Pneumonia is among the leading causes of morbidity and mortality worldwide. Although Streptococcus pneumoniae is the most likely cause in most cases, the variety of potential pathogens can make choosing a management strategy a complex endeavor.
- Hospital-acquired pneumonia (HAP) or nosocomial pneumonia refers to any pneumonia contracted by a patient in a hospital at least 48–72 hours after being admitted. It is the most common cause of death among nosocomial infections and is the primary cause of death in intensive care units. The majority of cases related to various rod shaped gram-negative organisms (52%) and Staphylococcus aureus (19%), usually of the MRSA type, and also Pseudomonas aeruginosa, and Enterobacter.
- Risk factors including; active cigarette smoking, alcohol abuse, underlying disease and severity, malnutrition, anemia, history of nosocomial infection during the same admission, pharmacologic immunosuppression (corticosteroids and chemotherapy), previous antibiotic therapy, antacid use (antiH2 and proton pump inhibitor), nebulization, invasive techniques (endotracheal intubation, tracheotomy, nasogastric tube), surgery, hospital admission in the previous month, previous ICU admission, and interval from admission to presentation of pneumonia
- Community-acquired pneumonia (CAP) refers to pneumonia contracted by a person outside of the healthcare system. CAP is common, affecting people of all ages, and its symptoms occur as a result of oxygen-absorbing areas of the lung (alveoli) filling with fluid. This inhibits lung function, causing dyspnea, fever, chest pains and cough.
- Risk factors including; age >65 years, smoking, alcoholism, immunosuppressive conditions, and conditions such as COPD, cardiovascular disease, cerebrovascular disease, chronic liver or renal disease, diabetes mellitus and dementia.
Infective endocarditis is an infection of the inner surface of the heart, usually the valves. Symptoms may include fever, small areas of bleeding into the skin, heart murmur, feeling tired, and low red blood cell count. This condition is usually caused by bacteria entering the bloodstream and infecting the heart. Bacteria may originate in the mouth, skin, intestines, respiratory system and urinary tract. When this condition is caused by bacteria, it’s also known as bacterial endocarditis. In rare cases, it can also be caused by fungi or other microorganisms. Risk factors including;
artificial heart valves, congenital heart disease, heart valve disease, hypertrophic cardiomyopathy, a history of endocarditis, history of illegal drug use, mitral valve prolapse and valve regurgitation (leaking), after procedures that allow bacteria access to the bloodstream, such as; dental procedures involving the gums, insertion of catheters or needles, procedures to treat infections.
Complicated skin & soft tissue infections
Complicated skin and soft tissue infections (cSSTIs) represent the severe form of infectious disease that involves deeper soft tissues. S aureus and streptococci are the predominant organisms responsible for most SSTIs. Involvement of methicillin-resistant Staphylococcus aureus (MRSA) further complicates cSSTI with increased hospitalization, health care costs, and overall mortality. Infections may present either as cutaneous abscesses with a collection of pus surrounded by an area of erythema and swelling or as diffuse, spreading infections, as in cellulitis or erysipelas.
Bone and joint infections
Bone and joint infections include septic arthritis, prosthetic joint infections, osteomyelitis, spinal infections (discitis, vertebral osteomyelitis and epidural abscess) and diabetic foot osteomyelitis. Many types of bacteria can cause bone and joint infections, including Staphylococcus aureus, also called staph, Enterobacter, and Streptococcus. Septic arthritis
is the inflammation of a joint due to a bacterial or fungal infection. The condition occurs when a penetrating injury, such as a puncture wound, occurs near or above a joint, allowing bacteria to directly enter the joint. Bacteria can also spread through the bloodstream to a joint from a recent infection or after surgery. The knee and hip are the most commonly affected joints in adults, whereas the hip is the most common site of infection in infants. Septic arthritis can quickly cause severe damage to the cartilage and bone within a joint. Prosthetic joint infections (PJIs)
represent one of the most disastrous complications in prosthetic surgery, requiring long hospitalization, prolonged antimicrobial treatment and repeated surgical interventions. Osteomyelitis
is inflammation of the bone caused by an infecting organism. Although bone is normally resistant to bacterial colonization, events such as trauma, surgery, the presence of foreign bodies, or the placement of prostheses may disrupt bony integrity and lead to the onset of bone infection. can also result from hematogenous spread after bacteremia. In most cases, a bacteria called Staphylococcus aureus, a type of staph bacteria, causes osteomyelitis. Certain chronic conditions like diabetes may increase your risk for osteomyelitis. Spinal infections
are most commonly either haematogenous or postsurgical. Haematogenous infections are most commonly due to S aureus. Streptococcus spp, aerobic Gram-negative bacilli and M tuberculosis should also be considered as should Brucella spp in endemic areas and fungi in immunocompromised patients. Diabetic foot infections
usually occur following skin ulceration in patients with neuropathy and/or vascular insufficiency. Infections can go on to cause adjacent osteomyelitis. In severe infections this can rapidly become limb and life threatening.
Urinary tract infections
Complicated urinary tract infections (UTIs) occur in the setting of a urinary tract that has metabolic, functional, or structural abnormalities. Complicated UTIs may involve both lower and upper tracts. They include cystitis (infection of the bladder/lower urinary tract) and pyelonephritis (infection of the kidney/upper urinary tract). Risk factors include female anatomy, increasing age, diabetes, obesity, and frequent intercourse (although UTI is not defined as a sexually transmitted infection).
Peritonitis is inflammation of the peritoneum, the thin layer of tissue covering the inside of your abdomen and most of its organs. The inflammation is usually the result of a fungal or bacterial infection. This can be caused by an abdominal injury, an underlying medical condition, or a treatment device, such as a dialysis catheter or feeding tube. Symptoms will vary depending on the underlying cause of your infection. Common symptoms of peritonitis include:
- tenderness in your abdomen
- pain in your abdomen that gets more intense with motion or touch
- abdominal bloating or distention
- nausea and vomiting
- constipation or the inability to pass gas
- minimal urine output
- anorexia, or loss of appetite
- excessive thirst
- fever and chills
Clostridium difficile infection-associated diarrhea & colitis
Clostridium difficile–associated diarrhea (CDAD) has been recognized with increased frequency as a cause of nosocomial illness. The clinical presentation varies from asymptomatic colonization to mild diarrhea to severe debilitating disease, with high fever, severe abdominal pain, paralytic ileus, colonic dilation (or megacolon), or even perforation.