Entomological surveillance is one of the tools used in monitoring and controlling vector-borne diseases. However, the use of entomological surveillance for arboviral infection vector control is often dependent on finding infected individuals. Although this method may suffice in highly endemic areas, it is not as effective in controlling the spread of diseases in low endemic and non-endemic areas. In this study, we examined the efficiency of using entomological markers to assess the status and risk of arbovirus infection in Ghana, which is considered a non-endemic country, by combining mosquito surveillance with virus isolation and detection. This study reports the presence of cryptic species of mosquitoes in Ghana, demonstrating the need to combine morphological identification and molecular techniques in mosquito surveillance. Furthermore, although no medically important viruses were detected, the importance of insect-specific viruses in understanding virus evolution and arbovirus transmission is discussed. This study reports the first mutualistic relationship between dengue virus and the double-stranded RNA Aedes aegypti totivirus. Finally, this study discusses the complexity of the virome of Aedes and Culex mosquitoes and its implication for arbovirus transmission.

A 66-year-old woman was referred to our hospital because of an incidental finding of a 50 mm mass in the lower lobe of the left lung with liver and lymph node metastases. Lymph node biopsy revealed mucinous adenocarcinoma. Chemotherapy was initiated, which markedly reduced the tumor size. Two months after starting chemotherapy, she developed dysphagia. A plain computed tomography scan revealed circumferential and concentric wall thickening of the lower esophagus adjacent to the lung tumor (Figure 1). Endoscopy showed stenosis in the lower esophagus with apparently normal overlying mucosa (Figure 1). Endoscopic ultrasound revealed a submucosal cystic lesion measuring 30 mm in diameter with an irregular septum (Figure 1). Fine-needle aspiration was performed for diagnosis, which also helped to reduce the volume of cystic fluid, thereby improving the esophageal stricture. Histology revealed adenocarcinoma with intracytoplasmic mucin (Figure 2). Immunohistochemistry staining showed abundant CK7 and HNF4a, consistent with invasive mucinous adenocarcinoma, suggesting esophageal metastasis from the lung tumor (Figure 2). Metastatic esophageal tumor is relatively rare, and most metastatic esophageal tumors take the form of submucosal solid tumors. [1][2][3][4] To the best of our knowledge, this is the first case of submucosal metastasis of invasive mucinous adenocarcinoma retaining mucin producibility. DISCLOSURESAuthor contributions: S. Kimura and M. Kobayashi drafted the article equally. I. Onishi provided the pathological diagnosis and assisted in preparation of the manuscript. M. Kobayashi supervised the article. The final version of the manuscript was approved by all authors. M. Kobayashi is the article guarantor. Figure 1. Computed tomography and endoscopic ultrasound images. (A) Computed tomography revealed circumferential and concentric wall thickening in the lower esophagus adjacent to the lung tumor. (B) The endoscopic view of the lower esophagus showing stenosis with apparently normal overlying mucosa. (C) Endoscopic ultrasound showed a submucosal cystic lesion measuring 30 mm in diameter with an irregular septum.

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