Attitude of Lesotho health care workers towards HIV/AIDS and impact of HIV/AIDS on the population structure

BACKGROUND

The impact and management of HIV/AIDS in Lesotho in the context of disaster management was investigated.

OBJECTIVES

Lesotho health care workers' perception on HIV/AIDS progression, whether HIV/AIDS was managed as a disaster, and the impact on the demographic profile was investigated.

METHODS

The empirical investigation included a literature study, and primary and secondary data analyses. Questionnaires (n=116) determined health care workers' perception of HIV/AIDS. Interviews with officers of Lesotho Disaster Management determined how HIV/AIDS was managed as a disaster. National population censuses and data from surveys were summarised to describe the impact of HIV/AIDS on the population structure.

RESULTS

Respondents' modal age group was 25 to 39 years, 28.4% viewed HIV/AIDS related deaths as very high and perceived that HIV/AIDS changed the age composition, sex and dependency ratio of the population. Although HIV/AIDS was declared a disaster, the Lesotho Disaster Management Authority only aided the National AIDS Commission. There was evidence that HIV/AIDS caused the population pyramid base to shrink, and an indentation in the active population.

CONCLUSION

Health care workers attributed HIV/AIDS to changing the demographic profile of Lesotho, also reflected in the population pyramid. Lesotho Disaster Management Authority played a supporting role in HIV/AIDS disaster management.

Critical appraisal of volumetric-modulated arc therapy compared with electrons for the radiotherapy of cutaneous Kaposi's sarcoma of lower extremities with bone sparing

OBJECTIVE

To evaluate the use of volumetric-modulated arc therapy [VMAT, RapidArc® (RA); Varian Medical Systems, Palo Alto, CA] for the treatment of cutaneous Kaposi's sarcoma (KS) of lower extremities with adequate target coverage and high bone sparing, and to compare VMAT with electron beam therapy.

METHODS

10 patients were planned with either RA or electron beams. The dose was prescribed to 30 Gy, 10 fractions, to mean the planning target volume (PTV), and significant maximum dose to bone was limited to 30 Gy. Plans were designed for 6-MV photon beams for RA and 6 MeV for electrons. Dose distributions were computed with AcurosXB® (Varian Medical Systems) for photons and with a Monte Carlo algorithm for electrons.

RESULTS

V(90%) was 97.3±1.2 for RA plans and 78.2±2.6 for electrons; similarly, V(107%) was 2.5±2.2 and 37.7±3.4, respectively. RA met coverage criteria. Concerning bone sparing, D(2%) was 29.6±1.1 for RA and 31.0±2.4 for electrons. Although acceptable for bone involvement, pronounced target coverage violations were obtained for electron plans. Monitor units were similar for electrons and RA, although for the latter they increased when superior bone sparing was imposed. Delivery times were 12.1±4.0 min for electrons and 4.8±1.3 min for the most modulated RA plans.

CONCLUSION

High plan quality was shown for KS in the lower extremities using VMAT, and this might simplify their management in comparison with the more conventional usage of electrons, particularly in institutes with limited staff resources and heavy workloads.

ADVANCES IN KNOWLEDGE

VMAT is also dosimetrically extremely advantageous in a typology of treatments where electron beam therapy is mainly considered to be effective owing to the limited penetration of the beams.

The evolving epidemic of drug-resistant tuberculosis among children in Cape Town, South Africa

SETTING

Tygerberg Children's Hospital, Cape Town, South Africa.

OBJECTIVE

To determine the prevalence and trend of drug resistance and human immunodeficiency virus (HIV) co-infection among children with culture-confirmed tuberculosis (TB).

METHOD

Prospective surveillance from March 2007 to February 2009, compared to three previous surveys (1994-1998, 2003-2005, 2005-2007). Drug susceptibility testing (DST) against isoniazid (INH) and rifampicin (RMP) was performed using genotypic and phenotypic testing. If multidrug-resistant TB (MDR-TB) was detected, further DST against ethambutol (EMB) and second-line drugs was performed.

RESULTS

A total of 294 children with a median age of 26 months (range 3 days-13 years) were diagnosed with culture-confirmed TB. DST results were available for 292 (99.3%); 41 (14%) were INH-resistant, including 26 (8.9%) with MDR-TB. Four children (1.4%) had RMP monoresistance. EMB resistance was present in 12/24 (50%) MDR-TB cases tested. Two isolates were resistant to ofloxacin; none had extensively drug-resistant TB. Of those tested, 29% (63/217) were HIV-infected. Any resistance to RMP increased between 1994 and 2009 (P < 0.001), as did RMP monoresistance (P = 0.009) and MDR-TB (P < 0.001). Sensitivity was 87.5% and specificity 100% for genotypic compared to phenotypic testing for INH resistance.

CONCLUSIONS

RMP, and consequently multidrug, resistance is increasing among children with TB in this setting. EMB resistance is common among children with resistance to RMP and INH.

