Abstract
Bloodborne infections are infectious ailments that can be transmitted from one person to another through contact with infected blood or body fluids. Human immunodeficiency virus (HIV) is a common example of a blood-borne disorder that is a public health concern globally. HIV is a retrovirus that attacks white blood cells, particularly CD4 cells, thereby lowering the body’s capacity to fight infections.
The disease is spread through unprotected sexual encounters with infected people, mother-to-child transmission, sharing of needles among drug users, transfusion with contaminated blood, or transplants with infected organs. The major symptoms of HIV infection include fever, headaches, muscle pain, and swollen lymph nodes. These symptoms are characteristic of a process known as seroconversion when the body reacts to the virus. The diagnosis of HIV infections involves the detection of antibodies in the blood. There is no cure for this bloodborne infection. However, patient compliance with antiretroviral therapy is helpful and can help infected people to live healthy, productive lives.
Introduction
A bloodborne infection can be defined as a contagious disorder that is disseminated through making contact with contaminated blood. Body fluids may also be responsible for the spread of bloodborne infections. Common examples of bloodborne infections include hepatitis B, Human immunodeficiency virus (HIV), hepatitis C, and viral hemorrhagic fevers such as Marburg, Ebola, and yellow fever, and Lassa (Fernando, 2018). The purpose of this paper is to discuss the HIV virus as an example of bloodborne infection. The mode of spread, symptoms, diagnosis, treatment, and prevention of the disease are also explained.
The HIV Virus
HIV is a virus that attacks the immune system and changes it, thereby leading to increased susceptibility to other infections. The disease may proceed to an advanced state known as Acquired Immunodeficiency Syndrome (AIDS) if the infected person does not undergo treatment. It takes approximately 10 to 15 years for an untreated, infected person to develop AIDS (Maartens, Celum, & Lewin, 2014). HIV targets specific cells of the immune system known as CD4 cells, which are part of T-helper cells. The purpose of T cells is to identify aberrant cells and infecting microorganisms. Therefore, HIV infection hampers the functioning of these cells and predisposes the affected person to opportunistic infections.
HIV is a ribonucleic acid (RNA) virus belonging to a family known as retroviruses. The genes of retroviruses are encoded in RNA instead of deoxyribonucleic acid (DNA). When retroviruses attack the host cell, they inject a copy of their genome into the new cell and alter its genome (Mailler et al., 2016). Reverse transcriptase, which is an enzyme that converts RNA to DNA, is then used to change the viral RNA to DNA. The new viral DNA is then integrated into the host DNA. As a result, the virus can multiply within the cell. Therefore, the life cycle of the HIV virus is grouped into seven key phases: binding, fusion, reverse transcription, integration, replication, assembly, and budding as shown in Figure 1 (U. S. Department of Health and Human Services, 2018).
In the binding phase, the virus attaches to a CD4 cell through gp41 and gp120 proteins that are found on the viral surface (Mailler et al., 2016). In the fusion stage, the virus is absorbed into the cell following attachment to the CD4 cell. During this process, the external coat of the virus is lost, leaving behind the capsid containing HIV RNA and three important enzymes. Reverse transcriptase then converts the single-stranded viral RNA into double-stranded DNA to match the human DNA in the cell in the reverse transcription stage.
Integration happens when the newly synthesized DNA virus traverses the nuclear membrane of the CD4 cells to reach the central nucleus where it is incorporated into the human DNA. The altered CD4 nucleus now receives instructions from the virus to produce raw materials for more new viruses. The assemblage of a new virus entails cutting up and joining of the viral particles, which is mediated by the enzyme protease. The newly formed virus leaves the cell by a process known as budding and infects new CD4 cells, which begins a new cycle. The old CD4 cell then dies. This process continues until most of the CD4 cells are destroyed.
Mode of Spread of the Infection
HIV is spread when mucous membrane or injured tissue of a healthy person make contact with blood, semen, breast milk, pre-seminal fluid, vaginal, and rectal fluids from an infected person (Joly, Odloak, & Rondó, 2016). Areas of the body that contain mucous membranes include the inner lining of the mouth, vagina, rectum, and opening of the penis. Infection may also occur when these fluids are introduced directly into the bloodstream through injection (Vun et al., 2016).
