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Figure 5: Yellow Fever vaccination is a necessary entry requirement for many African nations.

When Travelling, What Vaccines Or Preventive Medicine Should One Consider?

A shorter version of this article was published in Jurong Health’s OneHealth Health Journal, Issue 2, 2013

It all depends on a few factors.

Where is the person travelling to?

Vaccination requirements will be different for different countries. Vaccination for Yellow Fever for example, is required for many African and South American countries, even for entry purposes. Vaccination recommendations for hepatitis A are commonly recommended by many travel clinic websites for many parts of the world.

How long is he/ she going to be at his/ her place of destinations?

The risk of contracting an infectious disease will be higher for prolonged trips overseas. For example, people going on mission trips for 1 month or more in rural Cambodia may require vaccination for Japanese Encephalitis, whereas this is may not be so for most tourists doing a 4 day 3 night tour to Siem Reap.

What sort of accommodation is he/ she going to be at?

There is an increasing number of travellers who enjoy going to exotic places, where 5 star hotels may not be available or affordable to them. These group of travellers may be more at risk of infectious diseases due to lack of hygiene, clean food and water, insect bites etc. It is important for one to consult a travel clinic so that one can get advice to stay healthy, insect bite protection measures etc.

Figure 1: It is important for travel medicine physicians to enquire what sort of hotel the traveler is staying at, I came across this mud/ dung-wall hotel on my recent trip to Kenya. Inside, it is extremely cramped and dark, flies are not uncommon and there is certainly no air-conditioners and toilet facilities.

Figure 1: It is important for travel medicine physicians to enquire what sort of hotel the traveler is staying at, I came across this mud/ dung-wall hotel on my recent trip to Kenya. Inside, it is extremely cramped and dark, flies are not uncommon and there is certainly no air-conditioners and toilet facilities.

Figure 2: This is a 4-star lodge in Kenya, where conditions are a lot different. Electricity, hot water supplies, clean food and water, mosquito nets are all available.

Figure 2: This is a 4-star lodge in Kenya, where conditions are a lot different. Electricity, hot water supplies, clean food and water, mosquito nets are all available.

What sort of activities is he/ she going to do?

A major concern for travellers is getting into accidents overseas. Many travellers are keen to try tree zipping in Laotian forests, dogsledding across the frozen seas in Greenland, self-driving in Australia and New Zealand. They need to be aware of risks associated with such activities. Falls are common during tree zipping and dogsledding, roads can be slippery with a thin layer of ice during autumn and winter in Australia or New Zealand, such driving conditions can be very different from the road conditions at home. It is important to know what your patient is going to do at his/ her destination.

Figure 3: Dogsledding across the frozen seas in Greenland is not as easy as it looks. The sleds go up and down the mountains as well at great speeds. There is a fairly high chance that the sled may overturn.

Figure 3: Dogsledding across the frozen seas in Greenland is not as easy as it looks. The sleds go up and down the mountains as well at great speeds. There is a fairly high chance that the sled may overturn.

Others may enjoy volunteering work in lesser developed countries – building schools, teaching in villages, working with animals. Usually such trips will be more prolonged and vaccination requirements may be more complicated and involve things like prophylaxis for malaria, typhoid, hepatitis A and B, cholera and even rabies vaccination. Remember, there are only 10 countries/ regions in the world that are free of rabies: Australia and New Zealand, Japan and Singapore, Hawaii and Guam, Iceland, Denmark and the United Kingdom. For many Asian and African countries where rabies is common, it is important to convey to patients benefits of rabies vaccination, especially for those working with animals and what precautions to take in the unfortunate scenario of animal bites.

Figure 4: Beautiful Icelandic horses. Iceland is free of rabies, but many other countries are not and it is important to consider rabies vaccination for those planning to work with animals in their trips abroad.

Figure 4: Beautiful Icelandic horses. Iceland is free of rabies, but many other countries are not and it is important to consider rabies vaccination for those planning to work with animals in their trips abroad.

