Thesis (PhD)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: Healthcare workers (HCWs) wear latex gloves to protect themselves and their patients against
the transmission of microbial, viral and bloodborne diseases. These individuals are primarily
exposed to latex via cutaneous (direct contact) and mucocutaneous (inhalation of airborne
allergens on glove powder) routes. Repeated exposure leads to the formation of circulating
latex-specific IgE and subsequent sensitisation with varying clinical expression.
The airconditioning system of the Tygerberg Hospital (TBH) complex was investigated for the
presence of aerosolised cornstarch glove powder and proteins. Dust samples were collected
from 14 areas with different levels of latex glove usage. Dust samples were
spectrophotometrically compared to a calibration graph of pure glove powder. The detection of
starch and proteins in all the dust samples confirmed the presence of glove powder and
possibly airborne latex allergens in the airconditioning ducts. As expected, the high exposure
areas showed the highest concentrations of both starch and proteins. It is possible that other
proteins than latex were involved, but the confirmed high level of protein contamination should
be a cause for concern. Correlation between starch and protein levels was highly significant
(p<0.01) in all instances.
A total of 500 questionnaires were circulated for completion by HCWs from TBH. The response
rate was 69.8%. After considering specific inclusion criteria, a study group of 152 individuals
was compiled (28 males, 124 females). All subjects had current latex exposure and suffered
from at least three pre-defined symptoms.
Serum was collected from all subjects and dermal fluid from 31 subjects. Total IgE and latex specific
IgE analysis were done on all serum and dermal fluid samples. Latex-specific IgE was
positive (>0.35 IU/ℓ) in 23 serum and six dermal fluid samples. Skin prick tests (SPTs)for latex
were done on 59 subjects with negative serum latex-specific IgE and 34 had positive results.
Twelve subjects with negative latex-specific IgE and latex SPTs underwent patch tests with the
European Standard Series, a piece of latex glove and glove powder in petrolatum. Three
subjects had positive results to one or more of these allergens.
Western blot analysis for latex was done on all positive sera and dermal fluid collected from
these subjects. Western blot analysis for latex proved to be more sensitive than the capRAST,
because it was able to identify specific bands in samples with negative capRAST results. All
subjects showed a band for Hev b 1, which has been confirmed as a powder-bound airborne
allergen. Hev b 6.01 is associated with HCWs with cutaneous symptoms and this band was recognised by 81% of the subjects. These findings confirmed that airborne and cutaneous
routes are the major routes of exposure in HCWs.
According to their laboratory results, subjects were divided into the following subgroups and
compared statistically: Group A (serum positive, n=23), Group B (SPT positive, n=34) and
Group C (negative, n=25). Group D (withdrawn, n=70) could not be used for statistical
comparisons, due to incomplete results. An overall latex allergy prevalence of 38% was found.
Group A differed significantly from Group B and Group C for most clinical and special
investigations. Group A and B were also combined to represent all subjects with positive results
(Cohort AB). The Allergy Score and Class were highly significant when Cohort AB was
compared to Group C. The selection of clinical symptoms was confirmed to be relevant and
work-related deterioration on any of the symptoms should bear a high index of suspicion in the
evaluation of latex allergy. Numerical indices and specific symptoms showed high positive
predictive values and the Allergy Score produced statistical significance in the positive
subgroups when compared to the negative subgroup. Paired statistical significance was
confirmed between the Allergy Score and occupational exposure (number of years, hours and
pairs per week).
The areas with the highest occupational latex exposure in HCWs are the face and hands.
Different occupations also have different levels of exposure and two subgroups of HCWs (16
laboratory technologists and 13 theatre staff) were investigated for sebum content on different
facial areas and the palms and dorsal areas of both hands. Baseline measurements were done
before putting on gloves. In 21 subjects follow up measurements were done following three to
four hours of occupational exposure, but before washing their hands. Baseline and follow up
values were compared for all the different anatomical regions. Levels on the forehead and
cheeks increased over time, while the level on the nose decreased. All hand regions decreased
significantly during occupational exposure, suggesting that glove powder contributes to dryness
of the skin.
In conclusion, the problem posed by latex allergy will not be solved overnight and will probably
remain a major occupational hazard for years to come. It is currently not possible to avoid
exposure to latex, but it is imperative to institute safety measures to prevent further sensitisation
in predisposed individuals and manage those already affected. / AFRIKAANSE OPSOMMING: Gesondheidswerkers dra lateks handskoene om hulleself en hulle pasiënte te beskerm teen die
oordrag van mikrobiale, virale en bloed-gedraagde siektes. Die lateks blootstelling vind hier
hoofsaaklik plaas via kutane (direkte velkontak) en mukokutane (inaseming van lug-gedraagde
allergene op hanskoen poeier) roetes. Herhaalde blootstelling veroorsaak sirkulerende lateksspesifieke
IgE en sensitisasie met variërende kliniese beelde.
Die lugreëlingstelsel van die Tygerberg hospitaalkompleks is ondersoek vir die teenwoordigheid
van handskoenpoeier (stysel) en lateks proteïene. Stofmonsters is versamel in 14 areas wat
verskillende blootstellingsvlakke verteenwoordig het. Die stofmonsters is spektrofotometries
vergelyk met "n kalibrasiekurwe van suiwer hanskoenpoeier. Stysel en proteïene kon in al die
stofmonsters aangetoon word en het die teenwoordigheid van handskoenpoeier en moontlike
luggedraagde lateks proteïene in die lugreëlingstelsel bevestig. Soos verwag kon word, het die
hoogste stysel en proteïen waardes in hoë blootstellingsareas voorgekom. Hoogs beduidende
statistiese korrelasies (p<0.01) tussen die stysel en proteïenvlakke kon aangedui word in alle
monsters.
