Although smallpox has been eradicated, the pathogenesis of the disease (described here in the past tense) is instructive for other poxvirus infections.

The portal of entry of variola virus was the mucous mem branes of the upper respiratory tract. After viral entry, the following are believed to have taken place: (1) primary multiplication in the lymphoid tissue draining the site of entry; (2) transient viremia and infection of reticuloendothelial cells throughout the body; (3) a secondary phase of multiplication in those cells, leading to (4) a secondary, more intense viremia; and (5) the clinical disease.

In the preeruptive phase, the disease was barely infective. By the sixth to ninth day, lesions in the mouth tended to ulcerate and discharge virus. Thus, early in the disease, infectious virus originated in lesions in the mouth and upper respiratory tract. Later, pustules broke down and discharged virus into the environment of the smallpox patient.

Histopathologic examination of the skin showed proliferation and cytoplasmic inclusions of the stratum spinosum. There was infiltration with mononuclear cells, particularly around dermal vessels. Epidermal cells became swollen through distention of cytoplasm and underwent “ballooning degeneration,” with enlargement of cytoplasmic vacuoles. The cell membrane broke down and coalesced with neigh boring, similarly affected cells, resulting in the formation of vesicles. The vesicles enlarged and then became filled with white cells and tissue debris. All of the layers of the skin were involved, with subsequent dermal necrosis. Thus, scarring occurred after variola infection. Similar histopathology is seen with vaccinia, although vaccinia virus ordinarily causes localized pustular lesions only at the site of inoculation.

اخر الاخبار

اخبار العتبة العباسية المقدسة

أكاديمية التطوير الإداري تنظّم دورة في اللغة الفارسية لعدد من ملاكات العتبة العباسية المقدسة

استعدادًا لافتتاحه.. المشرف على قسم الشؤون الطبية يجري جولة في مركز السيد جعفر الحلي للخدمات الطبية.

الهيأة العليا لإحياء التراث تقيم الدورة العلمية التخصصية لكتاب في رحاب العقيدة

سماحة السيد الصافي يؤكد ضرورة تنمية الموارد المالية لدائرة التقاعد الوطنية وتعظيمها

المزيد

الآخبار الصحية

العلاج بالماء البارد.. باحثون يكشفون فوائده الصحية

من دون صالة رياضية.. عادة بسيطة لتحسين الصحة وخسارة الوزن

لصحة القلب وتفادي السرطان.. استهلك هذا النوع من الطعام

دراسة تحذر من خطر شرب القهوة في أكواب البلاستيك

المزيد

الآخبار التكنلوجية

إنجاز طبي تاريخي.. جراحة قلب بلا شق في الصدر

اليابان.. مراحيض توفر فحص للحالة الصحية عبر "تحليل البراز" !

اختراق واسع لمنصة "إنستغرام".. ونشر بيانات على "الدارك ويب"

علماء يحذرون: هكذا سيفنى كوكب الأرض

المزيد

مواضيع ذات صلة

Replication of Retroviruses

Classification of Retroviruses

Interactions of Tumor Viruses with Their Hosts

PAPILLOMAVIRUSES

General Features of Viral Carcinogenesis

Immunity and Prevention of Rabies Virus

Methods of Antiviral Susceptibility Testing: Influenza

Methods of Antiviral Susceptibility Testing: Genotypic Susceptibility Assays

Methods of Antiviral Susceptibility Testing: Phenotypic Assays

Pathogenesis and Pathology of Rabies Virus

Properties of the Rabies Virus

Coronavirus Infections in Humans