Human Tuberculosis Caused by Mycobacterium bovis, Taiwan

Human Tuberculosis Caused by Mycobacterium bovis, Taiwan

results for Japanese encephalitis virus-specifi c IgM. Of the 11 patients, 10 had no history of travel to India or other dengue-endemic countries. DF or DHF was initially diagnosed for 7 patients, and viral encephalitis, typhoid fever, or viral fever was diagnosed for others without serologic tests. Reverse transcription-PCR and virus isolation were performed at Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan, but the dengue virus genome was not detected, and no virus was isolated, likely because sample collection was delayed and the sample was transported to Japan in a deteriorated condition.
DF/DHF have been considered to be a possible public health threat to Nepal because DF/DHF epidemics have occurred recently in India and Pakistan, which reported several thousand cases and >100 deaths (6). The fi rst DF case in Nepal was reported in 2004 (7). Further, the fi rst DENV-2 strain of Nepal origin was isolated from a Japanese traveler who visited Nepal and in which DF developed after the patient returned to Japan. The isolated DENV-2 (GenBank accession no. AB194882) was 98% homologous with DENV-2 isolated in India (8). The prevalence of dengue virus antibody was reported to be 10.4% in the southwestern region of Nepal (9). These reports suggest that dengue virus has been circulating in Nepal for several years. Thus, DF/DHF has likely been misdiagnosed and illness caused by dengue virus underestimated in Nepal. In contrast, Japanese encephalitis has been a public health problem in southwestern region of Nepal, and large epidemics have occurred almost every year since 1978 (10). Nepal has no dengue surveillance programs, and health professionals do not usually consider dengue as a differential diagnosis.

Basu
Aboriginal persons in Taiwan were more likely to have TB caused by M. bovis and had a 5-fold higher reporting rate for TB (9) than nonaboriginal persons. Environmental and genetic factors may be associated with a higher reporting rate for TB among aboriginal populations (10), but the contribution of M. bovis infection needs to be investigated. Because only 1 major spoligotype and 2 similar MIRU patterns were found in this case series, spread of a predominant clone in Taiwan is likely. In addition, because of insuffi cient epidemiologic data, we were unable to determine the proportion of cases caused by reactivation of latent infection and those caused by recent transmission. In our study population, M. bovis infection in humans appeared to be predominately indigenous in Taiwan because no imported case was noted. We are now 516 Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 14, No. 3, March 2008

Marine Mammal Brucella Genotype Associated with Zoonotic Infection
To the Editor: Brucellosis is a zoonotic disease that remains endemic to many parts of the world. There are 6 classic Brucella species described with different preferred hosts. Human disease is most commonly associated with consumption of unpasteurized dairy products or with occupational exposure for veterinarians, agricultural workers, laboratory workers, meat industry workers, and hunters.
In recent years, it has become clear that novel members of the genus, yet to be formally named, are associated with a variety of marine mammal species, particularly dolphins, por-poises, and seals (1). To date there are 3 reports in the literature of naturally acquired infection of humans with Brucella species originating from marine mammals (2,3) One other case, representing infection of a laboratory worker, has also been reported (4). Two of the naturally acquired cases were reported in Peru (2). One person had consumed raw shellfi sh and swam in the Pacifi c Ocean but did not report any direct contact with marine mammals; the second person reported infrequent visits to the coast and no contact with marine mammals but had consumed raw shellfi sh. An additional naturally acquired case was recently reported from New Zealand, where extensive molecular testing characterized the strain involved as a marine mammal type (3). This patient again reported no exposure to marine mammals but did report that he fi shed regularly, had contact with uncooked fi sh bait, and consumed raw snapper. The cases in Peru were notable for severe, atypical symptoms; both patients had symptoms of neurobrucellosis. The New Zealand case was associated with spinal osteomyelitis (3). In contrast, the laboratory-acquired infection was mild and uncomplicated (4).
We have characterized these isolates by a variety of molecular approaches in conjunction with ongoing studies, which examine genetic diversity within Brucella species isolated from marine mammals. Multilocus sequence analysis (5) showed that all 3 isolates from naturally acquired human infection with Brucella species from marine mammals shared an identical genotype (ST27). In previous characterization of 56 Brucella isolates from marine mammals, ST27 was found only once. Strain F5/99, originally isolated from an aborted bottlenose dolphin fetus off the western coast of the United States (6), shares this genotype. Use of an alternative typing approach, based on restriction fragment length polymorphism analysis of outer membrane protein-encoding genes