Experts are sounding the alarm about a malaria-like tick-borne disease that kills up to 20 percent of people.
Human cases of babesiosis have more than doubled in the US in a decade, a trend some say is linked to climate change and the clearing of more land for development.
Only about 2,500 cases are officially diagnosed each year, but scientists warn that many likely fly under the radar because doctors don’t know how to test for them.
Infections are on the rise in the Midwest, Northeast and West and are most common in the summer months when ticks are active.
This week, experts also warned of rising cases of another tick-borne disease, the Powassan virus, which can leave victims with brain damage and lifelong disabilities.
Babesios disease is caused by microbes carried by the deer tick (left) and winter tick (right). The former is active in the summer months, while the latter comes out in the fall
The map above shows states in the US that have reported cases of babesiosis and the prevalence of the disease. It is endemic to states in the Northeast, Midwest, and West, and has also been recorded in the South
This chart, provided by the CDC, shows how many cases of babesiosis are recorded in the US each year. In 2011 there were just over 1,000, now there are 2,500
Researchers at the University of California, Riverside say they have decoded the first-ever high-quality genome of one of the microbes behind the disease.
They say this will help develop tools to diagnose the disease and new treatments for the disease that can also cause organ failure and an enlarged spleen and liver.
Babesia are single-celled organisms that normally circulate between ticks and deer, but can also infect humans through tick bites.
Patients show symptoms that initially resemble malaria, including fever, headache and muscle aches, one to six weeks after bites.
But in severe cases, they can progress to organ failure, a swollen spleen or liver, and anemia, caused by the pathogen destroying red blood cells.
Estimates suggest that about 0.5 percent of all patients die from the disease. But among the elderly and immunocompromised, the mortality rate can be as high as 20 percent.
The disease can be treated with antibiotics and antiparasitic drugs azithromycin and atovaquone.
According to the Centers for Disease Control and Prevention (CDC), about 2,500 people are diagnosed with the infection each year, up from just over 1,000 in the past decade.
But last month, the agency warned that the disease is becoming more common in eight of the 10 states that monitor the infection, especially in the Northeast.
But many cases are missed because patients may also be infected with Lyme disease. Experts also say that while most doctors know about Lyme disease, they don’t know as much about babesiosis or the warning signs to watch out for.
Healthy people who become infected are also unlikely to develop symptoms.
Columbia University scientists say that up to 20 percent of older patients who contract the disease die from the disease.
There are two types of microbes behind the disease called babesia microti – which is spread by the deer tick in the summer months – and B. duncani – spread by the winter tick in the fall and early winter.
For their study, researchers analyzed the genetics behind B. duncani for the first time.
They also built the 3D structure using a computer and found that it closely resembled the parasite behind malaria, or Plasmodium falciparum.
They said this may have helped it develop ways to evade immunity.
Dr. Stefano Lonardi, a geneticist involved in the research, said: ‘Once the genome is assembled and annotated, it can provide valuable information such as how the genes are organized, which genes are transcribed during infection and how the pathogen avoids the host. . immune system.’
The disease is caused by a single-celled organism that attacks red blood cells when it infects humans
Dr. Karine Le Roch, a cell expert who led the study, said: ‘Our data analysis revealed that the parasite has evolved new classes of multigene families, allowing the parasite to evade the host’s immune response.’
The team now plans to study how B. duncani survives in a tick to help develop new treatments.
Last month, the CDC said cases had risen between 2011 and 2019 in eight of the 10 states reporting cases of babesiosis. The increase was 25 percent.
At the same time, cases of Lyme disease — which can be confused with the disease — rose 44 percent.
The disease also became endemic in three new states: Maine, New Hampshire and Vermont.
Previously, it was only considered endemic to Connecticut, Massachusetts, Minnesota, New Jersey, New York, Rhode Island, and Wisconsin.
Megan Swanson, an epidemiologist with the agency, said: “Nine years of data show an increase in tick-borne illnesses in areas of the US where cases had previously been low.”
Babesiosis was first discovered in the US in 1969.
The research has been published in the journal Nature microbiology.