SUPER BUG

Anatomy of lungs & pleura

Pneumonia management

control of respiration

Pneumonia

B- cell responses

Causality in Medicine

Risk factors of LRTI

is defined as

an event that plays an important role, or regular/ predictable change in occurrence of the outcome.

has two types

necessary cause

component cause

which means that

removing this cause won't diminish the effect

Epidemiological triad

represents

the interaction between the agent, the host, and the environment with a specific time

Epidemiology of CAP

in Qatar

Worldwide

Strep. pneumoniae and mycoplasma pneumoniae are the most common pathogens causing CAP

It caused 3M deaths each year

The estimated incidence is 1.5-14 cases per 1000 persons-years

It affect mostly countries with aging population and poor access to health care

Epidemiology of COVID-19

includes

475M confirmed cases

58.5M active cases

6M deaths

411M recoveries

10.9B vaccine doses administered

5B people one-dose vaccinated

4B people fully vaccinated

is caused by

Infectious typical bacteria

Strep pneumonia

Characteristics are

Non-motile

Capsule

grow in pairs or chains

Gram (+)

Non-spore forming

Catalase (-)

Virulence Factors

1- CPS

4- CBPs

3- Lyt

2- PLY

Important for:

1- Resistance to phagocytosis and antibiotics

2- Adhesion

3- Highly immunogenic

4- protection

5- Vaccine development

Exotoxin

pore forming

Hemolysis activity

partial hemolysis of RBCs

Inhibit ciliary beating

Required for transmission

Stationary phase

Lyt A + Lyt C

Bacteria cell wall autolysis

release of

DNA

RNA

Ply

PsPA

PspC

Bind to factor H

Resist complement activation

bind to lactoferrin

allow the growth of bacteria

Chronic diseases

Smoking

Hospitalization

Recent viral infection

Age
< 2 , > 65

Weakened immune system

Such as

Asthma

Heart disease

COPD

Caused by

Organ transplant

Drugs (Chemotherapy - steroids)

HIV/AIDS

Incomplete vaccination

Investigations for pneumonia

Bronchoalveolar lavage

PCR - rapid tests

ABG (acidosis/respiratory failure)

Pulse oximetry

Urine antigen test (S.pneumoniae - legionella)

Sputum microscopy & culture

Blood microscopy & culture

CBC and serum test

Chest Xray

Resulting in

Leukocytosis (especially PMNs)

Elevated Urea/creatinine

Elevated lactic acid

Elevated procalcitonin

Elevated CRP

Normal D-dimer and ferritin

cap

hap

CURB 0-1

CURB ≥3

CURB=2

antibiotics + send patient
home

admit into the hospital for
observation

admit into the ICU

microlides

or

Tetracyclines

e.g,

e.g,

Doxycycline

ezithromycin

microlides/ tetracyclines + A/B

plura

Trachea and bronchi

A

B

penicillin

3rd generation cephalosporin

e.g,

e.g,

ampicillin

ceftriaxone

3rd generation cephalosporin + A/B

penicillin-b lactamase + A/B

A/B = microlides/ respiratory floroquinolone

HAP Early Onset

HAP Late Onset

respiratory fluoroquinolone

carbapenems

Amino-glycoside + microlides

penicillin-b lactamase

Amino-glycoside OR respiratory fluoroquinolone +A/B/C

Primary B cell response

B

C

A

Secondary B cell response

Exposure to the Ag for the first time

B-lactamase inhibitor - B-lactam

carbapenem

3rd generation cephalosporin 4rd generation cephalosporin

Naive B cell are activated

IgM production

Peaks one week after infection

Has weak potency

e.g,

The exposure of the Ag for the second time

e.g,

e.g,

Memory B cells are activated

IgG production

Peaks hours after infection

Has high potency

tazobactam -piperacillin

NOT ertapenem. imipenem doripenem meropenem

Herd immunity

ceftazidime cefepime

Defined as

It is when most of the population is immune to an infectious disease

can be achieved

Naturally exposed to the disease

Vaccines

defensive mecahnisms

Barriers

Mucocillary escalator

Innate cellular defenses

Type one alveolar cells

Type 2 alveolar cells

Alveolar macrophages

Interstitial macrophages

Humoral immunity through

consist of

viceral pleura

pleural cavity

parietal pleura

that divides by location into

costal

diaphragmatic

cervical

mediastinal

histology

consist of

simple squamous epithelium

subserous fascia

made of

loose areolar CT

pleural recess

include

costomediastinal recess

costodiaphragmatic recess

Trachea

is a

Fibrocartilaginous tube from C6 to T4/T5

bronchi

Anterolateral

U-shaped bars of hyaline cartilage

Posterior

Smooth muscle (trachealis)

consist of

primary (main) bronchi

seprated into

Right bronchus

Wider

Secondary bronchi

more vertical

shorter

left bronchus

Narrower

longer

horizontal

Right

Left

Superior

inferior

middle

SARS-Cov-2

Superior

inferior

Tertiary (segmental) bronchi

Supply bronchopulmonary segment

has

.

Structural proteins

COVID-19

important for

Causing infection

includes

S protein

E protein

M protein

N protein

diagnosed by

RT-PCR

Immune response

can detect

Viral RNA

looking for

IgM

IgG

medulla oblongata

the primary respiratory control center.

composed of

the dorsal respiratory group (DRG)

the ventral respiratory group (VRG)

contains

inspiratory neurons

Contain

both inspiratory and expiratory neurons

inputs

the peripheral (arterial) chemoreceptors

the central chemoreceptors

stimulated by

1- Significantly decreased Po

2- Increased H concentration

3-Increased Pco

stimulated by

increased Pco, via associated changes in H concentration.

CURB-65

is

Severity Score estimates mortality of community-acquired pneumonia to help determine inpatient vs. outpatient treatment.

Hospital-Acquired Infection

types

Pneumonia

Surgical site infections

Urinary tract infections​

Bloodstream infections

causes

Surgical procedures

Mechanical ventilation

Urinary catheters

Risk factors

Long hospital stay

Immunosuppression

Elderly

often

More serious than CAP

because

patients are immunosuppressed

Microbes are more virulent & might have antibiotic resistance