What increases the risk for infection?

From the Guidelines

The increased risk for infection is primarily due to compromised natural defenses, allowing pathogens to enter and multiply more easily, as a result of immunosuppressive states, such as neutropenia, and the use of immunosuppressive agents like corticosteroids and chemotherapy, as highlighted in the most recent guidelines 1.

Key Factors Contributing to Increased Infection Risk

• Impaired immune function due to conditions like cancer, HIV, or medications such as corticosteroids and chemotherapy
• Breaks in the skin barrier, such as wounds, burns, or surgical incisions
• Poor circulation limiting immune cell delivery to affected areas
• Presence of foreign bodies like catheters or implants that provide surfaces for bacterial colonization
• Malnutrition weakening immune responses
• Environments with high pathogen concentrations increasing exposure risk
• Disruption of normal protective microbiota from antibiotic use allowing opportunistic pathogens to flourish

Specific Considerations

• Patients with cancer are at increased risk of infection due to immunosuppression resulting from cancer treatment and sometimes from the disease itself, as noted in 1 and 1
• The risk of infection is further increased in patients with autoimmune inflammatory rheumatic diseases due to the immunosuppressive effect of the underlying disease and the use of immunomodulatory medication, as discussed in 1
• In patients with inflammatory bowel disease, the use of immunosuppressive agents, particularly in combination, increases the risk of opportunistic infections, as outlined in 1

Recommendations

Based on the most recent and highest quality evidence, it is essential to prioritize the prevention and management of infections in immunocompromised patients, including those with cancer, HIV, and autoimmune diseases, through the use of antimicrobial prophylaxis, vaccination, and careful management of immunosuppressive therapy, as recommended in 1 and 1.

From the FDA Drug Label

PRECAUTIONS Development of Drug Resistant Bacteria Prescribing sulfamethoprim and trimethoprim oral suspension in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria Clostridioides difficile Associated Diarrhea Clostridioides difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including sulfamethoxazole and trimethoprim, and may range in severity from mild diarrhea to fatal colitis.

The increased risk for infection is due to the development of drug-resistant bacteria and Clostridioides difficile associated diarrhea (CDAD) when sulfamethoxazole and trimethoprim is used without a proven or strongly suspected bacterial infection or prophylactic indication 2, 2.

• Key points:
  • Development of drug-resistant bacteria
  • Clostridioides difficile associated diarrhea (CDAD)
• Main idea: Sulfamethoxazole and trimethoprim increases the risk for infection when used improperly.

From the Research

Risk of Infection

The risk of infection is increased due to various factors, including:

• Immunocompromised state of patients, making them more susceptible to opportunistic infections such as Pneumocystis jirovecii pneumonia (PCP) 3, 4, 5
• Use of alternative prophylaxis regimens, which may not provide adequate protection against certain infections, such as nocardiosis 6
• Increasing prevalence of antibiotic-resistant pathogens in the hospital environment, making treatment more challenging 7
• Delayed or inadequate treatment, which can lead to poorer clinical outcomes and increased risk of infection 7, 5

Factors Contributing to Increased Risk

Several factors contribute to the increased risk of infection, including:

• Patient-related factors, such as immunocompromised state, underlying medical conditions, and previous infections 7
• Pathogen-related factors, such as antibiotic resistance, virulence, and transmission dynamics 7
• Drug-related factors, such as dosage, duration, and potential side effects of antimicrobial therapy 3, 4, 5

Clinical Implications

The increased risk of infection has significant clinical implications, including:

• Need for early empiric treatment with appropriate antimicrobial regimens, selected based on patient characteristics and local resistance patterns 7
• Importance of monitoring treatment response and adjusting therapy as needed to minimize the risk of treatment failure and development of resistance 7, 5
• Use of alternative prophylaxis regimens and treatment strategies, such as low-dose trimethoprim-sulfamethoxazole, to reduce the risk of adverse events and improve patient outcomes 3, 4