Volume 13 No 1                                                                                             June 1999

Latex Gloves: More harm than good!
C. DE BEER, J. CILLIERS
Department of Dermatology, Tygerberg Hospital and University of Stellenbosch.
P.J. TRUTER
School of Life Sciences, Cape Technikon.
P.C. POTTER

Department of Allergology, Groote Schuur Hospital.

Abstract
Health care workers (HCW) use latex gloves daily to prevent transmission of microbial and viral organisms to and from patients and specimens.  Repeated exposure to latex proteins (through direct skin contact or mucous membrane absorption) causes the formation of circulating latex-specific antibodies and increases the risk of sensitization.  HCW have the highest risk to develop latex hypersensitivity (LH).  Early detection of antibodies or predisposing factors (e.g. atopy or impaired skin barrier function) could assist in the identification and management of risk groups and limit possible sensitisation.
An experimental group with high latex exposure is compared to a control group from low or no exposure areas at Tygerberg Hospital, Cape Town.  A questionnaire targeted a thorough history of past and present latex exposure and identified risk factors in all subjects.  A complete physical examination confirmed possible clinical signs and symptoms of risk factors and LH.  Atopy was evaluated by means of clinical diagnostic criteria, complete haematogram and total serum IgE.  Latex-specific IgE antibodies were measured immunometrically.  Skin prick tests were performed on subjects with negative in vitro results, but with symptoms suggestive of LH.
An overall 20,8% prevalence of LH in personnel of the Tygerberg Academic Hospital was found.  Only 28,6 % of these patients suspected that they had LH, while 7,3% did not suspect and a further 35,7% did not know of underlying LH.  In the high exposure areas alone, the prevalence reached a value of 30,7%.  It is imperative to start instituting safety measures to manage the affected personnel and reduce or even prevent additional staff exposure and further rise in LH.  Prevention will in the long term be far more cost-effective than management of sensitized individuals.

 

The Use of a Mobile Laboratory for Tuberculosis Tracing in the Rural Free State
C.C. JORDAAN, M.N. JANSE VAN RENSBURG, P.L. BOTHA
Department of Medical Microbiology, University of the Free State.

Abstract
We have used a mobile laboratory (ML) to assist the existing health care services in the tracing and diagnosis of tuberculosis patients and to improve the control and treatment of tuberculosis (TB).  The visit to a rural area by the ML was co-ordinated with the local health care services.  The clinic to be visited was provided (2 weeks prior to the visit) with specimen containers for distribution among suspected TB cases.  Ziehl-Neelsen stained Smears were examined microscopically in the ML.  During April 1996 to October 1937 our ML visited fifteen regions in our province.  The ML visited several clinics in a day.  Of the 3218 specimens examined, 54 were positive (1,67%) and 32 were cultured.  The Qwa-Qwa region yielded the most positive specimens (18/359; 5%). 
Many problems were encountered of which lack of co-operation between the clinic staff and the ML was the most important.  Even though some clinics were visited twice, only a portion of the possible specimens were received.  Approximately 7800 organisms are necessary for a sputum specimen to be positive.  Because of the poor quality of most of the specimens, it is possible that many were falsely negative.  These and other problems will have to be overcome (e.g.  by education and training of health workers) if the ML is to become fully effective.
Tuberculosis (TB) is one of the most common opportunistic infections in Africa and is a major public health problem world wide.  TB accounts for more than 80% of all communicable diseases notified in South Africa and is at present regarded as one of the most serious health problems affecting the country.  Black and coloured communities are particularly at risk of developing TB.  The essence of tuberculosis control lies in identifying all patients with the disease and treating them fully.  This requires screening of high-risk groups, education of the public to ensure early diagnosis, adequate tracing of contacts, and the implementation of an effective anti-tuberculosis treatment regimen.
Case finding, especially in the rural areas can be a major problem.  TB case finding depends predominantly on voluntary self-presentation, which in turn is influenced by symptom recognition, cultural and social influences.  There are also enabling factors such as time, money and trained health workers4.  Appropriate and accessible health services are needed to control any disease.  The South African TB control programme provides some of the enabling factors such as free treatment and clinic-based rather than hospital-based services.  By using a mobile laboratory (ML) we have attempted to assist the existing health care services in the tracing and diagnosis of tuberculosis patients with the view to improving the control and treatment of the disease.

 

The Evaluation of b-Lactamase Inhibitor Combinations for Detection of Organisms Producing Extended-Spectrum b-Lactamases using the Double-Disc Test
M. SNYMAN, J. PITOUT, C. JORDAAN
Department of Medical Microbiology, University of the Free State.

Abstract
A study was undertaken to compare the following
b-lactamase inhibitors, amoxycillin/clavulanic acid tame), ampicillin/sulbactam (sam) and piperacillin 1 tazobactam (tzp) for detection of organisms producing extended spectrum b-lactamases using the double disc (DD) test.
The DD test as described by Jatlier etal, was performed on 35 control strains and 59 clinical strains (including Klebsiella pneumoniae, K.oxytoca, Esherichia coli, Proteus mirabilis, Enterobacter cloacae and E.  aerogenes) producing different types of
b-lactamases.  This test was repeated on days 3, 7, 14, 21 and 28.
The results of the different combinations on day 1 compared as follows: sensitivity of amc 98,6%, tzp 87,8 % and sam 77 %; specificity of all three was 90%.  Similar results for all three were obtained on days 3 and 7, but on day 28 the sensitivity of amc declined to 43,2 % , tzp to 35,1% and sam to 32,4%.  Amc proved to be the most sensitive combination for detecting ESBL-producing organisms.  The interpretation with tzp was highly subjective (except for E.  aerogenes) and sam fared poorly especially when an organism produced more than 1
b-lactamase.
We recommended that amc be replaced every 7 days with fresh discs and tzp should be further investigated for detection of ESBLs, in organisms producing Bush group 1
b-lactamases.  Enterobacteriaceae producing extended-spectrum b-lactamases (ESBLs) are an important cause of failure of therapy with the expanded-spectrum cephalosporins but some organisms do not appear resistant to these agents in routine susceptibility tests.  Therefore, it is necessary for a clinical microbiology laboratory to implement a special test such as a double-disc (DD) test designed for detecting organisms producing ESBLs.  Although this is generally a reliable test, there are several limitations.  One such limitation is that only fresh amoxycillin/clavulanic acid discs should be used because of the instability of clavulanic acid.  This additional cost puts an unnecessary financial burden on the cost-effective running of a clinical microbiology laboratory.

 


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