Distinct clinical and epidemiological features of tuberculosis in New York City caused by the RDRio Mycobacterium tuberculosis sublineage

Abstract

Background Genetic tracking of Mycobacterium tuberculosis is a cornerstone of tuberculosis (TB) control programs. The RDRio M. tuberculosis sublineage was previously associated with TB in Brazil. We investigated 3847 M. tuberculosis isolates and registry data from New York City (NYC) (2001–2005) to: 1) affirm the position of RDRio strains within the M. tuberculosis phylogenetic structure, 2) determine its prevalence, and 3) define transmission, demographic, and clinical characteristics associated with RDRio TB. Methods Isolates classified as RDRio or non-RDRio M. tuberculosis by multiplex PCR were further classified as clustered (≥2 isolates) or unique based primarily upon IS6110-RFLP patterns and lineage-specific cluster proportions were calculated. The secondary case rate of RDRio was compared with other prevalent M. tuberculosis lineages. Genotype data were merged with the data from the NYC TB Registry to assess demographic and clinical characteristics. Results RDRio strains were found to: 1) be restricted to the Latin American-Mediterranean family, 2) cause approximately 8% of TB cases in NYC, and 3) be associated with heightened transmission as shown by: i) a higher cluster proportion compared to other prevalent lineages, ii) a higher secondary case rate, and iii) cases in children. Furthermore, RDRio strains were significantly associated with US-born Black or Hispanic race, birth in Latin American and Caribbean countries, and isoniazid resistance. Conclusions The RDRio genotype is a single M. tuberculosis strain population that is emerging in NYC. The findings suggest that expanded RDRio case and exposure identification could be of benefit due to its association with heightened transmission.

Mycobacterium tuberculosis of the RD Rio Genotype Is the Predominant Cause of Tuberculosis and Associated with Multidrug Resistance in Porto Alegre City, South Brazil

“…Unfortunately, the status of RD Rio in these strains is unknown, and the prevalence of RD Rio in these places is yet to be defined. Our hypothesis is that RD Rio strains are able to transmit more efficiently in certain ethnic populations such as U.S.-born blacks and Hispanics and persons who were born in Latin American and Caribbean countries as was previously demonstrated (24).…”

“…The high transmissibility of RD Rio strains is also suggested by studies showing an elevated secondary case rate in San Francisco, CA (38), and New York, NY (24), while a higher active-TB case rate in persons infected by RD Rio strains was described in The Gambia (30). In Brazil, strains carrying RD Rio have been isolated from one-third of the TB cases from two geographically distant metropolises (21,22), a rate similar to that observed in the present study.…”

“…Additional data from other groups also indicate that RD Rio could be associated with drug resistance. Gavín et al described MDR strains of M. tuberculosis RD Rio sublineage (LAM9 subfamily) in Spain from Equatorial Guinean patients (39), and Brown et al showed that LAM1 (a marker for RD Rio ) was associated with resistance to both pyrazinamide and streptomycin in MTB cases from London, United Kingdom (33), while the study performed in New York, NY, demonstrated that RD Rio was associated with resistance to isoniazid (24). Although this is a matter of speculation, it is interesting that a strain from LAM4, a subfamily that contains both WT and RD Rio strains, is the major cause of XDR-TB in South Africa (17) and that both LAM9 (predominantly RD Rio but also containing WT) and LAM1 (exclusively RD Rio ) subfamilies were major contributors to drug resistance in Russia (14,16).…”

“…An additional reason for studying the features of the spoligofamilies was the recent discovery of RD Rio , a subfamily inside the larger LAM spoligofamily, which seems to be prevalent in several places in Brazil (18)(19)(20)(21)(22)(23) but also in many other countries, particularly in Central and South America, Europe, and Africa (19 (24) as well as with drug resistance (24). To confirm and expand these findings, the present study was undertaken in Rio Grande do Sul (RS), the southernmost Brazilian state, for which no data on RD Rio status and characteristics exist.…”

Comparison of the socio-demographic and clinical features of pulmonary TB patients infected with sub-lineages within the W-Beijing and non-Beijing Mycobacterium tuberculosis

“…From a public health perspective, these tools are helping to identify clinical features of predominant or emerging genotypes [28,29] and their epidemiological associations with outbreaks, transmission routes, and MDR in many parts of the world [20,30]. The Beijing spoligotype family is frequently found in Asian regions, and it has been seen in every corner of the world.…”