Introduction

Overview of babesiosis disease

Babesiosis is an infectious disease caused when a protozoan-infected tick, that is the tick-carrying Babesia genus, bites a host thereby transferring the sporozoites (developing part of the protozoan life cycle that is infective) into the host's bloodstream. The Babesia genus consists of 4 main types, they are: Babesia microti, Babesia divergens, Babesia duncani, and a species that has not been named but is regarded as Babesia MO-1.¹ 

The tick that transmits Babesia through their bites is called the Ixodes tick, which then causes the infection of the red blood cells. Babesiosis is prevalent in the United States and Europe, though different Babesia species may cause it. Some people can be asymptomatic, though the symptoms of babesiosis may include fever, fatigue, chills, and anaemia and may be severe in individuals with weak or deficient immune systems.² 

Importance of studying Babesiosis in pregnant people

Babesiosis has a negative effect on both the pregnant parent and child, hence, research shows that it is essential to study this disease in pregnant people. In this study, an acute babesiosis infection caused by Babesiosis microti can prevent a person assigned female at birth (AFAB) of childbearing age from getting pregnant.

Additionally, contacting babesiosis either during the first 3-months of pregnancy or the last trimester can cause stillbirths, termination of pregnancy, and congenital infection.³ There are some findings that report cases of transplacental transmission (transmission of babesiosis across the placenta).^2,4 

Transplacental and congenital infection cases were reported for children with 19 to 41 days of birth from pregnant parents who showed no symptoms of infection, who had a fever, cases with haemolytic anaemia in the infants, and thrombocytopenia.^2,4

Infection can occur in someone who has never been bitten by the Ixodes tick or visited one of the endemic countries through blood transfusion, that is transmission of blood from an infected person to a non-infected individual.² 

Unique challenges of babesiosis during pregnancy 

• Vertical transmission: There are reports that Babesia microti can be transmitted from pregnant people to their birth children. This can potentially lead to congenital infections, and flu-like symptoms or anaemia in newborns weeks after they are born³
• Difficulty in diagnosis: Diagnosing Babesiosis in pregnant people can be difficult. This is because babesiosis symptoms can mimic other pregnancy-related conditions, which also making it harder to manage the condition. This may lead to a misdiagnosis as HELLP syndrome (haemolysis, elevated liver enzymes, and low platelets) or other complications that occur during pregnancy⁴
• Treatment risks: The treatment options available for babesiosis infection are limited, and some of the medications available may pose risks during pregnancy. Research is ongoing to determine safe and effective therapies for infected pregnant people⁵
• Maternal health impact: Rapidly developing babesiosis infections can seriously impair maternal health, resulting in complications in both pregnant parents and infants that could be destructive³ 

Potential risk of babesiosis infection to parent and child

• Complications: Pregnant parents may face substantial challenges due to babesiosis because of its symptoms such as haemolytic anaemia, low platelet counts, and increased liver enzymes. This also mimics the HELLP syndrome, making diagnosis and treatment more difficult⁴
• Transplacental transmission: This is also known as the vertical transmission, meaning the disease is passed from mother to offspring through the placenta. Through this transmission, there is a chance that the foetus will contract Babesia microti, which may cause serious harm to the newborn’s health^3,6
• Increased morbidity: Due to immune system modifications, pregnant people are more vulnerable to serious infections, which raises the possibility of unfavourable consequences⁴
• Misdiagnosis: Babesiosis symptoms can be mistaken for the symptoms of complications that occur during pregnancy known as the HELLP syndrome. This is a major concern as it might cause a delay in starting proper treatment⁵

Epidemiology of Babesiosis 

In 1888, Victor Babes identified babesia during an investigation borne out of his curiosity to find out the reason behind the highly fatal red water fever affecting eastern European cattle. Victor Babes was able to find the organism responsible for babesiosis infection, but it was Theobold Smith and F.L. Kilbourne that found the carrier of the parasitic protozoan (transmitting agent).⁷ 

Babesiosis is prevalent in the Northeast and Midwest of the United States with 7,800 reported cases of hospitalisations recorded from 2010 to 2016, and with 71.2% of these cases occurring between June and August.⁹ A study reports that the growing numbers of deer and increased outdoor activity during the summer months is linked to an increase in babesiosis cases, which has led to an increase in incidence.

The rise in cases has been attributed to the spread of the white-tailed deer population, the invasion of animal habitats, and increased awareness among doctors.⁸ In 2018, 2161 cases were reported across 28 states, underscoring the importance of increased awareness and reporting mechanisms for this tick-borne illness.⁸

Pregnant people can become infected with Babesiosis through the bites of an infected Ixodes tick in late spring and summer. There have also been reports of maternal-foetal transfer, and congenital illnesses may result from this.

Diagnosis and treatment options 

Diagnosis of babesiosis during pregnancy 

Diagnosing babesiosis during pregnancy can be difficult because it has sticking features with the HELLP syndrome. Hence, diagnosing it in pregnant people requires a high degree of awareness of the symptoms. Often, diagnosis entails:^4,10,11 

• Blood test: To find Babesia parasites in red blood cells, a peripheral blood smear is examined under a microscope. For more sensitive detection, PCR testing is an additional option
• Clinical symptoms: Fever, chills, exhaustion, and haemolytic anaemia are possible symptoms. It is crucial to have a complete patient history that includes any possible tick exposure (where possible)
• Differential diagnosis: Because many of the symptoms of HELLP syndrome and babesiosis overlap, it is important to carefully evaluate the difference between the two to determine the best course of treatment

Treatment options

The treatment options available for babesiosis are limited, but they include: 

• Antimicrobial therapy: The most commonly used treatment is clindamycin plus quinine as it has better placental penetration and may be able to stop vertical transmission. However, QT prolongation is one serious adverse consequence of this combination^4,6
• Azithromycin + atovaquone: Another alternative is azithromycin combined with atovaquone, however the latter is less effective due to poor placental absorption⁶
• Blood transfusion: Red blood cell exchange transfusion is possible in severe cases such as when the patient is not responding to antibiotic therapy. It has demonstrated efficacy in treating parasitemia, particularly in patients with impaired immune systems, such as those who have had a splenectomy in the past⁹

There is no consensus on guidelines, or randomised studies available for the treatment of babesiosis during pregnancy. Experts advise treating pregnant people with or without symptoms because of the potential for serious consequences and vertical transmission. Monitoring the foetus closely is essential.⁴ 

FAQs

How can babesiosis be transmitted? 

Babesiosis can be transmitted through several ways: through the bite of an infected tick carrying a babesiosis infection, from blood transfusion from an infected person to a non-infected person, and through vertical transmission from a pregnant person to their infant child.

Is it possible for a newborn baby that hasn't been bitten by a tick to get infected? 

Yes, this is very possible. Some studies have reported cases of vertical transmission from a pregnant parent who has babesiosis infection to their infant child during delivery.

How best can pregnant people protect themselves against babesiosis?

Pregnant people can protect themselves against babesiosis by wearing protective clothes, avoiding tick exposure, using insect repellents, and consulting healthcare providers. 

Summary 

It is important to study babesiosis in pregnant people to promote maternal and foetal health as it can prevent pregnancy initiation, cause severe complications, and mimic HELLP syndrome. Hence it is crucial to understand the transmission mechanisms and effective management strategies for babesiosis infection.

Treatment options are limited but include several combination drug therapies and blood transfusions. Protection strategies are essential and include wearing protective clothes, avoiding tick exposure and using insect repellents to prevent tick bites; as well as consulting with a healthcare provider to ensure the best health outcomes for themselves and their child.