Immunizations
Required Vaccinations
Yellow Fever
This viral infection is transmitted by the day-time biting Aëdes aegypti mosquito typically found in urban, suburban, and rural areas.
A Yellow Fever vaccination certificate is required only for travellers coming from, or in transit through, infected countries. The vaccination requirement is imposed by this country for protection against the introduction of Yellow Fever since the vector Aëdes aegypti is present in its territory.
The following countries are considered infected:
AFRICA - Angola, Benin, Burkina Faso, Burundi, Cameroon, Central African Republic, Chad, Republic of the Congo, Democratic Republic of the Congo, Côte d'Ivoire, Equatorial Guinea, Ethiopia, Gabon, Gambia, Ghana, Guinea, Guinea-Bissau, Kenya, Liberia, Mali, Mauritania, Niger, Nigeria, Rwanda, São Tomé and Príncipe, Senegal, Sierra Leone, Somalia, Sudan, Tanzania, Togo, Uganda.
AMERICAS - Argentina, Bolivia, Brazil, Colombia, Ecuador, Guyana, French Guiana, Panama, Paraguay, Peru, Suriname, Trinidad and Tobago, Venezuela.
Note: A vaccination certificate is required for children over nine months of age.
Recommended Vaccinations
Routine Immunizations
Your trip is a good occasion for a reminder to keep your routine immunizations updated; more than 80% of adults in developed countries have not maintained their immunization status. The following vaccinations are recommended for your protection and to prevent the spread of infectious diseases.
Tetanus-Diphtheria, Poliomyelitis, Measles, Mumps, Rubella should be reviewed and updated if necessary.
Seasonal influenza vaccine is recommended for children, persons over the age of 50, and those of any age suffering from chronic heart disease, emphysema, asthma, renal disorders, immuno-suppressive disorders, and organ transplant recipients. Note: Flu seasonal patterns are opposite in the southern and northern hemispheres. If the flu vaccine is not available at the time of departure, contact your doctor or travel health clinic regarding influenza anti-viral protection.
Pneumococcal vaccine is recommended for persons over the age of 65 and persons of any age suffering from cardiovascular disease, diabetes, renal disorders, liver diseases, sickle cell disease, asplenia, or immuno-suppressive disorders.
Hepatitis A
The Hepatitis A virus is primarily transmitted through contaminated water and food or by the fecal-oral route, and may cause severe liver damage. Prevention includes good personal hygiene, ensuring safe water supply, eating well cooked foods, and peeling your own fruits.
Vaccination is recommended for all travellers over one year of age. The vaccine is often combined with Hepatitis B and affords excellent long-term protection for both viral diseases.
Typhoid Fever
This intestinal infection, caused by Salmonella typhi bacteria, is transmitted from person to person primarily through ingestion of contaminated food and water in areas with poor sanitary and hygienic conditions. Prevention includes good personal hygiene such as washing your hands frequently, ensuring safe water supply, eating well cooked foods, and peeling your own fruits. Vaccination is also recommended for travellers' protection.
Selective Vaccinations
Hepatitis B
The Hepatitis B virus is transmitted through infected blood products, sexual intercourse, or infected items such as needles or razor blades, and may cause severe liver damage.
Vaccination is recommended for persons on working assignments in the health care field (dentists, physicians, nurses, laboratory technicians), or for those working in close contact with the local population (teachers, aid workers, missionaries), or persons foreseeing sexual relations with locals. This vaccine is often combined with the Hepatitis A vaccine and affords excellent long-term protection for both viral diseases.
Japanese Encephalitis
This viral infection is transmitted by Culex mosquitoes in Asia and Southeast Asia. Transmission occurs throughout the year in tropical and sub-tropical climates, and during late spring, summer, and early fall in temperate areas. The mosquitos breed in flooded rice fields and irrigation projects. Pigs and some bird species are natural carriers of the virus.
Travellers to endemic areas should take measures to prevent mosquito bites. Insect-bite prevention measures include applying a DEET-containing repellent to exposed skin and applying permethrin spray or solution to clothing and gear. Using a permethrin-treated bed net will also decrease risk of infection.
Vaccination is recommended for persons travelling extensively in rural areas, living and working near rice growing rural and suburban areas, as well as other irrigated land where exposure to mosquitos transmitting the disease is high. Children are especially susceptible to the infection.
Note: Sporadic cases are reported throughout Indonesia and transmission occurs all year. Children under 15 years of age are at high risk.
