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 of all ages. However, Yellow Fever vaccination is not recommended for children under nine months of age. If travel is unavoidable and the child's physician considers vaccination unwise, ask for a certificate on the physician's own stationary stating the child's age being less than one year as a contraindication to vaccination. Although this is in accordance with World Health Organization resolutions, some countries may not honour such a certificate and the infant may be put under surveillance upon arrival.
IAMAT highly recommends Yellow Fever vaccination for all travellers over one year of age going to Senegal.
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.
Meningococcal Meningitis
This infection, primarily caused by Neisseria meningitides bacteria, is transmitted from person to person through infected droplets in the respiratory system. Menigococcal meningitis is usually spread easily in situations of close proximity and long-term contact such as living in close quarters (dormitories, military barracks), and sharing drinking and eating utensils.
Vaccination is advised for persons travelling extensively or on long-term working assignments in the meningitis belt of Africa's northern Savannah. This semi-arid area extends from the Atlantic to the Red Sea. Peak season for transmission of the infection occurs in March and April. Hajj pilgrims to Saudi Arabia are required to be vaccinated prior to entering the country.
Note: The entire country is infected.
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
Cholera
Cholera is an acute gastro-intestinal infection caused by vibrio cholerae bacteria. Risk of infection to travellers is low and vaccination is advised only for medical and rescue personnel working in endemic areas.
The best protection is to avoid potentially contaminated water and food. See IAMAT's 24 World Climate and Food Safety Charts describing the sanitary condition of water, dairy products, and food in 1440 cities. Meticulous food and water hygiene are essential when travelling in endemic areas.
Persons living and working in inadequate sanitary conditions and those with impaired defence mechanisms (deficient production of gastric acid due to surgery for duodenal or gastric ulcers), persons on antacid therapy, and users of cannabis (smoking marijuana reduces acid secretion of the stomach) are more susceptible to cholera infection. The World Health Organization announced in 1991 that Cholera vaccination certificates are no longer required by any country or territory.
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.
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.
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, including urban areas, risk present at all altitudes.
High risk months for Malaria are: January - December
Malaria transmission vector(s): A. funestus, A. gambiae
Incidence of Plasmodium falciparum Malaria: > 85%
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 Senegal.
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 in the whole country, including urban areas:
S. haematobium is endemic along the entire Sénégal River valley including the area of Lake Guiers, in the western regions of Cap Vert (including Dakar), Thiès, Dioubel and Sine Saloum, and in the two southern provinces of Sénégal Oriental and Casamance. Additional snail intermediate hosts for S. haematobium: Bulinus jousseaumei and Bulinus guernei.
S. mansoni is endemic in areas along the border with Guinea in (Sénégal Oriental province), in two localized areas at Kolda and Bignona (Casamance province); and in two localized areas in the north at Fatick (Sine Saloum) and at Fandène-St. Marcel (Thiès).
There is a risk of Schistosomiasis caused by: Schistosoma haematobium, Schistosoma mansoni
The main intermediate host snail is: Bulinus senegalensis, Biomphalaria pfeifferi, See text for intermediate snail host.
Prevention Guidelines:
OTHER DISEASES OF INTEREST TO TRAVELLERS
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.
Country at risk of Chikungunya fever.
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.
Country at risk of dengue transmission.
A dengue fever outbreak has been reported in Senegal for the first time in 2 decades. The Ministry of Health has registered 55 cases of dengue fever as of 14 November 2009. [ProMed-mail. Dengue/DHF update 2009 (48). ProMED-mail 2009; 23 Nov: 20091123.4016 <www.promedmail.org>. Accessed 25 November 2009.]
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 Senegal.
Hepatitis C
The Hepatitis C virus is transmitted from person to person through unscreeened blood transfusions, blood products, contaminated needles and instruments used for tattooing and body piercing. Travellers are at risk of infection in countries where the blood supply is not adequately screened and a transfusion is required after an accident. Avoid body piercing and tattooing. The virus may also be transmitted sexually.
Hepatitis C is endemic in Senegal.
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...).
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 Senegal.
Leishmaniasis
Human leishmaniasis is a disease caused by a parasite which is transmitted from domestic and wild reservoir hosts (often dogs and foxes) to humans by sandflies. The parasites that cause leishmaniasis are transmitted by the bite of the female phlebotomine sandfly. Sandflies bite in the evening and at night and are usually found in forests, the cracks of stone or mud walls, or animal burrows (contrary to what their name suggests, sandflies are not found on beaches). Peak transmission is May to October.
Cutaneous leishmaniasis is not fatal, but can cause facial lesions and crater-shaped sores, leaving patients seriously disfigured. Visceral leishmaniasis can be fatal, and causes fever, weight loss, anemia, and swelling of the spleen and liver.
