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Travel Diseases Brief Travel Related
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Tick-Borne Encephalitis (TBE) Some sources report as many as 10,000 cases of TBE referred to hospitals each year. Previous reporting of this disease may be much lower than the actual number of cases due to its similarity to other viral illness affecting the brain and under diagnosis. Disease contracted in Russia tends to more severe than other locations. Risk areas include woodlands, river banks, grasslands, cross country routes, picnic areas, and vineyards. Ticks resided on the underside of grasses and shrubs awaiting a passing by animal or person to which they latch on. They may climb some distance on their victim before feeding and are easily flicked off before they began to feed. After feeding begins, they are harder to remove, having their mouth parts embedded in the skin. Once imbedded they are easiest to remove with a "tick remover" which reaches under the mouth parts and pinches them out of the skin. A tweeters can be used if necessary. Do not squeeze or crush ticks or remove them with bare fingers. Once imbedded transmission of infectious agents by ticks may not take place immediately. There may be an incubation period of 8 to 14 days before the onset of symptoms which include fever, severe headache, nausea and vomiting, and sometimes confusion. This disease is generally milder in children than adults but can result in permanent impairment with neurological and psychological problems. After infection, the only known treatment is supportive until recovery. Ticks are seasonal in these regions from March to November depending on how far South. Not all ticks are infectious. An effective vaccine is available in Europe. It consists of a series of three injections over nine to 12 months. The first two are give three weeks apart which will result in 85% effectiveness. All children and adults traveling or living in these areas for extended periods should be vaccinated. This vaccine is difficult to find outside of central Europe. Lyme disease is prevalent in many of these areas and can be transmitted at the same time as the TBE virus depending on the type of Ixodes (hard tick). Ehrlichia and babesia may also be transmitted by these ticks. At least four out breaks of TBE have be associated with drinking raw goats milk from infected goats. A more severe type of TBE is RSSE known as the Russian spring-summer encephalitis and transmitted by the Ixodes persulcatus tick predominately in Russia, Japan, Belarus, Latvia, Lithuania and Estonia. When hiking use DEET on legs, pants and socks. Do a tick check of yourself after your outing. TBE
vaccines
Travelers' Diarrhea (TD) TD or "Turista" is a term well understood by experienced travelers to developing countries. It is defined as having three or more loose stools in a 24 hour period. Nearly one half of travelers will experience it during a trip. About 60% of travelers will have three to five stools per day and 25% of travelers will have over six stools per day, usually associated with cramping, nausea and weakness. Bloody stools and fever may be present. Symptoms may last from one to five days. High risk areas include Latin America, Africa, Asia and the Middle East. Intermediate risk areas include the former Soviet Union, Southern Europe, Israel, the Caribbean and South Africa. Experts suggest that the chances of getting TD may be the same today as it was 50 years ago in certain countries. Eating at street vendors is considered high risk, eating at restaurants moderate high risk and eating in private homes the least risk. Staying at "five star" hotels and eating at the best restaurants is advisable but no guarantee. The issue then, is not be the number of stars, but food preparation and storage, and hygiene of the kitchen staff. The most risky foods are thought to be those handled by people and served uncooked, include uncooked vegetables, especially the leafy type, and peeled fruits or fruits difficult to wash thoroughly, such as raspberries. Tainted water and ice are probably the most frequent causes of TD. At least seven studies have