1. Upper respiratory tract infection &Pneumonia Lecture No.1
Dr Dhaher Jameel Salih Al-habbo
FRCP London UK
Professor of medicine
Department of Medicine.

2. The classification of upper respiratory tract infections includes:
The common cold
Pharyngitis
Epiglotitis
Acute laryngitis
Acute laryngotracheobronchitis
Sinusitis
Otitis externa, otitis media and mastoiditis

3. Whooping cough.. History
Typically, the incubation period of pertussis ranges from days. Pertussis is a 6-week disease divided into catarrhal, paroxysmal, and convalescent stages, each lasting from 1-2 weeks.
Stage 1 - Catarrhal phase:The initial (catarrhal) phase includes nasal congestion, rhinorrhea, and sneezing, variably accompanied by low-grade fever, tearing, and conjunctival suffusion. Pertussis is most infectious when patients are in the catarrhal phase, but pertussis may remain communicable for 3 or more weeks after the onset of cough.

4. Whooping cough.. History
Stage 2 - Paroxysmal phase
Patients in the second (paroxysmal) phase present with paroxysms of intense coughing lasting up to several minutes. In older infants and toddlers, the paroxysms of coughing occasionally are followed by a loud whoop as inspired air goes through a still partially closed airway. Infants younger than 6 months do not have the characteristic whoop but may have apneic episodes and are at risk for exhaustion. Posttussive vomiting and turning red with coughing are common in affected children.
Stage 3 - Convalescent phase
Patients in the third (convalescent) stage have a chronic cough, which may last for weeks.

5. Physical Examination
In patients with uncomplicated pertussis, physical examination findings contribute little to the diagnosis. In all patients with pertussis, fever is typically absent. Most patients do not have signs of lower respiratory tract disease. Conjunctival hemorrhages and facial petechiae are common and result from intense coughing.

6. Physical Examination
 Dehydration is also common on presentation. Hypoxia should be considered and assessed.
The classic inspiratory gasp or whoop develops primarily in children aged 6 months to 5 years. It is usually absent in patients younger than 6 months and in most older vaccinated children and adults. However, it can often be observed in unvaccinated adults, as can posttussive emesis.

7. Diagnosis
The diagnosis of pertussis is made by isolation of B pertussis in culture. A polymerase chain reaction (PCR) test can also be performed.
The culture specimen should be obtained during the first 2 weeks of cough by using deep nasopharyngeal aspiration
For PCR testing, nasopharyngeal specimens should be taken at 0-3 weeks following cough onset
The CDC recommends a combination of culture and PCR assay if a patient has a cough lasting longer than 3 weeks
Early serial monitoring of white blood cell (WBC) counts is warranted

8. Managements
Limit the number of paroxysms& to Observe the severity of cough and provide assistance when necessary,Maximize nutrition, rest, and recovery
Pharmacologic therapy
Antimicrobial agents and antibiotics can hasten the eradication of B pertussisand help prevent spread
Erythromycin, clarithromycin, and azithromycin are the preferred agents for patients aged 1 month or older
Immunization
Prevention through immunization remains the best defense in the fight against pertussis.

9. INFLUENZA Three immunologic types are known: Type A; Type B Type C
The Orthomyxoviridae (influenza viruses)
Three immunologic types are known:
Type A;
Type B
Type C
Etiology
The standard nomenclature system for influenza virus isolates includes the following information:
-type, -host of origin, -geographic origin, -strain number, year of isolation
So far, 14 subtypes of HA (H1-H14) and nine subtypes of NA (N1-N9) in many different combinations have been recovered.
Antigenic drift and antigenic shift .
Minor antigenic changes are termed antigenic drift;
Major antigenic changes in HA or NA, called antigenic shift

10. Epidemiology& Pathogenesis
The three types of influenza vary in their epidemiologic patterns.
Influenza C is least significant: it causes mild, sporadic respiratory disease, but not epidemic.
Influenza B sometimes causes epidemics,
Influenza type A can causes around the world massive epidemics called pandemics.
Pathogenesis
Influenza virus spreads from person to person by airborne droplets or by contact with contaminated hands or surfaces.

11. Clinical findings Uncomplicated Influenza Incubation period: 1-4 days.
Symptoms usually appear abruptly and include:
chills, headache, dry cough- respiratory symptoms typically last another 3-4 days.
The cough and weakness may persist for 1-3 weeks.
- high fever- lasts 3 days
- generalised muscle aches,
- malaise and anorexia
Complications
-Pneumonia
Immunity to influenza is long-lived and subtype-specific.

