PHUKET: In the wake of a series of unexplained deaths in Chiang Mai earlier this year, Thai authorities are acting to prevent pesticide poisoning of tourists and to more closely monitor the causes of deaths of expats.

The report by the investigating body is likely to resonate on Phuket and in Pattaya and among envoys from many countries who would like more thorough investigations of all deaths of expat residents and tourists.

For Phuket and Pattaya, the most pertinent paragraph of the report reads: ''Surveillance of hospitalised tourists, already in effect, will be continued and a new protocol for investigation of fatal cases is being adopted.''

It's too early to say how far-reaching the new approach will be, but Thai authorities appear to be in the process of recognising that every tourist and expat death - whether in Chiang Mai, Phuket, Pattaya, Samui or Bangkok - needs to be properly investigated and an accurate cause of death determined.

Too often, local investigating police make the only decision on the cause of death. Chemical tests and autopsies are rare, and cannot be performed on Phuket.

It was the death of 23-year-old tourist Sarah Carter that first prompted an investigation in Chiang Mai - and other deaths became linked until authorities were forced to instigate a full and proper probe.

Official attitudes appear to have changed significantly since two young tourist women, a Norwegian and an American, died in mysterious circumstances after falling ill at the Laleena guesthouse on Phi Phi in 2009.

THE REACTION IN NEW ZEALAND
stuff.co.nz Thai authorities have ruled New Zealander Sarah Carter was exposed to chemicals similar to those found in pesticides before she died, but say her precise cause of death cannot be confirmed. A report into the death of Carter and five others was released by the Thai Public Health Ministry this afternoon.

nzherald.co.nz Toxic chemicals, pesticides or gas were likely behind the death of New Zealander Sarah Carter in Thailand, a new medical report shows. But the exact agent that killed Ms Carter a day after she fell violently ill at the Downtown Inn in Chiang Mai is still unknown.

tvnz.co.nz The report said that Carter and two of her friends, plus a Thai woman who was found dead in her room on February 3, were "most likely" to have the same cause of illness. They had probably been exposed to "some toxic chemical, pesticides or gas," however the agent cannot be identified. Ms Carter's friends recovered.

The report says while there were links in the cause of death between the six deceased, ''he specific agents that caused the deaths and illnesses in these events can not be identified and it can not be determined exactly how people were exposed to them.''

3news.co.nz Despite the lack of any solid reason for the deaths, Thai authorities say they are taking measures to reduce the risk of chemical and pesticide exposure to tourists.

newstalkzb.co.nz The father of Sarah Carter is pleased a report into her death in Thailand has finally been released. Richard Carter says the authorities seem to have carried out extensive and thorough testing.

THE FULL REPORT
Update 5
Results of the probe on Chiang Mai tourist and Thai guide deaths and illnesses completed

16 August 2011

Thai authorities have concluded their investigation into the deaths of five tourists and a Thai guide. Following the months-long investigation, experts ultimately could identify the likely cause of death for most cases, but not the specific agents. Experts also concluded that some, but not all of the cases appear to have been causally related. The conclusions, investigation constraints, and actions taken by Thai authorities are explained in detail below.

The investigation covered the six deaths and associated illnesses of three other tourists (travelling companions) in Chiang Mai between 11 January and 19 February of this year. The conclusions follow an exhaustive probe during which Thai and international experts from numerous disciplines were consulted in several rounds of face-to-face, tele- and video-conferences to consider the available scientific evidence. These included clinical and biological samples from patients, the results of on site environmental experiments, and chemical samples from one of the concerned hotels and a nearby market. Chemical and tissue samples were tested at certified laboratories in Thailand, the United States, Japan and Germany during the course of the inquiry.

The investigation also included interviews with co-travelers and some family members in the US, Canada, France and New Zealand in an effort to gather information about all possible exposures. Potential viral, gaseous, toxin and chemical hypotheses were considered by domestic and international partners. These include the Department of Disease Control and the Department of Medical Sciences at the Ministry of Public Health; the Provincial Public Health Office, Chiang Mai; Ramathibodi Poisons Centre, Bangkok; the Ministry of Agriculture and Cooperatives; the World Health Organization (WHO), and the United States Centers for Disease Control (US CDC). Staff of the consulates and embassies concerned were also kept informed.

The final conclusions were reached by the official Chiang Mai investigation team in conjunction with a review panel of outside experts in infectious disease, toxicology, pathology and forensic medicine, epidemiology, and environmental science and pesticide use.

