When will those new measures be implemented?
Some of the measures have already been adopted such as the surveillance of hospitalised tourist and the website for them to notified the authorities about any illnesses. This is to make sure that early actions are taken to address any health problems that may arise.
The province has also held several rounds of talks with hotel operators and among the health service sector to effect changes and ensure visitors enjoy their stay here in safety. Of course we can not prevent all incidents but we are taking measures to address potential problem areas.
Who drew the final conclusions for the inquiry?
The Thai authorities appointed an eight-member multidisciplinary expert panel, which worked closely with the investigation team to review all of the information from the investigation. This includes interviews, clinical, laboratory and environmental data. The investigation team drew the conclusions in consultation with the panel of experts.
Who is on the expert panel and who appointed them?
The eight-member expert panel was appointed by Chiang Mai province. It is composed of:
1) an infectious disease expert from the Faculty of Medicine, Chiang Mai University;
2) a clinical toxicologist from Ramathibodi Hospital, Bangkok;
3) a pathology and forensic medicine expert from Siriraj Hospital, Bangkok;
4) a senior epidemiologist from the Department of Disease Control, Ministry of Public Health;
5) an expert on pesticide use from the Faculty of Agriculture, Chiang Mai University;
6) an environmental specialist from Faculty of Medicine, Chiang Mai University;
7) a psychiatrist from the Faculty of Medicine, Chiang Mai University;
8) a cardiologist from the Chest Disease Institute, Department of Medical Services, Bangkok.
Why wasn’t the case of the Canadian man who died in January 2011 part of the investigation?
There were reports of a seventh death, a Canadian man who was not staying at the hotel where the Thai woman, the New Zealand woman and the United Kingdom couple also stayed but reportedly used its swimming pool. However the findings from the investigation did not confirm use of common hotel facilities and the available evidence from medical records and autopsy by forensic expert did not support linkage with other deaths. Therefore the death of this Canadian man was not included in the cluster.
Why did the investigation take so long?
Investigating several cases of unexplained deaths whose cause may or may not be the same is a complex undertaking. It involves many parallel investigations, several experts and the coordination of information from local, national and international sources.
For example, biological samples from these cases were also sent to laboratories both in Thailand and overseas to examine the tissues and test for microbes and toxins. It takes time to package these safely, send them, process them, get the results and analyse them. In addition, different types of hypotheses require different tests.
The testing for exposure to pest control products for example took some time as they include tests in foreign laboratories. Once those results came in, the expert panel and the investigation team had to review all of the information together. Only then can they draw conclusions and make recommendations.
Was the insecticide chlorpyrifos linked to at least one of the deaths?
Thai authorities have consulted national and international expert toxicologists. The available evidence suggests that chlorpyrifos was not the cause. There are four factors that led to this conclusion:
One is that chlorpyrifos normally has a strong odour, and survivors reported that they did not smell any strong smell.
The second is that a healthy adult would not fall ill or die of chlorpyrifos exposure unless they had ingested or inhaled large volumes of it.
The third is that the symptoms of chlorpyrifos poisoning are not consistent with the symptoms of the people who were affected.
The fourth is that a certain enzyme in the blood (called cholinesterase) of victims would have been below normal if chlorpyrifos were a cause and yet the blood of several of the cases (including the New Zealand women) showed normal levels.
Toxicologists in NZ also questioned the claim (see: letter from 3 local Toxicologists concerning our investigation)
What responsibility does Thailand have to the international community to report and resolve these cases?
The main responsibility is to communicate with the families of the cases. However because the majority of the cases involved people visiting Thailand, it also was necessary to share some information with embassies and the public health authorities of the concerned countries.
Information on this kind of event is also normally shared with other countries on a precautionary basis to alert them to the possibility of similar cases being identified in tourists returning from a holiday in Thailand. The normal mechanism for reporting of this kind is through the network established for the International Health Regulations.
Were the Koh Phi Phi deaths related?
The two cases from Phi Phi Island occurred in 2009 in Krabi province. In this case, one American and one Norwegian woman died, and their traveling companions fell ill. The cause of death was never determined. Because the cases were now two years ago, there is no possibility to conduct any further laboratory or other tests.
Related: Chiang Mai tourist death probe finds no common link
Related: Results of the probe on Chiang Mai tourist and Thai guide deaths and illnesses completed
Related: Timeline of events related to the investigation and deaths of tourists in Chiang Mai
Related: Roles and responsibilities of key partners in the Chiang Mai tourist death investigation