Rabies
This viral infection is transmitted through the saliva of infected animal bites which affects the brain and the spinal cord, and may be fatal.
A series of three (3) pre-exposure rabies vaccination shots is advised for persons planning an extended stay or on working assignments in remote and rural areas, particularly in Africa, Asia, Central and South America. The pre-exposure series simplifies medical care if the person has been bitten by a rabid animal. Although this provides adequate initial protection, a person potentially exposed to rabies will require two (2) additional post-exposure innoculations.
Persons who have not received the pre-exposure shots need five (5) injections in addition to rabies immune globulin (RIG). RIG is in short supply around the world and may not be available in remote areas. If a traveller has had the three pre-exposure shots, they will only need additional two shots; they do not need RIG.
Children are especially vulnerable since they may not report scratches or bites. They should be cautioned not to pet dogs, cats, monkeys, or other mammals. Any animal bite or scratch must be washed repeatedly with copious amounts of soap and water. Seek medical attention immediately.
As of 31 October 2009, the Indonesian Ministry of Agriculture is reporting a rabies outbreak on the island of Bali. There have been 15 deaths due to rabies. ProMED-mail. Rabies, canine, human - Indonesia (16): Bali alert. ProMED-mail 2009; 31 Oct: 20091031.3765. < www.promedmail.org>. Accessed 3 November 2009.
Human or equine rabies immunoglobulin is, for all practical purposes, not presently available in Bali. The supply of WHO-approved tissue culture rabies vaccines also cannot be assured. Travellers likely to be engaged in high risk activities for potential exposure should consider receiving pre-exposure rabies vaccine prior to their departure. If a traveller does incur a rabies exposure in Bali, the nearest facilities that are able to provide reliable post-exposure treatment are in Singapore, Bangkok and Australia, All of these can be reached by direct daily flights. [ProMED-mail. Rabies, canine, human - Indonesia (17): travel advice. ProMED-mail 2009; 1 Nov: 20091101.3772. < promedmail.org>. Accessed 3 November 2009.]
The number of human rabies deaths has increased to 27. So far all those affected have been local Bali inhabitants, but tourists and other visitors to the island should be forewarned of the risk and take precautions accordingly. [ProMED-mail. Rabies, canine, human - Indonesia (21): Bali. ProMED-mail 2009; 29 Dec: 20091229.4373. < www.promedmail.org>. Accessed 6 January 2010.]
The recommendations for vaccinations outlined above are intended as guidelines only. Your immunization needs depend on your health status, previous immunizations received, and your travel itinerary. Seek further advice from your doctor or travel health clinic.
Disease Risks
MALARIA
Infection is spread by the night-time - dusk to dawn - biting female Anopheles mosquito.
Malaria risk is present throughout the country, excluding urban areas, and excluding the areas specified:
Jakarta, Surabaya, Denpasar (Bali) and other large cities are risk free, including the beach resorts in southern Bali.
Sporadic cases of malaria in travellers have been reported from rural areas of Bali (Padangbai area), Bintan and Lombok islands.
Note: Persons travelling extensively in rural areas, on cruises between the islands, or making excursions to night festivals, must take a full course of malaria suppressive medication. Irian-Jaya reports a high incidence of malaria in all regions.
Malaria risk is present below the altitude of: 1200 meters
High risk months for Malaria are: January - December
Malaria transmission vector(s): A. sundaicus
Incidence of Plasmodium falciparum Malaria: 66%
Of the four species of human malaria parasites, Plasmodium falciparum is the most dangerous. The remaining percentage represents vivax group infections (benign forms of malaria caused by Plasmodium vivax, Plasmodium ovale and Plasmodium malariae.)
Areas with drug resistant Malaria: Multi-drug resistant (chloroquine and sulfadoxine-pyrimethamine) P. falciparum malaria is present in all malarious areas of Indonesia. Chloroquine resistant P. vivax malaria has also been reported.
Suppressive Medication Guide:
For details on anti-malarial drug side-effects, dosages for children and pregnant women, medications used around the world, and comprehensive protection measures, see: How to Protect Yourself Against Malaria (pdf)
SCHISTOSOMIASIS
Infection is transmitted by snails living in fresh water such as lakes, rivers, streams and ponds in the Caribbean, South America, Africa, and Southeast Asia.