Genetic mixed-stock analysis of Atlantic sturgeon Acipenser oxyrinchus oxyrinchus in a heavily exploited marine habitat indicates the need for routine genetic monitoring

Although a previous genetic mixed-stock analysis (gMSA) conducted in the early 1990s showed that marine-captured New York Bight Atlantic sturgeon Acipenser oxyrinchus oxyrinchus almost exclusively originated from the Hudson River, fish from southern U.S. rivers were well represented within this contemporary sample (n = 364 fish), at least during the autumn. Widely distributed spawning stocks are therefore exposed to heavy fishing activity and habitat degradation in this relatively small area, illustrating the need for spatial management across multiple management jurisdictions and routine gMSA to account for temporal change.

Molecular characterisation of rifampicin-resistant Mycobacterium tuberculosis strains from Morocco

Mutations in the rpoB gene associated with rifampicin (RMP) resistance were studied in 47 RMP-resistant and 147 RMP-susceptible clinical strains of Mycobacterium tuberculosis from Morocco using probe-based assay and DNA sequencing. RMP-resistant mutations were identified in 85% of RMP-resistant isolates. No mutations were observed among the 147 RMP-susceptible strains. Sequence analysis identified 10 alleles, including two deletions not previously reported. Nucleotide changes at codons 531, 526 and 516 were the most prominent, accounting for 74.4% of our RMP-resistant strains. These results demonstrate that resistance genotyping at these codons would be a good marker for the rapid detection of RMP resistance.

Evaluation of a rapid screening test for rifampicin resistance in re-treatment tuberculosis patients in the Eastern Cape

BACKGROUND AND OBJECTIVES

Patients with multidrug-resistant (MDR) tuberculosis (TB) are at high risk of treatment failure. It is anticipated that early identification of MDR-TB and appropriate treatment will improve patient outcome and disease control. We evaluated the rapid detection of rifampicin resistance in previously treated TB patients, directly from acidfast bacilli (AFB)-positive sputum using a phage-based test, FASTPlaque-Response (Biotec Laboratories Ltd, Ipswich, UK). The ability of rifampicin resistance to predict MDR-TB was also determined.

DESIGN

A prospective study was done comparing performance of the rapid phage test with conventional culture and drug susceptibility testing (DST) in AFB-positive TB patients.

SETTING

Five primary health clinics and one TB referral centre in the Port Elizabeth Metropolitan area, Eastern Cape.

OUTCOME MEASURES

Sensitivity, specificity and overall accuracy of the phage test were determined compared with gold standard culture and DST. Discrepant results were resolved by molecular detection of mutations conferring rifampicin resistance. The proportion of rifampicin-resistant strains that were MDR was also determined.

RESULTS

Previously treated patients were at a high risk of MDRTB (35.7%). Sensitivity, specificity and overall accuracy of FASTPlaque-Response for rifampicin resistance determination were 95.4% (95% confidence interval (CI): 91.0 - 99.8%), 97.2% (95% CI: 94.5 - 99.9%) and 96.5% (95% CI: 94.1 - 98.9%) respectively compared with conventional DST (unresolved), calculated for specimens that had both FASTPlaque-Response and conventional DST results available. FASTPlaque-Response results were available in 2 days instead of 28 - 85 days with conventional DST. However, only 70.6% of FASTPlaque-Response results were interpretable compared with 86.3% of conventional DST results. The majority (95.5%) of rifampicinresistant strains were MDR-TB.

CONCLUSIONS

Rapid detection of rifampicin resistance using FASTPlaque-Response could contribute to improved management of patients at risk of MDR-TB, such as previously treated patients. However, improvement in control of specimen-related contamination is needed to ensure that a higher proportion of FASTPlaque-Response results are interpretable. Where indicated, early modification of therapy could improve patient prognosis and reduce disease transmission.

Beijing and Haarlem genotypes are overrepresented among children with drug-resistant tuberculosis in the Western Cape Province of South Africa

Drug resistance among children with culture-confirmed tuberculosis (TB) provides an accurate measure of transmitted drug resistance within the community. We describe the genotype diversity in children with culture-confirmed TB and investigate the relationship between genotype and drug resistance. A prospective study was conducted from March 2003 through August 2005 at Tygerberg Children's Hospital, in the Western Cape Province of South Africa. All children (<13 years of age) diagnosed with culture-confirmed TB were included. Genotype analysis and phenotypic drug susceptibility testing were performed on the first culture-positive isolate from each patient. Mutation analysis was performed on all drug-resistant isolates. Spoligotyping was successfully performed on isolates from 391/399 (98%) children diagnosed with culture-confirmed TB. Drug susceptibility testing was also performed on 391 isolates; 49 (12.5%) were resistant to isoniazid, and 20 (5.1%) of these were resistant to both isoniazid and rifampin. Beijing was the most common genotype family, identified in 130/391 (33.2%) cases, followed by LAM in 114/391 (29.2%) cases. The presence of both Beijing and Haarlem genotype families was significantly associated with drug resistance (26/49 [53.1%] versus 113/342 [33.0%]; odds ratio, 1.7; 95% confidence interval, 1.0 to 2.9). The high prevalence of Beijing and LAM in children with culture-confirmed TB reflects considerable transmission of these genotype families within the community. The overrepresentation of Beijing and Haarlem genotype families in children with drug-resistant TB demonstrates their contribution to transmitted drug resistance and their potential importance in the emergent drug-resistant TB epidemic.

