Asturias has a prevalence of babesiosis higher than the European average, similar to malaria

A team from the Instituto de Saúde Carlos III (ISCIII) published in the magazine Parasites & Vectors an epidemiological study in which it analyzes the seroprevalence in a Spanish region, Asturias, of babesiosisa malaria-like infection caused by the parasite Babesia divergens and is usually transmitted by the bite of a marking.

The research authors reveal an increased risk of babesiosis in people who have already contracted Lyme disease, also caused by the bite of this arthropod, confirming the possibility of contracting both zoonoses consecutively or simultaneously after exposure to ticks in geographic areas where the two diseases are endemic.

star montero It is Luis Miguel Gonzalezof the Reference Laboratory for Investigation in Parasitology of the National Center of Microbiology of ISCIII, are the main authors of the work, in which the doctors Victor Asensi It is Julio Collazosas well as scientific teams from different hospitals in Asturias, the Hospital de Galdácano in Vizcaya and the University of Helsinki, Finland.

The results remind us of the importance of studying and monitoring emerging diseases in geographic areas with low prevalence of zoonotic infections, but with risk of increase for several reasons.

O seroprevalence is the percentage of people in a global population who have antibodies that indicate they have been exposed to an infection.

The authors of this study retrospectively evaluated the seroprevalence of babesiosis among the Asturian population who had already been diagnosed with Lyme disease. Data between 2015 and 2017 were analyzed, a period covering the intervening years in which two severe cases of human babesiosis occurred in Asturias.

The team cautions that the high seroprevalence of babesiosis in these patients previously infected with Lyme suggests that Asturias “It’s an emerging risk area for babesiosis, so increased surveillance is advised.”

Tick ​​bites and risk of co-infection

Specifically, the seroprevalence of babesiosis among persons previously infected with lyme disease (which increases the risk of co-infection after a tick bite) was estimated at 39.2% after performing tests to detect the parasite Babesia divergenswhich causes babesiosis.

This percentage translates into a prevalence of this infection in Asturias from more than 7 people per 100,000 inhabitantsnumbers that surpass the seroprevalence for babesiosis previously estimated in several European countries.

The study found no differences in epidemiology and risk factors among patients infected only with the parasite Borrelia burgdorferithat causes Lyme disease, and those infected with Borrelia burgdorferi have IgG antibodies against Babesia divergens (ie, those co-infected with Lyme and babesiosis).

This last group of patients who suffered the two infections consecutively or simultaneously lived in the central area of ​​Asturias, had a moderate clinical course and developed different humoral immune responses against the parasite that causes babesiosis.

Several years in circulation

The conclusions of the study indicate that the parasite Babesia divergens It has been circulating in Asturias for several years, and the epidemiological and seroprevalence results make this community a growing risk zone for this zoonosis.

This is an example that illustrates how emerging diseases such as human babesiosis can be relevant in geographic areas where its presence is considered low risk, and confirms the importance of studying this infection in Spanish and European regions affected by the disease. from Lyme.

The authors recommend that health authorities pay attention to the potential risk of human babesiosis in Asturias and other regions with large forested areas in Spain and Europe, where the infection may be an emerging disease with rpublic health risks.