McBryde Report Highlights Severe Problems with Tuberculosis in Western Province, Papua New Guinea

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Tuesday, 27 November, 2012
TB control vehicle in Madang 2009

A report just released “Evaluation of Ricks of Tuberculosis in Western Province Papua New Guinea” concludes that the prevalence of TB is very high (at least 500/100,000). This is one of the highest levels globally. From data in the WHO’s Global Tuberculosis Report 2012 the only countries with higher prevalences (cases/100,000) are Cambodia (817), South Africa (768), Democratic Republic of the Congo (512), Zinbabwe (547), and Myanmar (506). PNG in the WHO report had a prevalence of 534/100,000 for 2011; so the Western Province data is consistent with PNG nationally. McBryde is her report also warns that this figure of TB prevalence for the Western Province in most likely an underestimate owing to poor access of many people to diagnostic services.

Multidrug resistant cases (MDR TB) in PNG are also seriously high, with 50% of sputum positive cases in Daru and 25% of cases in Port Moresby being multidrug resistant. The WHO target is <3% of TB cases with MDR TB. Comparing rates of TB resistance in the Western Province with MDR TB in the other high incidence countries shows that the Western Province leads the world: Cambodia (<1%), South Africa (3.1%), Democratic Republic of the Congo (3.5%), Zinbabwe (1.7%), and Myanmar (4.2%). Some patients with MDR TB in the Western Province are newly diagnosed, proving MDR TB is spreading within the community. Thus, the Western Province in particularly and probably PNG nationally has an epidemic of MDR TB.

At least 6 cases of extensively drug resistant TB (XDR TB) have now been diagnosed (McBryde 2012). MDR TB is resistant to two of the first line drugs (isoniazid and rifampicin). XDR TB is MDR TB plus resistance to second line drugs (at least one fluoroquinalone and one injectable drug). Treating every case of multidrug resistant TB in PNG with DOTS-Plus or appropriate combinations of drugs is essential. Finding contacts of TB cases and implementing preventive therapy is also important. In a low incidence setting such as Australia the incidence of MDR TB in contacts who did not receive preventive treatment, when indicated, was very high at 2,878/100,000 per person year, but zero in those who received preventive treatment (Denholm et al 2012). The transmission rate of MDR TB in the PNG situation is liable to be much higher than in Australia.

Although TB is a disease of poverty and overcrowding, multidrug resistance is typically a sign of poor TB control, a systems failure. The PNG TB system has been recognized as being poorly functioning for many years. The high levels of drug resistant and the appearance of XDR TB poses a massive dilemma for clinicians and health managers. Patients with MDR and XDR TB must be properly treated to save their lives. However, if second line drugs are introduced into a poorly functioning TB control system, selection pressure will accelerate the development of XDR TB. So individual patients may benefit from treatment, but at the cost of the community being at increased risk of epidemics due to XDR TB.

This is a desperate situation that requires massive effort by the PNG Ministry of Health with support of outside partners. Australia’s moral obligation to assist and care for cross-border TB cases from PNG has been clearly and strongly stated in a position statement (Reynolds et al 2011).

Literature cited:

Denholm JT, Leslie DE, Jenkin GA, Darby J, Johnson PD, Graham SM, Brown GV, Sievers A, Globan M, Brown LK, McBryde ES. Long-term follow-up of contacts exposed to multidrug-resistant tuberculosis in Victoria, Australia, 1995-2010. International Journal of Tuberculosis and Lung Disease 2012t;16(10):1320-1325.
McBryde E. Evaluation of Ricks of Tuberculosis in Western Province Papua New Guinea. Burnett Institute; Melbourne. September & October 2012. Available online http://www.ausaid.gov.au/countries/pacific/png/Documents/png-tb-evaluation-of-risk.pdf
Reynolds PN, Turnidge JD, Gottlieb T, Moore MJ, Thoracic Society of Australia and New Zealand; Australian Society for Microbiology, Australasian Society for Infectious Diseases, Public Health Association of Australia. Cross-border patients with tuberculosis. Medical Journal of Australia 2011;195(9):523-524.
World Health Organization. Global Tuberculosis Report 2012. WHO; Geneva. 2012. Available online at www.who.int/tb/publications/global_report/en/

Posted by Rick Speare