Immunity after treatment of human schistosomiasis mansoni. III. Long-term effects of treatment and retreatment

Group mean Schistosoma mansoni reinfection patterns are presented for 2 years after treatment with oxamniquine in 1981 of over 100 9- to 16-year-old Kenyan schoolchildren, and for one year after retreatment in 1983 with either oxamniquine or praziquantel when most (nearly 700) infected people in the whole community were treated. Quality control confirmed comparable Kato egg counts throughout the study. Continuing transmission after 1981 raised prevalence to nearly its original level within 6 months, but intensity remained suppressed throughout the 2 year follow-up and very few children reacquired heavy infections (greater than 400 eggs/g). Age and sex had significant effects: reinfection diminished with age, especially among boys--a pattern not apparently attributable to differential water contact. Children with heavy pretreatment infections tended to develop heavy reinfections but this trend was not statistically significant on a group basis, nor were similar trends during the period of less pronounced transmission following the 1983 community treatment. Oxamniquine was equally effective in children receiving it in both 1981 and 1983, and the efficacy of praziquantel resembled that of oxamniquine. In this area of Kenya, repeated chemotherapy will be needed to contain transmission, probably annually or biennially, unless supplemented with other, effective control measures. These findings confirm the beneficial effects of treating even a limited segment of a community at intervals of a year or more without necessarily stopping transmission. They are also compatible with recent findings on potential immune mechanisms in man.     

Abnormal biochemical and cellular parameters in the blood of patients with Raynauds phenomenon

Finger blood flow is decreased in Raynauds Phenomenon (RP). This may be due not only to vasospasm, but also to blood abnormalities. 40 patients with Raynauds Disease (RD), 28 with suspected RP (SS) and 42 with secondary Raynauds syndrome (RS) were enrolled and compared to 50 controls. Results from base-line samples show that those with RP have abnormal haemostasis and rheology whereas those with mild Raynauds, RD do not. Blood sampled after cold challenge in 15 RS patients and 15 controls show that both groups exhibit platelet activation after emersion. The degree of activation however was much more marked in the RS patients. We have shown that abnormalities of haemostasis and rheology are found in patients likely to have endothelial damage (RS). These changes are probably a consequence rather than a cause of the disease. After cold challenge the results become more abnormal and correlate with severity of disease.     

Diagnostic tests for Helicobacter pylori: comparison and influence of non-steroidal anti-inflammatory drugs.

AIMS: To evaluate the efficacy of culture, histology, CLO-test, Helico-G and Pyloriset tests in diagnosing Helicobacter pylori in the presence or absence of non-steroidal anti-inflammatory drugs (NSAIDs). METHODS: Of 134 patients studied, 75 had taken NSAIDs. At endoscopy, biopsy specimens were taken for culture, histology, and CLO-test. Blood was also taken for enzyme linked immunosorbent assay (ELISA) (Helico-G) and latex agglutination (Pyloriset) tests. RESULTS: The sensitivity, specificity, and predictive values of histology and CLO-test, compared with culture, ranged from 90% to 97%, regardless of NSAID intake. In the 59 patients not taking NSAIDs Helico-G had a sensitivity of 75% (p < 0.05) and a specificity of 61%; Pyloriset's sensitivity and specificity were, respectively, 63% (p < 0.05) and 67%. In the 75 patients taking NSAIDs the sensitivity of Helico-G was 81% and its specificity 45% (p < 0.05); Pyloriset had a sensitivity of 61% (p < 0.05) and a specificity of 50% (p < 0.05). CONCLUSION: These findings suggest that H pylori is more reliably diagnosed by culture, histology, and CLO-test than by the serological tests used in this study, especially in patients treated with NSAIDs.     

A classification for dry eyes following comparison of tear thinning time with Schirmer tear test.

In a double-blind study a non-invasive method of examining the stability of the precorneal tear film was used to record tear thinning time on a population of 34 independently diagnosed dry eye patients. The results were compared with those for tear output, as inferred from the standard Schirmer tear test, and a correlation coefficient of 0.20 determined. The mean tear thinning time and Schirmer results for the population sample were 6.87 +/- 2.97 sec, and 5.62 +/- 5.69 mm wetting in 5 min, respectively. From a plot of tear thinning time against Schirmer a simple classification for dry eyes can be made. A Type A with normal tear stability and low output accounting for 14.70% of the dry eyes. A Type B with low tear stability and normal output, also accounting for 14.70% of the dry eyes. A Type C with low stability (less than 9.84 sec), and low output (less than 11.31 mm wetting in 5 min) accounting for 70.60% of the dry eyes.