Depression of erythrocyte glucose-6-phosphate dehydrogenase (G6PD) activity in enteric fever

Ninety adult Indian typhoid and paratyphoid fever (enteric fever, EF) patients and 91 controls were tested for glucose-6-phosphate dehydrogenase (G6PD) deficiency using the fluorescent spot test (FST) and the quantitative methaemoglobin reduction test ( QMRT ). There was a threefold higher incidence of G6PD deficiency in North Indian EF patients (10.6%) than in controls (3.6%) (P = 0.15) which may be attributable to the greater morbidity of the G6PD-deficient EF patients; six of nine had haemolytic anaemia. A transient depression of mean erythrocyte G6PD activity was observed in a subgroup of 49 non-deficient EF patients in whom the spectrophotometric G6PD assay was done. It did not appear to be related to reticulocyte count, chloramphenicol therapy, or differences in leucocyte contamination of the haemolysate used for the G6PD assay. If this depression of G6PD activity occurs in deficient patients as well, it may help to explain the haemolysis seen in them during EF. Of the three tests used, the QMRT and the spectrophotometric assay clearly identified G6PD deficiency in males during haemolysis, whereas the FST was unreliable in this situation.