Upper Respiratory Tract Infections

Babak Valizadeh,DCLS [email protected] 1389 / 07 / 29 2010.10.21

Upper Respiratory Tract Infections

Pharyngitis Sinusitis Otitis Diphtheria Pertussis

Laryngitis

Most caused by viruses Rhinovirus Influenza Adenovirus Parainfluenza : Larygotracheobronchitis M. catarrhalis is the most common bacterial species isolated from adult patients with laryngitis

Epiglottitis

Children : 2-6 Life-threatening Bacteria **** Bacteriologic culture ??? Direct swab of epiglottis, blood cultures Direct swab should be performed only if airway is secure

Epiglottitis Epiglottitis

Most common:H.influenza type b ****

Less common: H. influenzae type A Nontypable Haemophilus Haemophilus parainfluenzae Streptococci Staphylococci Epiglottitis

Throat swabs can be a useful specimen in determining upper airway colonization with H. influenzae type b and are usually only taken for epidemiological studies. Pharyngitis & tonsillitis Pharyngitis

 Viruses are the most common cause of pharyngitis in both adult and pediatric populations

 Primary infection with herpes simplex virus may be indistinguishable from infections due to other viruses or GAS

 Patients with Epstein-Barr virus (EBV) infection may present with an exudative tonsillitis or pharyngitis

Epstein-Barr virus (EBV) infection

Adenoviruses

Adenoviruses produce an acute pharyngitis that resembles streptococcal pharyngitis

Conjunctivitis often is present in addition/ Pharyngoconjunctival fever Coxsackie A virus

Some serotypes of Coxsackie A virus produce acute pharyngitis with vesicles in the posterior pharynx as part of hand, foot, and mouth disease.

 The infection typically occurs in children Antibiotics Often Overprescribed for Viral Respiratory Infections Infect Contr Hosp Epidemiol. 2010;31:11

 In Pennsylvania ; 196 had a viral assay positive for influenza A or B, parainfluenza, adenovirus, or respiratory syncytial virus

 Of these, 131 (69%) patients received antibiotics, including 125 (64%)who continued to receive antibiotics after diagnosis of viral RTI

 Clostridium difficile infection developed in 8 patients (6%) who continued on antibiotics

Pharyngitis

Normal pharyngeal flora, such as Staphylococcus aureus, Streptococcus pneumoniae, and Haemophilus influenzae, should not be reported from routine throat cultures

To do so encourages inappropriate antimicrobial therapy

Group A Streptococci GAS Pharyngitis

Presentation of upper respiratory tract infection with cough and rhinorrhea is suggestive of a nonstreptococcal etiology

In one study of pediatric patients : 36% of those presenting with cough & 45% of pediatric patients presenting with coryza symptoms had throat cultures that were positive for group A streptococci (GAS)

Throat culture

Throat culture remains the gold standard for the diagnosis of streptococcal pharyngitis

Sensitivity : 90% & Specificity : 99 %

Group A streptococci (GAS)

 Rapid antigen detection test in 10-30 minutes. (1980s)

 > 40 commercial Kit (POCT)

 Specificity > 95 % & sensitivity 62-90 %

 Negative Result Should be cultured or confirming using a Nucleic Acid method Group A Streptococcal Pharyngitis Therapy

For almost 5 decades, penicillin has been the drug of choice

Over the past 40 years have reported penicillin bacteriologic failure rates ranging from 10 to 30 percent and clinical failure rates ranging from 5 to 15 percent

Group A Streptococcal Pharyngitis Treatment Failure and Reinfection

Group A beta-hemolytic streptococci persist for up to 15 days on unrinsed toothbrushes

Pathogens are not isolated from rinsed toothbrushes after three days

Group A Streptococcal Pharyngitis Treatment Failure and Reinfection

Close Contacts :During epidemics, 50 percent of the siblings and 20 percent of the parents of infected children develop streptococcal pharyngitis

Group A Streptococcal Pharyngitis Treatment Failure and Reinfection

 Beta-lactamase– producing copathogens

 Amoxicillin-clavulanate is often used to treat recurrent streptococcal pharyngitis