Investigation findings:
The people who died and fell ill were grouped under four events based on suspected causes. The case findings are as follow:

Event 1:
One American woman, age 33, died on 11 January. Her friend, a Canadian woman, age 29, fell ill but recovered. Both stayed in the same room at Hotel ''A'' and developed severe vomiting on the night of 8 January.

The diagnosis based on clinical and pathological findings is that the American woman died from myocardial injury (injury to the heart muscle). Laboratory tests indicate that drugs and other suspected viruses (Adenovirus, Echovirus, EBV, Influenza A) are unlikely to be the cause. The suspected agent that caused her death is likely to be chemical or biotoxin in nature and it is probable that it might have been a pesticide. However, the exact agent could not be identified because the quantity of sample from the case was insufficient. The two women are likely to have the same cause of illness but no epidemiological linkage is found between them and other cases in other events.

Event 2:
One French woman, age 25, died on 19 January. She developed fever and other symptoms on 16 January before arriving in Chiang Mai where she checked in at Hotel ''B'' on 17 January with a female friend who remained well.

Based on the evidence gathered and the clinical presentations of the case, investigators and experts concur that the French woman had acute severe myocarditis (inflammation of all the heart muscles) that represents a sporadic case most likely due to a viral infection, rather than exposure to a poison. The clinical symptoms and inflammatory cells found throughout the heart muscle (confirmed in 3 different laboratories including two in Thailand and one at the US CDC) support this opinion. Although state-of-the-art tests were performed for many viruses and bacteria, no etiologic agent could be identified. There is also no epidemiological linkage with the other events.

Event 3:
a) One New Zealand woman, age 23, died on 6 February. Her two female traveling companions, both age 23 and also from New Zealand, fell ill but recovered. All three women stayed in the same room and developed severe vomiting on the morning of 3 February.
b) One Thai woman, age 47, a tour guide, was found dead in her room on the morning of 3 February.

The three NZ women had severe metabolic acidosis (abnormal acid level in circulation) and two of them suffered myocardial injury (injury to the heart muscle). Clinical symptoms of the Thai woman are unknown since she was found dead in her room. Forensic autopsy found nothing abnormal only a 40% occlusion of the right coronary artery. It is probable she died from sudden arrhythmia (abnormal rhythm of the heart beat).

The women grouped in this event stayed at Hotel ''C''. The Thai tour guide was in a room adjacent to that of the three NZ women. The investigation found that it is very likely the cause of the illnesses of these four women is the same given the timing of the onset of their illness and the proximity of their rooms. The cause is unlikely to be bacterial or viral. Pesticides in the organophosphate, organochlorine and carbamate group, such as cholpyrifos, are also unlikely to be the cause because they conflict with clinical specimens and blood test.

The clinical manifestation in the three NZ women, who were all hospitalised, can be explained by exposure to some chemicals such as those found in pesticides.

It should be noted that tests on blood and biological samples from the three NZ patients at US CDC and German laboratories returned negative results for suspected chemicals such as sodium monofluoroacetate (compound 1080) and phosphine gas. However negative results from some of these toxic substances do not necessarily confirm their absence as sometimes the suspected chemical is difficult to detect or dissipates easily from the biological specimen. Tests on the two rooms of the NZ and Thai women found aluminum molecules on carpet samples but it can not be definitively concluded that these came from pesticide containing aluminum phosphide. The aluminum molecules could have come from the paint on the walls and ceilings or from fluids used to clean air-conditioning units. Aluminum is an ingredient in paint and air-conditioning cleaning fluids and aluminum molecules were also found in other rooms sampled including that of the hotel manager.

Two separate rounds of environmental experiments on the air quality in their rooms were also carried out to test the theory of poisoning by carbon monoxide, sulphur dioxide, nitrous oxide and nitrous dioxide as the women stayed at the hotel during Chinese New Year when incense and ritual burning of silver and gold paper was carried out by a neighboring shrine. The experiments resulted in only a small amount of these gases entering the rooms and experts agreed that this should not have caused their illness.

Event 4:
An older couple from the United Kingdom - man (78) and woman (74) - was found dead in their room on the afternoon of 19 February. Consequently their clinical symptoms were unknown. Forensic experts estimated the time of death to be between 17-18 February. Autopsies and standard panels of tests for chemical, drug and pesticide were performed but found nothing abnormal. There is evidence of 40-80% occlusion in three coronary arteries in the man, and 30-60% occlusion in the woman. It is not unusual for older people to die from cardiac arrest but it is uncommon for a couple to die of this at the same place and around the same time,

As they also stayed at Hotel ''C'' albeit on a different floor to that of the women in Event 3, the possibility that the cause of this event is related to Event 3 cannot be excluded.

