health

Malaria Malaria is a disease that is transmitted through a mosquito
bite. It is a public health problem throughout many countries and affects
300 to 500 million people each year, according to the World Health
Organization (WHO). When an infected mosquito bites a human, the
Plasmodium (plaz-MO-dee-um) parasite* causes fever and symptoms
similar to those of the flu, such as extreme tiredness, muscle aches, nausea
(NAW-zee-uh), and chills. The Plasmodium parasite typically invades red
blood cells. Many symptoms of the disease are related to the destruction
of infected red blood cells and resulting anemia*. If left untreated,
malaria can cause seizures*, kidney* failure, and death. Medications can
treat malaria and prevent this disease in travelers. Malarial prophylaxis
(medicine that prevents malaria) is strongly recommended for individuals
traveling to endemic* areas. The specific medications to be used vary
regionally, depending on resistance patterns of the parasite. For those
residing in malaria hot spots, extensive trials of a potentially effective antimalarial
vaccine was initiated in 2008.

Cholera Cholera (KAH-luh-ruh) is a gastrointestinal* disease that
causes watery diarrhea, vomiting, and other symptoms. Without treatment,
it can lead to dehydration* and even death. People develop cholera
by eating food or drinking water that has been contaminated with the
cholera bacterium, Vibrio cholerae (VIH-bree-o KAH-luh-ray). Eating
contaminated shellfish or coming into contact with the feces* of an
infected person also can infect someone. A person with cholera is treated
to replace fluids lost through vomiting or diarrhea; some antibiotics may
reduce the severity and length of the illness.

Dengue fever Dengue (DENG-gay) fever is caused by a virus from
the Flavivirus (FLAY-vih-vy-rus) group transmitted to humans via the
bite of an infected mosquito. According to the CDC, up to 100 million
people worldwide develop symptoms of dengue fever each year, such
as fever, severe headaches, joint pain, and rashes. Dengue hemorrhagic
(heh-muh-RAH-jik) fever is a severe form of dengue that is associated
with bruising easily, bleeding from the nose or gums, and bleeding internally,
in addition to the other symptoms of dengue fever. No medication
can treat either form of the illness. Doctors recommend that people who
have dengue fever drink plenty of fluids to avoid dehydration and take
acetaminophen* for pain relief.

Filariasis A bite from an infected mosquito can transmit filariasis (fihluh-
RYE-uh-sis), a parasitic disease that affects the lymphatic system*.
When the infected mosquito feeds, tiny worms pass from it to the person,
where they travel to and grow in the lymph vessels. Someone with this
disease may not have noticeable symptoms, but filariasis can lead to permanent
damage to the kidneys and lymphatic system. It can also progress
to a condition called elephantiasis (eh-luh-fan-TIE-uh-sis), in which fluid
builds up in parts of the body and causes swelling and disfigurement. The
condition can be treated with medication.

Viral hepatitis Viral hepatitis (heh-puh-TIE-tis) is a viral infection of
the liver* that leads to inflammation of the organ. Infections caused by
the hepatitis B and C viruses are contracted sexually or through contact
with contaminated blood or other body fluids, but hepatitis A virus is
more contagious and is the hepatitis virus that more commonly infects
travelers. It can spread through person-to-person contact or through contaminated
water and food, especially shellfish and raw vegetables and
fruits. A person with hepatitis may have symptoms similar to those of the
flu, such as fever, chills, and weakness. People with hepatitis A may need
extra fluids and rest, but most recover without medication.

Leishmaniasis Travelers who are bitten by an infected sand fly can
develop leishmaniasis (leesh-muh-NYE-uh-sis), a disease caused by
Leishmania (leesh-MAH-nee-uh) parasites that can affect the skin or the
internal organs. People with the skin disease often have skin sores that
may spread to cause facial disfigurement. Those with the internal form of
the disease experience fever and an enlarged spleen* or liver and may need
to be hospitalized.

Plague Fleas that bite rodents infected with the bacterium Yersinia
pestis (yer-SIN-e-uh PES-tis) can transmit plague (PLAYG) to humans.
Two to six days after becoming infected with plague, a person may have
swollen and tender lymph nodes*, fever, cough, chills, and belly pain. The
plague can lead to severe respiratory illness, shock*, and death if a person
is not treated with antibiotics.

Rabies Although rabies (RAY-beez) in humans is rare in the United
States, people who travel to certain other countries may be at higher risk
for infection. The virus that causes rabies, from the Rhabdoviridae (rabdoh-
VEER-ih-day) family, is transmitted to humans through a bite from
an infected animal, and without treatment rabies can cause paralysis*,
seizures, coma*, and death. A person who has been bitten by an animal
suspected of having rabies has to receive injections of the rabies vaccine to
prevent the infection from developing.

