Nationwide HIV-, MDR-TB survey in Japan and collaborative study in the Philippines

Although the prevalence of pulmonary tuberculosis (TB) and HIV infection in Japan is low, careful monitoring of these two diseases is necessary. We conducted a nationwide survey on multidrug resistant (MDR)-TB (2011-2013) and HIV-TB (2007-2014) to understand the mode of prevention and the effect of therapy. A study on MDR-TB and HIV in San Lazaro Hospital (SLH) in the Philippines was also conducted. These studies introduced an international collaborative study against the global epidemics of HIV-TB/MDR-TB.

The nationwide survey of MDR-TB was done in hospitals that treat TB patients in Japan from 2011 to 2013. The HIV-TB survey has been done every year since 2007. Classic information such as chest X-ray (CXR) as well as computed tomography (CT) results for each patient were analyzed. Likewise, the presence of a cavity, involved segments, and patterns of parenchymal lesion were assessed. Finally, tentative diagnosis and disease activity, bronchogenic spread of the lesion with CT, and bronchiectasis were recorded. At SLH, sputa of suspected cases were subjected to GeneXpert testing and HIV testing was performed on all TB patients.

In the nationwide MDR survey in Japan, 171 patients were diagnosed as pulmonary MDR-TB (0.2% of total Mycobacterium tuberculosis (MTB) in Japan). Among them, 48 (28%) were foreigners and most were living in big cities. In Tokyo metropolitan areas, 27 out of 53 MDR-TB patients were foreigners: 13 were from China, 4 from the Philippines, and 3 from Myanmar. Thirty nine among 53 MDR-TB patients were cured or treatment was completed with favorable prognosis. Five deaths (9.4%) and six departures from Japan (11.3%) were noted. In the HIV-TB survey in National Hospitals, the HIV-positive rates on MTB were constantly low (0.23-0.46%) from 2007 to 2014. Among the reported 114 HIV-TB patients (0.37% of total MTB in National Hospitals), 17 were foreigners and 3 (2.6%) were MDR-TB cases (2 Chinese, 1 Japanese). Half of the HIV-TB patients have low CD4 cell numbers (<100/μL). Two out of the 3 MDR-TB patients were cured. Imme reconsitution inflammatory syndrome (IRIS) was found in 48% of all HIV-TB cases. At SLH in the Philippines, total numbers of GeneXpert examined cases were 1052 cases in 2015, and 122 Rifampicin resistant (RR)-TB cases (11.6%) were found and among the enrolled 96 cases 14 (15%) were found to be HIV positive.

Very low numbers of TB or HIV patients have been observed in Japan. An increasing number of foreign-born MDR-TB patients in the country was found. To combat against these global epidemics, an international collaboration against HIV-TB/MDR-TB is needed.