Haematological Infection

Infections are among the most serious complications for people with blood disorders, particularly those undergoing treatment or stem cell transplantation. Understanding your infection risk and how to protect yourself is crucial for managing your health.

Table of contents

• What Are Haematological Infections?
• Who Is at Risk?
• Types of Infections in Blood Disorder Patients
• Preventing Infections
• Diagnosing Infections
• Treatment Approaches
• Living with Infection Risk

What Are Haematological Infections?

Haematological infections are infections that occur in people with blood disorders or diseases affecting the blood and blood-forming organs. Hematology is the study of blood and blood disorders, and people receiving treatment for blood conditions face an increased risk of developing infections^[3].

The connection between blood and the body’s ability to fight infection is complex. Your white blood cells normally help protect your body from infection, but blood disorders and their treatments can weaken this natural defense system^[1]. When the immune system is weakened, infections can develop more easily and become more severe^[2].

Who Is at Risk?

People with hematological malignancies (blood cancers) face the highest risk of infection. This includes those with leukemia, lymphoma, and myeloma. The risk is particularly high during and after treatment, especially for those who have undergone stem cell transplantation^[3].

Several factors increase infection risk in blood disorder patients. Neutropenia, which means having too few neutrophils (a type of white blood cell), makes the body less able to fight bacterial infections. When neutropenia is prolonged, it also increases the risk of fungal infections^[3]. Impaired T-cell function, another immune system weakness, raises the risk for both fungal and viral infections^[3].

The type and intensity of treatment also affect infection risk. Chemotherapy, radiation therapy, and medications that suppress the immune system all make infections more likely^[8]. Patients receiving treatments that cause a decrease in the humoral immune response (antibody production) or T lymphocyte response are especially vulnerable^[8].

Types of Infections in Blood Disorder Patients

People with blood disorders can develop infections from bacteria, viruses, fungi, and parasites. Understanding the different types helps in recognizing symptoms early and getting appropriate treatment.

Bacterial infections are common, especially during periods of neutropenia. When someone with a blood disorder develops a fever during neutropenia, this is called febrile neutropenia and requires immediate medical attention. The widespread use of antibiotics has reduced mortality from bacterial infections, but the rise of antibiotic-resistant bacteria has become a major concern in many countries^[3].

Fungal infections typically occur when neutropenia lasts for an extended period or when T-cell function is impaired. These infections can be serious and require early diagnosis using imaging tests and laboratory tests that detect fungal antigens or DNA^[3].

Viral infections are particularly important for patients who have undergone stem cell transplantation, though they can also affect other blood disorder patients. Early diagnosis using tests that detect viral genetic material (nucleic acids) is essential for proper management. Prevention and treatment with antiviral medications are available for some viruses, especially herpesviruses^[3].

Preventing Infections

Preventing infections is a key part of managing blood disorders. Prevention strategies include both infection control measures and antimicrobial medications given before infection develops (prophylaxis)^[6].

Infection control measures are safe approaches that help reduce exposure to infectious agents. While not always completely effective, they form an important foundation of prevention^[6]. Basic infection control includes:

• Washing hands thoroughly and frequently with soap and water for at least 15 seconds^[17]
• Using alcohol-based hand sanitizer (with 70% alcohol) when soap and water aren’t available^[17]
• Avoiding contact with people who are sick or have symptoms like cough, cold, or fever^[12]
• Staying away from large crowds or public places when possible^[17]
• Wearing a mask when outside your own room in healthcare settings^[17]

Environmental precautions are also important. Patients should avoid gardening and contact with potting soil, raking wet leaves, standing water, and moldy places. Live plants are typically not recommended in hospital rooms^[17].

Antimicrobial prophylaxis involves taking medications to prevent infections before they occur. This approach is usually effective but must be carefully considered because it can increase antibiotic resistance, cause side effects, and add to healthcare costs^[6]. Healthcare providers evaluate each patient’s individual risk level, the types of infections most likely to occur, and the periods of highest risk when deciding whether to recommend prophylactic medications^[6].

Diagnosing Infections

Early diagnosis of infections in blood disorder patients is crucial but challenging. The clinical signs of infection may be subtle, and diagnostic tests don’t always perform well in immunosuppressed patients^[6].

An important principle in diagnosing infections in immunosuppressed patients is to “go for the bug” at the place of infection. This often means using invasive procedures like bronchoalveolar lavage (washing out the airways to collect samples) or biopsies to directly obtain samples for testing^[3].

Various tests help identify infections. Blood tests can detect signs of infection and identify specific infectious agents. Imaging tests like CT scans help locate infections, particularly fungal infections. Tests for antigens (parts of infectious organisms) or DNA/RNA (genetic material from infectious organisms) provide rapid and accurate diagnosis for many infections^[3].

Knowing when to seek medical help is critical. Anyone currently receiving blood cancer treatment should contact their healthcare team immediately if they develop a fever or feel unwell, as infections can develop very quickly and progress to sepsis, a life-threatening condition^[12].

Treatment Approaches

Treating infections in blood disorder patients relies on early diagnosis and rapid introduction of appropriate antimicrobial medications, often before the specific infectious agent has been identified^[3].

For bacterial infections, broad-spectrum antibiotics are typically started immediately when fever develops in neutropenic patients. These antibiotics target a wide range of bacteria and have reduced mortality from febrile neutropenia. However, healthcare providers must consider local patterns of antibiotic resistance when choosing medications^[3].

Treating fungal infections requires early diagnosis with imaging and laboratory tests, combined with appropriate antifungal medications. High-risk patients may receive antifungal prophylaxis to prevent these infections from developing^[3].

For viral infections, early diagnosis through nucleic acid testing allows for prompt treatment with antiviral medications when available. Some viruses, particularly herpesviruses, can be both prevented and treated with specific antiviral drugs^[3].

An important factor in recovering from infection is the restoration of the patient’s own immune defenses. This means that treating the underlying blood disorder and allowing the immune system to recover is essential for infection resolution^[6].

Living with Infection Risk

Living with increased infection risk requires ongoing vigilance and lifestyle adjustments. The level of precaution needed varies depending on the individual’s current immune status and treatment phase.

During active treatment or periods of low blood counts, more stringent precautions are necessary. This may include staying home most of the time, avoiding plants and certain foods like undercooked meat or unpasteurized cheese, and maintaining meticulous hygiene with frequent hand washing and cleaning of living spaces^[9].

Monitoring for signs of infection is essential. Patients and caregivers should regularly check temperature using a medical-grade thermometer and watch for symptoms such as fever, sore throat, cough, or shortness of breath. Any concerning symptoms should be reported immediately to the healthcare team^[17].

As immune function improves, many people can gradually relax some restrictions. Regular blood tests help healthcare providers assess immune status and guide decisions about precautions. Some patients check their blood counts monthly and adjust their behavior based on results^[9].

The emotional impact of living with infection risk shouldn’t be overlooked. While necessary precautions can feel isolating, they are often one of the few things patients can control about their condition. With time and recovery, anxiety about infections typically decreases, though some caution may remain permanent^[9].

Family members and friends play an important role in protecting loved ones from infection. This includes staying away when sick, practicing good hand hygiene, and understanding warning signs that require immediate medical attention^[12].