Are opportunities for vitamin A supplementation being utilised at primary health-care clinics in the Western Cape Province of South Africa?

OBJECTIVES: To determine missed opportunities and problems relating to implementation of the Vitamin A Supplementation Programme in urban and rural regions of the Western Cape Province of South Africa.MethodA cross-sectional survey was conducted at primary health-care (PHC) clinics in Cape Metropole, an urban region, and West Coast Winelands, a rural region, of the Western Cape. A purposive sample of clinics where more than 30 children were seen per day was drawn from 10 of the 11 districts in the Cape Metropole region and the two districts of the West Coast Winelands region. The number of children selected from each district was weighted in terms of population size for the two regions. At each clinic visited, the first five to 10 children seen on a day, and meeting the inclusion criteria for vitamin A supplementation (VAS) based on the vitamin A provincial policy guidelines, were selected. These included children with low birth weight (LBW), growth faltering, underweight and severe undernutrition, recurrent diarrhoea and lower respiratory tract infection (LRTI), tuberculosis, measles, HIV/AIDS and eye signs of vitamin A deficiency. Clinic records were reviewed following consultation with the PHC nurse to identify if the child required vitamin A, exit interviews were conducted with mothers/caregivers, and Road to Health Charts (RTHCs) were reviewed. At the end of the study, PHC managers were interviewed to determine if problems could be identified with the Programme. RESULTS: Forty-three of 123 (35%) and 13 of 40 (33%) of the fixed PHC clinics in the Cape Metropole and West Coast Winelands regions were visited, and a total of 300 children (234 from Cape Metropole, 66 from West Coast Winelands) with a mean (standard deviation) age of 24.3 (16.3) months and who met the inclusion criteria for VAS were selected. Of the total sample of children, 198 (66%) had multiple (i.e. more than one) indication and 102 (34%) had a single indication for VAS. There were a total of 617 indications for VAS in the two regions; 238 (39%) for growth faltering, 119 (19%) for underweight, 98 (16%) for LBW, 70 (11%) for LRTI, 51 (8%) for diarrhoea, 21 (3%) for HIV/AIDS and 20 (3%) for tuberculosis. A total of 102 (34%) of the children in the two regions received vitamin A supplements (Cape Metropole 29%; West Coast Winelands 52%). A record was made on the RTHC of 79 (77%) of the children who received VAS (Cape Metropole 76%; West Coast Winelands 79%). Twenty-four per cent of the mothers knew why their child had been given vitamin A (Cape Metropole 29%; West Coast Winelands 12%). Eleven per cent of the mothers had previously heard about the Vitamin A Supplementation Programme (Cape Metropole 12%; West Coast Winelands 6%). More than 81% of PHC managers indicated that health staff had been trained to implement the Vitamin A Supplementation Programme. The main problems identified by health staff in the two regions were lack of vitamin A capsules, inadequate training and difficulties in implementing the Programme. CONCLUSIONS: Opportunities to administer vitamin A were underutilised in both regions. Recommendations such as improving mothers' awareness of the benefits of vitamin A and training of PHC nurses were made to the provincial Department of Health and are being implemented to improve the effectiveness of the Programme.     

Two genetic defects in alphaIIb are associated with type I Glanzmann's thrombasthenia in a Great Pyrenees dog: a 14-base insertion in exon 13 and a splicing defect of intron 13

Glannzmann's thrombasthenia (GT) is an autosomal recessive bleeding disorder caused by qualitative or quantitative deficiencies of the platelet membrane glycoprotein alphaIIbbeta3. This is the first report of a molecular genetic basis for type I GT in dogs. As previously reported, a thrombasthenic Great Pyrenees dog (dog No. 1) experienced uncontrolled epistaxis despite results of coagulation screening tests, platelet quantitation, and von Willebrand factor quantitation that were within reference ranges. Platelet aggregation was minimal in response to agonists. Flow cytometry, autoradiography, and immunoblot experiments demonstrated either marked reduction or absence of glycoproteins alphaIIb and beta3. In this study, we report the presence of a 14-base insertion in exon 13 and defective splicing of intron 13 in the alphaIIb gene of two thrombasthenic dogs (Nos. 1 and 8). The insertion disrupted the fourth alphaIIb calcium-binding domain, caused a shift in the reading frame and resulted in a premature termination codon. Possible consequences of this mutation include decreased alphaIIb mRNA stability and production of truncated alphaIIb protein that lacks the transmembrane and cytoplasmic domains and a large portion of the extracellular domain. We identified the dam, sire, and three littermates of dog No. 8 as carriers of the alphaIIb mutation. Canine alphaIIb and beta3 genes share significant homology with the genes in human beings, making canine GT an excellent translational model for human GT. A defined molecular basis for canine GT will enhance ongoing gene therapy research and increase the understanding of structure-function relationships of this integrin.     

The immune response to dietary antigens and its influence on disease susceptibility in farm animals

Transient hypersensitivity reactions of the intestinal immune system to dietary antigens result in increases in enterocyte turnover and villous atrophy. These changes occur in the intestine of the post weaned piglet and precede the proliferation of E. coli and the development of post-weaning diarrhea. We therefore postulated that a transient cell mediated immune response to dietary antigens may increase susceptibility to disease. The interaction of dietary and microbial antigens upon the gut immune system has been investigated in mice and pigs and it has been shown that both exert powerful regulatory effects upon each other.     

Effect of aerosol challenge on a population of free lung cells in parenterally immunised calves

There is concern that parenteral respiratory vaccines may potentiate lung disease rather than protect against it. In vivo indicators of inflammation in calves were assessed to determine if vaccine-mediated inflammation occurs in the lung following aerosol challenge of parenterally immunised subjects. Preliminary results using a simple protein antigen suggest that changes in the free cell populations of the lung are likely to be a more sensitive indicator of immune-mediated inflammation than clinical parameters or peripheral changes in serum complement.     

Antibody production by the pig colon during infection with Treponema hyodysenteriae

When 47 pigs were dosed orally with cultures of Treponema hyodysenteriae, 44 (94 per cent) developed swine dysentery. Of those which recovered and were rechallenged, nine of 21 (43 per cent) showed clinical signs, as did one of 10 (10 per cent) challenged on a third occasion. Clinical disease was associated with development of specific IgG, IgA and IgM antibodies in serum and the local production of IgA in gut mucosal tissues. The appearance of antibody was not directly related to protection but rather indicated either prolonged exposure (in the case of serum IgG) or recent exposure to T hyodysenteriae (for secretory IgA). Infection also resulted in the appearance of IgG and IgA memory cells in gut-associated lymphoid tissue. However, these studies indicated that humoral immunity alone is not responsible for the onset of a protective response to T hyodysenteriae in the colon.