Follow-up of multibacillary leprosy patients using a phenolic glycolipid-I-based ELISA. Do increasing ELISA-values after discontinuation of treatment indicate relapse?

With the introduction of reproducible serological tests it was hoped that relapses in leprosy patients, after discontinuing treatment, could be detected before damaging reactions occurred and before the patients became infectious. The possible value of an ELISA using a semisynthetic analogue of phenolic glycolipid-I to detect antibodies to this antigen in order to predict a relapse in multibacillary patients was investigated. In contrast to that reported for paucibacillary patients, this test was useful to detect early relapses in multibacillary patients. In 3 out of 4 multibacillary patients who relapsed, the ELISA-values were increased. The decreased ELISA-values in the one relapsed patient could be attributed to the corticosteroid therapy. In the multibacillary patients who did not relapse after RFT, the ELISA-values were consistently low or decreased. In only one patient did the ELISA-values increase following his release from treatment and this patient was clinically suspected of developing a relapse.

Vitamin A status of pregnant and lactating women as assessed by serum levels in Machakos area, Kenya.

PIP: In a sample of 100 pregnant and 106 lactating women, the serum levels of vitamin A, carotene, retinol-binding protein (RBP), and pre-albumin (PA) were analyzed. The study was in response to the problem of inadequate hepatic reserves and serum vitamin A levels of newborns. On the presumption that these levels are related to the Vitamin A status of mothers during pregnancy, and the Vitamin A content of breast milk during lactation, attention was given to the Vitamin A status of pregnant and lactating women in studies of maternal and child nutrition in Machakos. The women were selected at random from the total population of pregnant and lactating women with infants of 0-12 months. Blood was taken before the midday meal, centrifuged, and sera were deep frozen. Mean serum levels of the 4 biochemical parameters of vitamin A status were in the range for well-nourished population groups. Correlations of r=0.76-0.85 were found between RBP and PA, but between Vitamin A and RBP the correlation was r=0.32-0.40. Some seasonal variations reflected crop availability. A review of very little available literature shows that Vitamin A status of lactating women in Ethiopia is poorer among less privileged women. Dietary intake of retinol equivalents in West African countries being adequate, reported serum levels in these countries are also generally adequate. Xerophthalmia among young children in Machakos is rare, with the possible explanation that seasonal intake of carotene-rich foods is enough to replenish liver stores, and protein status (RBP and PA serum levels) is adequate as well.^ieng

Immunochemical characterization of Mycobacterium leprae antigens by the SDS-polyacrylamide gel electrophoresis immunoperoxidase technique (SGIP) using patients' sera.

In this study the SDS-polyacrylamide gel electrophoresis immunoperoxidase (SGIP) assay was used for characterizing the antigenic components of Mycobacterium leprae using patients' sera. This technique involved the separation of mycobacterial sonicates on SDS-polyacrylamide gels, longitudinal sectioning of the gels, incubation with patients' sera and visualization of the antigen-antibody complexes by the indirect immunoperoxidase technique. A number of antigens present in M. leprae sonicates were recognized by leprosy patients' sera, some of which were seen in other mycobacteria as well. Antibody binding to a 33 kD antigen, present in both M. leprae and BCG sonicates, was reduced only in the latter after 6 months of multiple drug treatment of one patient. It is suggested that this is a common mycobacterial antigen with one or more M. leprae specific determinants. Several antigens were identified only in M. leprae sonicates, only by leprosy patients: a 12, 22, 28, 36, 41 and 86 kD component. These antigens lost their antigenicity after trypsin treatment, but were heat stable. Such M. leprae specific antigens may be useful for immunodiagnosis.

Agents affecting health of mother and child in a rural area of Kenya. X. Haemagglutination inhibiting antibodies against influenza A (H3N2) and influenza B virus in sera from children living in the Machakos District of Kenya.

In the framework of the Machakos Project bloodcollections from random samples of children under 5 years of age and living in a rural area of Kenya were done with regular intervals, Serum samples of two collections were tested for haemagglutination inhibiting antibodies against influenza A and B viruses. The children had been exposed to the Hong Kong/1/68 (H3N2) virus or its variants during one, two or three episodes of circulation and probably to only one epidosde of B/Hong Kong/8/73 virus. The results can be explained by the assumption that 30-40 percent of non-immune children were infected per epidosde of exposure to influenza A and not more than 12 percent per episode of influenza B circulation.

Poliomyelitis: epidemiology and prophylaxis. 5. Results of a two- and three-dose vaccination experiment.

In tropical countries, seroconversion rates following oral poliomyelitis vaccination are frequently unsatisfactory. In an area of the Machakos district in Kenya, 4000 children under 5 years of age have been registered and are visited fortnightly by trained field staff as part of a comprehensive, population-based, longitudinal surveillance project. It was considered possible that poliomyelitis vaccine, given orally to children twice or three times at home, would produce satisfactory conversion rates. After collection of blood from a random sample of the children, vaccine was given twice to all children under 5 years of age. Blood was then collected a second time from a different sample of children. After a third dose of vaccine, a third blood collection followed. The percentages of the children that received vaccine each round were calculated and the sera tested for antibodies. It appeared that the mean titre was more strongly related to age than to the number of doses of poliomyelitis vaccine received. Improvement of herd immunity after two vaccine distributions was significant for a few age groups and for two types of vaccine only. In none of the groups was a significant improvement obtained by the third vaccine distribution. The problems associated with vaccination by live poliomyelitis vaccine in tropical countries are discussed in relation to the results.