Upper Respiratory Tract Infections PDF

Upper respiratory tract infections Upper RTIs affect the nose, sinuses and throat. Common diseases include:  Common cold;  Tonsillitis – infection of the tonsils and tissues at the back of the throat;  Sinusitis – infection of the sinuses;  Laryngitis – infection of the larynx (v...

Upper respiratory tract infections Upper RTIs affect the nose, sinuses and throat. Common diseases include:  Common cold;  Tonsillitis – infection of the tonsils and tissues at the back of the throat;  Sinusitis – infection of the sinuses;  Laryngitis – infection of the larynx (voice box);  Flu - itis: inflammation 47  Lower respiratory tract infections Lower RTIs affect the airways and lungs. Common diseases include:  Flu – which can affect either the upper or lower respiratory tract;  Bronchitis – infection of the airways;  Pneumonia – infection of the lungs;  Bronchiolitis – an infection of the small airways that affects babies and children aged under two;  Tuberculosis – persistent bacterial infection of the lungs 48 Respiratory tract related structure - Ear Ears are connected to respiratory tract through Eustachian tubes. biology.stackexchange.com The most common organism colonizing the outer ear is coagulase-negative Staphylococcus. 49  Middle ear infections (Otitis media) The symptoms include: mild pain or discomfort inside the ear, a feeling of pressure inside the ear that persists, pus-like ear drainage and hearing loss. Ear infections occur when one of Eustachian tubes becomes swollen or blocked causing inflammation and fluid build up in the middle ear. The fluid is a perfect breeding ground for bacteria or viruses to grow into an ear infection. The most common bacterial types are Streptococcus pneumoniae, Haemophilus influenzae and www.drugs.com Moraxella catarrhalis. 50  Common RTI pathogens Bordetella pertussis Streptococcus pneumoniae (also called pneumococcus) Haemophilus influenzae Legionella Mycobacterium tuberculosis Klebsiella pneumoniae Moraxella catarrhalis Pseudomonas aeruginosa Mycoplasma pneumoniae Streptococcus pyogenes Neisseria meningitidis 51  Bordetella pertussis The whooping cough germ Extremely small (0.2 to 0.5 × 1 µm in diameter) gram-negative coccobacilli; nonfermentative but can oxidize amino acids as an energy source; strict aerobe. A human disease with no other recognized animal or environmental reservoir. www.portal.state.pa.us 52  The whooping cough (Pertussis) Pertussis is a highly communicable, vaccine- Age distribution for pertussis infections reported in 1988 (red preventable disease, lasting for many bars) and 2005 (blue bars). *Also prevalent in adult. weeks and typically afflicts children with severe coughing, whooping, and posttussive vomiting. After an incubation period, disease is characterized by the catarrhal stage (resembles the common cold), progressing to the paroxysmal stage (repetitive coughs followed by inspiratory whoops), then the convalescence stage (diminishing paroxysms and secondary Wikipedia 53 complication) Whooping cough girl movie https://www.youtube.com/watch?v=S3oZrMGDMMw 54  Treatment and prevention Treatment with macrolide (i.e., azithromycin, clarithromycin) is effective in eradicating organisms and reducing length of infectious stage. Vaccines containing inactivated pertussis toxin, filamentous hemagglutinin, and pertactin are highly effective. Chinese government vaccine program pertussis 55  Legionella Slender, pleomorphic, nonfermentative, gram-negative rods; nutritionally fastidious with requirement for L- cysteine and enhanced growth with iron salts. Legionellae are facultative intracellular bacteria that multiply in free-living amoebae in nature, and in alveolar macrophages, monocytes, and alveolar epithelial cells in infected hosts. Causing Legionnaires’ disease and pontiac fever. The later is an acute, nonfatal respiratory disease of mild upper respiratory infection that resembles acute influenza. Legionella pneumophila 56 Comparison of diseases caused by Legionella 57  Legionella species Legionella contains 53 species and 3 subspecies. Approximately half of these species have been implicated in human disease, with the others found in environmental sources. L. pneumophila is the cause of 90% of all infections; serotypes 1 and 6 are most commonly isolated. 58  退伍军人症 Legionnaires’ disease – the history Legionella was first discovered at the Bellevue Stratford Hotel in Philadelphia during July of 1976. The US Bicentennial Convention of the American Legion (an organization of United States veterans) was meeting. More than 4000 WWII veterans, including friends and family were congregating to be part of the 58th American Legion’s Convention. The second day of the convention some of the participants began falling ill. The symptoms included fever, coughing and difficulty breathing. All these symptoms could very possible be thought of as the common flu. A few days later one of the veterans from the convention died. As the next few days pass by, more and more of the Legionnaires die. By the end of the epidemic a total of 221 people had been infected and 34 had 59 died. http://www.legionellaprevention.org/history.html Legionnaires’ disease - legionellosis Pathogenesis: capable of replication in alveolar macrophages (and amoebae in nature); prevents phagolysosome fusion; Can be mistaken for the common cold or flu and miss the treatment opportunity. http://www.legionellaprevention.org/history.html 60  The effect that Legionella has on the lungs is deadly. The bacteria feed and multiply exponentially causing the lungs to fill up. The result, if not diagnosed correctly, could be a death similar to that of drowning. X-ray picture of Legionella infected lung http://oasis- rainharvesting.co.uk/legionnaires_disea se_risks 61 Transmission of Legionnaires’ disease Legionella cannot spread from one person to another person. The bacteria are commonly present in natural bodies of water. This bacterium grows best in warm water, like: hot tubs, cooling towers (air-conditioning units for large buildings), hot water tanks, large plumbing systems and decorative fountains. Human infections are most commonly associated with exposure to contaminated aerosols of water body (e.g., air conditioning cooling towers, whirlpool spas, shower heads, water misters). 62  Treatment and control Macrolides (e.g., azithromycin, clarithromycin) or fluoroquinolones (e.g., ciprofloxacin, levofloxacin) are the treatment of choice. Decrease environmental exposure to reduce risk of disease. For environmental sources associated with disease, treat with hyperchlorination, superheating or copper-silver ionization. 63