Breakbone Fever a.k.a. Dengue Fever

Most travelers have heard about dengue but don’t really know what it is or how bad it can be.  The nickname, breakbone fever, gives people a clue.  Dengue is a viral infection that is transmitted by infected mosquito bites and is endemic throughout the tropics and subtropics.  That means it is common in Mexico, Central and South America, Caribbean, South Asia, Southeast Asia, Africa, and northeastern Australia.  Over 100 countries have a risk of dengue.  According to the WHO, about half of the world’s population is now at risk for dengue.  Over the last few years, I’ve met many U.S. families returning from their trips worried about dengue or knew someone who recently got infected with dengue.  It is a leading cause of fever in returning travelers.

Dengue is a mean and smart virus.  It is more common in urban areas, as opposed to rural areas.  And the mosquitoes that carry dengue like to bite during the daytime as opposed to the nighttime.  There are 4 types of dengue viruses.  This means that many people who live in endemic country get infected with dengue more than once.  About 75% of people who get infected with dengue virus have no symptoms at all.  The rest, however, can develop a range of different symptoms, including fever, nausea/vomiting, abdominal pain, severe headache and eye pain, joint and bone pain, rash, and easy bleeding.  The incubation period ranges from 3-14 days.

Here’s the scary part.  As many as 5% of people who get dengue develop SEVERE DISEASE, which is called dengue hemorrhagic fever and dengue shock syndrome.  Children are more vulnerable to severe disease and more likely to die.  And people who had dengue in the past are more at risk for severe disease if they get infected with a different type of dengue virus a second time.  Dengue can cause leaky blood vessels which can lead to extra fluid in the lungs and abdomen and SHOCK.  Severe dengue also causes bleeding from GI tract, which shows up as bloody emesis or bloody/dark black stools.  Dengue can also cause hepatitis, pancreatitis, myocarditis, and encephalitis.

There are currently no licensed vaccines, prophylactic medications, or antivirals in the U.S. that protects us from dengue.  However, I learned at a recent international travel medicine conference that there are a few promising dengue vaccines in the pipeline.  The best way to prevent dengue currently is to AVOID MOSQUITO BITES by doing the following:

1. Use insect repellant, such as 20-30% DEET.

2. Wear loose clothing that covers exposed skin.  Clothing can also be pre-treated with permethrin, which will give extra protection.

3. Stay in places with window and door screens, bed netting, or air-conditioning.

4. Cover or avoid having standing or open water containers around the place you are staying in.  These are breeding grounds for mosquitoes.

What do you do if you or your child has a fever and develops other symptoms worrisome for dengue within 2 weeks after you return from your trip?  Go see your doctor right away.  There are blood tests available than can tell whether you have dengue. Many cases of dengue can be mild and be treated supportively at home.  But knowing the signs of severe dengue and getting EARLY appropriate treatment can be life-saving.

How to prevent typhoid fever while eating out on your trip

Eating at a restaurant in Ubud, Bali

The name itself is a little confusing.  Typhoid fever sounds too much like typhus fever, a completely different disease.  Typhoid fever is caused by the bacteria Salmonella typhi, whereas typhus fever is caused by bacteria in the Rickettsia family. You can get typhoid fever from eating or drinking contaminated food or water.  You can get typhus fever by being bitten by an infected human body louse or tick.  Which disease wins in the popularity contest of diseases in U.S. travelers?  Typhoid fever wins by an overwhelming majority.

The CDC estimates that there are about 21 million cases of typhoid fever and 200,000 related deaths each year.  Each year, there are about 5,700 cases of typhoid fever in U.S travelers, most who got the disease while traveling in a developing country.  Which countries have the most cases of typhoid fever?  SOUTH ASIAN COUNTRIES, including INDIA AND PAKISTAN,  have a 6-30X higher risk than other countries.  However, other areas with a high risk of typhoid fever include Southeast Asia, East Asia, Africa, Central and South America, and the Caribbean. Essentially most places you would visit outside of North America, Western Europe, Australia, and New Zealand have a risk of typhoid fever.

So how bad is getting typhoid fever?  Typhoid fever usually causes high fevers, headache, malaise, decreased appetite, enlarged liver or spleen, or a rash consisting of pink “rose spots.”  Diarrhea is uncommon. The serious complications of typhoid fever include intestinal hemorrhage or perforation, which can lead to death.  In the pre-antibiotic era, the fatality rate was up to 20-30%.  Now, antibiotics are the treatment of choice for typhoid fever.  But even with the right antibiotic, it can still take 3-5 days for people with typhoid fever to start feeling better.  Children who get typhoid fever may need to be treated as an inpatient in the hospital.  The incubation period for typhoid fever is 6-30 days.  So even if you’re back home from your travels, remember to tell your doctor about your travel history if you get a high fever.

Families often ask me during a pre-travel visit, “How do I prevent typhoid fever?  First of all, practicing SAFE FOOD AND WATER PRECAUTIONS is very important.  See my previous post “Is this safe to eat?”  for more details on these very essential tips. The same precautions used to prevent traveler’s diarrhea will also prevent typhoid fever.  However, we also know that people who are known as “asymptomatic carriers” can pass typhoid fever on to another person.   For example, if a restaurant waitress, who has recently recovered from typhoid fever, does not wash her hands with soap and water after using the restroom, she can contaminate the food or drinks she serves to a customer.  From my experience, it is RARE to find soap in restaurant bathrooms in Asia.  Have you ever heard of the case of Typhoid Mary?  In 1900, Mary Mallon, aka Typhoid Mary, was a cook in NYC and the first person in the U.S. to be identified as an asymptomatic carrier.  She unknowingly infected 51 people, 3 of whom died.  She spent nearly 30 years in isolation before she died.

GETTING THE TYPHOID FEVER VACCINE before your trip will also prevent typhoid fever.  There are 2 safe typhoid fever vaccines available that offer 50-80% protection from the disease.  The injectable Typhim Vi vaccine  can be given to people age 2 and older.  The oral live attenuated typhoid vaccine, Vivotif, can be given to people age 6 and older, who can swallow pills (4 relatively large pills over the course of 7 days).  The oral vaccine needs to be refrigerated and completed at least 1 week before your trip.  The injectable vaccine is best given 2 weeks before your trip to give time for the immunization to work.   But even if your trip is in a few days, it is still better to get the vaccine late than not getting it at all. For the repeat travelers, the injectable Typhim vaccine will need to be given again in 2 years and the oral Vivotif vaccine will need to be given again in 5 years.  Side effects of typhoid vaccines are uncommon and mild.  For the typhoid shot, fever, headache, and local skin reactions are the usual side effects.  For the oral typhoid vaccine, fever, headache, and the rare stomach upset can occur.

Typhoid fever vaccine is the #1 vaccine I recommend most for travelers to developing countries.  Primarily because this disease is still so common in developing countries, where sanitation is poor and contaminated water is common.  I love to eat at local restaurants when I travel, but I cannot guarantee the safety of their food or the level of hygiene their staff practices.  And knowing how ill people with typhoid fever can get was the primary reason why I vaccinated myself and my daughter from this disease before our trip to East and Southeast Asia.