Throat culture Throat culture / 2006

Diagnosis of Streptococcal Pharyngitis by Detection of Streptococcus pyogenes in Posterior Pharyngeal versus Oral Cavity Specimens

Carbohydrate antigen detection, nucleic acid probe detection, and bacterial culture

When testing for GAS pharyngitis, the throat remains the optimum site for sampling

Pharyngitis Group A streptococci (GAS)

INOCULATION OF CULTURE MEDIA 1+ to 4+

Throat culture

Throat culture Streptococcus pyogenes

 Gram-positive cocci in pairs and chains

 Catalase-negative

 Beta-hemolytic colonies large colony >0.5 mm in diameter on sheep BAP after 24 hours incubation

 Colonies are usually dry, peaked, or convex with a sharp periphery to the zone of hemolysis Group A streptococci (GAS) on sheep blood agar < 1% Nonhemolytic

Medium and atmosphere of incubation 24 & 48 hrs .(96%) Medium and atmosphere of incubation 24 & 48 hrs ,OLD

Sheep blood agar with Bacitracin incubated aerobically • Presumptive Identification Of GAS • Reduces sensitivity & Specificity

Sheep blood agar with Bacitracin & SXT incubated aerobically

Group A streptococci (GAS) on sheep blood agar Group A streptococci (GAS) on sheep blood agar Group A streptococci (GAS)

 Bacitracin : S/rare R & SXT : R

 Pyrrolidonyl arylamidase (PYR): +

 Serogrouping by particle agglutination approaches 100% accuracy Group A streptococci (GAS) Bacitracin 0.04 S>1 or 12-15mm

ASM 2004

Group B Streptococci are not associated with pharyngitis

Group A Streptococci (GAS) vs. Group B Streptococci

Group B Streptococci CAMP

Group B Streptococci Hippurate Hydrolysis : + Group B streptococci Bacitracin :R rare s & SXT : R

Groups C and G Streptococci

Groups C and G streptococci produce infections quite similar to GAS but milder than those of group A strains

Some strains contain fibrinolysins and streptolysins and infections can stimulate antistreptolysin O titers (ASO), similar to S. pyogenes.

Groups C and G Streptococci Beta-hemolytic Streptococci

Most of the evidence of Lancefield groups C and G Streptococci causing pharyngitis comes from reports of outbreaks Group C Streptococci

The beta-hemolytic group C Streptococci infecting humans include the large colony (>0.5 mm)

S.dysgalactiae subsp. equisimilis,the most common human isolate.

Group G Streptococci

Lancefield group G streptococci are subdivided into the "large colony" form and the "minute colony“ form (S. anginosus , VP : + )

 The "minute colony ( < 0.5 mm) form is not thought to cause pharyngitis. Groups C and G streptococci

Groups C and G streptococci are usually, but not exclusively, beta hemolytic

Unlike GAS, which are inhibited by 0.04 units/mL of bacitracin, the group C and G isolates are extremely variable in their bacitracin sensitivity, ranging from as few as 6 to 8 percent to as many as 30 to 67 percent

Groups C and G Streptococci SXT : S & Bacitracin :R-s

Groups C Streptococci SXT : S & Bacitracin :R-s

Groups C Streptococci latex agglutination for Serogrouping S.dysgalactiae subsp. equisimilis

Reporting

 NO β-hemolytic Streptococci isolated . No Streptococcus pyogenes isolated.  Streptococcus pyogenes isolated. 1+... 4+  β-hemolytic Streptococci ,Group C / G isolated.

