And Now, Something New To Worry About: Dengue Fever

Travelers may find themselves at risk because they are less likely to be aware of dengue than malaria, an even more common and life-threatening illness, said Anton Peleg, an infectious disease research fellow at Beth Israel Deaconess Medical Center in Boston. Peleg, one of the doctors who treated me, trained for a year in Brisbane, Australia, where he saw people returning with dengue fever from the Pacific Islands, Indonesia and New Guinea, among other places.

"Certain regions have intermittent outbreaks of dengue, as seen in the Cook Islands, and it is these regions [where] tourists are often at great risk, as the outbreaks are difficult to predict and preventative measures may not be utilized," Peleg said. He added, "With the current trends in global warming, dengue will no doubt continue to be a major public health problem and risk for the traveler."

So far this year, Brazil has reported more than 135,000 dengue cases and 17 deaths, according to the Pan American Health Organization. Paraguay declared a state of emergency with upward of 25,000 cases -- more than six times last year's total -- and 11 deaths. The Jakarta Post reports that 45 people have died from the disease in the Indonesian capital already this year, with more than 13,000 infected, triggering citywide fumigations of dengue-prone areas. And in the Cook Islands, health officials predict that the current cyclical outbreak, which began last June and is now winding down, will exceed 1,000 reported cases (out of a total population of about 18,000).

The Cook Islands Tourism Corp. was told by health authorities in February that about 10 tourists had contracted dengue there in the previous five months, and health officials in Auckland, New Zealand, received 29 notifications of dengue cases among returning travelers this year, with 19 from the Cook Islands and a small number from other Pacific Islands. However, the exact number of tourist infections in any particular country is generally difficult to determine because many people have mild symptoms and do not see a health-care provider. In addition, mandatory reporting of dengue does not exist in most countries, and laboratory confirmation is often lacking.

Other countries with recent or current outbreaks include Cuba (albeit officially unconfirmed), Pakistan, Mexico, Bolivia, the Dominican Republic and India, said Hamish Mohammed, an epidemiologist with the CDC Dengue Branch in San Juan, Puerto Rico. Nor is the United States immune. Dengue fever has appeared along the U.S.-Mexico border, with cases reported in South Texas in 1999 and 2005. Health officials estimate that 30 cases are confirmed each year among returning U.S. travelers.

Travelers like me.

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Mark and I returned home to Cambridge on Monday, Jan. 22, rested and healthy, looking forward to the new year. Five days later, I woke up with a strange feeling. I didn't have a stomachache or temperature, but my joints ached intensely, as if I were having an all-body arthritis attack.

I spent the weekend clutching a blanket and taking painkillers as my body grew chilled, then feverish. My walk was stilted, my skin sensitive to the touch. Mark assumed it was severe flu or fatigue after our long journey. My primary care doctor, Gary Trey, whose father once had dengue, considered the disease a possibility and urged me to head to the hospital if my fever spiked above 102 degrees.

On Monday, things got worse and I became dangerously dehydrated. I went to Beth Israel, where emergency room attendants hooked me up with intravenous fluids and ordered a CT scan, antibiotics, a pelvic ultrasound, a chest X-ray and blood tests. Given our travels, dengue quickly became a prime suspect that only a serology test sent to the CDC could confirm. (It did, two months later.)

In the Cook Islands, we'd slathered on sunscreen by day and insect repellent by night, not realizing that the dengue-infected female Aedes mosquito bites at its peak in the morning and late afternoon. Four dengue strains exist, and contracting one type does not confer immunity to the rest. In fact, subsequent infections are likely to be more serious.

Generally more severe in children and young adults, dengue fever incubates for three to 14 days, which is why many travelers do not get sick until they are home. (Malaria, another mosquito-borne disease, takes more than 10 days to appear.) More than half of dengue cases are asymptomatic. But symptoms can include a high fever for up to a week, intense headache, eye pain, muscle or joint pain, and body rash. Classic dengue often involves a rash that may include pinpoint-size bleeding spots on the skin, called petechiae, while DHF features capillary leaks and can lead to shock.