Pathogen Risk Analysis for Wild Amphibian Populations Following the First Report of a Ranavirus Outbreak in Farmed American Bullfrogs (Lithobates catesbeianus) from Northern Mexico.

Ranaviruses are the second deadliest pathogens for amphibian populations throughout the world. Despite their wide distribution in America, these viruses have never been reported in Mexico, the country with the fifth highest amphibian diversity in the world. This paper is the first to address an outbreak of ranavirus in captive American bullfrogs (Lithobates catesbeianus) from Sinaloa, Mexico. The farm experienced high mortality in an undetermined number of juveniles and sub-adult bullfrogs. Affected animals displayed clinical signs and gross lesions such as lethargy, edema, skin ulcers, and hemorrhages consistent with ranavirus infection. The main microscopic lesions included mild renal tubular necrosis and moderate congestion in several organs. Immunohistochemical analyses revealed scant infected hepatocytes and renal tubular epithelial cells. Phylogenetic analysis of five partial ranavirus genes showed that the causative agent clustered within the Frog virus 3 clade. Risk assessment with the Pandora⁺ protocol demonstrated a high risk for the pathogen to affect amphibians from neighboring regions (overall Pandora risk score: 0.619). Given the risk of American bullfrogs escaping and spreading the disease to wild amphibians, efforts should focus on implementing effective containment strategies and surveillance programs for ranavirus at facilities undertaking intensive farming of amphibians.

Clinicopathologic Features of Hydroa Vacciniforme-Like Lymphoma: A Series of 9 Patients.

Hydroa vacciniforme-like lymphoma is a recently recognized cutaneous T-cell lymphoma associated with Epstein-Barr virus. The disease is observed in children of Latin American or Asian ethnicity. The authors report the clinical, histopathological, and immunophenotypical features of 9 new Mexican patients (M:F = 2:1; mean age, 14.5 years; median age, 13.3 years; age range, 4-27 years), expanding on previous observations of this elusive disease. The most common clinical aspects were persistent facial edema with necroses and pitted scars. Histopathological analyses revealed variably dense lymphoid infiltrates with common angiodestructive features. Neoplastic cells expressed CD3 and cytotoxic markers in all cases and were constantly positive for Epstein-Barr virus (EBER-1). Expression of other markers was variable. Follow-up data revealed that all patients died within 6 months or less, thus showing a very aggressive course with poor prognosis.

Hydroa vacciniforme-like lymphoma with primarily periorbital swelling: 7 cases of an atypical clinical manifestation of this rare cutaneous T-cell lymphoma.

Hydroa vacciniforme-like lymphoma (HVL) is a rare cutaneous T-cell lymphoma that is usually seen in children of Hispanic or Asian origin. Association between chronic latent Epstein-Barr virus infection in both hydroa vacciniforme (HV) and HVL has been demonstrated and has recently been categorized by the World Health Organization as one of the Epstein Barr virus-positive lymphoproliferative disorders of childhood. Patients with HVL present with a cutaneous rash characterized by edema, blisters, ulcers, and scars mainly seen on the face and extremities that mimic HV; however, unlike in HV, the lesions tend to be extensive and deeper and are associated with severe scarring, necrosis, and systemic manifestations. We are reporting 7 cases of an unusual clinical variant of HVL with primarily periorbital edema. All of our patients in this series presented with progressive periorbital edema that was accompanied with systemic symptoms including fever, malaise, and lymphadenopathy. Most cases were initially misinterpreted as inflammatory processes including cellulitis, arthropod bite reactions, and periorbital lupus erythematosus. The biopsy of these lesions revealed an atypical lymphocytic infiltrate predominantly distributed in the deep dermis and in subcutaneous fat. Immunohistochemistry studies revealed a cytotoxic T-cell (CD8) profile. All cases were associated with Epstein-Barr virus infection. Our study presents a rare clinical variant of HVL with predominant periorbital edema. This variant could potentially be overlooked and misdiagnosed as an inflammatory condition; thus, it needs to be included in the differential diagnosis of periorbital edema in young patients.