© Gaurab Thakali

The letter that changed Maira Gutierrez’s life almost got tossed with the junk mail. Gutierrez, a then 24-year-old Californian, regularly donated blood at her employer’s blood drives and thought the Red Cross was just asking for donations. But when she ripped open that letter in 1997, she learned that she had been banned from ever donating blood again. Her blood had been tested as part of a pilot programme to screen donated blood for Chagas disease, and she had tested positive.

“At the beginning, I was just confused. What are they talking about? What is this? I had never heard of it. How did I get it?” Gutierrez says.

Her doctor didn’t know much more, either. He told her she had probably picked up the parasite that causes Chagas as a child in her native El Salvador. Frustrated with a lack of answers, Gutierrez turned to an infectious disease specialist. He told her (incorrectly) that there weren’t any treatments and she would just have to cross her fingers and hope she wasn’t among the roughly one-third of victims whose infections progressed to heart failure. Gutierrez went back and forth between doctors looking for answers and treatment for more than a year before she finally gave up.

“I had my physical. I was fine. I didn’t see anything, I didn’t feel anything. So I just assumed that if my physical was fine and everything was coming up fine, that I was fine. So I stopped trying,” she says.

Life went on. She got married and had two kids. Her career at Universal Studios advanced. As the diagnosis retreated further into the past, it seemed more and more like a bad dream. Then, in 2008, her sister called, hysterical. “Put on channel 11,” she said. “There’s a story about Chagas.”

By the time Gutierrez had flipped on the TV, the segment was over, but her sister had managed to copy down the phone number of Sheba Meymandi, the director of the Center of Excellence for Chagas Disease in Los Angeles. The next week, Gutierrez was in Meymandi’s office. Finally, she got answers – and treatment.

Gutierrez had almost certainly been infected with the Chagas parasite before she fled El Salvador’s civil war in 1981 at age eight. For nearly 20 years, the parasite had lurked silently in her body. Like nearly all people with Chagas, she had had no idea she was infected and had missed any opportunity for prompt treatment.

To Mejia, cases like this emphasise the need for better education and diagnostics for tropical diseases. Diagnosing someone with a parasite generally involves testing for antibodies against the organism or looking under the microscope to see the parasite in action, both of which are time-consuming and inexact. In comparison to other areas of infectious disease, which have largely moved to DNA-based diagnosis, work on most tropical diseases hasn’t kept pace. Mejia and Hotez hope to change that by creating cheap, easy-to-use diagnostic tools. Mejia spent three years building new tests from the ground up; a pilot study in Ecuador revealed that his tests were five times more sensitive than traditional microscopy at detecting Giardia parasites, which cause an infection called giardiasis.

Treatments, too, need to advance – something that Gutierrez, like many other Chagas sufferers, knows all too well. As soon as Meymandi confirmed her diagnosis, she started a three-month course of nifurtimox, one of the two available anti-parasitic drugs that can treat Chagas. Both cause serious side-effects, such as headaches, nausea, appetite loss, rashes and psychiatric symptoms. In her three months taking nifurtimox, Gutierrez lost 25 pounds.

She was fortunate that Meymandi knew how to get the drug in the first place. Drug manufacturers don’t believe the market for Chagas treatments is great enough to justify jumping through the regulatory hoops to obtain FDA approval, which means the agency hasn’t made them available by prescription, despite the fact that these medications are used safely around the world. This means that physicians can only obtain the drugs from the CDC via a special research protocol.

“Most physicians have a hard enough time…dealing with the preauthorisations that they need to get drugs from the insurance companies, let alone having to do all of this paperwork to treat one patient,” Meymandi says. Patients must also be monitored closely, which requires extra appointments for patients and extra paperwork for physicians.

Even then, the drugs aren’t always effective. Cure rates are almost 100 per cent if given soon after infection, but Gutierrez had been infected for at least 30 years and the drugs had no effect on the number of parasites in her body. “The CDC considers me a complete fail,” she says, and there is no other treatment to try.

She has now begun to develop early signs of heart failure. Although the only symptom so far is palpitations, Meymandi can see the channels in Gutierrez’s heart muscle where the parasites have eaten holes in her heart. Since no other treatments for Chagas disease are available, Gutierrez must live with the knowledge that she could die of a heart attack any day.

It is the nature of these diseases – neglected diseases, diseases of poverty, call them what you like – that they can go unnoticed for years, chewing away at the health of individuals and communities. As poverty, geography, climate and social factors combine to bring tropical diseases out of hiding once again in the US South, physicians, politicians and the general public have to take the warning signs seriously and recognise that the tools available for tackling tropical diseases are sorely lacking. With diseases like Chagas now known to be prevalent and transmissible within the USA, better awareness, better tests and better treatments are all urgently required. Otherwise, as Hotez says, the number of people affected and infected will only continue to rise as this perfect storm grows ever stronger.