Schistosomiasis risk is present absent from most of the country, risk exists only in restricted areas:
Only the centre of Sulawesi is considered endemic. Risk is present in the Lindu valley and localized around Lake Lindu (villages of Anca, Langko, Tomado, and Puroo), and in the Napu valley (about 50km southeast of Lindu valley) affecting Wuasa, Maholo, Winowanga, Alitupu, and Watumaeta. Snail intermediate host is a subspecies: Oncomelania hupensis lindoensis.
Public health control programs are ongoing and have reduced infections rates, however re-infection remains a continuous problem.
There is a risk of Schistosomiasis caused by: Schistosoma japonicum
The main intermediate host snail is: Oncomelania hupensis.
Prevention Guidelines:
OTHER DISEASES OF INTEREST TO TRAVELLERS
Avian Influenza
H5N1 avian influenza is predominantly a disease of birds. The virus does not pass easily from birds to people and does not pass from person to person (except in very rare cases of close contact with an infected blood relative). Human infection with the H5N1 virus is still a rare occurrence. Direct contact with infected poultry or surfaces and objects contaminated by their feces is considered the main route of human infection. The most likely routes of exposure include slaughtering, defeathering, butchering and preparation of poultry for cooking.
The risk to humans from avian influenza is believed to be very low and no travel restrictions are advised. Travellers should avoid visiting animal markets, poultry farms and other places where they may come into contact with live or dead poultry, or domestic, caged or wild birds and their excretions. Travellers are also advised to: cook poultry and egg dishes thoroughly. (Well-cooked poultry is safe to eat). Wash hands frequently with soap and water if around poultry.
The World Health Organization (WHO) does not recommend travel restrictions to countries experiencing outbreaks of H5N1 avian influenza in birds, including countries which have reported cases of human infection.
The Ministry of Health of Indonesia has confirmed 6 human cases of H5N1 Avian Influenza in 2010 (5 deaths in 2010). Of the 168 cases confirmed in Indonesia, 139 have been fatal. The risk of avian influenza to travellers, however, is very low, since almost all human cases have occurred in those who have had direct contact with live, infected poultry, or have had close contact with infected family members who were blood relatives.
Chikungunya Virus
Chikungunya fever is a viral disease transmitted to humans by the bite of infected mosquitoes (Aëdes aegypti). Aëdes aegypti mosquitoes feed predominantly in the daytime. Symptoms include fever, headache, fatigue nausea, vomiting, muscle pain, rash and joint pain.
Travellers should take measures to prevent mosquito bites. Insect-bite prevention measures include applying a DEET-containing repellent to exposed skin, applying permethrin spray (or solution) to clothing and gear, and sleeping under a permethrin-treated bednet at night.
Endemic in Indonesia. Chikungunya has been reported across Indonesia.
Over 12,000 people in Lampung province, have reportedly contracted chikungunya since mid December [2009]. Tulangbawang and Mesuji have been reported as the worst hit regencies in the province, where the disease has affected between 3000 and 4000 people in both regions consecutively. [ProMED-mail. Chikungunya (01): Indonesia (Lampung). ProMED-mail 2010; 01 Jan: 20100101.0015. <promedmail.org >. Accessed 15 Jan 2010.]
At least 420 people in Sidomulyo, South Lampung regency, have been infected with the mosquito-borne chikungunya [virus] since early in the month [January 2010], prompting local health authorities to declare the outbreak an emergency. [ProMED-mail. Chikungunya (02): Indonesia (Lampung). ProMED-mail 2010; 16 Feb: 20100216.0551. <www.promedmail.org >. Accessed 24 Feb 2010.]
Health authorities in South Lampung have declared a special alert for the chikungunya virus in the Bakauheni district, after 121 residents contracted the disease. In South Kalimantan regency of Banjar [Borneo] at least 4500 people were infected with the disease over the past 40 days. [ProMED-mail. Chikungunya (03): Indonesia (Lampung). ProMED-mail 2010; 24 Feb: 20100224.0617. <www.promedmail.org >. Accessed 9 March 2010.]
Cutaneous Larva Migrans
Cutaneous larva migrans (known as creeping eruption, caused by dog and cat hookworms) is contracted from walking barefoot on moist sandy beaches contaminated by animal feces containing hookworm larvae. Wear shoes or sandals. At the beach, always sit on a towel (washed after each use) and wash with soap and water after each barefoot walk.
Risk is present in Indonesia.