What background/ previous medical history does the traveller have?

How up to date is he/ she is with respect to immunizations?

People who are immunosuppressed may not be candidates for Yellow Fever vaccination.

Figure 5: Yellow Fever vaccination is a necessary entry requirement for many African nations.

Figure 5: Yellow Fever vaccination is a necessary entry requirement for many African nations.

One may get a rough idea of which vaccinations are recommended on travel medicine webpages online but recommendations will vary for each individual traveller. It is highly recommended to consult a travel medicine clinic, especially for travels to exotic countries, for prolonged periods or if you are planning to do extreme sports and activities.

What are some problems associated with extreme weather conditions and how can these be prevented?

I suppose the most commonly encountered extreme weather conditions are the bitter cold in wintry countries and the extreme heat during summer in the Middle East or desert locations. Minus 20 degrees Celcius is very common during winter in places such as Greenland, Canada and Alaska. It is important you have the correct clothing to keep warm. It is important to keep the hands, neck and ears well protected and have waterproof boots. Generally, the winter clothes we purchase locally are quite useless against the cold in these countries. Tour operators in Finland and Greenland usually provide winter wear for hire and these are great for combating the cold and highly recommended. 50 degrees Celcius is not uncommon in the desert during summer.

Travellers are again advised to have adequate sun protection, and again the necessary clothing to cover up body parts so as to prevent sunburns. Sunglasses are important to protect the eyes from glare not only during summer or beach vacations, but in certain cold countries as well when sunlight is present because sunlight reflected from the snow can be quite glaring. Adequate fluid intake is always advised in hot countries and of course common sense advice to avoid sports activities in the midday and afternoon sun in tropical countries. For beach holidays, always ensure that you have the appropriate sun protection cream as well.

Air tickets to such places will be cheaper during periods of weather extremes/ low season, but travellers also need to know that flight cancellations and delays are common during winter because of heavy snow or fogs and in desert countries during summer, one may need to take a cab for distances even less than 3 blocks of flats because the heat is simply unbearable.

Figure 6: Weather in Egypt and some Middle Eastern countries can be at their extremes during summer.

Figure 6: Weather in Egypt and some Middle Eastern countries can be at their extremes during summer.

Figure 7: Breathtakingly beautiful, it is essential for one to have proper clothing and preventive measures for motion sickness to enjoy the beauty of Illulisat Icefjord, UNESCO World Heritage Site, Greenland.

Figure 7: Breathtakingly beautiful, it is essential for one to have proper clothing and preventive measures for motion sickness to enjoy the beauty of Illulisat Icefjord, UNESCO World Heritage Site, Greenland.

What should travellers be mindful about when travelling with the young or the elderly?

Travellers should bear in mind that the very young and the elderly are more prone to falling ill and accidents and may not be that adventurous in travel to exotic countries. They may not tolerate long flights and weather extremes well. Roads in certain countries may have many potholes, making it unsafe for the elderly to walk, or roads may be very windy, making it extremely giddy for the elderly and young children to sit in a car. Again, it really depends on what sort of activities one is doing during his/ her travels.

For example, Luang Prabhang in Laos is great for the elderly and young children if you just want an expensive hotel and quiet place to relax, but they may not enjoy the rough elephant rides that go up the hills in the forest when the weather is hot and humid or enjoy the 1 hour drive to the waterfalls where the roads are windy and there may be 9 bends for every minute.

Hiking up the mountains in places like Bhutan or up the Great Wall of China may again be a toil for the elderly, especially for those with cardiac, respiratory illnesses or problems with their hips or knees. The icy roads in Greenland are extremely slippery during winter and spring. I had 2 falls in a single day when I was there in March, the hotel manager told me she had 3, and my trusted local guide had 2, all in a single day, and all very young adults. Certainly not a good idea for the elderly or those that require a walking stick.

Altitude illnesses may be a consideration especially for places such as Tibet, Peru and it is important to consider having a rest day on the day of arrival just to acclimatize. Having adequate rest and food before or during travels help prevent altitude illness as well.