Investigation Constraints
As most of the deceased were foreign nationals and there were no evidence of a criminal cause, their bodies were quickly turned over to relatives who took them home. Some relatives also did not want an autopsy to be performed, consequently biological samples were limited and were insufficient for the large number of tests that had to be undertaken.

In addition current laboratory technologies to detect many toxins are subject to certain limitations, especially given the time lag between the deaths and arrival of samples at laboratories. Certain tests also require that samples be taken by a particular method and stored and transported in special containers. This was not possible because the need for testing for these toxic causes were not foreseen at the time of death.

What the findings mean
Despite the best efforts of the Thai authorities and their international partners in undertaking an exhaustive investigation, the specific agents that caused the deaths and illnesses in these events can not be identified and it can not be determined exactly how people were exposed to them.

However, the investigation team and the panel of experts agree that available evidence suggests the following:

1. Event 1: the two cases in this event, an American and a Canadian woman, have similar clinical manifestations as those of the three NZ women in Event 3. Although there is a possibility that these two events might have the same causative agent, investigators cannot find supporting evidence.
2. Event 2: the illness and death of the French woman is not related to any other cases or events. It is a sporadic case of myocarditis most likely of viral origin.
3. Event 3: the four women, three New Zealanders and one Thai, are most likely to have the same cause of illness, probably exposure to some toxic chemical, pesticides or gas, but the agent can not be identified.
4. Event 4: this event, involving the older English couple, is possibly related to Event 3 as they occurred in the same hotel but again laboratories could not establish a direct link or the specific cause.

Investigators spent five months pursuing numerous hypotheses about potential causes. More than 350 drug, chemical and organism tests were done in each fatal case and more than 1250 tests were done on the New Zealand case. These tests were done in laboratories both in Thailand and overseas and a large number of personnel in Chiang Mai and Bangkok, as well as from the WHO and US CDC, worked on these events. However, as difficult as it may be to accept, the precise cause cannot be confirmed.

Actions taken by Thai authorities to reduce future risks
Thai authorities are taking measures to reduce the risks of chemical and pesticide exposure to future visitors to Chiang Mai and will also apply to other provinces in Thailand;
1) A panel will be set up to investigate and recommend stricter measures for the use of chemicals including pesticides in hotel and market areas.
2) A channel to receive notification of illness of tourists and expatriates has been set up. Visitors can post their notification at www.chiangmaihealth.com or call 053-216592. Events will be verified and investigated.
3) Surveillance of hospitalised tourists, already in effect, will be continued and a new protocol for investigation of fatal cases is being adopted.
4) Retailers of household and agricultural chemicals (pesticides) must declare a watch list of products whose procurement and sales are to be closely monitored. The provincial health office will carry out periodic checks on them.
5) Hotel operators must use only licensed pest control companies and their contracts must specify which chemicals are to be used and samples collected and sent for testing by the authorities twice a year.
6) Municipal authorities are to give safety advice and monitor public cerebrations where the burning of ritual papers and other materials are performed in communities, temples and shrines as part of traditional festivals.
7) Develop the food safety standard at eateries and among street vendors, especially around the Night Bazaar area, frequented by tourists in Chiang Mai.
8) Health Education Cards to advice tourists about food safety and other health concerns will be made available to foreign visitors to the province.
9) The Ministry of Public Health will apply these measures to safeguard tourists in other provinces.

Additional information on these events - Timeline of events, Frequently Asked Questions (FAQ), Roles & Responsibilities of Partners - are published on the website of the Department of Disease Control (www.ddc.moph.go.th). Any persons who may have specific medical or public health concerns about this event are invited to report them or make queries using this email address: askcmevent@gmail.com.

Acknowledgement
The investigation team would like to express their appreciation and thanks to the following agencies for their assistance in this investigation: The provincial health office in Chiang Mai; the Forensic Department of Chiang Mai University; the Pathology Department of Chiang Mai University; the Toxicology Centre of Ramathibodi Hospital, Mahidol University; the Faculty of Dentistry, Mahidol University; the Department of Medical Science, Ministry of Public Health; the Department of Disease Control, Ministry of Public Health; the Faculties of Medicine, Science and Agriculture, Chiang Mai University; Central Laboratories, Ministry of Agriculture and Cooperatives; Osaka University; the International Health Regulation (IHR) Focal Point of New Zealand; the IHR focal point of the USA; the IHR focal point of France; the International Emerging Infectious Disease Program of the Thai and US CDC Collaboration; the US Center for Diseases Control and Prevention; and the World Health Organisation.