Beta-hemolytic Streptococci

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Arcanobacterium haemolyticum

Formerly Corynebacterium haemolyticum

Tonsillitis, pharyngitis and causing rash in young adults (15 to 25 years old) and occasionally in children

It is suggested that in cases of treatment failure and repeat incidences of tonsillitis, isolation of A. hemolyticum should be considered Arcanobacterium haemolyticum

Treatment of pharyngitis with penicillin may fail to eradicate

Erythromycin has also been used in the treatment of A. haemolyticum infections

Arcanobacterium haemolyticum

After 48 hours incubation on blood agar A. haemolyticum colonies exhibit narrow zones of ß -hemolysis and are 0.5mm in diameter

In cases where A. haemolyticum is suspected, incubation of culture plates may need to be extended up to 72h

Arcanobacterium haemolyticum

CO2-enriched atmosphere

A. haemolyticum, whose hemolysis is more pronounced on human and rabbit blood agar than on SBA

Two different biotypes of A. hemolyticum • Smooth type isolated mainly from wounds • Rough type isolated mainly from respiratory tracts Arcanobacterium haemolyticum

The majority of A. haemolyticum isolates produce small, dark pits under colonies growing on ordinary BA medium

The pitting of the agar underneath the colony, when the colony is pushed aside

Arcanobacterium haemolyticum

A. haemolyticum is a catalase-negative, gram- positive or variable rod whose morphology is dependent on the growth media and conditions

Similar to that of C. pseudotuberculosis and C. ulcerans , positive reverse CAMP test • A. haemolyticum is Catalase & Urea negative

Arcanobacterium haemolyticum SBA 48hrs

Arcanobacterium haemolyticum

Arcanobacterium haemolyticum Reverse CAMP tests

Arcanobacterium haemolyticum Reverse CAMP tests

Mixed Aerobic / Anaerobic Infection or Colonization

Borrelia vincentii and Fusobacterium species are associated with the infection known as Vincent's angina

It is characterized by ulceration of the pharynx or gums and occurs in adults with poor mouth hygiene or serious systemic disease

VINCENT'S ANGINA

>2 Borrelia & Fusobacterium / OIF

Lemierre's Syndrome / postanginal septicemia / 1936

 Acute pharyngeal infection with the anaerobe Fusobacterium necrophorum

 The acute pharyngitis is followed by a septic thrombophlebitis of the internal jugular vein

 Dissemination of the infection to multiple sites distant from the pharynx

 In the preantibiotic era, Lemierre's syndrome was often fatal Lemierre's Syndrome / postanginal septicemia

Lemierre's syndrome generally occurs in healthy adolescents and young adults

Fusobacterium necrophorum is a nonmotile

Gram-negative anaerobe occurring in the normal flora of the pharynx, gastrointestinal tract, and female genital tract Lemierre's Syndrome / postanginal septicemia

Confirmation of Lemierre's syndrome is provided by demonstration of F. necrophorum on blood culture

Treatment of Lemierre's syndrome is high-dose parenteral antibiotics directed against anaerobes (clindamycin, metronidazole, chloramphenicol, imipenem)

Capnocytophaga spp.

Capnocytophaga spp. , fusiform bacteria that are normally present in the oropharynx

Capnocytophaga spp have also been associated with ulcerations of the oral mucosa and positive blood cultures, particularly in patients with severe neutropenia

Capnocytophaga spp.

Capnocytophaga spp. resistance to vancomycin, colistin, and trimethoprim.

Capnocytophaga spp. recovered from 96% of oropharyngeal cultures on selective Neisseria medium compared with only a 6% recovery on chocolate agar plates inoculated in parallel ( CO2 / 48-72 hrs.) Candida infections

These infections are common in immunodeficient patients particularly during severe Neutropenia

 Patients receiving antibiotics are also prone to fungal infections

Candida species may rarely cause severe invasive oesophagitis

Candida infections

Infection of the buccal mucosa, tongue or oropharynx is usually due to Candida albicans

Species of yeast other than C. albicans, such as Candida krusei and Candida glabrata can also occasionally colonize the mouth but are rarely associated with infection Candida infections

Candida infections

Salivary Glands Infections

Sialadenitis or infections of the salivary glands (parotid, submandibular, sublingual and accessory parotid) include suppurative, chronic bacterial and viral parotitis

Mumps, influenza and enteroviruses are the usual viral agents of parotitis

MOUTH SWABS

 Parotitis pus exuding from the parotid glands and is sampled via the mouth

 The predominant organisms causing suppurative parotitis are staphylococci • Enterobacteriaceae • Other Gram negative bacilli • Viridans streptococci • Anaerobes  Chronic bacterial parotitis is due to Staphylococci, or mixed oral aerobes and anaerobes Culture media, conditions and organisms