The most common method of HIV infection is unprotected sexual intercourse (anal or vaginal) with an infected person. Injection drug users who share needles can transmit the infection among themselves. Blood transfusions with infected blood or organ transplants can also spread HIV. However, the likelihood of contracting HIV through this method is minimal due to stringent measures taken to screen blood and organs before transfusions and transplants respectively.
HIV-positive mothers can spread the disease to their babies in the course of gestation, during childbirth, or breastfeeding in what is referred to as mother-to-child transmission. Healthcare workers can also get infected through unintentional contact with contaminated fluids through injuries from infected sharps or handling body fluids from infected patients (Rice, Tomkins, & Ncube, 2015). Contrary to misinformed myths and perceptions, one cannot contract HIV from hugging, handshakes, or a closed-mouth kiss with an infected person. In addition, sharing items such as utensils, toilet seats, and doorknobs cannot spread HIV.
Epidemiology
HIV is among the leading public health challenges all over the world. UNAIDS statistics show that approximately 36.9 million people all over the world were HIV-positive in 2017. Out of this number, 1.8 million were children below the age of 15. About 5000 new HIV infections per day occurred in 2017, bringing the total number of infected to 1.8 million people. It is also estimated that 10% of these new infections occurred in children under 15 years through breastfeeding, pregnancy, or childbirth.
About 75% of the infected people were aware of their status, whereas the remaining 25% still required access to HIV-testing services. In the same year, nearly 940,000 people succumbed to HIV-related infections globally, which was a significant reduction from 1.4 million in 2010 and 1.9 million in 2004 (Global Statistics, 2018).
The prevalence of HIV is higher in low- and middle-income countries compared to developing countries. For example, the 2017 statistics show that 53% of the global HIV infections were reported in eastern and southern regions of Africa, whereas 16% of the contagions were observed in central and western Africa (Global Statistics, 2018). On the other hand, 14% of the infections were reported in Asia, whereas only 6% were noted in Europe and America.
HIV infections affect not only individual health but also the well-being of households and communities. The disease is linked to negative economic growth. Furthermore, other public health problems such as food insecurity and other infectious diseases are also rampant in countries with high HIV infections (Global Statistics, 2018).
Symptoms
The symptoms of HIV differ from one person to another. However, most people often experience flu-like signs in the first few days following infection. These symptoms are attributed to the body’s response to the virus in a process known as seroconversion (Lin, Gianella, Tenenbaum, Little, & Hoenigl, 2017). Specific indications include fever, fatigue, sore throat, headache, joint pain, muscle aches, and enlarged lymph nodes. When these symptoms appear, the virus has gained access into the bloodstream and began multiplying. Therefore, the body reacts by mounting an immune response. Fatigue is also evident in later stages of HIV infection.
The function of lymph nodes is to protect the body by ridding it of infectious bacteria and viruses. Therefore, lymph nodes become inflamed when there is an infection. Rashes may also develop in the form of pinkish breakouts or itchy boils.
Gastrointestinal disturbances such as queasiness, vomiting, and diarrhea may also be experienced in the advanced stages of HIV infection. Unrelenting dry coughs that are not relieved by antibiotics or inhalers can be experienced in HIV patients with severe infections. Night sweats can also be experienced in the early and later stages of HIV even in cool temperatures. Since HIV presents with a wide array of unspecific symptoms that may be observed in other illnesses, it is necessary to get tested.
Diagnosis
The diagnosis of HIV infection involves testing blood for the presence of antibodies specific to the HIV1 or HIV2 virus, which the body usually develops to ward off infections. However, it may take between 6 weeks and 3 months for the body to develop HIV antibodies. This period is known as the window period. An individual in the window period may still pass on the virus to other people. Enzyme-linked immunosorbent assay (ELISA) is an antibody test that is used to diagnose HIV. However, the test may not be very accurate in the initial stages of infection before the body mounts a proper antibody response. Positive ELISA tests should be Western blotting. Saliva tests can also be used to diagnose the disease. Nonetheless, positive saliva tests need to be confirmed by blood tests.