been done to establish a connection between the travelers eating habits and the chance of getting TD. However, only one study actually showed any relationship between a travelers dietary precautions and TD. Nevertheless, it seems reasonable that personal hygiene and eating precautions should be observed. It's cause can be traced to viral, bacterial and parasitic agents. Some countries have a high percentage of cases related to certain organisms. Worldwide, the most common cause is the bacteria Enterotoxigenic Escherichia coli (ETEC) making up about 70% of the cases. This bacteria secretes a toxin similar to the cholera toxin but responds quickly to antibiotics, sometimes even with one or two doses. Most travel specialists prescribe ciprofloxacin (Cipro®) 500 mg twice a day for three days. For short trips or those of a crucial nature, taking one 500 mg tablet daily as a preventative is reasonable and highly effective in preventing TD. It is now available in generic form. Adding loperamide (Imodium®) one or two tabs, up to four times a day improves symptoms faster than antibiotics alone. Do not use loperamide for extended periods of time or if there is bloody diarrhea, increasing abdominal pain or increasing abdominal distention. Ciprofloxacin has lost effectiveness for TD in parts of Asia, especially Thailand and India, because of bacterial resistance resulting from the high usage of this drug by Asian food producers. In India and Thailand, azithromycin is the preferred agent for TD. Azithromycin (Zithromax®) Most often prescribed as a Z-PAK® containing six 250 mg tabs or a TRI-PAK® containing three 500 mg tabs. Take 500 mg daily for three days at onset of symptoms. Occasionally, it may cause nausea and cramps, in which case taking 250 mg twice a day (or breaking the 500 mg tab in half) will be equally effective. This drug is thought to be highly effective world wide and is the preferred drug for travel in Thailand and India due to resistance to ciprofloxacin. Some experts consider it to be the antibiotic of choice for traveler's diarrhea in children. More recently rifaximin (Xifaxan®) has been introduced to the US market. Taking 200mg three times a day for three days at the unset of symptoms is highly effective against Enterotoxigenic Escherichia coli. It has activity against other pathogens, but is non-absorbable, thus not effective against invasive organisms causing bloody diarrhea. Some experts are prescribing rifaximin 200 mg daily for short trips as a preventative. Dehydration from TD may occasionally become severe, requiring oral rehydration solution (ORS) or iv fluids. ORS was developed to treat life threatening dehydration associated with cholera. It can be made from common kitchen baking items or purchased in premixed packets. ORS is not particularly tasteful and should be sipped not gulped. Recipes are available at this site: http://rehydrate.org/solutions/index.html
Typhoid Fever Typhoid fever was common in the US until the mid 1900's. It remains particularly troublesome in developing countries of Central America, South America (especially Peru), Africa, the Middle East, Asia (especially India) and in Haiti. Multidrug resistant typhoid has arisen in many countries of Southeast Asia, especially Thailand and India, which makes vaccination even more desirable. Good hand washing and eating food that is well cooked and served hot, as well as drinking purified water are important in the prevention of typhoid.
Typhoid vaccines Typhim Vi® is the brand name injectable vaccine. It is tolerated well but not recommended for children under two years of age. The oral Ty21a and the injectable Typhim Vi® are both thought to be about 70% effective. Consequently, food and water precautions should be observed even with vaccination. There is no data on safety of either vaccine in pregnancy. There is a theoretical concern in using live bacteria in pregnancy. Both vaccines are thimerosal-free. Typhim Vi® should be boosted every two years if needed while Ty21a should be booster every five years. Some experts believe that both vaccines should be boosted every two years as needed. They may be used interchangeably for boosting.