Staphylococcus aureus

S. aureus has sporadically been reported as a cause of peritonsillar abscess

Pus may be aspirated from the abscess and sent for culture

Neisseria meningitidis

 Throat swabs may be an aid to diagnosis of meningococcal meningitis

 N. meningitidis can be isolated from a throat swab in about half the cases of invasive meningococcal disease

 The strain isolated from the throat is likely to be of the same group and type as that isolated from cerebrospinal fluid and blood

Sinusitis

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Sinusitis

 Sinus development is a process that may take up to 20 years, although the ethmoid and maxillary sinuses are already present at birth

 Development of sphenoid and frontal sinuses starts in the first few years of life

 Sinusitis is a very common infection in early childhood, accounting for about 5 to 10% of upper respiratory tract infections Sinusitis

It is often underdiagnosed in children because the symptoms are nonspecific

In addition, physical examination and radiology are of little value in young children

Etiologic diagnosis requires culturing an aspirate of sinus secretions Acute Sinusitis Diagnosis Pediatrics/ 01/30/2009

Patient age at which pediatricians reported first considering the diagnosis of acute sinusitis 0 to 5 months in 6%  6 to 11 months in 17%  12 to 23 months in 36%  24 to35 months in 21%, 36 months or older in 20% Acute Sinusitis Diagnosis Pediatrics/ 01/30/2009

Purulent rhinorrhea (55%) Nasal congestion (43%) The minimal number of days of symptoms before considering the diagnosis of sinusitis 10 to 13 days for 37% 14 to 16 days for 38% Sinusitis

Viral upper respiratory tract infection is an important cause of acute sinusitis Rhinoviruses Influenza virus Parainfluenza virus Adenovirus Sinusitis

The etiology of community-acquired infection may be viral, mixed viral- bacterial, bacterial or occasionally fungal

 Nosocomial infection is usually bacterial or occasionally viral ,nasotracheal intubation Sinusitis

Acute sinusitis ( 10 to 30 days) Chronic disease (30 to 120 days)  S. pneumoniae, H. influenzae (non- encapsulated ) & M. catarrhalis most frequently isolated bacterial  S. pneumoniae 30 - 40%  H. influenzae and M. catarrhalis each account for approximately 20% of cases Sinusitis

Group A streptococcus, other α-haemolytic Streptococci, S.aureus, & anaerobic bacteria

Sinusitis

Nosocomial sinusitis The most common bacterial isolates :  S. aureus  P.aeruginosa  S.marcesens  K.pneumoniae  Enterobacter spp. & P.mirabilis.  The condition is often polymicrobial Sinusitis

Occasionally, fungi cause of community- acquired sinusitis, particularly in tropical and subtropical

Fungal infections are usually due to filamentous fungi

Sinusitis

Aspergillus spp. (especially Aspergillus flavus), Rhizopus and Mucor

Candida spp and Cryptococcus neoformans are other causes of infections in patients who are immunocompromised

Chronic rhinosinusitis (CRS)

Chronic rhinosinusitis (CRS) is defined as an inflammatory disease of the nasal and paranasal mucosa persisting and symptomatic for longer than 3 months

The etiology and pathogenesis of the disease are still unknown

Frequency and Identification of Fungal Strains in Patients with Chronic Rhinosinusitis Iranian Journal of Pathology (2008)3 (3), 135 - 139

Fungal infection is frequent in patients with chronic rhinosinusitis

Positive fungal cultures of paranasal sinuses mucus were seen in 49% of cases and 5% of controls

Aspergillus was the most frequent

Sinusitis

Chronic sinusitis  S. pneumoniae  H. influenzae  Streptococci of the “anginosus” group  M. catarrhalis  S. aureus  Pseudomonas species  Anaerobes • Aerobic Gram-negative bacteria