Figure 8: the steep walks and long hikes of Taksang Monastery makes this quite an unsuitable activity for the very young and the elderly. 90% of visitors to Bhutan will attempt this climb, only 60% will reach the monastery.

Figure 8: the steep walks and long hikes of Taksang Monastery makes this quite an unsuitable activity for the very young and the elderly. 90% of visitors to Bhutan will attempt this climb, only 60% will reach the monastery.

What are some important things for those with chronic illness to remember when travelling?

Well, the most important thing I suppose is to know your own limitations. You got to know your own medical conditions and take the necessary precautions. Do study your travel itinierary before your trip. If you can’t do certain activities when with a tour group, it is important to let your tour operator know. For example, if you have very bad osteoarthritis of the knees, it is unlikely you are going to tolerate 4 hours hiking up to the Tiger’s Nest Monastery and the other 4 hours coming down. If you have severe anaemia, chronic cardiac or respiratory condition travelling to places with high altitudes may not be a good idea. Do seek advice from your doctor and ask his/ her opinion before making your plans.

The other thing to remember is to please have enough medications to last you for your trip and pack these in your hand luggage rather than check-in luggage in case of delays. If you require syringes for conditions like diabetes, please have a doctor’s note in case people at the customs enquire. It is also important to have all your medications clearly labeled again for possible customs requirements. A spare prescription is a good idea in case your medications get lost.

Deep vein thrombosis. Should people be concerned about deep vein thrombosis when flying long distances. Who is at risk and how to prevent this?

Well, the answer for this is a definite yes. People who are obese, those with certain blood disorders, smokers, pregnant ladies, those taking oral contraceptives, people with a past history of deep vein thrombosis, are at higher risks. Do ensure adequate hydration and frequent leg exercises, getting up to walk around when you are on long flights. Personally, I’d advise people to breakup their flights if they are travelling for more than 12 hours. Even without the risks of deep vein thrombosis, it becomes extremely tiring to sit in flights lasting more than 12 hours and having more connecting flights thereafter. It makes a lot of difference if you rest a day or two at the transit destination – that’s one reason why airport hotels are so popular nowadays.

Motion sickness. What can be done to curb this ailment?

Motion sickness( kinetosis or travel sickness) is a condition in which a disagreement exists between visually perceived movement and the vestibular system’s sense of movement. Depending on its cause, this is also be referred to as seasickness, car sickness, simulation sickness or airsickness. Dizziness, fatigue, headaches, nausea and vomiting are all common symptoms.

Depending on its cause, various methods to curb this include:

  • For car sickness: look out of the window of the moving car and gaze towards the horizon in the direction of the travel, this helps to re-orientate your inner sense of balance; chewing on sweets or small snacks.
  • For sea sickness: at night, or in a ship cabin without windows, it is helpful to simply close your eyes, or if possible, take a nap.
  • Medications: oral medications such as Dramamine (dimenhydrinate) and Sturgeron (cinnarizine) may be useful. Transdermal patches such as Scopolamine may also be useful. Interestingly, many pharmacological treatments which are effective for nausea and vomiting in some medical conditions may not be effective for motion sickness. For example, Maxolon (metoclopramide) and Stemetil (prochlorperazine), although widely used for nausea and vomiting, are ineffective for prevention and treatment of motion-sickness.

Jet lag. In cases of jet lag, is melatonin recommended? How does one adjust one’s body clock?

Jet-lag is caused by disruption between the body’s circadian system and the new day and night cycle at the new destination. Loss of sleep alone caused by the travel itself often contributes to jet-lag. For flights going through 6 or more time zones, most travellers will take 4-6 days to re-establish a normal sleeping pattern and not to feel tired during the day. The severity of jet-lag symptoms largely depends on the number of time zones crossed. They are worse the greater the number of time zones are crossed. Westbound travel generally causes less disruption, as it is easier to lengthen rather than to shorten the natural circardian cycle.

