Infections of Respiratory

System

Acute Respiratory Infections in Children

Introduction:

Respiratory tract infections are

described according to the areas of

involvement.

The upper respiratory tract or upper airway

consists of primarily the nose & pharynx.

The lower respiratory tract consists of

bronchi & bronchioles.

Acute Upper Respiratory Tract Infections in Children:

Most URTIs are caused by viruses &

are self-limited.

Acute naso-pharyngitis & pharyngitis

(including tonsillitis) are extremely

common in pediatric age groups.

pharyngitis

Inflammation of throat

Winter or early spring

Can be viral or bacterial

Viral

No fever

Less pain

More severe

Symptoms of common cold

H influenza,adenovirus& rhinoviruses

Bacterial

Mostly group A streptococci (15 to 30%)

Fever & pain

Less severe

No flue like symptoms

Unusual pathogens: N.gonnorrhoeae,C.dephtheriae

Lab Diagnosis

The primary goal of lab diagnosis is to differentiate between bacterial and viral pharyngitis

The secondary goal is to be able to detect the uncommon bacterial causes

Specimen Collection

SWAB

swab vigorously the tonsillar areas and posterior pharynx

Avoid tongue and other oral structures (normal flora)

After collecting the specimen, swab may be placed in transport medium

Culture

Culturing the specimen collected will isolate bacterial pathogens (e.g streptoccocci spp)

For culturing a non selective medium is used such as sheep blood agar

Other Methods

LATEX Agglutination Coagglutination test Enzyme immunoassays Rapid antigen detection test (RAPD)

Sinusitis

Viral infection associated with the common cold

Infection of one or more paranasal sinuses

Caused by:

Viral : influenza & para influenza

Bacterial : H.influenzae & C.pneumoniae

Fungal sinusitis are uncommon in normal people but can be found in immuno compromised individuals

Lab Diagnosis

To make a microbial diagnosis of sinus infection , sinus puncture and aspiration is used

Its an invasive and highly painful procedure and is not appropriate for use in routine practice

Only done when person is severely ill or immunocompromised or if there is a suspicion of cranial extension of the infection

Lab Diagnosis

Direct microscopic examination:

Only useful if specimen drawn directly from sinus puncture, gram staining can be done to find dominant bacterial type

Culture :

Samples are inoculated on media such as SBA ,CHOC, MacConky agar

BRONCHITIS Bronchitis is inflammation of the mucous

membranes of the bronchi, the airways that carry airflow from the trachea into the lungs.

Acute Bronchitis Chronic Bronchitis

Acute Bronchitis

Acute bronchitis is an inflammation in the larger branching airways (trachea and bronchi).

Usually arises in connection with a cold or flu.  

Chronic Bronchitis A type of chronic obstructive pulmonary disease

Bronchitis is a term that describes inflammation of the bronchial tubes that results in excessive secretions of mucus into the tubes with tissue swelling that may narrow or close off bronchial tubes.

Defined by a productive cough that lasts for 3 months or more per year for at least 2 years

Clinical Manifestations Cough And Fever- Primary Manifestations Sore Throat Runny Nose Nasal Congestion  Low-grade Fever Malaise Production of Sputum.

In Case of Chronic Bronchitis Yellow or green colored sputum production Wheezing Shortness of Breath

Acute Bronchiolitis Inflammation of the bronchioles, the smallest air

passages of the lungs.

Infectious disease of infants

Caused by Respiratory Syncytial Virus

Presents coughing, wheezing, and shortness of breath

Laboratory Diagnosis Diagnostic cultures not indicated in

uncomplicated cases In case of secondary bacterial

bronchitis culture data may be useful Collection of sputum minimally

contaminated with oral flora

PneumoniaCommunity Acquired Pneumonia

Nosocomial Pneumonia

Aspiration Pneumonia

Signs and Symptoms

Dyspnea Cough High fever  Sweating chills uncontrollable

shaking Sharp or stabbing

chest pain

Rapid, shallow breathing that is often painful

Community Acquired Pneumonia

One of several diseases in which individuals who have not recently been hospitalized develop an infection of the lungs

Occurs because the areas of the lung which absorb oxygen(alveoli) from the atmosphere become filled with fluid and cannot work effectively.