12. Laboratory Diagnosis Diagnosis of influenza relies on:
a-isolation of the virus;
b-identification of viral antigen or viral nucleic acid in the patient’s cells, or
c-demonstration of a specific immunologic response.
Other tests are: ELISA and RIA. Paired acute and convalescent sera are necessary, because normal individuals usually have influenza antibodies. A fourfold or greater increased in titer must occur to indicate influenza infection.

13. Treatment 1-Amantadine and rimantadine, 2-Zanamivir and Oseltamivir
3-All people at risk in whom influenza develops
4-Persons with severe influenza
5-For persons who wish to shorten the duration of illness.

14. Prevention A-Inactivated viral vaccines
The vaccine is usually a cocktail containing two influenza A subtypes (H1N1, H3N2) and a type B virus of the strains isolated in the previous winter’s outbreaks.
Annual influenza vaccination is recommended for high-risk groups.:
• Persons >50 years old
• those with either chronic heart or lung disease,
• adult and children with asthma, or metabolic or renal disorders, immunossuppression, hemoglobinopathy
•residents of nursing homes;
• persons who might transmit influenza to high-risk groups :
- medical personnel,
- employees in chronic care facilities,
- household members.

15. Community-acquired pneumonia (CAP)

16. Community-acquired pneumonia (CAP)
UK figures suggest that an estimated 5-11/1000 adults suffer from CAP each year, accounting for around 5-12% of all lower respiratory tract infections.
The incidence varies with age, being much higher in the very young and very old, in whom the mortality rates are also much higher.
World-wide, CAP continues to kill more children than any other illness.

17. Community-acquired pneumonia (CAP)
Most cases are spread by droplet infection and occur in previously healthy individuals but several factors may impair the effectiveness of local defences and predispose to CAP. 
Strep. Pneumoniae remains the most common infecting agent, and thereafter, the likelihood that other organisms may be involved depends on the age of the patient and the clinical context.
Viral infections are an important cause of CAP in children, and their contribution to adult CAP is increasingly recognised.

18. Clinical features
Pneumonia usually presents as an acute illness in which systemic features such as fever, rigors, shivering and vomiting predominate .
Pulmonary symptoms breathlessness and cough, painful and dry, but later accompanied by the expectoration of mucopurulent sputum.
Proteinaceous fluid and inflammatory cells congest the airspaces, leading to consolidation of lung tissue.
This improves the conductivity of sound to the chest wall (bronchial breathing and whispering pectoriloquy).
Crackles are often also detected

19. Common clinical features of community-acquired pneumonia (CAP)
1-Streptococcus : Rapid onset, high fever and pleuritic chest pain;.
2-Mycoplasma pneumoniae: Children and young adults.
Rare complications include haemolytic anaemia, Stevens- Johnson syndrome, erythema nodosum, myocarditis, pericarditis, meningoencephalitis, Guillain-Barré syndrome.
3-Legionella pneumophila:Middle to old age. Local epidemics around contaminated source, e.g. cooling systems in hotels, hospitals. Person-to-person spread unusual.
4- Chlamydia pneumoniae, Haemophilus influenzae, Staphylococcus aureus.

20. Investigations
The objectives are to exclude other conditions that mimic pneumonia ,assess the severity, and identify the development of complications.
A chest X-ray usually provides confirmation of the diagnosis. In lobar pneumonia, a homogeneous opacity localised to the affected lobe or segment usually appears within hours of the onset of the illness .
Radiological examination is helpful if a complication such as parapneumonic effusion, intrapulmonary abscess formation or empyema is suspected.

21. Pneumonia of the right middle lobe

22. This CXR demonstrates a lobar pneumonia

23. Investigations
Many cases of CAP can be managed successfully without identification of the organism, particularly if there are no features indicating severe disease.
A full range of microbiological tests should be performed on patients with severe CAP .
The identification of Legionella pneumophila has important public health implications and requires notification. In patients who do not respond to initial therapy, microbiological results may allow its appropriate modification.
Microbiology also provides useful epidemiological information

24. Gram stain of sputum showing Gram-positive diplococci characteristic of Strep. pneumoniae (arrows).

25. Investigations All patients:
Sputum:direct smear by Gram and Ziehl-Neelsen stains. Culture and antimicrobial sensitivity testing
Blood culture: frequently positive in pneumococcal pneumonia
Serology: acute and convalescent titres for Mycoplasma, Chlamydia, Legionella, and viral infections. Pneumococcal antigen detection in serum or urine
PCR: Mycoplasma can be detected from swab of oropharynx

