Indoor Social Networks in a South African Township: Potential Contribution of Location to Tuberculosis Transmission

CITATION: Wood, R. et al. 2012. Indoor social networks in a South African township : potential contribution of location to tuberculosis transmission. PLoS ONE, 7(6): e39246, doi:10.1371/journal.pone.0039246.The original publication is available at http://journals.plos.org/plosoneBackground We hypothesized that in South Africa, with a generalized tuberculosis (TB) epidemic, TB infection is predominantly acquired indoors and transmission potential is determined by the number and duration of social contacts made in locations that are conducive to TB transmission. We therefore quantified time spent and contacts met in indoor locations and public transport by residents of a South African township with a very high TB burden. Methods A diary-based community social mixing survey was performed in 2010. Randomly selected participants (n = 571) prospectively recorded numbers of contacts and time spent in specified locations over 24-hour periods. To better characterize age-related social networks, participants were stratified into ten 5-year age strata and locations were classified into 11 types. Results Five location types (own-household, other-households, transport, crèche/school, and work) contributed 97.2% of total indoor time and 80.4% of total indoor contacts. Median time spent indoors was 19.1 hours/day (IQR:14.3–22.7), which was consistent across age strata. Median daily contacts increased from 16 (IQR:9–40) in 0–4 year-olds to 40 (IQR:18–60) in 15–19 year-olds and declined to 18 (IQR:10–41) in ≥45 year-olds. Mean daily own-household contacts was 8.8 (95%CI:8.2–9.4), which decreased with increasing age. Mean crèche/school contacts increased from 6.2/day (95%CI:2.7–9.7) in 0–4 year-olds to 28.1/day (95%CI:8.1–48.1) in 15–19 year-olds. Mean transport contacts increased from 4.9/day (95%CI:1.6–8.2) in 0–4 year-olds to 25.5/day (95%CI:12.1–38.9) in 25–29 year-olds. Conclusions A limited number of location types contributed the majority of indoor social contacts in this community. Increasing numbers of social contacts occurred throughout childhood, adolescence, and young adulthood, predominantly in school and public transport. This rapid increase in non-home socialization parallels the increasing TB infection rates during childhood and young adulthood reported in this community. Further studies of the environmental conditions in schools and public transport, as potentially important locations for ongoing TB infection, are indicated.http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0039246Publisher's versio

Reducing length of stay for acute diabetic foot episodes: employing an extended scope of practice podiatric high-risk foot coordinator in an acute foundation trust hospital

BACKGROUND: To enhance the acute management of people with diabetic foot disease requiring admission, an extended scope of practice, podiatric high-risk foot coordinator position, was established at the Great Western Hospital, Swindon in 2010. The focus of this new role was to facilitate more efficient and timely management of people with complex diabetic foot disease. The aim of this project was to investigate the impact of the podiatric high-risk foot coordinator role on length of stay, rate of re-admission and bed cost. METHOD: This study evaluated the difference in length of stay and rate of re-admission between an 11- month pre-pilot period (November 2008 to October 2009) and a 10-month pilot period (August 2010 to June 2011). The estimated difference in bed cost between the pre-pilot and pilot audits was also calculated. Inclusion criteria were restricted to inpatients admitted with a diabetic foot ulcer, gangrene, cellulitis or infection as the primary cause for admission. Eligible records were retrieved using ICD-10 (V9) coding via the hospital clinical audit department for the pre-pilot period and a unique database was used to source records for the pilot phase. RESULTS: Following the introduction of the podiatric high-risk foot coordinator, the average length of stay reduced from 33.7 days to 23.3 days (mean difference 10.4 days, 95% CI 0.0 to 20.8, p = 0.050). There was no statistically significant difference in re-admission rate between the two study periods, 17.2% (95% CI 12.2% to 23.9%) in the pre-pilot phase and 15.4% (95% CI 12.0% to 19.5%) in the pilot phase (p = 0.820). The extrapolated annual cost saving following the implementation of the new coordinator role was calculated to be £234,000 for the 2010/2011 year. CONCLUSIONS: This audit found that the extended scope of practice coordinator role may have a positive impact on reducing length of stay for diabetic foot admissions. This paper advocates the role of a podiatric high-risk foot coordinator utilising an extended scope of practice model, although further research is needed

The acutely infected diabetic foot is not adequately evaluated in an inpatient setting

OBJECTIVE To evaluate the standard of evaluation and treatment of the infected diabetic foot ulceration at a 551-bed university teaching institution. DESIGN A retrospective review of a 4-year consecutive sample (1991-1994). POPULATION Two hundred fifty-five patients who were admitted to a hospital for care of an infected diabetic foot ulceration. Patients were subdivided into the following 4 dichotomous variables: (1) whether the patient underwent a lower-extremity amputation, (2) whether the patient was admitted once or multiple times, (3) whether the patient underwent intraoperative debridement, and (4) whether the patient was admitted to medical or surgical services. RESULTS All groups that were evaluated had undergone a less than adequate foot examination. Of the admitted patients, 31.4% did not have their pedal pulses documented; 59.7% of the admitted patients were not evaluated for the presence or absence of protective sensation. Nearly 90% of the wounds were not evaluated for involvement of underlying structures, and foot radiographs were not performed in 32.9% of the patients. There were more blood cultures ordered (62.0%) than wound cultures (51.4%). CONCLUSION The results of this study highlight the need for a systematic, detailed lower-extremity examination for every diabetic patient who is admitted to a hospital, particularly those who are admitted with a primary diagnosis that involves a foot complication. </jats:sec

Value of white blood cell count with differential in the acute diabetic foot infection

The authors reviewed the admission leukocyte indices of 338 consecutive admissions (203 males, 135 females, mean age of 60.2 +/- 12.9 years) with a primary diagnosis of diabetic foot infection in a multicenter retrospective study. The mean white blood cell count on admission for all subjects studied was calculated at 11.9 +/- 5.4 x 103 cells/mm3. Of all white blood cell counts secured for patients admitted with a diabetic foot infection, 56% (189 out of 338) were within normal limits. The average automated polymorphonuclear leukocyte percentage was calculated at 71.4 +/- 11.1% (normal range 40% to 80%). Normal polymorphonuclear leukocyte values were present in 83.7% of subjects. The authors stress that the diagnosis of a diabetic pedal infection is made primarily on the basis of clinical signs and symptoms, and that a normal white cell count and white cell differential should not deter the physician from taking appropriate action to mitigate the propagation of a potentially limb-threatening pedal infection.</jats:p