(D.) *Epidemiology : Corynebacterium diphtheriae is an exclusive - - PowerPoint PPT Presentation

Diphtheria (D.) *Epidemiology :

• Corynebacterium diphtheriae is an exclusive inhabitant of human mucous

membranes & skin .

• Spread by : air borne resp. droplets , direct contact with resp. secretions of

symptomatic individuals , or exudates from infected skin lesions .

• Organisms can remain viable in dust or fomites up to 6m.
• Transmission through contaminated milk & an infected food handler has been

proved.

• Gray – brown , leather – like adherent pseudomembrene .

* Clinical manifestations : ** resp.tract . diphtheria :

• Inf. Of anterior nares which is more commpon among infants , causes

serosanguineous , purulent , erosive rhinitis with membren formation . shallow ulceration of the external nares & upper Lip is c-r .

• In tonsillar & phargngeal diph. ; sore throat is a universal early symptom , half have

fever , unilat. or bilat. Tonsillar membrane formation extend to involve the uvula , soft palate , post . oro phargnx , or glottic areas .

• Soft tissue edema & enlarged L.n , can cause a bull – neck appearance .
• Inf. Of larynx , trachea & bronchi : patient with laryngeal dipht. are at significant risk for

suffocation .

** Cutaneous dipht. : Is an indolent , non progressive , infection c.r. by asuperficial , ecthymic , non healing ulcer . ** infection at other sites : ear , eye , genital tract . * diagnosis : Culture of the specimens from nose & throat p& mucocutaneous Lesion . * Toxic cardiomyopathy : 10 – 25% of patients .  First evidence c.r. occurs during 2nd & 3rd wk. of illness , as pharyngeal dis. Improves .  Tachycardia out of proportion to fever is common . Prolonged PR interval & changes in the ST – T wave on ECG . First , 2nd & 3rd degree heart block . H.F. may appear insidiously or actuely . Recovery is usu. Complete.

* Prognosis : Virulence of organism , P. age , immunization status , site of infection , speed of administration of antitoxin . * Prevention : Vacc. * Asymptomatic contacts :

• Antimicrobial prophylaxsis : using ergthromycin 40 – 50 mg /kg/d. , divided

qid Po for 7d. or single inj. of Beng. Penicillin G.

• Dipht. toxoid vacc. , who not received abooster dose within 5y.

* Asymptomatic carriers :

• Antimicrobial prophylaxsis is given for 7d.
• Toxoid if abooster has not been given within 1y .

* Toxic Neuropathy :  Occur acutely or 2 – 3 wk.  Local paralysis of soft palete occur .  Weakness of post. Pharyngeal , laryngeal & Facialn .  Risk for aspiration.  Symmetric polyneuropathy lod – 3m.  Distal M. Weakness.  Complete nerologic recovery is likely . * Treatment :

• 1. Antitoxin : 20.000 – 120.000 u.
• 2. Antimicrobal therapy :
• erythromycin : 40 – 50 mg / Kg /d. , divided every 6hr. Po or I.V.
• Aqueous crystalline penicillin 100.000 – 150.000 U/kg/d. or orocaine

pencillin 250.000 – 50.000 u/kg/d . * Therapy is given for 14 days .

• 3. bed rest : usu. For ≥ 2wk. until the risk for symptomatic cardiac

damage has passed .

Diphtheria (D.) * epidemiology : Corynebacterium diphtheriae is an exclusive inhabitant of human mucous membranes & skin . Spread by : air borne resp. droplets , direct contact with resp. secretions of symptomatic individuals , or exudates from infected skin lesions . Organisms can remain viable in dust or fomites up to 6m. Transmission through contaminated milk & an infected food handler has been proved . gray – brown , leather – like adherent pseudomembrene . * Clinical manifestations : ** Resp.tract . diphtheria : inf. Of anterior nares which is more common among infants , causes serosanguineous , purulent , erosive rhinitis with membren formation . shallow ulceration of the external nares & upper Lip is c.r. in Tonsillar & pharyngeal diph. ; sore throat is a universal early symptom , half have fever , unilat. or bilat. tonsillar membrane formation extend to involve the uvula m soft palete , post . oro pharynx , or glottic areas . soft tissue edema & enlarged L.n , can cause a bull – neck appearance . inf. Of larynx , trachea & bronchi : patient with larynheal dipht. are at significant risk for suffocation .

** cutaneous dipht. : Is an indolent , non progressive , infection c.r. by a superficial , ecthymic , non healing ulcer . ** infection at other sites : Ear , eye , genital tract . * diagnosis : Culture of the specimens from nose & throat & mucocutaneous lesion . ** complications : Toxic cardiomyopathy : 10 – 25% of patients . First evidence c.r. occurs during 2nd & 3rd wk. of illness , as pharyngeal dis. Improves. Tachycardia out of proportion to fever is common . Prolonged PR interval o& changes in the ST – T wave on ECG. First , 2nd & 3rd degree heart block . H.F.may appear inosidiously or actuely . Recovery is usu. Complete . Toxic Neuropathy : Occur acutely or 2 – 3 wk. Local paralysis of soft palete occur . Weakness of post. Pharyngeal , laryngeal & facial n. Risk for aspiration . Symmetric polyneuropathy 10 d – 3m . Distal M. weakness . Complete nerologic recovery is likely .