Culture media, conditions and organisms Nose swab

Nasal colonization with S. aureus /MRSA

Klebsiella ozaenae

Ozaenia (ozena) is a chronic atrophic rhinitis, The condition can destroy the mucosa and is characterized by a chronic, purulent and often foul-smelling nasal discharge Streptococcus pneumonia

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Streptococcus pneumoniae Archives of Internal Medicine, September 27, 2010

Positive pneumococcal urinary antigen test result in adult patients hospitalized with community- acquired pneumonia (CAP)/ Immunochromatographic

Specificity of the pneumococcal urinary antigen test was 96% and that its positive predictive value ranged from 88.8% to 96.5%

Streptococcus pneumonia

 Gram-positive cocci in pairs and chains

 Catalase-negative

 Alpha hemolytic on sheep BAP

 Colonies are usually transparent, slightly mucoid, or flattened (resemble a checkers playing piece), not peaked Streptococcus pneumonia

S. pneumoniae S. pneumoniae S. pneumoniae

Optochin Susceptibility

Disk containing optochin (5 μg ethylhydrocuprein hydrochloride)

SBA plate

Plate is incubated overnight at 35° C in CO2

Optochin Susceptibility

A zone of inhibition greater than 14 mm with a 6-mm disk

A zone of inhibition greater than 16 mm with a 10-mm disk are considered susceptible and a presumptive identification of S. pneumoniae S. Pneumoniae Optochin susceptibility test > 14 or > 16 mm

Streptococcus pseudopneumoniae 2004

A newly Streptococcus pseudopneumoniae discovered organism

S. pseudopneumoniae strains do not have pneumococcal capsules Streptococcus pseudopneumoniae 2004

Streptococcus pseudopneumoniae are resistant to optochin (inhibition zones, less than 14 mm) when they are incubated under an atmosphere of increased CO2

But are susceptible to optochin (inhibition zones, >14 mm) when they are incubated in ambient atmospheres ; False Positive

S. Pneumoniae The bile solubility 2% sodium deoxycholate/ 2hrs

Haemophilus

. Haemophilus Haemophilus Haemophilus

H. influenzae appear as large colorless to gray, opaque colonies with no discoloration of the surrounding medium.

Haemophilus SBA vs. Chocolate agar

Haemophilus ID “Quad” Plates/ 5% horse blood

X XV

V Horse

Moraxella catarrhalis

. Moraxella catarrhalis

Formerly called Branhamella catarrhalis

M. catarrhalis is now considered an important pathogen in respiratory tract infections, both in children and in adults with underlying COPD

M. catarrhalis may be the single cause of sinusitis, otitis media

Moraxella catarrhalis

B-lactamase-producing strains, which now account for approximately 90 % of isolates

Susceptible to amoxicillin- clavulanic acid, cefixime, ciprofloxacin

Moraxella catarrhalis

Colony morphology; lack of pigmentation of the colony on blood agar

Growth at 22°C on nutrient agar Moraxella catarrhalis

 In typical Gram stains, M. catarrhalis presents itself as a gram-negative diplococcus with flattened abutting sides

 The bacterium has a tendency to resist destaining

Moraxella catarrhalis

 Colonies on blood agar are nonhemolytic, round, opaque, convex, and grayish white

 The colony remains intact when pushed across the surface of the agar

Moraxella catarrhalis

Identification Oxidase : Positive  DNase production : Positive Reduction of nitrate and nitrite : Positive Tributyrin hydrolysis / Butyrate Disk : Positive Failure to produce acid from glucose, maltose, sucrose, lactose, and fructose Kovac’s oxidase & Butyrate Disk in 2 minute

OTITIS Ear Infections

Otitis externa

In general, infection of the external auditory canal resembles infection of skin and soft tissue

Otitis Externa

 Otitis externa can take an Acute or a Chronic form

 Acute form affecting 4 in 1,000 (0.4%)persons annually

 Chronic form affecting 3% to 5 % of the population

 Acute disease commonly results from bacterial (90 percent of cases) or fungal (10 percent of cases) Otitis Externa

Chronic disease often is part of a more generalized dermatologic or allergic problem

The chronic form is commonly of a fungal or allergic origin or is the manifestation of dermatitides Otitis Externa