Causes problems like Difficulty breathing  Fever Chest pains Cough

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

Usually caused by a bacterial infection, rather than a virus.

Nosocomial Pneumonia

Aspiration pneumonia is bronchopneumonia that develops due to the entrance of foreign materials into the bronchial tree, usually oral or gastric contents (including food, saliva, or nasal secretions)

Aspiration Pneumonia

Laboratory Diagnosis

Involves no risk to patients Care must be taken to avoid

contamination of specimen with oropharengeal flora

Collection of deep sputum in order to get lung secretions not saliva or drainage from nasopharynx

Expectorated sputum examined for its character- preliminary indication

Specimen Collection

Fiberoptic bronchoscopeo Useful for direct specimens from lower

respiratory tracto Use of protected brush extended from

the end of bronchoscopeo Helpful for diagnosing aerobic and

anaerobic infections of lungs

Other Specimen Collection Method

Quality of specimen determined by a direct Gram- stained smear.

Elimination of contaminants from oropharyngeal region

Determination of neutrophils and epithelial cells under low power magnification

Sample >25 neutrophils and <10 epithelial cells per field- free of contamination

Samples> 25 squamous epithelial cells- should not be cultured

Direct Microscopic Examination

Gastrointestinal Tract Infections

What are GIT infections? It is any infection of the digestive tract caused by

bacteria, viruses or parasites. All may have common clinical features of nausea, vommiting, diarrhoea and anorexia

Causative agents of GIT infections

1. Bacteria (E.coli)2. Virus ( Rotavirus)3. Protozoa ( Entamoeba histolytica)4. Worm ( Ascaris)

Bacterial GIT infections

Symptoms

• Symptoms of dehydration

• Diarrhoea (does not get better in 5 days but get worse)

• Fever• Loss of appetite• Stomach cramping• Pale skin• Blood in stool• Rice water stool

Diagnosis

MacConkey agar

EMB agar Blood agar

Fluorescent antibody staining

Treatment• Antimicrobial agents like trimethoprim-

sulfmethoxazole or an oral penicillin may reduce the symptoms

• Antimotility drugs• Fluid replacement therapy along with oral

rehydration salts• Treatment of HUS (HEMORRHAGIC Uremic

Syndrome) may require dialysis

Viral GIT infections

ROTAVIRUS

• Members of the family Reoviridae• Infect cells of the villi of the small intestine

leading to epithelial atrophy• Decrease the lactase production resulting in milk

intolerance• This decreases the absorptive capacity of bowel

as well as stimulating the enteric nervous system• Viral gastroenteritis is also known as “stomach flu”

Symptoms

Signs of dehydration

• Sunken eyes• Low blood pressure• No tears• Dry or sticky

mouth Abdominal pain Diarrhoea Nausea Chills and fever Joint stiffness Weight loss

Diagnosis

ELISA Latex agglutination assay

Treatment

• Increased fluid intake• Salt replacement (orally or IV)• FDA approved live rotavirus vaccine• No antiviral therapy

AYISHA NASIM***

*FOOD POISONING*

DEFINATION***

• Inflammation of GI tract • Occurs due to consumption of food

containing toxins, which may be due to • microbes secreting toxins (preformed

toxins)• chemicals (Heavy metals)

• Acute onset• Usually < 10 days

IN CASE OF ***

Incubation Period if Short

{Minute to hours}

Chemical toxinsE.g., copper poisoning

Neurotoxins, histamine, allergensE.g. Shellfish toxins

IN CASE OF ***

Incubation Period: Short to medium

{1-12 hours}

Bacterial enterotoxinsE.g., Staphylococcal or

Bacillus cereus

IN CASE OF ***Incubation Period: Long

{6 hours – 10 days}

Bacterial infections

E.g., Salmonella,Shigella

MAIN TYPES OF FOOD POISONING ***Staphylococcal Food Poisoning

Clostridium perfringens

Food Poisoning

BACILLUS CEREUS FOOD

POISONING

Clostridium botulinum

Food Poisoning Shigella

food poisoning

Salmonella food

poisoning

1:STAPHYLOCOCCAL FOOD POISONING***• Scenario – picnic

• Encounter – from skin, nose or wound of infected person

• Entry – bacteria gets in food via contact; toxin gets in person via ingestion

• Spread – toxin spreads

• Multiplication – only in food, not in person

• Avoid Host Immune Response – resistant to stomach acid

• Damage – enterotoxins

2:CLOSTRIDIUM PERFRINGENS FOOD POISONING***• Scenario – cold meat pie

• Encounter – spores contaminate meat, germinate on storage of

cooked stews, etc.• Entry - ingestion

• Spread – toxin may spread, bacteria do not

• Multiplication – bacteria sporulate, don’t replicate; in a food borne infection the bacteria replicate

