Serological reactivity to a synthetic analog of phenolic glycolipid I and early detection of leprosy in an area of low endemicity.

A total of 23,863 individuals living in an area of low endemicity for leprosy were tested by enzyme-linked immunosorbent assay with a semisynthetic analogue of the phenolic glycolipid I antigen of Mycobacterium leprae. The proportion found positive was 3.86% which was significantly higher than that in a sample of a population known to be free of leprosy. Clinical examinations as well as Mitsuda and skin smear tests were organized for those defined as seropositive. The proportion of individuals with lepromin reactions of less than 3 mm increased 18.9% per serological interval as antibodies rose though it was not statistically significant. As a result of the clinical and bacteriological examinations, 2 cases with clinical signs and heavy bacillary load were found, whereas acid-fast bacilli were demonstrated in 2 other individuals without clinical manifestations of leprosy. The usefulness of the system for control purposes is discussed.

Survey for secondary dapsone and rifampicin resistance in Cuba.

A total of 1211 Cuban multibacillary leprosy patients treated for at least 5 years were clinically and bacteriologically examined. They were being treated according to a 2-phase monotherapy regimen with RMP first and DADDS afterwards. On skin-smear examination 50 patients were found positive, of which 9 showed a BI of 3+ or higher at any site. With regard to the clinical status the only cases found with clinical signs of relapse were 5 out of 7 long-standing patients with BI of 4+ and 5+. A 6th patient of this high BI group who showed a good clinical condition, except for a heavy infiltration of both earlobes, was receiving a second RMP course when examined and biopsied for this research. These 9 patients were biopsied and susceptibility tests to RMP and DDS performed. The results showed that in 1 case the Mycobacterium leprae were resistant to both drugs; the organisms from 2 other patients were susceptible to RMP but low-grade resistant to DDS. Those from another patient were susceptible to RMP and fully resistant to DDS. In 3 other cases the bacilli did not multiply in any of the mice but 1 of these strains was from the patient taking a second RMP course, therefore this strain might also be susceptible to RMP and resistant to DDS. In the last 2 cases multiplication was only observed in 2 of the controls and in 1 of the 0.0001% DDS treated mice; therefore, these experiments were not conclusive, and the AFB recovered were inoculated into fresh mice to repeat the tests but these failed to multiply.

Serodiagnosis of leprosy in patients' contacts by enzyme-linked immunosorbent assay.

Serum samples from 3336 contacts of leprosy patients were tested for antiphenolic glycolipid I antibodies by enzyme-linked immunosorbent assay with the albumin coupled synthetic disaccharide antigen. The overall positivity rate was 9.3%. No significant differences were seen between a group of household contacts of lepromatous patients and those of the other types of the disease. The proportion of ELISA positives was slightly higher in the relatives as compared to workplace contacts and neighbours but significantly different only between the two former (p less than 0.05). Among those contacts with absorbance values higher than 0.100, 5 new leprosy patients were diagnosed, 2 of them with positive skin smears. A sixth contact was detected with a very high absorbance value in whom no single skin lesion was found but whose lepromin reaction was 0 mm and the skin smear showed a bacteriological index of 3+.

[Monitoring of the treatment effectiveness in patients with leprosy using solid-phase immunoenzyme assay]. / Monitoreo de la eficacia del tratamiento en pacientes con lepra mediante el ensayo inmunoenzimático sobre fase sólida.

Serum samples from 184 lepers are studied by means of solid phase ELISA with the semisynthetic antigen disaccharide-bovine albumin analogous of phenolic glycolipid I of Mycobacterium leprae. Patients are grouped according to the clinical presentation of the disease and course of time elapsed since the institution of therapy. Bacilloscopic examinations were made also in 116 patients who were positive at diagnosis. For serologic testing, absorbance values over 0,160 were considered positive. Results in multibacillary patients showed a gradual and significant decrease both of mean absorbance values and in the seropositive ratio in connection with the length of treatment. It was also found that phenolic anti glycolipid antibodies increased with the value of the bacteriologic index. This system is useful in monitoring the effectiveness of chemotherapy in multibacillary leprosy.