HSV-2-infected individuals are at higher risk for acquiring HIV when practicing unprotected sex with HIV-positive persons, in particular during an outbreak with active lesions. Epidemiology
Worldwide rates of either HSV-1 and/or HSV-2 are between 60 and 95% in adults. HSV-1 is more common than HSV-2, with rates of both increasing as people age. HSV-1 rates are between 70% and 80% in populations of low socioeconomic status and 40% to 60% in populations of improved socioeconomic status. An estimated 536 million people or 16% of the population worldwide were infected with HSV-2 as of 2003 with greater rates among women and in those in the developing world. Rates of infection are determined by the presence of antibodies against either viral species.In the US, 58% of the population is infected with HSV-1 and 16% are infected with HSV-2. Among those HSV-2-seropositive, only 19% were aware they were infected. During 2005–2008, the prevalence of HSV-2 was 39% in blacks and 21% in women.The annual incidence in Canada of genital herpes due to HSV-1 and HSV-2 infection is not known (for a review of HSV-1/HSV-2 prevalence and incidence studies worldwide, see Smith and Robinson 2002). As many as one in seven Canadians aged 14 to 59 may be infected with herpes simplex type 2 virus and more than 90 per cent of them may be unaware of their status, a new study suggests.
Several systemic illnesses have been associated with plastic bronchitis:
Cardiac: constrictive pericarditis, congenital heart disease
Pulmonary: asthma, allergic bronchopulmonary aspergillosis, aspergillosis, bronchiectasis, cystic fibrosis, tuberculosis, pneumonia, and bronchocentric granulomatosis
Disorders of lymphatic drainage: lymphangiectasia, lymphangiomatosis
Miscellaneous: acute chest syndrome/sickle cell disease, amyloidosis, rheumatoid arthritis, membranous colitis, inhaled irritants, neoplastic (lymphoma)The most common form of plastic bronchitis follows cardiac surgery for congenital heart disease, especially the Fontan procedure. Systemic blood flow is diverted to pulmonary flow, elevating pressures in the pulmonary venous system, and promoting leaks of proteinaceous and lipid-rich fluids from the lymphatics into the bronchial tree. Diagnosis
The diagnosis of plastic bronchitis is confirmed by recovery of casts that have been coughed up or visualized during a bronchoscopy. There is no specific cytologic, pathologic or laboratory test that is diagnostic for casts due to lymphatic PB. Imaging
Simple chest X-rays may reveal collapse due to airway obstruction. The contralateral lung may be hyperinflated. Casts can be visualized within the major airways using computerized axial tomography scans.Heavy T2-weighted MRI, and, as appropriate, intranodal lymphangiogram and/or dynamic contrast-enhanced MR lymphangiography may be useful for identifying pathological lymphatic tissue or lymphatic flow. Management
Acute therapy for PB is often focused on removal or facilitated expectoration of the casts. This is followed by short and long term efforts to identify and remediate the underlying condition resulting in the excessive airway leakage or inflammation that is causing the casts to form.PB can present as a life threatening emergency when the casts obstruct the major airways resulting in acute respiratory distress.