• Avoid Host Immune Response – bacteria are acid resistant

• Damage – toxin increases capillary permeability resulting in ileal fluid accumulation. It accounts for about 20% of bacterial diarrhoea.

• {done by enterotoxin producing strain type A}• { b-toxin producing type C strain- cause bloody diarrhoea, abdominal pain}

3.CLOSTRIDIUM BOTULINUM FOOD POISONING***

• Encounter - Home canned vegetables, potatoes, fish & preserved sea food• food contaminated with spores • anaerobic conditions

• Entry - Ingestion• Spread – toxin spreads from GI tract to nerve terminals

hematogenously • Multiplication - NONE• Avoid Host Immune Response

• Toxin: Resistant to proteolysis in stomach due to accessory proteins

• Absorption: Alkaline pH of intestine dissociates toxin from proteins, allows absorption into circulation

• Damage – exotoxin produces flaccid paralysis

DIAGNOSIS***

• Gross & microscopic stool examination

• Stool culture• Identification tests• Endoscopy if noninfectious

etiology suspected (inflammatory bowel disease)

TREATMENT***

ELMO

WHAT IS MENINGITIS..??

• an inflammation of the meninges; the membranes that cover the brain and spinal cord

• Condition is classified as medical emergency

BACTERIA

VIRUSFUNGU

S

CERTAIN

DRUGS

CLINICAL DIAGNOSIS

• KERNIG’S SIGN

• BURDZINSKI’S SIGN

• JOLT ACCENTUATION MANEUVER

• GLASS TEST

• Blood test (complete blood count) LeukocytopeniaPossible thrombocytopenia

• Blood cultures (40-70% positive)• PCR• CSF analysis (Lumbar puncture; ICP

level)• CT and MRI scan

LABORATORY DIAGNOSIS

TREATMENT Antibiotics are given depending upon the

type of infectious agent and clinical manifestations

Usually broad spectrum antibiotics are given initially

ENCEPHALITIS

RABBIYA TAHIR

Encephalitis is an acute inflammation Of the brain mostly due to the infections. Encephalitis with meningitis is known as meningoencephalitis.

DIAGNOSISBRAIN IMAGING

   CEREBROSPINAL        FLUID TESTS

      BLOOD TESTS

       BRAIN BIOPSY

Flu like symptoms

Severe symptoms

confusion

drowsiness

Visual sensitivity to light

Irratibility

Stiff neck 

Muscle weakness

Sudden impaired judgement

seizures

paralysis

SYMPTOMS

headache

Memory loss

Poor responsivene

ss

TREATMENT

Zovirax Foscavir

Phenytoin Acetaminophen 

Dexamethasone

INTRODUCTION

Rabies (From Latin: rabies, "madness")  is  a  viral disease  that causes acute encephalitis (inflammation of the brain) in warm-blooded animals.

Rabies,  or  'hydrophobia',  is  known  as  a  disease  that makes dogs sick and mad.

When an animal gets sick, it may start to bite. People are most  often  infected  by  the  bite  of  a  dog,  bat  or monkey.  In  Europe  the  virus  is mainly  carried  by  the fox.

CAUSATIVE AGENTThe virus that causes rabies is a 

lyssa virus. Lyssavirus is a genus of viruses belonging to the family Rhabdoviridae, in the order Mononegavirales. 

SIGNS AND SYMPTOMSSymptoms may include: Anxiety, stress, and tension Drooling Convulsions,  Excitability Exaggerated sensation at the bite site Low-grade fever Muscle spasms Numbness and tingling Pain at the site of the bite Restlessness Swallowing difficulty 

MODE OF TRANSMISSION The commonest mode of transmission in man is by the bite of

a rabid animal or the contamination of scratch wounds by virus- infected saliva. 

