Dengue fever is a viral infection that gets little press but is becoming an increasingly serious public health threat around the world, including the Americas. It’s spread through a bite from infected mosquitoes, and so far the only way to prevent it is to keep mosquito populations down and avoid mosquito bites as much as possible.
There is no vaccine against the disease and no specific medications to treat it, but anyone who suspects an infection should get medical attention immediately. It’s a serious illness, and in some cases can be fatal if untreated.
The main carrier is the Aedes aegypti, the same mosquito responsible for yellow fever, but it is also carried by the Aedes albopictus, a resilient, adaptable mosquito colloquially known as the Asian tiger mosquito because of its coloration: black with white stripes.
Aedes aegypti is endemic to Panama, but Aedes albopictus originated in Asia and has only recently spread to other parts of the world, including the United States. It was not discovered in Panama until 2002.
The disease comes in two forms. Classic dengue fever is characterized by high fever, nausea, vomiting, headache, and pain in the back, joints, and eyes. Pain can be intense, which is how the disease earned the ominous nickname “breakbone fever.” Symptoms are often milder for younger children. Recommended treatment includes pain medications, rest, and drinking lots of fluids under a doctor’s care while the virus runs its course.
Dengue hemorrhagic fever (DHF) is a far more serious form of the disease. It can be fatal if not properly recognized and treated. With good medical care, however, the mortality rate is generally less than 1 percent. Symptoms include a fever that lasts 2–7 days, accompanied by symptoms that are easily confused with those of other illnesses, such as nausea, vomiting, headache, and stomach pain. This stage is followed by signs of hemorrhage, including a tendency to bruise easily, bleeding nose or gums, and sometimes internal bleeding. Without treatment, this stage can be followed by circulatory failure, shock, and death.
Both dengue fever and DHF are caused by four distinct but closely related viruses. All four now exist in Panama. Infection by one type provides no immunity against later infection by another type.
Dengue epidemics are becoming increasingly common in the Americas. In 1993 Panama had its first reported case of dengue in nearly 50 years. In 2007, there were more than 1,000 dengue cases, and 2 cases of DHF. (By way of comparison, Costa Rica  reported more than 25,000 cases of dengue and 300 of DHF in 2007. The population of Costa Rica is about 4.1 million vs. 3.3 million for Panama.)
Dengue thrives in poorer urban areas, and by far the largest concentration of cases has occurred in the sprawling San Miguelito district on the outskirts of Panama City . But dengue is a risk anywhere mosquitoes are found. I was surprised during my last visit at the number of people in comfortable (though usually rural) surroundings I met who’d had a bout of dengue. Mosquito populations are kept down through removing or covering standing pools of water and through fumigation. Panamanian officials have been lax about this in recent years, but they have ramped up their sanitation and fumigation efforts recently. Anyone with uncovered water containers on their property can be fined.
Yellow fever was the most dreaded disease in Panama until a massive sanitation and public health program eliminated it from the isthmus in 1906. While it has never had a serious resurgence in Panama (the most recent known case was in 1974), the country has to be constantly on guard against the possibility. Panama provides a perfect home for the disease and its local vector, the Aedes aegypti mosquito. Relaxed sanitation standards helped the mosquito reestablish itself on the isthmus in 1985, which sparked a new public-health push to control it. So far, the mosquito has brought with it dengue fever but not yellow fever.
The biggest concern is that the disease will be brought to the country by foreign visitors from a neighboring country that still has the disease, such as Colombia, which experienced a yellow-fever outbreak in 2004 that killed several people.
Yellow fever symptoms typically come in two phases. The first is characterized by fever, intense muscle pain, nausea, headache, chills, and vomiting. For about 15 percent of sufferers, there is a drop-off in symptoms that is followed in a few days by a return of the fever, and sometimes jaundice (hence the name “yellow fever”), stomach cramps, vomiting, and hemorrhaging. About half of these latter patients die within 10–14 days after the onset of the first symptoms. There is no cure, but most people do survive a yellow-fever attack. Those who do are immune to the disease thereafter, which is a mild consolation. Seek medical help immediately at the first sign of symptoms.
Malaria is a tenacious disease that has not been entirely eradicated either in Panama or most of the rest of the world where it’s endemic. But it was drastically reduced during Panama Canal  construction days as a result of the same sanitation program that eradicated yellow fever. It’s been kept at bay ever since.
Chloroquine-resistant strains of the disease exist in eastern Panama, but any strain found west of the Panama Canal is not believed to have acquired immunity to this medication.
Symptoms of malaria usually do not appear until at least a week after infection from the bite of an Anopheles mosquito. Flu-like symptoms such as fever, chills, headache, muscle pain, and fatigue are common. Malaria can also cause anemia and jaundice. Symptoms can be intense or quite mild. Those infected may not realize it for some time, which is dangerous. Malaria is a serious disease and potentially fatal if not treated quickly. The U.S. Centers for Disease Control urge any traveler to an endemic area to get medical care immediately at the first sign of fever or flu-like symptoms for a full year after returning home. Be sure to tell the doctor where you’ve been.
Leishmaniasis is a parasitic disease spread by bites from infected sand flies. The type most commonly found in Latin America is known as cutaneous leishmaniasis, which is characterized by skin sores and is far less serious than visceral leishmaniasis, which attacks the internal organs but is found primarily in Brazil, Africa, and southern Asia.
There is no vaccine for leishmaniasis; the best way to avoid the small chance of contracting it in Panama is to reduce contact with sand flies as much as possible. The only travelers likely to be at risk in Panama are adventurous types who travel far off the beaten track.
Sores develop weeks or even months after the victim is bitten by an infected sand fly. The sores may be painless, and they may or may not scab over. Untreated sores can last from weeks to years and develop into prominent craters on the skin. Anyone who suspects an infection should see a tropical-medicine specialist for diagnosis and treatment.
Chagas’ disease is a parasitic infection carried by triatomine bugs (blood-sucking insects sometimes known as the assassin, cone nose, or kissing bug). The parasite, Trypanosoma cruzi, often produces a small sore at the point where it enters the body. If this happens around the eye, the eyelid may become swollen. Other symptoms can include a fever and swollen lymph nodes, but infection can be asymptomatic. There is no vaccine against the disease. Those who suspect they might be infected should see a tropical-medicine specialist for diagnosis and treatment. Chronic infections can cause damage to the heart and intestines and even death.
It’s rare for travelers to contract Chagas’ disease, in Panama or anywhere else. The bugs tend to infest ramshackle buildings made of palm thatch, mud, or adobe, especially those with lots of nooks and crannies in the walls and roof. The disease can also be spread through transfusions of blood that has not been screened for the parasite.
Panama has found about 500 cases of Chagas’ disease in the entire country in the last 25 years, and the Pan American Health Organization has noted a marked decline in the presence of the disease since 1993. Central Panama seems more vulnerable to the disease than other parts of the country.