Dengue Fever
Dengue is transmitted via the bite of an infected Aëdes aegypti mosquito. Aëdes aegypti mosquitoes feed predominantly in the daytime. Symptoms consist of sudden onset of fever, headache, muscle aches, and rash. Dengue hemorrhagic fever may occur particularly after a second infection with a different strain. Travellers at risk should take measures to prevent mosquito bites. Insect-bite prevention measures include applying a DEET-containing repellent to exposed skin and applying permethrin spray or solution to clothing and gear.
Year-round risk, elevated during the rainy season from November through April. Risk is higher in densely populated urban areas where mosquitoes breed in stagnant pools of water. The highest incidence of dengue is in East Java. Dengue hemorrhagic fever is common.
A dengue fever epidemic reportedly occurred in Medan, North Sumatra throughout October and November [2009], commonly associated with the rainy season in Indonesia. [ProMED-mail. Dengue/DHF update 2009 (47). ProMED-mail 2009; 15 Nov: 20091115.3944. <www.promedmail.org>. Accessed 20 November 2009.]
Since December 2009 there has been a dengue fever outbreak in Balikpapan, East Kalimantan. There have been 2 deaths and 176 others have been treated in hospital. [ProMED-mail. Dengue/DHF update 2010 (03). ProMED-mail 2010; 19 Jan: 20100119.0211. <www.promedmail.org>. Accessed 20 January 2010.]
The local administration in Jember regency, East Java, has recorded a total of 141 cases of dengue fever in the first 11 days of the new year [2010] and say the number may increase in the coming weeks. [ProMED-mail. Dengue/DHF update 2010 (03). ProMED-mail 2010; 19 Jan: 20100119.0211. <www.promedmail.org>. Accessed 20 January 2010.]
The Jakarta Health agency recorded 914 cases of dengue fever as of 3 February 2010. Most of the cases occurred in East Jakarta, which recorded 309 cases, followed by South Jakarta with 267 cases, North Jakarta with 131 cases, West Jakarta with 123 cases, and Central Jakarta with 84 cases. [ ProMED-mail. Dengue/DHF update 2010 (06). ProMED-mail 2010; 08 Feb: 20100208.0426. <www.promedmail.org>. Accessed 10 February 2010.]
The Health Ministry has reported that in the current rainy season, dengue fever cases have increased in the provinces of Riau, Jakarta, West Java (Bekasi), East Java (Kediri, Lumajang, Malang), West Kalimantan, Central Kalimantan, South Kalimantan, West Sulawesi, and North Maluku. Dengue cases have also been reported in Bali, Bangka Belitung, East Kalimantan, Gorontola, and Palu. [ProMED-mail. Dengue/DHF update 2010 (08). ProMED-mail 2010; 22 Feb: 20100222.0597. <www.promedmail.org>. Accessed 23 February 2010.]
Around 45 community units in 14 sub districts in Yogyakarta have become dengue fever endemic areas since three years ago. Up until 19 July 2010, there have been 814 patients and one [death]. [ProMED-mail. Dengue/DHF update 2010 (37). ProMED-mail 2010; 20 July: 20100720.2435. <w
Giardiasis
Giardiasis is a worldwide intestinal parasitic infection. Symptoms include chronic diarrhea, bloating, low-grade fever, nausea and headaches. It is caused through the ingestion of contaminated food and water by cysts of the protozoa Giardia lamblia, G. intestinalis and G. duodenalis. It occurs in areas with poor sanitation and areas where surface water is used for drinking. Person-to-person transmission occurs when Giardia cysts from the stool of an infected person are passed from hand-to-mouth and is the cause of outbreaks in daycare centers, dormitories and chronic care centers. Fresh water bodies (lakes, rivers, streams, ponds) which are open to human and animal fecal contamination are the source of infection for canoers, kayakers, campers and hikers . Prevention includes: meticulous personal hygiene, food safety precautions and purification of drinking water (boiling water or other methods).
Risk of food and water-borne disease exists in Indonesia.
Hepatitis E
Hepatitis E is caused by infection with the hepatitis E virus. It is transmitted mainly through contaminated water or food by the fecal-oral route. It is common in countries with low standards of sanitation. Prevention includes good personal hygiene, ensuring water supply is safe, and following food safety measures (eating food well-cooked and hot, peeling your own fruits, etc...).
High risk for Hepatitis E exists in Indonesia.
