Author(s): Denning DW, Quiepo SC, Altman DG, Makarananda K, Neal GE
Aflatoxin is immunosuppressive in experimental conditions. This study addressed its potentially contributory role in the poor outcome of acute lower respiratory infections (ALRI) in children in The Philippines. The catchment area included peri-urban slums and middle-class housing. One hundred and fifteen children (mean age 2.1, range 0.08-12 years) were enrolled and their serum and urine obtained at presentation with ALRI. Aflatoxins in serum and aflatoxin metabolites in urine were measured by previously validated ELISA tests. Using the 1986 WHO criteria for the severity of ALRI, 31% had mild, 12% moderate, 49% severe and 8% severe complicated pneumonia. Eighty of 97 (82%) chest radiographs were abnormal. Ninety per cent of the children were below average weight for age, using Filipino standards, with a mean of 79% (range 27-157%). Thirteen (11%) children died. Aflatoxin in their serum, reflecting recent ingestion, was detected in 33%, with a mean positive value of 462 pg/ml. Aflatoxin metabolites (reflecting chronic ingestion) were detected in 64 of 65 urines collected, with a mean value of 0.1-4.77ng/ml. None of the children with detectable serum aflatoxin died. Anorexia and impaired consciousness were strongly associated with a poor outcome (prolonged fever or death). There was a strong association between undetectable serum aflatoxin concentrations and death (p = 0.004), perhaps reflecting anorexia. There was no relationship between the concentration of urinary aflatoxin metabolites and outcome. Serum was also obtained from 29 mothers on admission and none contained detectable aflatoxin. As virtually all the children had evidence of exposure to aflatoxin, a potentially immunosuppressive role in the context of pneumonia cannot be excluded. PIP: Between December 1986 and January 1987 at the Research Institute for Tropical Medicine, a small hospital serving inhabitants of peri-urban slums and middle-class housing in Alabang, the Philippines, clinical researchers measured aflatoxin in the serum and urine of 115 children aged less than 13 who had a cough for less than three weeks (i.e., acute lower respiratory infection [ALRI]). They wanted to learn whether consumption of aflatoxin found in many foods in the Philippines could increase ALRI-related mortality among Filipino children. Almost all 115 children had probably been exposed to aflatoxin. 59% were admitted to the hospital. 11% of the hospitalized children died. No child died among those not admitted to the hospital. 73% of all children were severely malnourished. 82% had abnormal chest radiographs. 49% had severe ALRI, 31% mild ALRI, 12% moderate ALRI, and 8% severe-complicated ALRI. 67% of the children and none of the mothers had no detectable aflatoxin in their sera. The mean and median aflatoxin levels in the positive sera were 462 and 140 pg/ml, respectively (range, 20-5600 pg/ml). 64 of 65 sera had some aflatoxin metabolites (0.1-4.77 ng/ml). The mean aflatoxin metabolite/creatinine ratio was 1.27 (range, 0.19-4.43). Undetectable serum aflatoxin was associated with death (p = 0.006). Both anorexia and impaired consciousness level were significantly associated with death (p 0.001). The concentration of urinary aflatoxin metabolites had no apparent effect on outcomes. These findings do not support the hypothesis that aflatoxin acts as an immunosuppressant. Since almost all children tested had aflatoxin metabolites (indicating recent ingestion of aflatoxin), however, the researchers could not exclude aflatoxin's role as a potential immunosuppressant.