Studies have shown that melatonin is highly effective in preventing and reducing jet lags. Occasional short term use appears safe. The recommendation for use is for adult travellers flying across 5 or more time zones, especially when travelling in an eastern direction, and for those with previous history of jet lags. For those who are prone to jet lags, some recommend the use of melatonin even for 2-4 time zones. However, the drug is to be used with caution in people with a history of epilepsy and those on multiple medications, especially warfarin. Do consult your doctor prior to starting this medication. (Herxheimer A, Petrie KJ, 2002)

How does one enjoy the food overseas, while preventing tummy trouble? (For water example, must one use bottled water to brush teeth as well?)

Do make sure you are aware of the local cuisines served at your place of destination. Bhutanese chilli and cheese, Egyptian cuisine are not to everyone’s taste and for vegetarians, your diet of choice may not be easily available in places like Mongolia. Fast food chains are definite safe options but these may not be available in rural areas. Whenever I travel overseas, I will tell my travel operator to change all diet options to Western food when travelling to exotic countries. Local cuisines are easily available when required, but the reverse may not be true.

Traveller’s diarrhea remains the commonest ailment to affect travellers worldwide.

Ensure that food purchased are freshly prepared and well-cooked. Always wash and peel fruits before consumption . I’d avoid street foods, especially on the first few days of arrival in most countries.

For the more rural countries, where clean toilets are difficult to come by, say Africa, India and Nepal, I’d also avoid coffee, dairy food, ice and salads as well – you certainly don’t want a bout of diarrhea or irritable bowel syndrome to spoil your trip. Bottled and canned drinks by large international companies such as Coca Cola are also safe because these have much higher standards of bottling.

Figure 9: When travelling to less developed countries, the canned drink here is a good choice, but ice may not be such a good idea if it is not served in 5-star hotels or proper restaurants.

Figure 9: When travelling to less developed countries, the canned drink here is a good choice, but ice may not be such a good idea if it is not served in 5-star hotels or proper restaurants.

Water wise, I’d certainly use bottled water for teeth brushing if tap water from that particular country is not suited for drinking.

What are some useful over the counter medicines to pack on a vacation?

Some useful over the counter medications to pack include:

Analgesics: paracetamol, aspirin, ibuprofen – useful for pain relief and fever, and also for headaches of AMS (Kayser et al, 2008)

Antihistamines such as clarinase: for allergic rhinitis which may be more common during spring time in Australian, American and European countries especially when the flowers are in full bloom; for simple runny nose.

Charcoal and lomotil: for simple diarrhea.

Famotidine or losec: for simple gastric pains.

Maxolon or stemetil: for vomiting in case of food poisoning.

Acetazolamide: to prevent altitude illness

Topical ointments: Insect repellent and sun protection creams, calamine lotion

These will again differ depending on your travel destination and length of travel.

What other advice do you suggest for travellers?

It is fun to read up on your travel destination before your trip. Important things to look out for include dangers and annoyances for example, pickpockets in many European countries; scams and con tactics; hazardous traffic conditions etc. You also get a good idea on what to expect for your destination and perhaps select which are the more interesting and safer places to visit. Travel books such as Lonely Planet, National Geographic and various webpages such as Tripadvisor, Virtual Tourist are all good sources of information.

It is recommended that you see your travel clinic for travel advice at least 6-8 weeks before your trip. This is especially so if you intend to travel to exotic or rural places, spending more than 1 month away, or doing adventurous activities. Vaccinations is only one aspect of preventive medicine. There are other precautions that may need to be discussed, for example, malaria prophylaxis in tropical countries, the risks of schistosomiasis from bathing in rivers of Africa or Egypt etc. Each year, schools across Scotland send students on exchange programmes to Malawi. Between 2005-2009, 22.8% of Scotland’s new cases of schistosomiasis from Malawi, 41.5% diagnosed in 15-24 year olds. (Blach et al, 2012)

Ladies planning long trips overseas may want to consider a gynaecological check-up. (Dawood, 2002)
Travel insurance is also very important. Apart from stolen or lost items, delays and missed airport connections, please make sure your travel insurance covers you for medical evacuations in case of emergencies. If you are doing extreme activities overseas, you may need special insurance coverage. It may be difficult to obtain cover for an expedition from travel insurers. For such cases, one may need to approach a specialist insurance broker or company eg. British Mountaineering Council. (BMC webpage)

Remember, no matter how cheap medical care is in a given country, it is likely that you will not be able to enjoy these subsidized rates which are only for locals.

