Other signs include high blood pressure in the lung (pulmonary hypertension), heart failure, difficulties getting enough oxygen to the body (hypoxia), and respiratory failure requiring support with breathing masks, such as bilevel positive airway pressure machines or ventilators. Staphylococcus aureus, Haemophilus influenzae, and Pseudomonas aeruginosa are the three most common organisms causing lung infections in CF patients. : 1254  In addition, opportunistic infection due to Burkholderia cepacia complex can occur, especially through transmission from patient to patient.In addition to typical bacterial infections, people with CF more commonly develop other types of lung diseases. Among these is allergic bronchopulmonary aspergillosis, in which the bodys response to the common fungus Aspergillus fumigatus causes worsening of breathing problems. Another is infection with Mycobacterium avium complex, a group of bacteria related to tuberculosis, which can cause lung damage and do not respond to common antibiotics.Mucus in the paranasal sinuses is equally thick and may also cause blockage of the sinus passages, leading to infection. This may cause facial pain, fever, nasal drainage, and headaches. Individuals with CF may develop overgrowth of the nasal tissue (nasal polyps) due to inflammation from chronic sinus infections. Recurrent sinonasal polyps can occur in 10% to 25% of CF patients. : 1254  These polyps can block the nasal passages and increase breathing difficulties.Cardiorespiratory complications are the most common causes of death (about 80%) in patients at most CF centers in the United States.
Progressive outer retinal necrosis (PORN) syndrome is a form of chorio-retinitis, an infection in the retina, the back of the eye. The disease is most commonly caused by the Varicella zoster virus and is found almost exclusively in patients with HIV/AIDS (acquired immunodeficiency syndrome). Progressive outer retinal necrosis is the second most common opportunistic retinal infection in North America among people with AIDS. The reason this disease process is considered opportunistic is precisely because it only presents in patients with AIDS, a disease that attacks and weakens the immune system, making space for other infections, like Varicella zoster virus (VZV) and Herpes simplex virus (HSV), to attack the body. The syndrome, PORN, falls under the umbrella of Necrotizing Herpetic Retinopathy, along with Acute Retinal Necrosis (ARN). Although fairly similar processes, the two forms of retinopathy have different presenting symptoms. Acute Retinal Necrosis, or ARN, is damage more central in the retinal portion of the eye with dead or necrotic areas well defined. ARN also presents with inflammation within the eye and is often painful. Progressive outer retinal necrosis (PORN) is a chorioretinitis presenting with multiple lesions in the peripheral retina. Unlike ARN, this disease process has no signs of intraocular inflammation, the hallmark feature, or vascular involvement. Presentation (Signs and Symptoms)
The presentation of the disease is dependent on the patients AIDS prognosis. If the immune system has been significantly weakened by AIDS, a patient will likely present with worse and faster progressing PORN.