Travellers should take measures to prevent sandfly bites. Insect-bite prevention measures include applying DEET-containing repellent to exposed skin, permethrin spray (or solution) to clothing and gear and sleeping under a permethrin-treated bednet.
Risk of cutaneous leishmaniasis occurs throughout the country especially in the northwest (Keur Moussa in the Theis Region) and has been reported in the northeast along the Mauritanian border. Sporadic cases occur annually among expatriates stationed in the country.
Leptospirosis
Leptospirosis is a worldwide bacterial disease affecting domestic and wild animals: cattle, dogs, cats, pigs, and rodents. Humans become infected through exposure to infected animals or through contact with water, soil and mud contaminated with the urine of infected animals. The bacteria can enter through skin and mucous membranes of the mouth, eyes, and nose. The disease is not known to spread from person to person.
Leptospirosis can occur sporadically, in epidemics (mostly after storms, heavy rainfalls and floods), or endemically (in agricultural areas with large livestock operations or rodent infestations). It is an occupational hazard for those who work outdoors or with animals (farmers, sewer workers, veterinarians, fish workers, rescue and military personnel). It is also a serious recreational risk for campers, hikers, swimmers, and outdoor sports enthusiasts who participate in whitewater rafting, kayaking, and canoeing.
The incubation period can range from 2 to 30 days. Most infections are relatively mild and include fever, myalgia, headache, red eyes, abdominal pain, and vomiting. Severe cases present with jaundice, hemorrhage, myocarditis, and renal failure. Prevention: Outdoor sports travellers may want to consult their doctor about taking preventive medication during their trip to avoid infection even through short-term exposure.
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 endemic and a major public health problem in Senegal.
DISEASES PRESENT - LOW RISK TO TRAVELLERS
Dracunculiasis / Guinea Worm Disease
Dracunculiasis or Guinea Worm Disease, is caused by the parasite Dracunculus medinensis. The disease affects poor communities in remote parts of Africa that do not have safe drinking water. There is no treatment for Guinea Worm Disease. Removal of the worm as it emerges from the infected person's skin is curative or surgical removal by a trained doctor.
Anyone who drinks standing pond water contaminated by persons with Guinea Worm Disease is at risk for infection. People who live in villages where the infection is common are at greatest risk.
Echinococcosis
Echinococcosis is a potentially fatal parasitic disease that affecting wildlife, commercial livestock and humans. Humans become infected by accidentally swallowing the eggs of the E. multilocularis tapeworm. Humans can be exposed to these eggs by directly ingesting food contaminated with stool from infected foxes or coyotes. This might include grass, herbs, greens or berries collected from fields. Humans may also be contaminated by petting infected cats or dogs. These pets may shed the tapeworm eggs in their stool and their fur may be contaminated.
Basic hygiene practices such as thoroughly cooking food and vigorous hand washing before meals can prevent the infective eggs entering the human digestive tract.
Endemic Flea-Borne Typhus
Endemic typhus (murine typhus) is caused by the bacteria Rickettsia typhi and is transmitted by fleas that infest rats, especially during exposure in rat-infested premises, such as warehouses, stores, and grain elevators. Flea-infested rats can be found throughout the year in humid tropical environments, especially in harbour or riverine environments. In temperate regions, they are most common during the warm summer months.
Limiting exposure to vectors or animal reservoirs remains the best means for reducing the risk of disease. Risk for travellers is low. Persons who are occupationally exposed to rats ( naturalists, geologists, agricultural workers) should avoid vector-infested habitats, use repellents and wear protective clothing.
Filariasis
Lymphatic Filariasis is a parasitic disease caused by nematodes Wucheria bancrofti and Brugia malayi. The parasites are transmitted to humans through the bite of an infected mosquitoes (Aedes, Anopheles, Culex and Mansonia mosquitoes can be vectors) and develop into adult worms in the lymphatic vessels, causing severe damage and swelling (lymphoedema).
Short-term travellers to endemic areas are at low risk but should take preventive measures against mosquito bites. Travellers visiting endemic areas for longer periods of time and who are exposed to infected mosquitoes can become infected. Prevention measures include applying a DEET-containing repellent to exposed skin, applying permethrin spray or solution to clothing and gear and sleeping under bednets.
Onchocerciasis
Onchocerciasis (also known as River Blindness) is caused by a parasitic worm and is spread by the bite of an infected blackfly. Multiple infectious bites are necessary for a person to get the disease. Infected persons may not have symptoms, but a skin rash, eye lesions and/or bumps under the skin can occur. Eye lesions can progress to blindness.
The disease is found most frequently in rural agricultural villages that are located near rapidly flowing streams. Travellers should take precautions against blackfly and other insect bites. Risk to casual travellers is low.
Tungiasis
Tungiasis is a skin infestation of the Tunga penetrans flea found in tropical parts of Africa. Tungiasis affects persons walking barefoot or lying in infested sand or soil.
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.