Intestinal Parasites
Food-transmitted parasitic infections can be prevented by washing salads and/or vegetables or thoroughly cooking food to destroy infective eggs. Travellers should avoid raw or undercooked food that may be contaminated. Soil-transmitted infections may be avoided by not walking barefoot and not touching soil with bare hands.
Amoebiasis (amoebic dysentery) is a parasitic infection causing intestinal disease. Transmission occurs by eating food that is contaminated with feces from an infected person or drinking water containing amoebic cysts. Transmission also occurs sexually by fecal/oral contact. Infection rates are highest in areas where sanitation is poor.
Ancylostomiasis (hookworm, Necator americanus) is an intestinal parasite of humans. It causes mild diarrhea and abdominal pain. Humans can become infected by direct contact with contaminated soil, generally through walking barefoot, or accidentally swallowing contaminated soil. Do not walk barefoot or touch soil with bare hands where hookworm is common or where there may be fecal contamination of soil. Common in tropical and subtropical regions.
Angiostrongyliasis (roundworm) is a parasitic infection found mainly among people who eat snails, prawns, crabs, vegetables, contaminated by the mucous of infected slugs, land snails or aquatic snails.
Ascariasis (roundworm, Ascaris lumbricoides) is an intestinal helminthic disease. The primary route of infection is ingestion of eggs from contaminated soil or vegetables.
Trichuriasis (whipworm, Trichuris trichuria, Trichuris vulpis) is an intestinal parasite of humans, primarily affecting children. They may become infected if they ingest soil contaminated with whipworm eggs. Some outbreaks have been traced to contaminated vegetables (due to presumed soil contamination). Most commonly found in countries with warm, humid climates.
Risk is present in Indonesia.
Melioidosis
Melioidosis is an infectious disease caused by the bacterium Burkholderia pseudomallei. Melioidosis is predominantly a disease of tropical climates, especially in Southeast Asia where it is endemic. The bacteria causing melioidosis are found in contaminated water and soil and are spread to humans and animals through direct contact with the contaminated source. Anyone working in the field of agriculture is at risk.
There is no vaccine for melioidosis. Prevention can be difficult since contact with contaminated soil and standing water is very common in rice-growing areas. Persons with diabetes and skin lesions should avoid contact with soil and standing water in these areas.
Risk is present in Indonesia.
Scrub Typhus
Mites ("chiggers") transmit Orienta tsutsugamushi, the agent of scrub typhus. These mites occur year-round in a large area. Their prevalence, however, fluctuates with temperature and rainfall. Infection may occur on coral atolls in both the Indian and Pacific Oceans, in rice paddies and along canals and fields, on oil palm plantations, in tropical to desert climates and in elevated river valleys. Humans may encounter the vector of scrub typhus in recently disturbed habitat (e.g. forest clearings) or other persisting mite foci infested with rats and other rodents. Limiting exposures to vectors or animal reservoirs remains the best means for reducing the risk for disease. Prevention includes avoiding vector-infested habitats, using repellents and protective clothing, and the prompt detection and removal of mites from clothing.
Sexually Transmitted Infections
Avoid unprotected sexual contact. If you are going to have sex with a stranger, use latex or polyurethane condoms consistently and correctly. Bring your own condoms from home.
Some countries have entry restrictions for travellers with HIV / AIDS. See The Global Database on HIV Related Travel Restrictions for details on this country.
Traveller's Diarrhea
Diarrhea is the most common cause of illness during travel. The source of illness is the ingestion of contaminated food or water, person-to-person transmission, or recreational exposure to water bodies. The infective agents can be bacteria, viruses, protozoa or toxins found in food. Good personal hygiene practices (including frequent and thorough hand washing), proper food handling, and water purification are the most effective methods to prevent infection.
Consult your doctor for the best treatment options tailored to your needs, including taking prescription medication on your trip in case you suffer from diarrhea. Travellers with chronic conditions are more susceptible to infections and should consider taking preventive medication.
See our Guide to Healthy Travel for prevention and treatment tips.
Tuberculosis
Tuberculosis is transmitted from person to person through inhalation of airborne infectious respiratory droplets. Travellers who have only casual contact with infected persons are at low risk.
However, travellers visiting friends and relatives (especially young children) in developing countries, persons on working assignments in the health care field (dentists, physicians, nurses, laboratory technicians), long-term travellers and those who have close and prolonged contact with the local population (teachers, missionaries, Peace Corps volunteers) are at risk. Travellers at risk should have a pre-departure TB skin test and be re-tested after leaving the country.