Whooping Cough (Pertussis) Since 1980, however, US pertussis cases have increased from less than 2000 cases per year to over 25,000 documented cases by 2004. The true number of cases is estimated to be over 600,000 per year. Most of these cases are in adolescents and adults, for which there was no vaccine until 2005. Outbreaks occur in 3-5 year cycles. Previous pertussis infection or childhood vaccination does not give long lasting immunity. Pertussis is a highly infectious bacterial infection of the upper respiratory tract which starts with "cold" like symptoms lasting three to five days. It progresses to a non-productive, barking cough that is difficult to control. Adults rarely "whoop" like young children. Infants may not cough but suddenly stop breathing and become cyanotic (turn blue). Respiratory arrest may be the first sign of pertussis in an infant. In severe cases, coughing can cause vomiting, fractured ribs, pneumothorax, seizures or rarely cerebral hemorrhage. Pneumonia is the most common complication of pertussis. At the least, it results in an annoying cough for patients and their family, disrupting sleep, eating and daily activities for at one month or more. The Chinese call it the "100 day cough." If treated with antibiotics before coughing begins, the cough may be prevented, but it is rarely recognized early enough. The cough is due the Bordetella pertussis bacteria secreting a toxin which binds tightly to tissues of the voice box and windpipe (larynx and trachea). This bacteria is related to one that causes kennel cough in dogs. Coughing lasts one month or more. Neither cough syrups, steroids or bronchodilators afford relief, though antibiotics may shorten the course if given early. Temporary relief of coughing can be obtained by nebulizer treatments with 1% xylocaine (Lidocaine®), an anesthetic. Persons with pertussis should be treated, however, even with up to four weeks of symptoms to prevent spread to family members, co-workers, classmates and others. According to the CDC, healthcare workers exposed to pertussis should be treated to prevent infection. Infected healthcare workers should be off work for five days and treated with antibiotics. Azithromycin, used as a Z-PAK®, is a five day treatment and tolerated better than erythromycin. Both erythromycin and TMP-SMX must be used for 14 days. Clarithromycin (Biaxin®) may be use 500 mg twice a day for seven days. Adolescents and adults are the
major carriers of pertussis in the US. All unvaccinated travelers are at risk for pertussis. See a
video clip of an infant with whooping cough at this site:
Pertussis vaccine for adults and adolescents In March of 2006, the CDC published it's recommendation that
all adolescents age 11-18 years receive one dose of Tdap to prevent pertussis
infection.
All unvaccinated travelers are at risk for pertussis.
In December of 2006, the CDC published
it's recommendation that adults, in particular certain
groups, such as physicians, nurses, dentists and other health care workers
with direct patient contact, receive one dose of the
newly licensed Tdap vaccine to prevent pertussis infection
and outbreaks. All unvaccinated travelers are at risk for pertussis. Currently, Tdap is not licensed for use in adults over 65 years of age. Recommendations for use of Tdap among this older adult group will be available in the future. A large number of pertussis cases are in the elderly. All unvaccinated travelers are at risk. Precautions in using tetanus and pertussis containing vaccines include a history of encephalopathy (e.g., coma, prolonged seizures) not attributable to an identifiable cause occurring within 7 days of a pertussis vaccine; and Guillain-Barré Syndrome (GBS) occurring within 6 weeks of a dose of a tetanus toxoid-containing vaccine.
Yellow Fever (YF) In 1802, YF decimated Napoleon's army while he attempted to subdue rebellion in the French colony of Haiti. In the late1700's until the early 1900's, epidemics occurred in the Caribbean, Central America and along the Southern and Eastern coast of the US, extending from New Orleans to Philadelphia and Baltimore. YF was commonly known as both, "yellow jack" due to the yellow appearance of the victim and "vomito negro" because vomiting blackened blood was characteristic in the last hours. Mild infections may have no symptoms or present only with headache and fever. Severe infection results in liver and kidney failure, followed by death in 15% - 80% of victims, within 4 to 5 days. YF's terrible death and epidemics were associated with poverty, suffering and business depression due to quarantines and community panic. In 1882, a young army physician, William Gorgas, survived YF infection while stationed at Fort Brown, Texas. Now immune, he was frequently drafted for service where YF existed. His expertise in YF grew during extended duty at Fort Barrancas, Florida, a post notorious for its epidemics.