Acute OE is unilateral in 90 percent of patients

Peaks in persons 7 to 12 years of age, declines after 50 years of age Otitis Externa

Approximately 50 percent of bacterial cases involve Pseudomonas aeruginosa, followed in incidence by Staphylococcus aureus and then various aerobic and anaerobic bacteria

Hypersensitivity reaction to neomycin & Malignant external otitis Pseudomonas aeruginosa

Mycotic infection

 Mycotic infection of the ear is a superficial, chronic or subacute infection of the external auditory canal

 Partial deafness can occur due to occlusion of the ear canal by hyphae.

Aspergillus species Yeasts

Desquamating epithelium, soft cerumen & purulent discharge & Aspergillus

A Study on the Frequency of Fungal Agents in Otitis Externa in Semnan Iranian Journal of Pathology (2006)1 (4), 141-144

Otomycosis was diagnosed in 8 (11. 4%) of 70 cases

Candida parapsilosis (5 cases)  Candida glabrata (2 cases) Candida.krusei (1 case) Acute otitis media infection

Acute otitis media (AOM) is a very frequent infection in children.

 Before the age of 1 year, around 50% of children have experienced at least one period of AOM

This proportion rises to 70% at the age of 3 years Acute otitis media infection

Acute otitis media is defined by the co- existence of fluid in the middle ear and signs and symptoms of acute illness

Streptococcus pneumoniae 40% H.influenzae , nontypeable 30% Moraxella catarrhalis 20%

Acute otitis media infection

Less frequent causes , specially in children :

S. pyogenes,  S. aureus Gram-negative bacilli  Respiratory syncytial virus Parainfluenza viruses Alloicoccus otitidis

Alloicoccus otitidis

10 months to 3 years Chronic OM (2-5 previous episodes of OM) > 5 days / extremely slow  Large G pos Cocci in cluster ,Catalase +/- Resistance to Erythromycin & SXT PYR & LAP : + SBA & CA : +

DIPHTHERIA

. DIPHTHERIA

 Diphtheria is an acute infectious disease of the upper respiratory tract and occasionally the skin.

 It is caused by toxigenic strains of Corynebacterium diphtheriae

 4 biotypes - gravis, mitis, intermedius and belfanti

 Strains of Corynebacterium ulcerans DIPHTHERIA

 Milder infections resemble Streptococcal pharyngitis and the pseudo-membrane may not develop, particularly in vaccinated individuals

 The bacteria can also be carried without any symptoms

 Most cases of pharyngitis associated with isolation of non-toxigenic strains of Corynebacterium diphtheriae

DIPHTHERIA

Non-toxigenic strains of C. diphtheriae may be encountered in clinical specimens, especially those taken from persons previously immunized against diphtheria toxin.

DIPHTHERIA

 Man is the only reservoir of the disease for Corynebacterium diphtheriae

 C. ulcerans generally causes mild pharyngitis

 The normal reservoir of C. ulcerans is cattle and human cases have been associated with the consumption of raw dairy products  Human-to-human transmission of C. ulcerans has been shown

DIPHTHERIA

Corynebacterium diphtheriae SBA 24hr ,white, creamy

Corynebacterium

LMBS / ASM 1992 ASM 1992

Corynebacterium diphtheriae CTBA & Tinsdal agar

ASM 2004

ASM

Pertussis

Whooping Cough Pertussis

Viruses generally have an incubation period of 2 to 7 days

Bordetella pertussis & Mycoplasma pneumoniae & Chlamydophila pneumoniae have longer incubation periods (1 to 3 weeks ). Pertussis

A gradual onset of symptoms (2 to 3 days) is more characteristic of bacterial causes than of most viral causes Pertussis

Incubation period is 1-3 wk

Primarily affects adolescents and young adults

 In some series, 10 to 20% of patients have cough with a duration of >2 wk

Pertussis

Whooping occurs in a minority of patients

Fever is uncommon

A marked leukocytosis with lymphocytic predominance can occur

Pertussis 2006

A recent prospective study, B. pertussis comprised only 1% of cases of acute bronchitis Pertussis

