The enzyme-linked immunosorbent assay (ELISA) was successfully applied to detect IgE antibodies against parasitic antigens by using an additional antibody layer to attain an amplification effect. The sera of 18 Gurkha patients with clinical manifestations of acute trichinosis and 35 Chinese with other parasitic infections were tested for antibodies to Trichinella spiralis by IgE-, IgM- and IgG-ELISA, IgG-radioimmunoassay (RIA) and indirect haemagglutination test (IHA). ELISAs for detection of IgE and IgM antibodies provided a 100% specific and sensitive diagnosis. Although IHA, IgG-RIA and IgG-ELISA detected antibodies in 94% of patients, non-specific reactions were also observed in the two last named methods. Muscle biopsies were positive in only 56% of patients.

Sera from 2,499 randomly selected Chinese inhabitants of Hong Kong were tested for the presence of Toxoplasma gondii antibodies using the indirect fluorescent antibody test. The over-all prevalence was 9.8%. The prevalence was significantly higher in the 10 to 19 and 30 to 39 year age group and the highest level of titres was found in the 20 to 29 group. There was no significant difference in prevalence between the male and female population and between the rural and city dwellers. The distinctly low prevalence of toxoplasmosis in Hong Kong can probably be attributed to the absence of cats in most domestic households and the preference of the people to eat well-cooked meat (commonly beef and pork).

Radiological investigations play an important role in the treatment course of patients with coronavirus disease 2019 and radiologists should be familiar with the imaging characteristics. Being an integral component of the healthcare system, radiology departments have made adaptations to enhance infection control and strengthen the service. In this article, we review the radiological features of COVID-19 on chest radiography and computed tomography, and share experiences on the adaptive approach of radiology departments amidst the COVID-19 pandemic.