Other routes have been implicated in the past, such as through mucous membranes

Infection by aerosol Man to man transmission

DIAGNOSISRabies diagnosis in humans: Several  tests  are  necessary  to  confirm  or  rule  out  rabies  in  a human. 

No  single  test  can  be  used  to  rule  out  rabies  in  humans  with certainty.

Cerebral  inclusion  bodies  called  Negri bodies are  100% diagnostic for rabies infection.

Diagnosis  can  be  made  from  saliva, serum, urine, and cerebrospinal fluid samples, but this is not as sensitive.

The skin biopsy specimen is examined by dFA for the presence of rabies antigen in cutaneous nerves at the base of hair follicles.

Saliva  may  be  tested  by  virus  isolation  or  nested  reverse transcription polymerase chain reaction (RT-PCR) methods.

DIRECT FLUORESCENT ANTIBODY TEST

Positive dFA Negative dFA

DIAGNOSIS

Rabies diagnosis in animals:The  direct  fluorescent  antibody  test (dFA)  is  most  frequently  used  to diagnose  rabies.  This  test  can  be performed  on  brain  tissue  of  animals suspected of being rabid. 

MANAGEMENT AND PREVENTION Once  rabies  is  established,  there  is  nothing much  that could be done except intensive supportive care. 

However,  two  decades  ago,  research  scientists developed an extremely effective new rabies treatment regimen that provides protection from the disease. 

When  administered  after  an  exposure  (post-exposure prophylaxis).

The treatment can also be used for protection before an exposure occurs (pre-exposure prophylaxis).

 

BACTEREMIA…AN INTRO

• Presence of viable bacteria in the bloodstream

• It can be:Sustained/transient Metastatic /systemic leading to meningitis, pericarditis, endocarditis, osteomyelitis and infectious arthritis.

• Development of sepsis (a consequence of bacteremia)

pneumonia

cathetherization

Indewelling devices

Surgical treatment

abscess

Brushing

Conditions leading to bacteremia

Conditions• Decubitus ulcer• Chronically ill and immunocompromised patients

• IV drug users and IV catheterization

• IV drug users and IV catheterization

Type of bacteremia• gram-ve bacteremia• gram –ve and gram +ve bacteremia

     staphylococcal bacteremia

• bacteroids bacteremia

Important differentiation• If an infection in the abdomen causes bacteremia, the organism is most likely a gram-negative bacillus.

•  If an infection above the diaphragm causes bacteremia, the organism is most likely a gram positive.

Gram –ve bacteria Gram +ve bacteria

Symptoms 

• Asymptomatic patients• Mild fever• tachypnea, shaking chills, persistent fever, altered sensorium, hypotension, and GI symptoms (abdominal pain, nausea, vomiting, diarrhea)  suggests septic shock.

• Septic shocks develop in 25-40% of patients with significant bacteremia.

Diagnosis and treatment

• Blood tests • Blood culture• PCR amplification of microbial genes  followed by gel electrophoresis.

• Some of the different medications used in the treatment of Bacteremia include: 

• Daptomycin • Cubicin• High risk people are given antibiotics before procedures that can cause bacteremia.

Sepsis: Blood poisoning

Excessive systemic inflammatory response to infection leading to life-threatning complications.

Elevated plasma concentration of cytokines

More common and dangerous in Elderly people Weakened immune system Infants under 3 months Chronic infections

Trauma/ operation/ infection

Sepsis/ MODS

Excessive inflammatory

response

Inadequate oxygen supply

Tissue injury

Recovery

Adequate oxygen supply

Signs & symptoms

Fever Chills and severe shaking Increased heart rate Low blood pressure Rapid breathing Confusion, disorientation & dizziness Decreased urination Rash throughout the body Pain in joints

Diagnosis

Blood test: white blood cell count Evidence of infection Clotting problems Impaired oxygen availability

Blood culture before antibiotic treatment Other samples include

Sputum Urine Abscess contents

imaging tests include X-rays CT scan Ultrasound MRI

Cardiac monitor

Treatment

Hospitalization (ICU) Life saving measures

Medication: Antibiotics Vasopressors Others: costicosteroids, insulin

painkillers or sedatives Therapy Surgery

What is a UTI ?What is a UTI ?

