Schistosomiasis Japonica in American Military Personnel: Clinical Studies of 600 Cases during the First Year after Infection

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Abstract
Summary and Conclusions 1. Water centrifugal sedimentation is a simple rapid method of stool examination for detecting eggs of Schistosoma japonicum in the stools of infected patients. 2. This method requires no chemical reagents and only a minimum amount of standard laboratory equipment. 3. In our experience it was more efficient than direct smear examination of stool material free of grossly visible bloody mucus, or examination by acid-ether, zinc sulfate, or brine flotation. Viability of eggs found after treatment can be determined. 4. Direct smear examination of mucus present in some stools revealed a high percentage of positives for S. japonicum in such material. Occasionally, trophozoites of E. histolytica were also found in this material. 5. Water centrifugal sedimentation done repeatedly in the course of the diagnosis of suspected schistosomiasis or for evaluation of specific therapy will frequently detect the presence of other protozoa and helminths in addition to S. japonicum. 6. In our experience in these studies the stool method of choice in the study of schistosomiasis japonica patients was as follows: (a) Careful visual examination of the gross stool for the presence of bloody mucus. Direct smear examination of this material if present. (b) Water centrifugal sedimentation of all specimens not containing grossly visible bloody mucus and specimens negative by direct smear of bloody mucus if present. (c) Routine zinc sulfate and brine flotation for the detection of protozoa and helminths other than S. japonicum which may or may not be found by water centrifugal sedimentation, and which may be present in a high percentage of patients under observation for schistosomiasis japonica. 7. From 20 to 30 stool examinations during a period of 4 to 6 weeks were required to detect light asymptomatic infections in a group of patients exposed on Leyte. Eggs had not been detected previously in any of these individuals and none had received treatment. 8. Stool examinations should be begun 30 days after completion of treatment and continued for 8 to 10 weeks, 3 stools weekly. Most treatment failures are discovered from 5 to 12 weeks after completion of therapy with fuadin or tartar emetic. In the interval between these studies at Moore General Hospital and the present, numerous techniques have been introduced which were designed to increase the probability of detecting eggs of schistosomes. These methods are critically evaluated in a recent review by Stoll (37). In follow-up studies of schistosomiasis japonica in veterans and prisoners of war subsequently to be reported we have carried out most of these techniques. The method we now use is a combination of alcohol sedimentation, (38) hatching, and treatment of the alcohol sediment with ether, hydrochloric acid, sodium sulfate and Triton NE. (39). Summary and Conclusions (1) An analysis was made of 315 electrocardiograms taken on 100 patients during various stages of treatment with tartar emetic and fuadin for schistosomiasis infection. (2) Eleven per cent of the patients showed an increased amplitude of P-waves in leads II and III. (3) Forty-five per cent of the patients showed a fusion of S-T segment and T-waves. (4) Ninety-nine per cent of the patients showed varying degrees of decrease in amplitude of T-waves in all leads resulting in deep inversion in many cases. This change was more pronounced during tartar emetic treatment than during fuadin treatment. (5) The Q-T interval was prolonged beyond the limits of normal in 27 per cent of the patients in this study. (6) The etiology and significance of these changes is unknown. It is our opinion that they represent a transient side action of antimony not indicative of cardiac damage or serious impairment of cardiac function. (7) Recent antimony therapy must be considered in evaluating abnormal EKG's found in veterans. C) Effect of Treatment on the Intradermal Antigen Test. As previously noted, one of the main purposes in conducting tests with the intradermal cercarial antigen was an attempt to evaluate cases which had been previously diagnosed as having schistosomiasis and who had been treated before they reached this hospital. In a group of 57 men who had been reported to have positive stools overseas, but in whom repeated stool examinations were negative, 23 or 40 per cent had a positive skin test. In examining these cases an attempt was made to correlate this observation with the amount of treatment each group had received. It was found that the group with positive skin tests had had an average of 61 cc. of fuadin, while the negative group had an average of 48 cc., a difference of no statistical significance. The length of time which had elapsed between the last date of treatment and the skin test was of no significant difference either, it being an average of 6.6 months in the positives and 6.1 months in the negatives. This observation was of considerable interest in view of the statement made by Culbertson (78) that “positive skin reactions persist for years after the need for treatment is ended.” In our experience, the skin test with 1:5000 dilution became negative in at least 60 per cent of proven cases within 6 months after completion of successful therapy. It is of interest in this connection that Alves and Blair (58) recently reported that 85 per cent of a group of 53 patients treated intensively for S. haematobium and S. mansoni infections developed negative skin tests to cercarial antigen two to three months after completion of successful treatment. The proper evaluation of the treatment given patients with schistosomiasis japonica presents many difficulties in view of the fact that a single course o treatment is frequently found to be insufficient, and because of the necessity for repeated stool examinations to determine whether or not therapy has been adequate. It would, therefore, be of considerable value if a simple means could be found to determine the...

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