Possible case scenarios and logistic issues in H5N1 pandemic

Respiratory infections unique to Asia

Asia is a highly heterogeneous region with vastly different cultures, social constitutions and populations affected by a wide spectrum of respiratory diseases caused by tropical pathogens. Asian patients with community‐acquired pneumonia differ from their Western counterparts in microbiological aetiology, in particular the prominence of Gram‐negative organisms, Mycobacterium tuberculosis, Burkholderia pseudomallei and Staphylococcus aureus. In addition, the differences in socioeconomic and health‐care infrastructures limit the usefulness of Western management guidelines for pneumonia in Asia. The importance of emerging infectious diseases such as severe acute respiratory syndrome and avian influenza infection remain as close concerns for practising respirologists in Asia. Specific infections such as melioidosis, dengue haemorrhagic fever, scrub typhus, leptospirosis, salmonellosis, penicilliosis marneffei, malaria, amoebiasis, paragonimiasis, strongyloidiasis, gnathostomiasis, trinchinellosis, schistosomiasis and echinococcosis occur commonly in Asia and manifest with a prominent respiratory component. Pulmonary eosinophilia, endemic in parts of Asia, could occur with a wide range of tropical infections. Tropical eosinophilia is believed to be a hyper‐sensitivity reaction to degenerating microfilariae trapped in the lungs.

This article attempts to address the key respiratory issues in these respiratory infections unique to Asia and highlight the important diagnostic and management issues faced by practising respirologists.

Allogeneic stem cell transplantation with T cell-depleted grafts for lymphoproliferative malignancies

In non-Hodgkin lymphoma allogeneic stem cell transplantation (SCT) can be curative, but with standard dose conditioning patients may have substantial morbidity and mortality from graft-versus-host disease (GVHD); for aggressive malignancies, reduced intensity conditioning may result in higher recurrence. Patients with advanced follicular lymphoma (n = 12), transformed B cell malignancy (n = 11), and non-CD30+T cell lymphomas (n = 17) responsive to chemotherapy who had an HLA-identical sibling were offered T cell depleted (CAMPATH-1 G or H antibodies) SCT. Conditioning was with ablative doses of chemotherapy or radiotherapy. Before SCT, patients with follicular lymphoma had a median of 3 treatment courses, and those with transformed B cell and those diagnosed with T cell non-Hodgkin lymphoma had 2 (range, 1-3). At SCT the median age was 46 years (range, 21-59 years) and the number of CD34+ cells infused was 2.85 x 10(6)/kg. All patients showed engraftment but 7 patients (17.5%) developed GVHD. In total 12 subjects expired of transplant-related causes (n = 6) or from disease recurrence. One-year transplant-related mortality was 15%. There was no difference in survival across diagnostic groups. At a median of 1051 days, 70% survived and 68% are without disease. By reducing the incidence and severity of GVHD, patients can tolerate myeloablative doses of chemotherapy satisfactorily. This has resulted in low treatment-related mortality and adequate protection from disease recurrence.