26. Investigations
Severe community-acquired pneumonia The previous tests plus consider:
Tracheal aspirate, induced sputum, bronchoalveolar lavage, protected brush specimen or percutaneous needle aspiration. Direct fluorescent antibody stain for Legionella and viruses
Serology: Legionella antigen in urine.
Pneumococcal antigen in sputum and blood. Immediate IgM for Mycoplasma
Cold agglutinins: positive in 50% of patients with Mycoplasma

27. Investigations
Pulse oximetry provides a non-invasive method of measuring arterial oxygen saturation (SaO2) and monitoring response to oxygen therapy.
Arterial blood gas is important in those with SaO2 < 93% or with features of severe pneumonia, to identify ventilatory failure or acidosis.
The white cell count may be normal or only marginally raised in pneumonia caused by atypical organisms, whereas a neutrophil leucocytosis of more than 15 × 109/L favours a bacterial aetiology.
A very high (> 20 × 109/l) or low (< 4 × 109/l) white cell count may be seen in severe pneumonia.
Urea and electrolytes and liver function tests should also be checked.
The C-reactive protein (CRP) is typically elevated

28. Management
Oxygen: should be administered to all patients with tachypnoea, hypoxaemia, hypotension or acidosis with the aim of maintaining the PaO2 ≥ 8 kPa (60 mmHg) or SaO2 ≥ 92%. High concentrations (≥ 35%), preferably humidified, should be used in all patients who do not have hypercapnia associated with COPD.
Assisted ventilation should be considered at an early stage in those who remain hypoxaemic despite adequate oxygen therapy.
Noninvasive Ventilation (NIV ) may have a limited role but early recourse to mechanical ventilation is often more appropriate

29. Management Fluid balance:
Intravenous fluids should be considered in those with severe illness, in older patients and in those with vomiting.
Otherwise, an adequate oral intake of fluid should be encouraged.
Inotropic support may be required in patients with circulatory shock.

30. Antibiotic treatment
Prompt administration of antibiotics improves outcome.
The initial choice of antibiotic is guided by clinical context, severity assessment, local knowledge of antibiotic resistance patterns, and at times epidemiological information, e.g. during a mycoplasma epidemic.
In most patients with uncomplicated pneumonia a 7-10-day course is adequate, although treatment is usually required for longer in patients with Legionella, staphylococcal orKlebsiella pneumonia.
Oral antibiotics are usually adequate unless the patient has severe illness, impaired consciousness, loss of swallowing reflex or malabsorption.

31. Management Most patients respond promptly to antibiotic therapy.
However, fever may persist for several days and the chest X-ray often takes several weeks or even months to resolve, especially in old age.
Delayed recovery suggests either that a complication has occurred or that the diagnosis is incorrect .
Alternatively, the pneumonia may be secondary to a proximal bronchial obstruction or recurrent aspiration.
The mortality rate in adults managed at home is very low (< 1%); hospital death rates are typically between 5 and 10%, but may be as high as 50% in severe illness

32. Antibiotic treatment for CAP
Uncomplicated CAP :Amoxicillin 500 mg 8-hourly orally.
If patient is allergic to penicillin: Clarithromycin 500 mg 12- hourly orally or Erythromycin 500 mg 6-hourly orally.
If Staphylococcus is cultured or suspected: Flucloxacillin 1-2 g 6- hourly i.v. plus Clarithromycin 500 mg 12-hourly i.v.
If Mycoplasma or Legionella is suspected: Clarithromycin 500 mg 12-hourly orally or i.v. or Erythromycin 500 mg 6-hourly orally or i.v. plus Rifampicin 600 mg 12-hourly i.v. in severe cases.
Severe CAP: Clarithromycin 500 mg 12-hourly i.v. or Erythromycin 500 mg 6-hourly i.v. plus Co-amoxiclav 1.2 g 8-hourly i.v. or Ceftriaxone 1-2 g daily i.v. or Cefuroxime 1.5 g 8-hourly i.v. or Amoxicillin 1 g 6-hourly i.v. plus flucloxacillin 2 g 6-hourly i.v.

33. Management

34. Complications of pneumonia
Para-pneumonic effusion-common
Empyema .
Retention of sputum causing lobar collapse
DVT and pulmonary embolism
Pneumothorax, particularly with Staph. aureus
Suppurative pneumonia/lung abscess
ARDS, renal failure, multi-organ failure
Ectopic abscess formation (Staph. aureus)
Hepatitis, pericarditis, myocarditis, meningoencephalitis
Pyrexia due to drug hypersensitivity