Final Diagnosis -- Mycobacterium caprae meningoencephalitis

DIAGNOSIS CSF culture identified Mycobacterium caprae (Loewenstein-Jensen culture positive after 21 days).

The final diagnosis was Mycobacterium caprae meningoencephalitis due to reactivation in a single paratracheal lymph node (diameter of 1,5cm). Autopsy did not show any other lesion.

On further inquiry, his wife admitted that the patient had been involved in euthanizing cattle which had been infected with Mycobacteria in his livestock in the early 60s. After this event, he had stopped cattle breeding. Otherwise, she could not re-member any occasion, where he could have been infected.

DISCUSSION

M. caprae is a cluster within the M. tuberculosis complex. M. caprae was mainly recognized in domestic and wild animals of continental Europe. A recent Spanish study reported M. caprae isolates in 7.4% of M. tuberculosis positive animals³. It was found most often in cattle, followed by goats, sheep, pigs, wild boars, one red deer and one fox. M. caprae was almost never identified outside Europe (except from a European patient in Australia and a cow in Algeria).

The clinical picture of pulmonary M. bovis and M. caprae infections in humans is identical to M. tuberculosis. However, human-to-human transmission is very rare and mainly found in immunocompromised cases¹. Likely means of transmission are contact with livestock and contaminated food (especially milk). In Germany, between 1999 and 2001 46 patients were identified in suffering M. caprae infections, 35 of them between 61 and 80 years old². In the same series in 166 patients suffering M. bovis or M. caprae, only 4 had CNS involvement. To our knowledge, this is the only case with suspected M. caprae reactivation infecting CNS after decades.

A positive QuantiFERONŽ serum reaction after transfer to the neurological intensive care unit hinted to a Mycobacterium infection and tuberculostatic treatment with Isoniacid, Rifampicin and Ethambutol was started consecutively. Despite appropriate therapy, meningoencephalitis progressed with fatal outcome.

REFERENCES

1. Evans JT, Smith EG, Banerjee A et al. Cluster of human tuberculosis caused by Mycobacterium bovis: evidence for person-to-person transmission in the UK. Lancet 2007; 369: 1270-1276.
2. Kubica T, Rusch-Gerdes S, Niemann S. Mycobacterium bovis subsp. caprae caused one-third of human M. bovis-associated tuberculosis cases reported in Germany between 1999 and 2001. J.Clin.Microbiol. 2003; 41: 3070-3077.
3. Rodriguez S, Bezos J, Romero B et al. Mycobacterium caprae infection in livestock and wildlife, Spain. Emerg.Infect.Dis. 2011; 17: 532-535.

Contributed by W. Struhal, MD, M. Vosko, MD, PhD, M. Mitterhumer, MD, G. Syre, Prof. MD, D. Zeiner, MD, Daniel Floery, MD, Franz Fellner, Prof. MD, G. Ransmayr, Prof. MD, F. Gruber, MD