Factors related to volunteer comprehension of informed consent for a clinical trial.

The informed consent process has become a universal requirement for research involving human subjects. Its goal is to inform volunteers regarding research in order to make decision to participate or not. This study aimed to measure volunteers' comprehension levels concerning the clinical trial and to find out factors associated with that comprehension levels. Eighty-one volunteers who enrolled in a malaria clinical trial were recruited into the study. A semi-structured questionnaire was used to collect the information. Non-participant observation was used to observe the process of informed consent. Volunteers were interviewed three days after being recruited into the trial. The results show the volunteers' comprehension was low. Only 44% of volunteers had an acceptable level of comprehension. It also revealed that 20 volunteers were not aware of being volunteers. Most volunteers knew about the benefits of participating in the trial and realized that they had the right to withdraw from the study, but not many knew about the risks of the trial. The results indicated the method of informing about the trial affected the volunteers' comprehension level. No relationship was found between comprehension level and volunteers' socio-demographic characteristics and their attitude toward the consent process. The findings from this study demonstrate volunteers who participated in the clinical trial were not truly informed. Further studies regarding enhancing volunteers' understanding of the trial are needed.

Strengthening of national capacity in implementation of antimalarial drug quality assurance in Thailand.

Substandard and counterfeit pharmaceutical products, including antimalarial drugs, appear to be widespread internationally and affect both the developing and developed countries. The aim of the study was to investigate the quality of antimalarial drugs, ie, artesunate (ART), chloroquine (CHL), mefloquine (MEF), quinine (QUI), sulfadoxine/pyrimethamine (S/P) and tetracycline (TT) obtained from the government sector and private pharmacies in 4 Thai provinces: Mae Hong Son, Kanchanaburi, Ranong, and Chanthaburi. Three hundred sixty-nine samples of 6 antimalarial drugs from 27 government hospitals, 27 malaria clinics, and 53 drugstores, were collected. Drug quality was assessed by simple disintegration test and semi-quantitative thin-layer chromatography in each province; 10% passed, 100% failed and doubtful samples were sent to be verified by high performance liquid chromatography (HPLC) at the Thai National Drug Analysis Laboratory, (NL). Fifteen point four percent of ART, 11.1% of CHL and 29.4% of QUI were substandard. Based on the finding, drug regulatory authorities in the country took appropriate action against violators to ensure that antimalarial drugs consumed by malaria patients are of good quality.

Declining mefloquine sensitivity of Plasmodium falciparum along the Thai-Myanmar border.

Mefloquine sensitivity of Plasmodium falciparum along the Thai-Myanmar border, both in vitro and in vivo, following different first-line treatments for uncomplicated falciparum malaria patients in these areas during the period 1997--2003 were studied. Standard in vitro micro tests and in vivo efficacy according to World Health Organization methodologies were performed. P. falciparum isolates along the Thai-Myanmar border with in vitro sensitivity to mefloquine have had up to a ten-fold decrease in sensitivity compared to a baseline done in 1986, conducted one year after the drug was first introduced to Thailand. The reduction in the mefloquine sensitivity of P. falciparum isolates in Tak Province developed rapidly, with the highest IC50 of 1,254 nM in 1997. The IC50 declined to 1,067 and 737 nM in 1999 and 2001, respectively, but there was no statistically significant difference in the sensitivity. The sensitivity of P. falciparum isolates from Mae Hong Son, Kanchanaburi, and Ranong, where the first line treatment was mefloquine 15 mg/kg single dose, continued to decline, where in 2001 the IC50 were 1,087, 941, and 1,116 nM, respectively, in these provinces. The difference in sensitivities of P. falciparum isolates in Mae Hong Son and Ranong in 2001, compared to 1997, was statistically significant (p<0.05). Good therapeutic efficacy of the artesunate-mefloquine combination in Tak Province was observed. Adequate clinical responses (ACR) were 89.5% and 92.3% in 1997 and 2002, respectively. The efficacy of mefloquine alone in Mae Hong Son, Kanchanaburi, and Ranong has significantly dropped. ACR in 1997 and 2001 in Mae Hong Son were 87.8% and 73.2%, respectively, in Kanchanaburi were 82% and 59.6%, respectively, and in Ranong were 96% and 31.6%, respectively.

Mekong malaria. II. Update of malaria, multi-drug resistance and economic development in the Mekong region of Southeast Asia.

In an expansion of the first Mekong Malaria monograph published in 1999, this second monograph updates the malaria database in the countries comprising the Mekong region of Southeast Asia. The update adds another 3 years' information to cover cumulative data from the 6 Mekong countries (Cambodia, China/Yunnan, Lao PDR, Myanmar, Thailand, Viet Nam) for the six-year period 1999-2001. The objective is to generate a more comprehensive regional perspective in what is a global epicenter of drug resistant falciparum malaria, in order to improve malaria control on a regional basis in the context of social and economic change. The further application of geographical information systems (GIS) to the analysis has underscored the overall asymmetry of disease patterns in the region, with increased emphasis on population mobility in disease spread. Of great importance is the continuing expansion of resistance of P. falciparum to antimalarial drugs in common use and the increasing employment of differing drug combinations as a result. The variation in drug policy among the 6 countries still represents a major obstacle to the institution of region-wide restrictions on drug misuse. An important step forward has been the establishment of 36 sentinel sites throughout the 6 countries, with the objective of standardizing the drug monitoring process; while not all sentinel sites are fully operational yet, the initial implementation has already given encouraging results in relation to disease monitoring. Some decreases in malaria mortality have been recorded. The disease patterns delineated by GIS are particularly instructive when focused on inter-country distribution, which is where more local collaborative effort can be made to rationalize resource utilization and policy development. Placing disease data in the context of socio-economic trends within and between countries serves to further identify the needs and the potential for placing emphasis on resource rationalization on a regional basis. Despite the difficulties, the 6-year time frame represented in this monograph gives confidence that the now well established collaboration is becoming a major factor in improving malaria control on a regional basis and hopefully redressing to a substantial degree the key problem of spread of drug resistance regionally and eventually globally.