Schistosomiasis Schistosomiasis is a disease caused by parasitic
Schistosoma (shis-tuh-SO-mah) worms that infect humans when they
come into contact with contaminated water. The worms must spend part
of their life cycle growing in freshwater snails before they enter and infest
humans. Common symptoms include rash, fever, muscle aches, and
chills. Years later, if left untreated, schistosomiasis can lead to permanent
liver damage or damage to the urinary tract*. In certain areas of the world,
the free swimming larvae of Schistosoma that primarily infect aquatic
birds may penetrate the skin of humans and lead to an itchy rash, called
swimmer’s itch. This symptom resolves over a short period of time and
does not lead to systemic* infection.

Typhoid fever According to the CDC, typhoid (TIE-foyd) fever
affects up to 16 million people worldwide each year, although only about
400 cases occur in the United States (and the majority of those are among
individuals who contracted it while traveling abroad). A person who has
contact with water or food contaminated with Salmonella typhi (sal-muh-
NEH-luh TIE-fee) bacteria may develop symptoms such as fever, weakness,
rash, stomach pain, or headache. Typhoid fever is treatable with
antibiotics.

Typhus Typhus (TY-fis) is transmitted by the bites of fleas or lice
infected with Rickettsiae (rih-KET-see-eye) bacteria. Symptoms of typhus
include an extremely high fever, rash, nausea, joint pain, and headache.
Patients often become very sick, and without treatment the disease can be
life threatening. However, it is treatable with antibiotics.

Viral hemorrhagic fevers Viral hemorrhagic (heh-muh-RAH-jik)
fevers (VHF) are a group of rare but potentially life-threatening viral
illnesses that cause symptoms ranging from fever, extreme tiredness, and
dizziness to bleeding from the eyes and ears, kidney failure, and seizures.
Humans contract VHF after exposure to people or animals that have been
infected with one of a variety of viruses. Examples of VHF include Ebola
virus infection and Lassa fever.

Yellow fever The yellow fever virus (from the flavivirus group) is transmitted
to humans by a mosquito bite. Within a week of being infected,
a person may experience fever, muscle aches, nausea, or vomiting. Most
people recover within three to four days, but according to WHO about
15 percent of people with yellow fever develop a more serious form of the
disease that can cause bleeding, kidney failure, and death. An effective
vaccine is available for yellow fever and is often recommended for travelers
who will be visiting areas where the disease is found.

Trypanosomiasis African trypanosomiasis is a parasitic illness commonly
known as sleeping sickness. The Trypanosoma (trih-pan-o-SO-mah)
parasite is transmitted to humans through a bite from the tsetse fly, after
which a person may develop a skin sore, high fever, extreme tiredness,
swollen lymph nodes, and swelling around the eyes. The disease is called
sleeping sickness because people who have an advanced form of it can have
an uncontrollable urge to sleep. If untreated, trypanosomiasis can cause
the brain and membranes around the brain to swell and become inflamed.
The disease can be treated with hospitalization and medication.
American trypanosomiasis is found in the western hemisphere. It is
also known as Chagas’ disease. It is transmitted to humans by the bite
of the Reduviid (kissing bug) The disease is caused by the protozoan
parasite, Trypanosoma cruzi. WHO estimates that 16 to 18 million persons
are infected with Trypanosoma cruzi every year. Acute infections are
usually mild but repeated infections can lead to damage to the digestive
tract or heart.

Tuberculosis Tuberculosis (TB) reemerged as a major public health
problem in the early 2000s. Experts estimate that up to one-third of the
world population has been infected by a TB bacterium at some point.
The reemergence of this disease is becoming even more troubling because
multiple-drug resistant strains of TB were also emerging. Therefore, travelers
who develop any symptoms suspicious of TB (low-grade fevers,
weakness, night sweats, cough, and weight loss) should see a doctor as
soon as the symptoms are observed.

Avian influenza Avian influenza is largely confined to birds such as
chickens, ducks and geese. However, people experiencing prolonged close
contact with infected birds have developed the disease. As of early 2009,
sustained human-to-human transmission had not occurred.
Although primarily affecting birds, a relatively small number of human
cases have been reported. The mortality (death) rate among humans as of
late 2008 was approximately 60 percent. Many experts predicted that
avian influenza would mimic the influenza pandemic* of 1918 and 1919.
Global travel is seen as a major potential factor in the possible spread
of this virus, especially with marked increase in travel to the Far East,
Indonesia, and the Indian subcontinent.