Summary

22.1 Infectious Process

• Infections are one of leading causes of death and disability globally. As we have learned from the COVID-19 pandemic, it is important to be prepared for outbreaks of infections.
• Nurses must remain knowledgeable about common infections, including how they spread and how best to treat them. Additionally, it is important for nurses to understand the underlying functions and mechanisms of the human immune system, so they may better care for patients with infections.
• The first step in the immune response is the body’s recognition of an antigen. Infection results when a pathogen is able to evade the immune response.
• The immune response usually begins with the physical barriers that prevent pathogens from entering the body, destroy them after they enter, or flush them out before they can establish themselves as an infection. These barriers include the skin and mucus membranes.
• White blood cells, or leukocytes, are the primary cells of the immune system. They fight off pathogens to prevent infection. There are several specific types of leukocytes, including monocytes, lymphocytes, neutrophils, basophils, and eosinophils.
• The lymphatic system drains and filters various body fluids and returns them to the bloodstream. It includes organs such as lymph nodes, the spleen, and thymus, as well as bone marrow and a network of vessels and ducts.

22.2 Viral and Fungal Infections

• Viral infections are common and can be highly destructive, as evidenced by the 2020 COVID-19 pandemic. There are many kinds of viruses, but they all consist of a piece of DNA or RNA protected by a coating of protein. When a virus infects a host, it invades the host’s cells, injects its genetic material, and uses the host’s components to replicate and produce more viruses. This cycle risks destroying the host’s cells and threatens their health and, in some cases, life.
• Humans can become infected by viruses by swallowing or inhaling them (via droplets), being stung or bitten by insects, or having sexual contact or intercourse; a mother can also transfer a virus to her fetus in utero or during birth. Most viral infections cause vague general symptoms including fatigue, muscle aches, and headache. Two of the most common viral infections today are COVID-19 (caused by the novel coronavirus) and influenza (caused by the influenza virus).
• Caring for patients with viral infections requires vigilant assessment skills, technical knowledge, and compassion. Nurses are on the frontlines of caring for these patients and must remain knowledgeable and informed about the most up-to-date clinical practices and interventions to provide care that ensures optimal patient outcomes. For serious infections, this may involve administering antiviral medications and providing respiratory support. When vaccines exist, it is also important for people to be vaccinated.
• Human immunodeficiency virus (HIV) was discovered in the 1980s. It is a retrovirus, meaning that infected cells can insert viral DNA into healthy host cells, permanently altering and infecting them.
• HIV targets specific cells of the immune system, particularly a type of WBC called CD4. As WBCs are destroyed, the immune system starts to fail. Eventually, the infected individual will no longer have a functioning immune system, putting them at risk for a variety of opportunistic infections and the development of acquired immunodeficiency syndrome (AIDS).
• HIV can be difficult to detect and diagnose in the early stages because patients may be completely asymptomatic or have vague symptoms that resemble the flu. In addition to several kinds of diagnostic tests, laboratory values such as viral load, total WBC count, and CD4 count, in particular, are key to diagnosing the disease and monitoring its progress.
• Nursing care for the patient with HIV or AIDS requires knowledge of the disease process, technical skills for monitoring viral load, and the ability to provide holistic, nonjudgmental care.
• Medical treatment for HIV is aimed at slowing the progression of the disease and controlling symptoms. Several classes of antiretroviral medications developed in recent decades have effectively turned HIV into a chronic, manageable condition rather than the death sentence it once was.
• Hepatitis is characterized by inflammation of the liver and often results from a viral infection. There are several types of hepatitis, each of which varies slightly regarding transmission and symptoms. Types A, B, and C are the most common.
• Hepatitis A can be contracted through ingestion, whereas types B and C are transmitted by parenteral contact. Hepatitis C is often undiagnosed.
• Hepatitis A is usually asymptomatic or characterized by vague symptoms such as fatigue and nausea. Hepatitis C manifests as malaise, nausea, right upper-quadrant pain, dark urine, and jaundice. Hepatitis B has a wider range of clinical manifestations; late-stage findings include confusion, coma, ascites, and GI bleeding.
• General laboratory testing for hepatitis begins with blood testing to examine liver function. A hepatitis virus serological test panel can be used to detect antibodies to hepatitis viruses A, B, and C.
• Hepatitis remains a global health concern, highlighting the need for nurses to remain knowledgeable and prepared to care for patients with this kind of infection. Nurses must stay up to date with current research, advocate for vaccination, and promote safe practices to prevent disease transmission and limit complications.
• Collaboration with interdisciplinary teams, ongoing professional development, and a commitment to evidence-based practice are essential in nurses’ efforts to mitigate the burden of hepatitis on individuals and communities worldwide.
• Fungal infections are caused by fungi. They are usually mild. However, in some cases, they can become life-threatening, especially in patients with underlying immunocompromise.
• One of the most common types of fungal infections is candidiasis, or oral thrush. Oral thrush causes white, patchy lesions in the mouth because of fungal overgrowth. It can be treated with topical antifungal medications or, in more severe cases, oral or IV antifungals.
• Nursing care for patients with oral thrush involves treatment of symptoms, promotion of adequate hygiene, and patient education.

22.3 Antibiotic Resistance

• There are several mechanisms by which bacteria can become resistant to antibiotics, including having impenetrable outer membranes, pumps that remove the medications, and the ability to remodel, or change in some way, so the medications are no longer effective.
• The two most common diseases of antibiotic resistance encountered in practice include infection by methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus.
• Antibiotic stewardship refers to efforts to improve antibiotic-prescribing strategies so that infections are treated effectively without contributing to the development of antibiotic resistance.
• One of the most important roles of the nurse in preventing antibiotic resistance is educating patients about taking their antibiotics as prescribed, because when patients stop a course of medication early, bacteria are often not sufficiently treated, which contributes to their increased risk of developing resistance to medications.

22.4 Preventing Secondary Infections

• A secondary infection arises after treatment of a different, primary infection, and often results in a more complicated and prolonged recovery process.
• One of the most common secondary infections is named for the bacterium Clostridioides difficile (C. diff).
• C. diff poses significant challenges in health-care settings, requiring diligent nursing care to manage symptoms, prevent transmission, and promote recovery.
• Nursing interventions for C. diff include stool sample collection, implementing isolation precautions, promoting hydration, managing electrolytes, and symptom management.
• Medical treatment for C. diff includes stopping the antibiotic that likely caused the infection and switching to a new antibiotic. In severe recurring cases, a colectomy or fecal transplant may be necessary.