Do seek medical advice and contact your travel clinic on your return should you become ill during your travels.

About the author:

Dr. Robin Yong is a senior resident physician with Health and Wellness department at Alexandra Hospital and Jurong Medical Center. He has a special interest in Travel Medicine and Emergency Medicine and is currently under taking a Graduate Diploma in Travel Medicine.


  1. Blach O., Rai B., Oates K., Franklin G., Bramwell S. 2012. An outbreak of schistosomiasis in travellers returning from endemic areas: the importance of rigorous tracing in peer groups exposed to risk of infection. Journal of Public Health. (Oxford, England) Mar;34(1):32-6.
  2. BMC webpage. Available at: https://www.thebmc.co.uk/ [Accessed 29 May 2013]
  3. Dawood, R. 2002. Traveller’s health: how to stay healthy abroad, 3rd edition. Oxford, Oxford University Press.
  4. Herxheimer A, Petrie KJ, 2002. Melatonin for the prevention of jet lag. Cochrane Database System Review. 2002;(2): CD001520.
  5. Kayser B, Hulsebosch R, Bosch F. 2008. High altitude medicine and biology. Low-dose acetylsalicylic acid analog and acetazolamide for prevention of acute mountain sickness. Spring;9(1):15-23.
  6. Spinks A, Wasiak J, Villanueva E, Bernath V, 2007. Scopolamine (hyoscine) for preventing and treating motion sickness. In Wasiak, Jason. Cochrane database of systematic reviews (Online) (3): CD002851.
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A Case Report Of Puffer Fish Poisoning In Singapore

This article was published in the medical journal Case reports in Medicine, December 2013.

Although many Asians regard puffer fish as a delicacy since ancient times, puffer fish (Lageocephalus scitalleratus) is also a well- known source of possibly lethal food poisoning. The fish is gaining popularity in Singapore and can be found in quite a few restaurants now. Puffer fish contains tetrodotoxin (TTX), a potent poison affecting the neural pathway. Puffer fish poisoning may cause a constellation of symptoms, such as giddiness, numbness and tingling sensation of the mouth, paresthesia, and muscle weakness. Severe cases may present with respiratory depression, circulatory failure, and death. TTX poisonings have been reported in Japan, Taiwan, Hong Kong, Bangladesh, and the United States (Haque et al. 2008). We report a case of mild poisoning and suggest observation for such cases.

1. Introduction

TTX is one of the most potent and oldest known neurotoxins, and puffer fish poisoning is common along the coasts of Asian countries [1–4]. TTX poisonings have been reported in Japan, Taiwan, Hong Kong, Cambodia [3], Bangladesh [4], and the United States. Also referred to as Fugu (meaning “river pig” in Japanese), balloonfish, blowfish, bubblefish, globefish, Patka fish, swellfish, toadfish, toadies, honey toads, sugar toads, and sea squab, the puffer fish [5] is commonly found in coastal regions of the tropics such as the Indian Ocean and in the South Pacific. They are relatively uncommon in the temperate zone and completely absent from cold waters [6].

Even with its long history of toxic effects, the fish is considered a delicacy in Japan especially and is prepared by licensed puffer fish cooks only in Japan. Despite this, reports of up to 50 deaths annually occur in Japan from puffer fish poisoning [7, 8]. In Taiwan, more than 100 cases were reported from 1998 to 2008, and the mortality rate was about 10% [9]. Ingestion of the flesh, viscera, or skin of toxic tetraodontiform fishes can cause poisoning. There are reports of a distinct relationship between gonadal activity of the fish and its toxicity, the fish being most lethal for consumption immediately prior to and during their reproductive periods [10, 11]. The highest concentration of the toxins is found in the viscera (gonads, especially the ovaries; liver; and intestine) and skin. The body musculature is usually free of poison [1].

