International Spread of MDR TB from Tugela Ferry, South Africa

We describe a death associated with multidrug-resistant tuberculosis and HIV infection outside Africa that can be linked to Tugela Ferry (KwaZulu-Natal, South Africa), the town most closely associated with the regional epidemic of drug-resistant tuberculosis. This case underscores the international relevance of this regional epidemic, particularly among health care workers.

M ultidrug-resistant (MDR) and extensively drugresistant (XDR) tuberculosis (TB) pose an increasing challenge to international health (1), particularly in the context of HIV infection. An outbreak of XDR TB around a rural hospital in Tugela Ferry (KwaZulu-Natal Province, South Africa) in 2006 received widespread international attention, in part because of the high case-fatality rate. More recent work has highlighted the risk for MDR TB among health care workers (2) in South Africa. We report a death outside of Africa associated with MDR TB that can be directly related to the epidemic of drug resistance in Tugela Ferry, the center most closely associated with the epidemic.

The Study
A 42-year-old South Africa-born health care worker was admitted to a regional hospital in the United Kingdom with a 1-month history of fever, cough, and weight loss associated with cervical lymphadenopathy, choroidal tuberculoma ( Figure), and pleural effusion. The patient had no history of TB treatment and no known family contact with TB. He had moved to the United Kingdom 6 years earlier. Extrapulmonary TB diagnosis was based on microscopic examination of a cervical lymph node specimen, and co-infection with HIV was identifi ed (CD4 count 5 cells/μL).
After arrival in the United Kingdom, the patient worked as a temporary nurse in several health care facilities. Before that, the patient worked at the Church of Scotland Hospital in Tugela Ferry during 1996-2002 in general medical wards. This facility was the focus of the 2006 report of XDR TB, and most MDR isolates identifi ed there during 2005-2007 were XDR TB (3).
A presumptive diagnosis of MDR TB was made 7 days after the patient sought care at the hospital. A line probe assay (INNO-LiPA Rif.TB; Innogenetics, Ghent, Belgium) performed on cervical lymph node aspirates identifi ed Mycobacterium tuberculosis and a hybridization pattern consistent with rpoB gene mutation (associated with rifampin resistance and a high risk for MDR TB). Treatment was altered from weight-appropriate doses of rifampin, isoniazid, pyrazinamide, and ethambutol to include levofl oxacin, amikacin, cycloserine, and protionamide. Because of known sensitivity patterns from isolates at Tugela Ferry and the possibility of XDR TB, para-aminosalicylic acid and linezolid were added to treatment, and intravenous amikacin was changed to capreomycin. Treatment was subsequently changed on the basis of culture results. The patient required 35 days of mechanical ventilation for likely pulmonary immune reconstitution syndrome after initiation of antiretroviral treatment. Although discharged from intensive care after successful treatment of TB, the patient remained hospitalized and died 90 days after fi rst seeking care. Samples cultured from >1 site showed evidence of widespread MDR TB. More than 500 potentially infectious contacts were identifi ed, but no secondary cases of TB have been diagnosed.
Culture confi rmed the M. tuberculosis isolate from the patient to be resistant to rifampin, isoniazid, pyrazinamide, and ethambutol but sensitive to amikacin, capreomycin, moxifl oxacin, para-aminosalicylic acid, and linezolid. These resistance and sensitivity characteristics identifi ed the isolate as MDR TB rather than an XDR TB strain. Automated sequencing of rpoB revealed the L533P mutation previously associated with rifampin resistance (4-6) but not the D516G mutation found in XDR TB strains previously isolated from patients at Church of Scotland Hospital and from other hospitals within KwaZulu-Natal (7).
To explore whether the patient's isolate was related to the F15/LAM4/KZN strain genotypes associated with the Tugela Ferry outbreak (8) (Table). Single-locus variation is prognostic of a close relationship within a clonal complex with confi dence exceeding 99% (9). Furthermore, the patient's isolate genotype also specifi cally best matched that of an F15 strain (also differing by 1 locus), in a database of 209 South African isolates containing a large variety of genotypic families (11).

Conclusions
The risk for TB among health care workers in developing countries is well recognized (12) but has become more of a public health concern with evidence of the nosocomial transmission of MDR and XDR TB in South Africa. Nosocomial transmission of drug-resistant TB has been reported from well-resourced settings (13), but this case highlights how migration of health care workers can link the 2 settings.
When taken together, the clinical and molecular epidemiologic data in this case support the hypothesis that infection was acquired in South Africa and most likely while the patient was based in Tugela Ferry. Health care workers in South Africa are signifi cantly more likely to be admitted to a hospital with MDR or XDR TB than are population controls (2), and this patient had prolonged occupational exposure at a hospital strongly associated with drug-resistant TB. Although F15/LAM4/KZN strains are frequent in South Africa, MDR versions of this genotype emerged in the KwaZulu-Natal Province in the mid-1990s, at the same time that the prevalence of HIV was increasing to hyperendemic levels and before antiretroviral therapy was widely available (8). The fact that this patient's isolate and the XDR strains from Tugela Ferry have different rpoB mutations suggests that these strains arose independently from the locally circulating F15/LAM4/KZN strain pool, as already suggested for other MDR F15/LAM4/KZN strains (7).
access to molecular diagnostic testing remains variable despite recent advances (15). The INNO-LiPA Rif.TB assay used here provided useful information with an indication of potential multidrug resistance. However, despite early molecular testing, identifi cation of MDR or XDR TB still depended on conventional methods of susceptibility testing.
Potentially toxic medications could have been avoided if more extensive molecular testing for resistance to secondline drugs (particularly quinolones and aminoglycosides) were achievable in close physical proximity to the patient. The poor outcome for MDR and XDR TB in HIVpositive patients is well recognized in disease-endemic settings (3), and this case confi rms the high risk for death even in well-resourced settings. This case also highlights defi ciencies in screening policies at national borders and within occupational health, particularly for health care workers not in permanent employment. Barriers to HIV and TB testing are multifactorial, and TB screening methods have limitations; nonetheless, in this situation, there were several missed opportunities for diagnosis of TB and HIV that could have prevented this patient's death.
This report serves as a reminder that XDR or MDR TB and HIV in sub-Saharan Africa represent not just a regional epidemic but also a challenge to international health. Although this challenge has yet to fully emerge, this case highlights the potential risk to health care workers in areas of low and high transmission.