An infection of urinary tract caused by germs, that

enter the urethra and then the bladder. This can lead to infection in the bladder itself, which can spread to

the kidneys

Type of urinary tract infected:Type of urinary tract infected:

• Cystitis Bladder• PyelonephritisKidney• Rarely the site of infectionUreter• UrethritisUrethra

E.Coli

80-85%Candida Staphylococcus

Saprophyticus

ChlamydiaCAUS

ESKlebsiella Species

Proteus Mirabilis Mycoplasma Enterococci

Who is at risk for a UTI?Who is at risk for a UTI?

People with spinal cord injuries• Difficulty emptying the bladder• Bacterial growth in the urine

Abnormality of the urinary tract

Diabetics

Patients using catheters

Types of UTITypes of UTI

• Upper urinary tract Infections:–Pyelonephritis

• Lower urinary tract infections–Cystitis (“traditional” UTI)–Urethritis (often sexually-

transmitted)–Prostatitis

Pathogenesis of UTIPathogenesis of UTI

Urethra colonised by bacteria

Bacteria enters bladder

Pathogens colonise bladder due to adherence properties

Pathogens attach to uroepithelial mucosa

Secretion of cytokines causing inflammation

PyelonephritisPyelonephritis

Pyelonephritis is a bacterial infection that most often occurs

when there is a persistent backflow of urine from the

bladder into the ureters or the kidney pelvis. It can be acute or

chronic

SymptomsSymptoms

• Flank Pain• Fever

Higher than 102 degrees Fahrenheit

Persists for more than 2 days

• Skin changes Flushed or

reddened Moist and Warm

• Severe abdominal pain Occurs

occasionally

• Urination Problems Blood in the urine Cloudy or

abnormal Urine color

Strong urine odor Nocturia Painful Urination Increased

Frequency

• Muscle Tenderness• Chills with shaking• Nausea and

Vomiting

DiagnosisDiagnosis

• Wide variation • exists in the clinical presentation, • severity, • options, and • disposition of the disease. • The triad of flank pain, fever, and nausea

and vomiting prompts examination and investigation.

Physical Examination

• Temp > 38.0ºC

• Tachycardia• Abdominal

Tenderness• Renal

Scarring• Odor• Appearance

Laboratory Tests

• Urinalysis • Pyuria• Bacteriuria• Haematuria• Urine Culture• Blood

Cultures - infection

• WBC Casts

Imaging Studies

• 99m-Tc-DMSA

• Ultrasound• shows

abnormalities in the kidney & bladder

• CT scan of abdomen

• MRI• Voiding

cystourethrogram• urethra & bladder

abnormalities• IVP

TREATMENTTREATMENT• The goals of treatment are to:

Control the infectionRelieve symptoms

• Symptoms go away within 48 to 72 hours • Antibiotics: are given after a urine culture

identifies the bacteria. A 10- to 14-day course of antibiotics.Mild infections: treated orally.

fluoroquinolones,Moderate - severe infections – parenteral aminoglycosides,

Interstitial cystitisInterstitial cystitis

• Inflammation of bladder• Age and Sex• Women : E.Coli• Men:S

Sign and SymptomsSign and Symptoms

• Decreased bladder capacity• Urinary urgency• Urinary frequency (60%)• Urinary discomfort• Pelvic pain• Low grade fever

• Bladder biopsy• Urinalysis• Urine culture• Urine cytology• Cystoscopy• Video urinodynamics• Imaging test• Potassium sensitivity test

DiagnosticsDiagnostics

UrinalysisUrinalysis

• Color• Clarity• Odor• Specific gravity• pH• Protein• Glucose• Ketones• Microscopic analysis

Urine culture testUrine culture test

• Detection and identification of bacteria and fungi

• Agar plate at room temp.• Size ,shape• Gram test• Escherichia coli gives pink color• Lactobacillus gives purplish color

CystoscopyCystoscopy

• Cystoscope• Examination of urethra and

bladder

UreteroscopyUreteroscopy

• Ureterscope• Laser beam• Examination of ureter

Cont…Cont…

• Local anesthetic• Saline• 15-30 mins• Avoid urination • Drink two 8-ounce glasses of

water each hour for 2 hours