شلل الاطفال "Polioviruses "Poliomyelitis

Microstudy (Microbiology lectures) Clinical virology قناة متخصصه لشرح مادة الميكروبيولوجي والمناعة لجميع طلبة الكليات العمليه لينك حساب الفيسبوك للتواصل والاستفسار https://www.facebook.com/profile.php?... شلل الأطفال هو مرض يسببه فيروس يؤثر بشكل رئيسي على الحبل النخاعي أو جذع المخ. ويمكن لشلل الأطفال في أشد حالاته تفاقمًا أن يؤدي إلى فقدان القدرة على تحريك أطراف معينة. كما قد يؤدي إلى صعوبة في التنفس، وفي بعض الأحيان إلى الوفاة. ويُعرف هذا المرض أيضًا بالتهاب سنجابية النخاع. Polioviruses They cause poliomyelitis, which in its full blown picture affects the CNS, destroys the motor neurons in the spinal cord, causing flaccid paralysis. The infection causes muscle weaknesses leading to inability to move or walk In severe conditions, polio may cause paralysis and death. Fortunately, most poliovirus infections are subclinical. Pathogenesis and Clinical Findings Mode of Infection: Infection occurs by the ingestion of food or drink contaminated by stools ,Fecal–oral route of cases or carriers. It replicates in the oropharynx and intestinal tract. Incubation period is 7-14 days. Outcome of infection ,Clinical Findings 1.Inapparent infection :The organism multiplies in the oropharynx (Tonsils) and the Payer's patches in the intestine and it is excreted in the stool and Infection may stop at this stage 2.Abortive infection :Infection may continue and the virus passes to the deep cervical and deep mesenteric lymph nodes. Then it invades the blood stream. Viraemia is associated with mild symptoms of fever, malaise, headache, nausea, and vomiting. The disease may be stopped at this stage 3. Non paralytic poliomyelitis ,Aseptic meningitis: when occurs; it is manifested by stiffness and pain in the back and neck. Usually recovers but may progress to paralysis. 4. Paralytic poliomyelitis: occurs only in 0.1-1% of cases. The virus affects the anterior horn cells of the spinal cord . Death of the neurons cells results in paralysis of the muscles innervated by those neurons→ flaccid paralysis #شلل #شلل_الاطفال #poliomielite #poliovaccine #virology #sabine #OPV #vaccine #vaccination #microbiology