To date, there is no known antidote available. Management remains supportive; hence people should be made aware of the potential risks of eating puffer fish, understand the symptoms and signs of poisoning, and quickly seek medical attention when such symptoms occur.

2. Case Report

A previously well 35-year-old Japanese lady with no significant past medical history presented to our emergency department with giddiness and weakness of the left upper limb and both lower limbs. She complained of numbness and tingling sensation around the mouth areas. There was no gastrointestinal symptoms. The symptoms occurred an hour after having fugu sashimi for lunch at a local Japanese restaurant. Her accompanying boyfriend has specified that they had ordered the gonads of the puffer fish, and these were cooked in hot soup. Apparently, they finished the meal because it was a high-end restaurant and food was described as very tasty. Her boyfriend who was with her at the restaurant had consumed less of the soup and was asymptomatic. Clinically, her parameters were stable. Heart rate was stable at 80 beats per minute and respiratory rate at 18 per minute. The patient remained conscious and alert throughout her consult and admission. On examination, she had decreased power over the left upper limb and both lower limbs. She was unable to get up from the bed to walk. A CT brain was done within the hour and this was normal. The electrocardiogram was normal, with no arrhythmias noted. Full blood count and electrolytes were also within normal limits. She was given oral stemetil initially for her nonspecific giddiness without relief of symptoms.

The patient was given activated charcoal and admitted for further observation. Her symptoms resolved the following day, after about 24 hours after ingestion of the fugu. She was discharged well and remained well following a telephone fol- lowup a week later. Although tetrodotoxin may be quantified in serum, whole blood, or urine to confirm poisoning, these tests are not available to us locally.

A report was subsequently filed with the National Envi- ronmental Agency, who then sent its team to do a check on the restaurant. Puffer fish is partially banned in Singapore. In Singapore, restaurants are allowed to import and serve only the flesh of the puffer fish, and special permits are required for this. Importation of the skin, gonads, and other parts of the fish is forbidden. The restaurant was found to be importing other parts of the puffer fish as well from Japan, including the gonads, and falsely declaring it and labeling it as other fish types.

3. Discussion

Puffer fish toxicity is a well-known type of fish poisoning. Puffer fish can be deadly if not prepared properly. Puffer fish poisoning toxicity results from consumption of incorrectly prepared puffer soup, fugu chiri, and sometimes from eating raw puffer meat, sashimi fugu. While chiri may be much more likely to cause death, sashimi fugu often causes intoxication, light-headedness, and numbness of the lips and is often eaten for this reason. The toxin cannot be deactivated by heat, cooking, or drying as it is heat stable and water soluble [12, 13].

Patients with puffer fish poisoning usually develop symptoms within 30 minutes to 6 hours of ingestion, with recovery usually in 24 hours [14, 15]. The duration, rapidity of onset, and severity of symptoms are dependant on the quantity of TTX consumed. Tetrodotoxin acts by blockage of the sodium channels of the heart myocytes, skeletal muscles, and the central and peripheral nervous systems. Tetrodotoxin also stimulates the chemoreceptor trigger zone in the medulla oblongata resulting in depression of the respiratory and vasomotor centres [16–18].

Clinical features include headache, diaphoresis, body numbness, dysarthria, dysphagia, nausea, vomiting, abdomi- nal pain, generalized malaise, weakness, and lack of coordina- tion. In more severe cases, hypotension, cardiac arrhythmias, muscle paralysis, and cranial nerve dysfunction may develop. Death results from respiratory failure and cardiovascular collapse and in severe cases can occur as early as 17 minutes after ingestion [19].