Tuberculosis is highly endemic in Indonesia.
DISEASES PRESENT - LOW RISK TO TRAVELLERS
Plague
Plague is mostly a zoonotic bacterial infection of rodents caused by Yersinia pestis and is transmitted to humans and animals through bites by infected fleas. Person to person infection can occur through respiratory secretions. Rapid diagnosis and treatment with antibiotics is imperative since untreated infection has a high mortality rate. The Plague vaccine is no longer commercially available.
Most travellers are not at risk from the Plague, however, persons who may be occupationally exposed to wild rodents (anthropologists, archeologists, geologists, spelunkers) or hunters, hikers, and campers in endemic areas must avoid contact with rodents.
Risk is present on the island of Java, south of Surakarta.
Food and Water Safety
All local water should be considered contaminated. All tap water used for drinking, brushing teeth, and making ice cubes should be boiled (bringing water to a good rolling boil is sufficient). Good brands of bottled water are available; check cap seal and ensure that the bottle is uncapped in your presence.
Milk should be boiled before consumption because of possible improper refrigeration during distribution. Powdered and evaporated milk are available and safe. Butter should not be used as a table food. Cream, ice cream, and whipped cream should not be consumed. Cheese, unless cured, is best avoided. Yoghurt is safe only if it is known to be made from pasteurized milk.
All meat, poultry, and fish must be well cooked and served while hot. Pork is best avoided; vegetables should be well cooked and served hot. Salads are best avoided. Fruits with intact skins should be peeled by you just prior to consumption. Avoid raw and undercooked eggs, and dishes prepared with raw eggs (steak tartar, mayonnaise, and dressings). Avoid cold buffets, uncured cheeses, custards, and any frozen desserts.
First rate hotels and restaurants serve purified drinking water and reliable food. However, the hazard is left to your judgement.
Gastro-intestinal infections are the most common illnesses affecting travellers and can occur in any country you are visiting. Proper food handling, drinking purified water, and maintaining good personal hygiene are key to prevention. Below is a summary of the agents causing gastro-intestinal illnesses.
Bacterial Contamination
It is estimated that about 85% of traveller’s diarrhea is caused by bacteria of which the following are the most important agents:
Enterotoxigenic Escherichia coli (ETEC) and Enteroaggregative Escherichia coli (EAEC) account for most cases of traveller’s diarrhea associated with contaminated food and water world wide. They are the cause of large outbreaks in developed countries when food and water sanitation have not been properly maintained. Symptoms include watery stools, abdominal cramps, and possible vomiting lasting three to seven days.
Campylobacter jejuni is more prevalent in developing countries and is associated with contaminated water, undercooked food, and unpasteurized milk. Symptoms include diarrhea, abdominal cramps, and fever lasting from two to ten days.
Salmonella enteritidis is associated with contaminated eggs, poultry, milk, fruits, and uncooked vegetables. Symptoms include diarrhea, vomiting, abdominal cramps, and fever lasting from four to seven days. Infected persons can become asymptomatic carriers and shed the bacteria for years, becoming the source of infection for others through poor hygiene practices.
Shigellosis is a human infection caused by one of four species and transmitted by fecal-oral route due to unsanitary conditions, contaminated food and water, and overcrowded living conditions. Symptoms include diarrhea, abdominal cramps, fever, and may cause bloody diarrhea and mucous lasting four to seven days.
Vibrio cholera is associated with contaminated water, raw and undercooked seafood. Cholera infection in travellers is rare; symptoms include watery diarrhea and vomiting lasting three to seven days, but can lead to severe dehydration and death in undernourished persons. Vibrio parahaemolyticus is also related to the consumption of raw and undercooked seafood. Vibrio vulnificus is associated with contaminated shellfish and raw oysters in particular, and has caused septicemia in persons with liver disorders.
Viral Contamination
Gastro-intestinal infections caused by viruses account for about 5%. The main agents are Norovirus, associated with outbreaks at large gatherings and on cruise ships, and Rotavirus, which is more prevalent in developing countries. Symptoms include vomiting, diarrhea, fever, and myalgia lasting 12 to 60 hours.
Protozoal Contamination
Gastro-intestinal infections with protozoa account for about 10% of traveller’s diarrhea, but may cause prolonged illnesses (lasting weeks) and cause serious complications if not diagnosed in a timely manner.
