The Radiologic Manifestations of H5N1 Avian Influenza

Abstract

Avian influenza is caused by the H5N1 subtype of the influenza A virus. Human transmission is either directly through close contact with infected birds usually poultry or their secretions. To date 178 people throughout South East Asia have been infected with 85 deaths. Patients usually present with a rapidly progressive pneumonia that can result in respiratory failure and acute respiratory distress syndrome. The chest radiograph therefore remains the most convenient and accessible imaging modality. Studies have shown that most radiographs are abnormal at the time of presentation with multifocal consolidation the commonest radiographic finding. During the course of disease, pleural effusions and cavitation can also develop. Consolidation that involves > or = 4 zones on presentation or at day 7 after the onset of symptoms and subsequent development of acute respiratory distress syndrome are generally associated with an adverse outcome. Chest CT examinations performed during the convalescent period have demonstrated persistent ground glass attenuation and segmental consolidation. Additional features included pseudocavitation, pneumatocoele formation, lymphadenopathy, and centrilobular nodules. Overall the appearances are suggestive of mild fibrosis.

Pulmonary imaging of pandemic influenza H1N1 infection: relationship between clinical presentation and disease burden on chest radiography and CT

“…In our cohort, consolidation was the most prevalent CXR finding of viral pneumonia, similar to most published studies of various viral influenzas [13][14][15][16]. Approximately 67% of the initial radiographs in our series were negative, similar to the 58% that were L Abbo, A Quartin and M I Morris et al negative in the H1N1 study of Agarwal et al [12].…”

“…Approximately 67% of the initial radiographs in our series were negative, similar to the 58% that were L Abbo, A Quartin and M I Morris et al negative in the H1N1 study of Agarwal et al [12]. Bay et al [16] described lower lobe predominance, but Qureshi et al [15] did not. Most patients in our study did not have a radiographic zonal predominance, but of the minority that did 81% were in the lower zone.…”

Karakteristik Klinis dan Epidemiologis Avian Influenza A (H5N1) Anak Di Indonesia, Tahun 2005-2007

“…30 Saat pertama datang pemeriksaan radiologis umumnya abnormal dengan gambaran konsolidasi unilateral atau bilateral, selama perjalanan penyakit dapat berkem bang menjadi efusi pleura dan kavitasi. 54,56 Konsolidasi yang mengenai lebih atau sama dengan 4 zona saat pertama datang atau 7 hari setelah awitan gejala dan adanya ARDS umumnya berhubungan dengan prognosis buruk. 56 Pemeriksaan CT dada yang dilakukan sesudah periode konvalesen menunjukkan persistent ground glass attenuation and segmental consolidation.…”

“…54,56 Konsolidasi yang mengenai lebih atau sama dengan 4 zona saat pertama datang atau 7 hari setelah awitan gejala dan adanya ARDS umumnya berhubungan dengan prognosis buruk. 56 Pemeriksaan CT dada yang dilakukan sesudah periode konvalesen menunjukkan persistent ground glass attenuation and segmental consolidation. Dapat juga terjadi pseudocavitation, pneumatocoele, lymphadenopathy, dan centrilobular nodules, secara keseluruhan diduga terjadi fibrosis ringan.…”

“…Dapat juga terjadi pseudocavitation, pneumatocoele, lymphadenopathy, dan centrilobular nodules, secara keseluruhan diduga terjadi fibrosis ringan. 56 Sangatlah bermanfaat untuk memulai terapi antiviral sedini mungkin, 30 oseltamivir dapat memperpendek masa sakit dan mengurangi lama perawatan apabila diberikan dalam 48 jam pertama sesudah awitan. [58][59][60][61] Sampai saat ini pengobatan oseltamivir dimulai segera setelah adanya dugaan infeksi H5N1.…”