 Whooping cough syndrome is caused by Bordetella pertussis, but it may also be caused by Mycoplasma pneumoniae, and by viruses such as Adenoviruses and enteroviruses

 Bordetella parapertussis causes a mild form of infection

 Bordetella pertussis is a pathogen for humans only; no animal reservoir

Pertussis

 B. pertussis usually infects, and causes severe respiratory disease in young children, although it does cause disease in adults

 Symptoms can be more virus-like in adults and older children

 The diagnosis of pertussis, particularly in the vaccinated population, should rely on laboratory confirmation

Pertussis

 Vaccination reduces the incidence of disease and the duration of pharyngeal carriage of B. pertussis

 Neither vaccination nor natural disease confers complete or lifelong protective immunity against pertussis or reinfection

 Immunity wanes after 5–10 years from the last pertussis vaccine dose Pertussis Clinical findings

 Catarrhal period (1–2 weeks): illness onset insidious (coryza, mild fever, and nonproductive cough); infants can have apnea and respiratory distress.

 Paroxysmal period (2–6 weeks): paroxysmal cough, inspiratory “whoop,” vomiting.

 Convalescent period ( >2 weeks): paroxysms gradually decrease in frequency and intensity Pertussis Clinical Manifestations

The cough, which is initially intermittent, becomes paroxysmal

Paroxysms of cough usually increase in frequency and severity as the illness progresses and usually persist for 2–6 weeks.

Paroxysms can occur more frequently at night..

Pertussis Clinical Manifestations

Approximately 80%–90% of patients with untreated pertussis will spontaneously clear B. pertussis from the nasopharynx within 3–4 weeks from onset of cough .

 Untreated and unvaccinated infants can remain culture-positive for >6 weeks

Recommended Antimicrobial Agents CDC / 2005

Macrolide antibiotic 5-day course of azithromycin  7-day course of clarithromycin  14-day course of erythromycin. Alternative agent  14-day course of trimethoprim-sulfamethoxazole Incidence CDC / 2005

During the preceding 3 decades, reports of pertussis steadily increased again in the United States, from 1,010 cases in 1976 to 25,827 in 2004

Approximately 60% of cases are in adolescents (aged 11–18 years) and adults (aged >20 years)

Highly contagious Acellular Pertussis Vaccine January 2007

Identification

 Gram-negative bacterium

 Culture / gold standard but sensitivity : 50%-60% • nearly 100% specificity

 Direct fluorescent antibody (DFA), 60% to 70% sensitive when compared with culture and can lack specificity

 Positive polymerase chain reaction (PCR)**** • real-time PCR Specimen Collection

B.pertussis colonizes the ciliated epithelial cells of upper respiratory tract

Specimens obtained from throat, sputum, or anterior nose are unacceptable because these sites are not lined with ciliated epithelium

Culture, which is most sensitive early in the illness Specimen Collection

Nasopharyngeal aspirate .****

It is advisable to take two pernasal swabs: one for the culture of Bordetella species and the other for viral culture

Specimen Collection

The only swab fibre recommended for diagnosis of whooping cough is Dacron Swabs should be transported in charcoal- based transport medium such as Regan- Lowe

NO Calcium alginate & Cotton Swabs

Nasopharyngeal swabs for diagnosis of Bordetella pertussis & Viral disease

Nasal Wash & Nasal Aspirate Culture media

 Bordet-Gengou • Potato infusion agar with glycerol and sheep blood with methicillin or cephalexin* (short shelf-life)

 Regan and Lowe***** • Charcoal agar with 10% horse blood (Sheep) with Without cephalexin (4- to a-week shelf-life)

 Incubation : at least 7 days (to 12 days) in humidified atmosphere without elevated CO2

Culture media

Visible growth after 3-5 days

Confirmation, differentiation between B. pertussis and B. parapertussis is of general importance, by slide agglutination

Regan - Lowe & Bordet-Gengou Regan - Lowe Regan - Lowe Bordetella pertussis / 2-3minute safranin "0“or Fschin 0.2% Identification Identification