Real-life Contagion: Governments unite to fight dengue outbreak in Marshall Islands

By Tyler M. Sharp, PhD

The whole thing was straight out of a movie.  An outbreak of dengue fever on a small island chain in the middle of the Pacific. A local government requesting assistance to control the outbreak.  In the end, CDC, the US Department of Defense, the World Health Organization (WHO), USAID, local governments as well as those of Taiwan, Japan and Australia were involved in the response. If we were going to succeed in our mission, we all had to communicate and work together. Amazingly, through concerted teamwork over many long days, we ultimately worked as one unit and beat the outbreak. 

As an Epidemic Intelligence Service officer at the CDC Dengue Branch, I had recently characterized a large dengue outbreak in Puerto Rico. This had given me some experience with the basics of disease surveillance, analysis of epidemiologic data, and clinical case management of dengue patients.  But was I really ready to try and translate what I had learned to the field? Was it even safe for me to go? I certainly didn’t want to end up going down in the line of duty, like Kate Winslet’s character in the Hollywood blockbuster Contagion.  But as it turned out, not only did I survive, but so did each of the nearly 1,300 dengue cases that the outbreak produced.

Day 0. 

Three children are seen at a hospital in Majuro, the capital of the Republic of the Marshall Islands.  All complain of the same symptoms: fever, headache, and body pain.  One of them had a bad nosebleed.  An astute pediatrician who saw all three children was the first to connect the dots: “This is dengue.”

In all fairness, the pediatrician had an advantage.  She had trained in the Philippines, knew that dengue was a mosquito-borne illness, and had seen more than her fair share of cases during her medical residency in Manila. Like most of the tropics, dengue is endemic in the Philippines, meaning that it has dengue year round. Her awareness of what dengue looks like clinically, coupled with the inquisitiveness of a lab technician who had received some dengue rapid diagnostic test kits from WHO, were probably the most important steps in identifying this outbreak early on.  Once the pediatrician sent blood to the lab to confirm the cases, the alarm bells were sounded.  Over the next few days, the Ministry of Health began a massive public awareness campaign: radio and television announcements advised residents of the symptoms that they should be on the lookout for (fever with headache, body pain, and nausea), and ways to avoid mosquito bites. They also began an intense clean-up campaign to rid Majuro of any water containers that might serve as breeding sites for mosquitoes.

Day 7. Case count: 30

I was at my desk revising a brochure for travelers on how to avoid dengue.  Little did I know, in just a few days I would be the traveler trying to avoid dengue in the middle of an outbreak.  After a flurry of emails and a hurried conversation with the Secretary of Health from the Marshall Islands, we learned that there were now 30 confirmed cases of dengue. Due to the rapidly increasing case count, a State of Emergency would be declared by the President and cabinet the next day. Accordingly, the Secretary was asking for help from CDC and the US Department of Defense to help combat the outbreak.

Over the next few hectic days at the Dengue Branch in San Juan, we decided that two mosquito experts and I would go to Majuro.  The mosquito guys would find out which mosquitoes were present in Majuro and identify the water containers they were breeding in. This information would then be used to determine the type of insecticide that the Navy and Army teams would use once they arrived a few days later.  The epidemiologic data that was coming from the hospital would be used to define geographic hot spots of dengue cases. Each day, this information would be fed back to direct the vector control team.  That way, if different neighborhoods lit up at different times during the outbreak, the vector control team would show up there within a few days. All of this would be coordinated between organizations on daily conference calls so that everyone was aware of the latest developments. 

 After a couple days of scurrying around trying to identify everything we mighty possibly need while in Majuro (bed nets, mosquito repellent, pediatric Tylenol, office supplies, and more than an armful of electronics for data collection and processing), we finally departed San Juan for Majuro at 5AM the day before Halloween.

 Day 13. Case Count: 292

 After 48 hours in transit, the CDC team finally arrived in Majuro along with a medical epidemiologist from WHO.  After quickly briefing the US Ambassador to the Marshall Islands, we next headed over to meet our new co-workers at the hospital. First on the agenda was reviewing the most recent case counts. They informed us that they now had 292 cases. We were still in the 50’s when we’d left San Juan; what had happened?!  Basically, the outbreak took off. We had thought that it would take a few weeks for the case count to get into the hundreds, if ever did at all, but frankly, our expectations were wrong. Majuro was teeming with dengue.

Once the initial shock of the first meeting wore off, our primary order of business was to make sure that the clinicians were up to speed on how to treat dengue. Without adequate care, dengue can be deadly. Over the next few days, I worked with the medical epidemiologist from WHO and another who had recently arrived from CDC to present a course on the proper clinical management of dengue to every physician and nurse in Majuro.

We were also going to have to make sure that there was good surveillance throughout the Marshall Islands to be sure that if there were cases on the outer islands, we would hear about it. This would turn out to be no small feat since the Marshall Islands are both remote (it’s four-and-a-half hours by plane west of Honolulu) and isolated (its landmass of just 70 square miles is more than 1,000 miles from the northernmost to southernmost point). Most communication between the 29 atolls and 5 islands is via short wave radio, and transportation is limited to either seaplanes that only fly every few months or week-long journeys by boat.

 Day 17. Case Count: 459

When I woke up, it was pouring down rain. At breakfast, one of the guys on the mosquito team was complaining of fever and nausea; I was worried that he had dengue, but he refused to stay in the hotel to rest. Instead, we all slogged through floodwaters to arrive drenched and dreary at the hospital.  I should have taken the weather as a sign; we got nothing but bad news once we arrived:

•  Two nurses had become patients and were now sick with dengue
• Eight patients had arrived overnight and the hospital was out of beds
• Blood-fed dengue mosquitos had been found inside the hospital
• And most troubling, several pregnant women had been diagnosed with dengue

After sending a few more-than-slightly panicked emails to my boss back in San Juan and meeting with a recently-arrived USAID representative, I did what ended up being the best thing for me given the situation: I spent 5 hours on a boat.

To be continued…