The progression of TTX poisoning is classified as follows.

  • Grade 1. Paresthesiae around the mouth, with mild gastrointestinal symptoms.
  • Grade 2. Paresthesiae spreading to the trunk and extremities, with early motor paralysis and lack of coordination.
  • Grade 3. Widespread paralysis, hypotension, and aphonia.
  • Grade 4. Impaired conscious state, respiratory paraly- sis, severe hypotension, and cardiac arrhythmia [20].

Diagnosis is usually made from medical history and toxidrome. Tetrodotoxin levels can help confirm diagnosis if history is ambiguous [21]. Diagnosis is mainly from patient’s signs and symptoms in the presence of a positive history of puffer fish consumption or the detection of TTX in leftover food. If leftover food is unavailable, the determination of TTX in the patient’s urine and/or plasma by mass spectrometry (MS) methods is essential to confirm the diagnosis [22].

Although various methods for the determination of TTX have been published, most of them are not available locally and in most countries. With better knowledge of the condition and good supportive care, the case-fatality rate was noted to have declined dramatically from 80% to 33% in 1974– 1979 as compared to the early 20th century [23]. Patients surviving for more than 24 hours are believed to have good chances of recovery [24].

To date, there is no specific treatment for TTX poisoning and management remains largely symptomatic and supportive. Removal of unabsorbed toxin may be attempted by induced vomiting or gastric lavage or by giving activated charcoal to bind to any unabsorbed toxin. Since tetrodotoxin is less stable in an alkaline environment, instillation of 2% sodium bicarbonate has been suggested [1]. Cysteine has also been claimed to be effective in individual cases of puffer fish poisoning [25]. Other advocated treatment options have included cholinesterase inhibitors (neostigmine) [26], naloxone, and steroids. In animal studies, monoclonal antibodies and 4-aminopyridine have shown promising potential [27]. For mild cases like our patient, hospitals generally observe them for 24–48 hours and discharge when asymptomatic [28]. Patients with acute poisoning are symptomatic within 24 hours and usually recover without residual deficits although some take a few days to recover [29]. As such, it could also be recommended that mild cases may be observed in an observation unit in the emergency department for up to 24 hours and discharged if there is no progression of the symptoms. A telephone followup may be made the following day to ensure that the symptoms have resolved.

A few years back, there was a local newspaper report of a case of puffer fish poisoning by a local chef who was tasting imported fugu which his restaurant had bought and prepared in Japan with the toxins removed before export. In Japan, each prefectural local government has its own qualifying system for chefs, who are not allowed to serve fugu in other prefectures. Such a certification is not valid or available in Singapore [30]. Even with supposedly “nontoxic species” of puffer fish, there have been case reports of toxicity occurring [31]. The Japanese Ministry of Health and Welfare (presently the Ministry of Health, Labour, and Welfare) published a guideline for edible puffer fish in 1983, with updates in 1993 and 1995 [32–34]. In Taiwan and China, consumption of puffer fish is banned [35]. In Singapore, puffer fish is becoming popular, and currently there is no available method for testing for TTX in biological samples.

In Singapore, healthcare providers are not required to report such illnesses. Due to underrecognition, milder cases may remain undiagnosed or unreported; hence the actual number of poisonings may be much greater. There are about 30 cases of poisoning by marine toxins reported in the United States annually. It is estimated from cases with available data that one person dies every 4 years from toxic seafood poisonings [36].


The objective of the case report is to highlight recognition and management of puffer fish poisoning. A dietary history is important, which is often neglected in many busy accident and emergency departments.
Mild cases may be observed in the emergency department and discharged with a telephone followup if the symptoms do not progress after 24 hours. We would like to recommend that rapid notification of public health authorities be made essential. This will allow timely investigation by the relevant authorities to identify the source of contaminated seafood and prevent further poisonings [29]. A food and dietary history is important, especially in younger patients who present with nonspecific neurological signs and symptoms after a meal. Health professionals should be aware of the condition so as to institute early and appropriate management.


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