Transmission of YF by mosquitoes was not recognized until the "mosquito man" Cuban physician and researcher, Carlos Juan Finlay, proposed this concept in the late 1800's. The mosquito theory was difficult to prove and even his friend Gorgas, now stationed in Havana, was slow to accept it. A yellow fever board was organized by Major Walter Reed which, in spite, of the boards own doubts about the mosquito theory, subsequently proved that mosquitoes did transmit YF. In 1900, Dr. Lazear, Walter Reed's close friend died unwittingly of YF during these research studies. In 1901, Walter Reed returned to the US from Cuba. Now famous in the medical field, he was awarded two honorary degrees and appointed as professor of bacteriology in the Army Medical School (which became the Walter Reed Army Institute of Research). Twenty-four army volunteers participated in these unique studies. They were awarded a special gold medal by Congress in 1924. After unsuccessful attempts to control YF outbreaks by quarantine and sanitation measures, Gorgas adopted the mosquito theory. The elimination of mosquito breeding sites by removing sources of free standing water in areas of habitation, brought about eradication of YF in Cuba and an international reputation for Gorgas. Both YF and malaria were prevalent in Panama and defeated the French in their attempt to build the Panama Canal. In 1902, Gorgas was placed on the new Panama canal project to control YF and malaria. Suffering intense bureaucratic hindrance, he was labeled a "visionary with no practical methods." By 1905, the US project was in trouble with widespread panic and demoralization in Panama, when high ranking officials died of YF. The rank and file of men now believed they were doomed like the French, who lost 1/3 of their workers in one year. Fortunately, President Teddy Roosevelt and a newly appointed chief engineer supported Gorgas' efforts in mosquito control, saving the US Panama Canal project. Though the Aedes aegpyti mosquito was present in many parts of the US and the Caribbean, YF is now found only in parts of South America, Africa and Panama. It has been estimated that 200,000 cases occur yearly with 30,000 deaths mostly in the sub-Saharan Africa. Yellow fever virus activity is known to far exceed the reported epidemic zones of activity. This is currently the only disease for which the World Health Organization (WHO) officially makes vaccination requirements for international travel. Proof of vaccination may be required for the following reasons:
If proof of vaccination is required, the vaccination must be done at least 10 days before entry. Certificates are good for 10 years. As per the WHO, the International Certificate of Vaccination or Prophylaxis (ICVP) for yellow fever is a legal document. It must be filled out and stamped at an official yellow fever vaccination site and must be complete in every detail to be valid. To prevent importation and indigenous transmission of YF, a number of countries require a certificate of vaccination from travelers arriving from endemic areas, even if only in transit. Such requirements may be strictly enforced. You may be denied entrance unless you submit to taking the vaccine at that time or quarantine. This can put one at risk for HIV and hepatitis B and C from contaminated needles. Also, in some situations, the vaccine may be ineffective due to improper handling. When traveling to Mecca for Hajj for pilgrimage, all travelers arriving from countries known to be infected with yellow fever (World Health Organization Weekly Epidemiological Record) must present a valid yellow fever vaccination certificate in accordance with the International Health Regulations. Because of the potential for fatal infections and the unpredictability of outbreaks, vaccination is encouraged for any potential exposure. Fatalities in unvaccinated tourists in Africa and South America have been reported in the recent past. There is no treatment for YF. According to the State of South Dakota "yellow fever vaccination center guidelines":
Yellow Fever Vaccine
Vaccine associated encephalitis (vaccine associated neurotropic disease) is
also a rare event following vaccination and most often associated with age
younger that 9 months and immunosuppression. YF vaccination should
never be done in infants less than 6 months old and should not be done in
infants less 9 months unless there is a very high risk of virus exposure.
"...The reported frequency of (severe) yellow fever adverse events in
the United States is presumed to be quite rare and on the order of 1 per
400,000 doses." Patients receiving the YF vaccine are at risk for encephalitis or other serious adverse events when immunosuppressed from:
Thymus disorders including: thymoma, thymectomy and myasthenia gravis are additional risk factors. In these cases, individuals should not be vaccinated but postpone or avoid traveling to yellow fever areas. If travel is unavoidable, the traveler should be aware of YF risks, use extra precautions for mosquito avoidance, and obtain a vaccination waiver letter from their physician. Family members of immunosuppressed patients may receive the YF vaccine. Hypersensitivity reactions can occur, especially if a serious allergy exists to eggs, chicken and gelatin. Generally, individuals who can eat eggs or egg products may receive the vaccine. The YF vaccine is pregnancy category C, which means it can be given in pregnancy but large scale studies to verify its safety are lacking. Effectiveness of the YF vaccine is markedly reduced in pregnant women. Use only if clearly indicated. There have been no reports of harm to nursing infants of mothers vaccinated with the YF vaccine. There is a theoretical risk of transmission of the live (17D) virus. It should be done only if risk of YF cannot be avoided or postponed. Page 1
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