Ewing's sarcoma of the vulva--a case report

Extraosseous Ewing's sarcoma of the vulva is extremely rare with only three such cases described. A 26-year-old woman presented with Ewing's sarcoma of the vulva. She received chemotherapy to shrink the lesion. However, the response was suboptimal and she subsequently received radiotherapy. Although resection was planned, she developed chest metastases within a short period of time and subsequently died.

The detection of Mycobacterium tuberculosis in bone marrow aspirate using the polymerase chain reaction

SETTING

Tygerberg Hospital, South Africa.

OBJECTIVE

Bone marrow aspirate and biopsy were obtained from 37 patients who were in-patients at the Tygerberg hospital. The specificity and sensitivity of the polymerase chain reaction (PCR) in the detection of Mycobacterium tuberculosis in bone marrow aspirate was evaluated.

DESIGN

The PCR was compared to standard culture as well as to clinical and bone marrow biopsy data in 24 patients with suspected tuberculosis (TB).

RESULTS

12 of the 24 patients eventually had definite or probable TB and in these 12 patients the detection incidence was 42% for PCR and 25% for culture.

CONCLUSION

This study confirms that it is possible to use PCR to detect M. tuberculosis in bone marrow aspirate material and that this technique is more sensitive than culture methods. The PCR technique has the added advantage of being a rapid test yielding results within 2 days of sampling. Overall sensitivity for the detection of M. tuberculosis in bone marrow aspirate may be improved to 58% [corrected] by using both culture and PCR techniques.

Laboratory experience and guidelines for avoiding false positive polymerase chain reaction results

Despite the widespread use of polymerase chain reaction (PCR) for diagnosis of infectious diseases, the technology has not been generally introduced into routine diagnostic laboratories. One of the most serious problems which has influenced the acceptance of this technology is the occurrence of false positive PCR results. This study describes the experience, in a hospital laboratory setting, of using PCR for the diagnosis of heat-labile enterotoxin-producing E. coli, M. tuberculosis, M. paratuberculosis and human papillomavirus. Results indicate that a build-up of amplicons, generated during the amplification process in the laboratory, is the main source of PCR-contamination. Protocols are described that include both physical and chemical procedures to prevent contamination. The use of photo-induced psoralen is recommended for those laboratories already involved in PCR work where amplicons are likely to be present. An enzymatic system (uracil-N-glycosylase) was evaluated and is recommended for workers intending to start diagnostic PCR. Attention was given to simple control measures which are easily implemented in a routine diagnostic laboratory. Protocols such as these are likely to have a major impact on the introduction of PCR-based methods into routine laboratories.

Papulonecrotic tuberculid. Identification of Mycobacterium tuberculosis DNA by polymerase chain reaction

Sections from 22 formalin-fixed, paraffin-embedded skin biopsies from 12 patients with papulonecrotic tuberculid (PNT) were examined for the presence of Mycobacterium tuberculosis DNA with use of the polymerase chain reaction. All patients had a positive tuberculin skin test and a compatible clinical picture and responded to antituberculous therapy. Histological examination showed the typical morphology of PNT lesions with dermal necrosis surrounded by an ill-formed granulomatous infiltrate. Mycobacterial DNA was detected in 11 of the 22 biopsies. None of the negative controls showed positive DNA identification by amplification. Great care was taken in avoiding false-positive results due to contamination. After reviewing the literature, we believe this is the first time that PNT lesions have been investigated by PCR for the presence of mycobacterial DNA. These findings provide direct proof that mycobacterial products are present in PNT lesions and support the theory that this organism is in some way responsible for the development of PNT.

The use of the polymerase chain reaction test in the diagnosis of tuberculosis

Current techniques for laboratory diagnosis of tuberculosis have some serious limitations. These include the high cost and time required for the current assays. The development of a rapid, sensitive, specific and low-cost assay is therefore of considerable importance. We report here the development and laboratory testing of a polymerase chain reaction DNA-based diagnostic test for the presence of Mycobacterium tuberculosis in sputum. The assay shows a high level of sensitivity and specificity and requires considerably less capital, consumables and time inputs than existing laboratory tests. We believe this technology is ready for large-scale evaluation and use, particularly in hospital-based laboratories.