Kerrigan McCarthy

Cryptococcus gattii Infection: Characteristics and Epidemiology of Cases Identified in a South African Province with High HIV Seroprevalence, 2002–2004

We describe 46 Cryptococcus gattii-infected persons identified by population-based surveillance conducted in South Africa. Most patients with C. gattii infection presented with meningitis. The mortality rate during hospitalization was 36%. We found no significant differences between persons with and persons without C. gattii infection with regard to clinical presentation, acquired immunodeficiency syndrome diagnosis, concomitant conditions, or prior opportunistic infections. C. gattii isolates had low MICs to the tested antifungal drugs.

Altered PBP 2A and Its Role in the Development of Penicillin, Cefotaxime, and Ceftriaxone Resistance in a Clinical Isolate of Streptococcus pneumoniae

ABSTRACT We report the unusual involvement of altered PBP 2A in the development of β-lactam resistance in Streptococcus pneumoniae. This was investigated amid three identical serotype 14 isolates (designated isolates 1, 2, and 3, respectively) of pneumococci cultured successfully from the blood of a human immunodeficiency virus-seropositive child with recurrent pneumonia. The passage of this strain through its human host induced several changes in the bacterium, which is typical of the adaptive and evolving nature of the pneumococcus. An efflux resistance mechanism, which conferred increased ciprofloxacin resistance, was induced in isolates 2 and 3. In addition, faster growth rates and larger capsules were also observed for these isolates, with respect to isolate 1. Notably, compared to isolates 1 and 2, isolate 3 showed a decrease in penicillin, cefotaxime, and ceftriaxone resistance. This change was associated with the replacement of an altered PBP 2A for an unaltered PBP 2A. In all likelihood, these events produced a strain which evolved into a fitter and more virulent type, isolate 3, that resulted in an aggravated pneumococcal infection and ultimately in the patients death.

Prevalence, risk factors and risk perception of tuberculosis infection among medical students and healthcare workers in Johannesburg, South Africa

BACKGROUND Tuberculin skin test (TST) and interferon gamma release assays (IGRAs) are both recommended for routine screening of healthcare workers (HCWs) in low tuberculosis (TB)-burden countries. More recently, based on scarce data, the World Health Organization strongly recommended that IGRA should not be used for occupational screening in high-burden settings. OBJECTIVE To assess the prevalence of latent tuberculosis infection (LTBI) determined among highly exposed HCWs and low-exposed medical students in Johannesburg, South Africa. Methods. We performed a cross-sectional study using both TSTs and IGRAs to determine the prevalence rate of LTBI in 79 medical students and 120 HCWs providing HIV and/or TB care. RESULTS The prevalence of LTBI among HCWs was 2- to 4-fold higher than that among medical students (56.7% v. 26.6% TST-positive; 69.2% v.15.2% IGRA-positive, respectively), with 3-fold higher odds for TST positivity and 12-fold higher odds for IGRA positivity among HCWs compared with students. Despite the perception of being at high risk, few HCWs protected themselves against LTBI. The majority of HCWs reported that they would participate in annual TST or IGRA screening. CONCLUSION Infection control strategies and occupational screening programmes for professional and lay HCWs, as well as medical students, should be implemented in all high-burden settings. Further research is needed to determine whether IGRA or TST is the optimal assay for periodical screening of HCWs in high-burden settings.

Impact of reduced hospitalisation on the cost of treatment for drug-resistant tuberculosis in South Africa.

SETTING The cost of multidrug-resistant tuberculosis (MDR-TB) treatment is a major barrier to treatment scale-up in South Africa. OBJECTIVE To estimate and compare the cost of treatment for rifampicin-resistant tuberculosis (RR-TB) in South Africa in different models of care in different settings. DESIGN We estimated the costs of different models of care with varying levels of hospitalisation. These costs were used to calculate the total cost of treating all diagnosed cases of RR-TB in South Africa, and to estimate the budget impact of adopting a fully or partially decentralised model vs. a fully hospitalised model. RESULTS The fully hospitalised model was 42% more costly than the fully decentralised model (US

Using Top-down and Bottom-up Costing Approaches in LMICs: The Case for Using Both to Assess the Incremental Costs of New Technologies at Scale

13,432 vs. US

High incidence of latent tuberculous infection among South African health workers: an urgent call for action

7753 per patient). A much shorter hospital stay in the decentralised models of care (44-57 days), compared to 128 days of hospitalisation in the fully hospitalised model, was the key contributor to the reduced cost of treatment. The annual total cost of treating all diagnosed cases ranged from US

Implementation and Operational Research: What Happens After a Negative Test for Tuberculosis? Evaluating Adherence to TB Diagnostic Algorithms in South African Primary Health Clinics

110 million in the fully decentralised model to US

A Framework to Inform Strategies to Improve the HIV Care Continuum in Low- and Middle-Income Countries

190 million in the fully hospitalised model. CONCLUSION Following a more decentralised approach for treating RR-TB patients could potentially improve the affordability of RR-TB treatment in South Africa.

Cost-effectiveness of Xpert MTB/RIF for tuberculosis diagnosis in South Africa: a real-world cost analysis and economic evaluation

Abstract Purpose Estimating the incremental costs of scaling‐up novel technologies in low‐income and middle‐income countries is a methodologically challenging and substantial empirical undertaking, in the absence of routine cost data collection. We demonstrate a best practice pragmatic approach to estimate the incremental costs of new technologies in low‐income and middle‐income countries, using the example of costing the scale‐up of Xpert Mycobacterium tuberculosis (MTB)/resistance to riframpicin (RIF) in South Africa. Materials and methods We estimate costs, by applying two distinct approaches of bottom‐up and top‐down costing, together with an assessment of processes and capacity. Results The unit costs measured using the different methods of bottom‐up and top‐down costing, respectively, are

Laboratory-acquired infections of Salmonella enterica serotype Typhi in South Africa : phenotypic and genotypic analysis of isolates

US16.9 and