The prevalence of culture-positive tuberculosis, and multidrug-resistant and extensively drug-resistant tuberculosis (MDR-TB and XDR-TB respectively) has decreased significantly between 2005 and 2008 at the Church of Scotland Hospital (COSH) in Tugela Ferry in KwaZulu-Natal, due to an improved infection control programme.
A point prevalence survey of the inpatient TB wards for one single day in both 2005 and 2008 showed that for the patients screened (n=25 and 35 respectively), the proportion of patients with culture-positive TB has decreased from 88% to 25.7%. The proportion with drug-resistant (DR) TB has also dropped dramatically from 64% in 2005 to only 8.6% in 2008.
These declines indicate that fewer patients are able to transmit TB to others in the facility.
The Infection Control Manager of the facility, Kathryn Catterick, presented the findings and methods of the Church of Scotland Hospital (COSH) at the Fourth South African AIDS Conference in South Africa. Simple and feasible measures that are already outlined in national policy were used and practices were monitored on an ongoing basis.
Church of Scotland Hospital was the first site to identify the presence of XDR-TB in HIV-positive patients, when, in 2005 it detected an alarmingly high death rate among patients previously doing well on antiretroviral therapy.
COSH is a rural 40 to 50-bed district hospital with congregate wards serving a population of around 172,000 patients. The annual TB incidence is 1054 per 100,000 and the annual incidence for MDR-TB is 141 per 100,000. Since 2005, 820 confirmed drug-resistant TB cases have been seen at the facility, 43% of which were MDR-TB and 57% XDR-TB.
Nosocomial transmission of TB (that which takes place in a healthcare setting and is secondary to the condition originally being treated) is a documented problem in this facility. In COSH in 2005, it was found that, of the 53 cases of XDR-TB, 85% of the isolates had similar genetic fingerprint by spoligotype, 55% had not previously received TB treatment and 67% had been hospitalised in the last two years.. These findings indicate that most patients acquired XDR-TB from others in the hospital.
Since 2005, 13 healthcare workers have been diagnosed with drug-resistant TB and nine have since died. Nosocomial transmission due to poor infection control practices in South Africa is also evidenced in the fact that for 2006, 2442 more cases in absolute numbers of all MDR-TB patients occured in people diagnosed with TB for the first time and not in re-treatment cases.
A synergistic and multifaceted approach was used in the infection control programme including the appointment of an infection control officer and cough officers. Cough officers screened every patient entering ambulatory care on five days of the week.
In the outpatient clinic it was found that 10.8% of those screened were AFB smear-positive. In the Gateway clinic, 6.5% were smear-positive and 9% in the ARV clinic. However, culture testing showed that 20% of patients screened in the ARV clinic were culture-positive, including DR-TB cases, indicating a high prevalence of smear-negative TB.
Attempts to reduce patients' length of stay were also made. However it was found that, although the number of admissions was decreasing, the length of stay was not significantly different.
Natural ventilation is emphasised in COSH. In 2006 extractor fans were installed and an open-window policy was instituted. Unannounced audits were conducted to monitor the opening of windows. In the male ward, this improved from 78% of the time to 93%. In the female ward, improvements was observed from 68% to 82%. To reduce risk of transmission, the DOT office and the ARV clinic were moved to the periphery of the hospital.
In 2007, a staff survey regarding understanding and knowledge of mask and respirator use was conducted, followed by mask education on the use of N95 respirators. Fit testing and fit checks were regularly conducted. In unannounced audits, it was found that respirator use amongst staff was consistently as high as 95%.
Staff are also screened for TB regularly and voluntary testing and counselling and testing for HIV are promoted. Staff are discreetly moved to lower risk areas if they are HIV-positive.
The proportionate decrease in the number of TB cases being diagnosed in COSH is assumed to be due to the improved infection control programme. The approach must be multifaceted and continuously monitored. Through utilising existing resources, strategies that are feasible, practical and measurable can be implemented in rural facilities to prevent nosocomial TB transmission. However, Kathryn Catterick emphasised that infection control measures in communities are being neglected.
Catterick K et al. Feasible and effective infection control programme to limit nosocomial transmission of drug-resistant TB in Tugela Ferry. Fourth South African AIDS Conference, Durban, abstract 455, 2009.