Giardia lamblia (Giardiasis) and Entamoeba hystolytica (Amebiasis) are the most important agents in this category and both infections are acquired through contaminated food and water, as well as person to person transmission due to poor hygiene practices. Cryptosporidium and Cyclospora cayetanensis are implicated with contaminated food, water, and fresh produce (berries).
Toxins Causing Food Poisoning
Clostridium perfringens is the most important agent causing food poisoning in developed countries. The spores of the bacterium germinate on cooked food that is cooled and stored at room temperature over a prolonged period of time. After ingestion, the spores produce an enterotoxin in the small intestine causing abdominal pain, diarrhea, and vomiting. Foods implicated are meats and poultry.
Staphylococcus aureus enterotoxins are spread by unsanitary practices of infected persons. The foods implicated are custards, creamy desserts, meats, and salads.
Clostridium botulinum bacteria produce a very potent toxin. It is associated with improperly canned food, lightly preserved vegetables, salted fish, and meats. Symptoms include nausea, vomiting, and neurological symptoms such as blurred and double vision, paralysis of respiratory and motor muscles that may progress rapidly.
Seafood Poisoning
Fish and shellfish can be contaminated with the toxins produced by marine micro-organisms called dinoflagellates found in all oceans, especially in coral reef areas. Larger fish have usually more toxins accumulated in the skin, musculature, and organs, as these toxins are passed up through the food chain. The toxins are not destroyed through cooking, smoking, or freezing, they are odorless and tasteless, and do not alter the appearance of the fish.
Ciguatera Fish poisoning is the most common illness in this category. The most affected fish are amberjack, barracuda, grouper, kahala, parrotfish, sea bass, red snapper, surgeon fish, ulua. Symptoms usually appear within a few hours but can be delayed for a day or more and include nausea, vomiting diarrhea, muscle pain, itchiness, dizziness and temperature reversal (hot feels cold and cold feels hot). Symptoms can last for months. Persons who had a previous episode of ciguatera fish poisoning should avoid a second exposure as symptoms will be more severe. Prevention: Avoid large fish (more than 2.5 to 3 kilos [6 lbs]) or fillet of large fish, avoid head, roe, intestines and liver where the toxin is more concentrated.
Scombroid poisoning is the result of improper handling and refrigeration of fish containing high levels of natural occurring histidine (amino acid in protein). Contamination with bacteria will convert histidine to histamine-causing symptoms similar to allergic reactions, which occur very rapidly and include headache, abdominal cramps, diarrhea, itching, flushed face, and paralysis may occur. Scombroid poisoning occurs worldwide and affects fish from the Scombridae family: yellow tuna, mackerel, skipjack, and bonito. It can also affect other species such as herring, bluefish, sardine, anchovy, amberjack, and mahi-mahi. Prevention: Proper handling and immediate refrigeration of catch.
Shellfish poisoning is associated with the algal blooms (red tides) occurring in temperate and tropical areas. Shellfish – oysters, clams, cockles, mussels, crabs, lobsters – filter or ingest toxins produced by dinoflagellates micro-organisms. Each different toxin produces characteristic symptoms:
- Symptoms of diarrheic shellfish poisoning occur about 30 minutes to hours after ingestion and include nausea, vomiting, and diarrhea. Recovery occurs within two to three days.
- Symptoms of neurotoxic shellfish poisoning appear rapidly after ingestion and include tingling of mouth, arms and legs, stomach upset, and severe muscle pain. Recovery occurs within two to three days.
- Symptoms of paralytic shellfish poisoning appear rapidly after ingestion and include nausea, numbness of face arms and legs, headache, loss of coordination and dizziness, in severe cases respiratory failure and paralysis may lead to death.
- Symptoms of amnesic shellfish poisoning occur within 24 hours of ingestion and include vomiting, diarrhea, and disorientation. Permanent short-term memory loss has been observed, and in severe cases seizures, paralysis, and death may occur. Persons with kidney disease are especially vulnerable.
Puffer Fish poisoning (Fugu) is caused by a tetrodotoxin accumulating mainly in the liver, intestines and ovaries of puffer fish, ocean sunfish, globe fish, and porcupine fish. Symptoms appear between six and 20 hours and include profuse sweating, salivation, headache, hypothermia, and neurological symptoms of paralysis and respiratory failure. The mortality rate is very high.