After diagnosing HIV infection, it is important for the patient to undergo viral load testing to quantify the amount of virus in the bloodstream. A viral load test can also be used to diagnose early infection. Furthermore, the efficacy of treatment can be monitored by viral load findings. Three main techniques used to measure HIV viral load are branched DNA, reverse transcription-polymerase chain reaction, and nucleic acid sequence-based amplification assay (Gullett & Nolte, 2015). The three tests use the same basic principles where HIV is identified using DNA sequences that are complementary to those in the virus.
Treatment
No cure is available for HIV. However, various treatment methods can be used to prevent the multiplication of the virus thus boosting the immunity of the infected person. These drugs are referred to as antiretroviral therapy (ART). Different drugs can be used to target specific phases of the HIV life cycle. For example, HIV drugs that block the binding of the virus to CD4 receptors are referred to as entry inhibitors.
The reverse transcription stage can be blocked by two different reverse transcriptase inhibitors: nucleoside/tide and non-nucleoside (Rai, Pannek, & Fichtenbaum, 2018). On the other hand, medications that impede the viral integration process are referred to as integrase inhibitors, whereas the production of new viruses by assembling different components is blocked by protease inhibitors. Budding inhibitors block the exit of the new HIV virus from the old CD4 cells while maturation inhibitors impede the last assembly process.
Current recommendations show that HIV treatment should commence at the time of diagnosis to lower the probability of sickness and death by up to 57% (Poorolajal, Hooshmand, Mahjub, Esmailnasab, & Jenabi, 2016). Initiating treatment when CD4 cell count has dropped to 350 cells per milliliter increases adverse effects and reduces the survival period. Timely treatment maintains immunity by preserving the CD4 cells and minimizes the likelihood of transmitting the infection through low viral loads.
Prevention
Preventing HIV infection can be achieved by targeting each mode of infection. For example, couples are advised to avoid risky sexual behavior by getting tested and knowing each other’s HIV status. Consistent and correct condom use is also recommended with each sexual encounter for people who do not know each other’s HIV status, particularly commercial sex workers and men who have sex with other men. Limiting the number of sexual partners is also important to minimize the likelihood of contracting HIV.
Abstinence from injecting drugs also lowers the risk of becoming infected with HIV. However, drug users should use only sterile injections and avoid sharing them. Sexually transmitted infections (STIs) increase the likelihood of getting HIV because of damaged mucous membranes (Pelligrino, Zaitzow, Sothern, Scribner, & Phillippi, 2017). Therefore, testing and getting treated for STIs is necessary to prevent HIV infection.
Currently, pre-exposure prophylaxis (PrEP) is available for individuals who are HIV-negative but perceive themselves to be at risk of HIV infection. PrEP entails taking a drug called Truvada, which is a combination of two medications, every day (Straub, Berger, & Cruz, 2017). The presence of the PrEP medication in the bloodstream prevents the development of infection in the event that a person is exposed to the virus. PrEP is recommended for discordant couples, people who engage in risky sexual behavior, or injection drug users who share needles. PrEP has been shown to reduce the risk of HIV infection by 90% through sexual intercourse and by 70% through injection use (Dimitrov, Mâsse, & Donnell, 2016).
Conversely, post-exposure prophylaxis (PEP) is a prevention regimen that is administered to people following potential exposure to HIV. It may be given to someone who has had unprotected intercourse with an infected person or healthcare workers who may have been inadvertently exposed to HIV at work. For PEP to be effective, it should be taken within the first 3 days of exposure and continued for 4 weeks (Maartens et al., 2014).
HIV-positive mothers can protect their babies from the virus by attending antenatal clinics during pregnancy. The prevention of mother-to-child transmission entails giving specific drugs to pregnant women all through pregnancy as well as the newborn babies for 4 to 6 weeks (Cohn, Whitehouse, Tuttle, Lueck, & Tran, 2016). The medications prevent the development of infection in case the baby contracted the virus during childbirth.
Conclusion
HIV is a deadly bloodborne infection that is marked by immunosuppression. There is no cure for the disease, but infected people can stay healthy for a long time through antiretroviral therapy. On the other hand, new HIV infections can be prevented by taking adequate precautions that are specific to each mode of infection.
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