"n Totaal van 500 vraelyste is gesirkuleer vir voltooiing deur TBH gesondheidswerkers, waarvan
69.8% voltooide vraelyste terugontvang is. Na evaluering van insluitingskriteria, is "n
studiegroep van 152 individue saamgestel (28 mans, 124 vrouens). Almal het huidige lateks
blootstelling en ten minste drie het vooraf gedefinieerde simptome gerapporteer.
Serum is van die hele groep versamel en dermale vog van 31 proefpersone. Totale IgE en
lateks-spesifieke IgE vlakke is op alle serum en dermale vog bepaal. Positiewe resultate
(>0.35 IU/ℓ) is verkry in 23 serum en ses dermaIe vog monsters. Velpriktoets vir lateks is op 59
proefpersone uitgevoer en 34 daarvan het positiewe resultate opgelewer. Twaalf proefpersone
met negatiewe lateks-spesifieke IgE en velpriktoets resultate het kutane plaktoetse ondergaan
met die Europese Standaard Reeks, "n stukkie lateks handskoen en handskoenpoeier in
petrolatum. Drie proefpersone het positiewe resultate teen een of meer van die allergene
gehad.
Westerse kladanalise vir lateks is op alle positiewe serum gedoen, asook die dermale vogte van
hierdie proefpersone. Westerse kladanalise vir lateks blyk baie meer sensitief te wees as die
capRAST, aangesien dit spesifieke bande kon identifiseer in monsters capRAST resultate. Alle
monsters het "n band getoon vir Hev b 1, "n poeier-gebinde, luggedraade allergeen. Hev b 6.01
is geassosieer met gesondheidswerkers met velsimptome en hierdie band is gevind in 81% van die monsters. Hierdie resultate bevestig dat die belangrikste blootstelling aan lateks in
gesondheidswerkers deur die vel en inaseming plaasvind.
Proefpersone is in die volgende drie groepe verdeel volgens laboratorium resultate en
statisties vergelyk: Groep A (positiewe serum, n=23), Groep B (positiewe velpriktoetse, n=34)
en Groep C (negatief, n=25). Groep D (onttrek, n=70) kon nie vir betekenisvolle statistiese
vergelykings aangewend word nie, as gevolg van onvolledige resultate. 'n Finale lateks allergie
prevalensie van 38% is gevind. Groep A het hoogs beduidend verskil van Groep B en C vir die
meeste van die kliniese en spesiale laboratoriumondersoeke. Groep A en B is gekombineer om
alle proefpersone in te sluit met positiewe resultate (Kohort AB). Die Allergie Telling en Klas
van Kohort AB was hoogs beduidend in vergelyking met Groep C. Die gekose simptome is
bevestig as relevant en enige werksverwante verergering van simptome moet met 'n hoë mate
van agterdog bejeën word in lateks allergie. Numeriese indekse en spesifieke simptome het
hoë positiewe voorspellingswaardes gelewer en die Allergie Telling was hoogs beduidend in die
positiewe subgroep in vergelyking met die negatiewe subgroep. Gepaarde statistiese
beduidenheid is ook gevind tussen die Allergie Telling en beroepsblootstelling (jare van
blootstelling, uur en paar handskoene per week).
Die meeste beroepsblootstelling aan lateks in gesondheidswerkers vind plaas op die hande en
gesig. Verskillende beroepe het ook verskillende blootstellingsvlakke en two subgroepe
gesondheidswerkers (16 laboratorium tegnoloë en 13 teater personeel) is ondersoek vir die
sebumgehalte op veskillende areas van die gesig en hande. Basislynvlakke is gemeet voordat
handskoene aangetrek is en in 21 gevalle is opvolgvlakke gemeet na drie tot vier uur
beroepsblootstelling, maar voor die hande gewas is. Basislyn en opvolgvlakke is met mekaar
vergelyk vir al die anatomiese areas. Die voorkop en wange het 'n toename in sebumgehalte
getoon, terwyl dié van die neus afgeneem het. AI die areas op die hande toon 'n hoogs
beduidende afname tydens beroepsblootstelling, wat impliseer dat hanskoenpoeier moontlik
bydra tot droogheid van die vel.
In samevatting, die lateks allergie probleem sal nie oornag opgelos word nie en sal waarskynlik
'n belangrike beroepsrisiko bly vir die aansienlike toekoms. Totale vermyding van lateks is tans
onmoontlik en daarom is dit van uiterste belang om voorsorgmaatreëls in plek te stel om
verdere sensitisasie in blootgestelde individue te verhoed en die wat reeds geaffekteer is,
effektief te hanteer.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/49883 |
| Date | 12 1900 |
| Creators | De Beer, Corena |
| Contributors | Walzl, Gerhard, Cilliers, Jacques, Stellenbosch University. Faculty of Medicine & Health Sciences. Dept. of Biomedical Sciences. Molecular Biology and Human Genetics. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
| Format | 225 p. : ill. |
| Rights | Stellenbosch University |
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