a relatively high level of genetic diversity and no linkage disequilibrium was found in five of the studied areas, the exception being the Yala province (Southern peninsular Thailand), where a clonal population structure was revealed and in Kanchanaburi province (Western Thailand). This finding is particularly relevant in the context of malaria control, because it could help in understanding the special dynamics of parasite populations in areas with different histories of, and exposure to, drug regimens.

A Randomized Controlled Trial on the Effectiveness of Court-Type Traditional Thai Massage versus Amitriptyline in Patients with Chronic Tension-Type Headache

This study aimed to evaluate the effectiveness of the court-type traditional Thai massage (CTTM) to treat patients with chronic tension-type headaches (CTTHs) comparing with amitriptyline taking. A randomized controlled trial was conducted. Sixty patients diagnosed with CTTH were equally divided into a treatment and a control group. The treatment group received a 45-minute course of CTTM twice per week lasting 4 weeks while the control group was prescribed 25 mg of amitriptyline once a day before bedtime lasting 4 weeks. Outcome measures were evaluated in week 2, week 4 and followed up in week 6 consisting of visual analog scale (VAS), tissue hardness, pressure pain threshold (PPT), and heart rate variability (HRV). The results demonstrated a significant decrease in VAS pain intensity for the CTTM group at different assessment time points while a significant difference occurred in within-group and between-group comparison (P < 0.05) for each evaluated measure. Moreover, the tissue hardness of the CTTM group was significantly lower than the control group at week 4 (P < 0.05). The PPT and HRV of the CTTM group were significantly increased (P < 0.05). CTTM could be an alternative therapy for treatment of patients with CTTHs.

SHORT-TERM EFFECTS OF COURT-TYPE TRADITIONAL THAI MASSAGE ON PRESSURE PAIN THRESHOLD AND PAIN INTENSITY IN PATIENTS WITH CHRONIC TENSION-TYPE HEADACH

This study aimed to evaluate the short-term effects of the court-type traditional Thai massage (CTTM) on pressure pain threshold and pain intensity to treat patients suffering from chronic tension-type headaches (CTTHs) comparing with amitriptyline taking. A randomized controlled trial was conducted. Sixty patients diagnosed with CTTH were evenly divided into the treatment and control group. The treatment group received a 45-minute course of court-type traditional Thai massage the control group was prescribed to take 25 mg of amitriptyline once a day before bedtime lasted. The results were evaluated in short-term day 1 after intervention, The measurement consisted of Visual Analog Scale (VAS), Tissue hardness and pressure pain threshold (PPT). The results demonstrated that there was a significant decrease in pain intensity for the CTTM group at different assessment while a significant difference occurred between-group comparison (P<0.05). Moreover, the PPT of the CTTM group was significantly increased (P<0.05). It can therefore be concluded from the findings that CTTM seems to be an effective therapy for stress-related variables and increased the PPT as well as reducing pain intensity for the CTTHs.

THE EFFECTS OF TRADITIONAL THAL SELF-MASSAGE USING WILAI MASSAGE STICK TM IN PATIENTS ON UPPER TRAPEZIUS WITH MYOFASCIAL TRIGGER POINTS: A RANDOMIZED CONTROL TRIAL

The purpose of this study was to investigate the effects of traditional Thai self-massage using Wilai massage stick TM in patient with upper trapezius with myofascial trigger points. Sixty patients were randomly allocated to either a massage group using Wilai massage stick TM or a medication group. Both groups were advised to have the same daily stretching exercise. Pain intensity, pressure pain threshold (PPT) and tissue hardness were assessed at baseline, and the fifth day after the last treatment session. The results showed that after 5 days of treatment, there are significant improvement in all assessment time points (p<0.05). The adjusted post-test mean values for pain intensity, PPT and tissue hardness were significantly better in the massage group than medication group (p<0.05). We conclude that traditional Thai self-massage using Wilai massage stick TM provides better results than taking medication for patients who have upper trapezius pain associated with MTrPs.

Effects of traditional Thai self-massage using a Wilai massage stickTM versus ibuprofen in patients with upper back pain associated with myofascial trigger points: a randomized controlled trial

[Purpose] The aim of this study was to examine the effects of traditional Thai self-massage using a Wilai massage stickTM versus ibuprofen on reducing upper back pain associated with myofascial trigger points. [Subjects and Methods] Sixty patients who were diagnosed as having upper back pain associated with myofascial trigger points were randomly allocated to either a massage group using a Wilai massage stickTM or a medication group taking ibuprofen for 5 days. Both groups were advised to perform the same daily stretching exercise program. Pain intensity, pressure pain threshold, tissue hardness, and cervical range of motion were assessed at baseline, immediately after the first treatment session, and on the fifth day after the last treatment session. [Results] The massage group had significant improvement in all parameters at all assessment time points. Similar changes were observed in the medication group except for the pressure pain threshold and tissue hardness. The adjusted post-test mean values for each assessment time point were significantly better in the massage group than in the medication group. [Conclusion] Tradition Thai self-massage using a Wilai massage stickTM provides better results than taking ibuprofen for patients who have upper back pain associated with myofascial trigger points. It could be an alternative treatment for this patient population.