TY - JOUR
T1 - Group A streptococcal infections in injection drug users in Barcelona, Spain
T2 - Epidemiologic, clinical, and microbiologic analysis of 3 clusters of cases from 2000 to 2003
AU - Sierra, Josep M.
AU - Sánchez, Francesca
AU - Castro, Pedro
AU - Salvadó, Margarita
AU - De La Red, Gloria
AU - Libois, Agnes
AU - Almela, Manuel
AU - March, Francesca
AU - Español, Montserrat
AU - Sambeat, Maria Antonia
AU - Romeu, Joan
AU - Brugal, Maria Teresa
AU - De Olalla, Patricia García
AU - Gatell, Jose Maria
AU - Vila, Jordi
AU - García, Felipe
AU - Colomés, Jose Luís López
AU - Caylà, Joan A.
AU - Coll, Pere
PY - 2006/5
Y1 - 2006/5
N2 - An unexplained resurgence of Group A streptococci (GAS) infections has been observed since the mid-1980s in the United States and Europe, particularly among intravenous drug users (IDUs). Several risk factors have been identified. Mutations in the capsule synthesis regulator genes (csrRS) have been associated with an increase in virulence. From January 1998 to December 2003, we conducted a prospective and retrospective descriptive analysis of invasive GAS soft-tissue infections in IDUs in Barcelona, Spain. Clinical features were collected, and we conducted a surveillance study to identify risk factors associated with GAS soft-tissue infections. We analyzed chromosomal DNA by low cleavage restriction enzymes and used pulsed-field gel electrophoresis (PFGE) and variable gene sequence typing (VGST) of the emm gene to disclose the epidemiologic relationship between the strains. We analyzed the influence of clonality (M-type) and mutations in csrRS genes of these strains on clinical features. We identified 44 cases, all of which were grouped in 3 clusters: fall 2000, fall 2002, and fall 2003. Cellulitis with or without abscesses (75%) and fever (90.9%) were the most common clinical manifestations. Distant septic complications were infrequent (18.2%). Although all patients had severe infections (mainly bacteremic needle abscesses), their outcome with antibiotic therapy, usually β-lactam, was successful in all cases. However, surgery was needed in 40.9% of patients.Through the surveillance study we found that infected patients had a higher number of drug injections per day (odds ratio [OR], 18.84; 95% confidence interval [CI], 4.83-79.4; p < 0.00001), shared paraphernalia for drug use more frequently (OR, 11.11; 95% CI, 3.24-39.04; p < 0.0001), were in a higher proportion both currently unemployed and homeless (OR, 4.22; 95% CI, 1.5-12.15; p < 0.0001), were not in a methadone maintenance program (OR, 0.03; 95% CI, 0-0.19; p < 0.00001), and more often bought drugs at a specific site (OR, 33.92; 95% CI, 7.44-174.93; p < 0.00001) and from a specific dealer (OR, 72; 95% CI, 8-3090; p < 0.00001), compared with patients not infected. The fall 2000 cluster was polyclonal, whereas the other 2 clusters were mainly due to the same strain of GAS (emm 25.2), and were defined as epidemic outbreaks. Clinically, the cases due to the clonal strain presented abscesses and needed surgery more frequently (p < 0.001 and p ≤ 0.005, respectively). On the other hand, mutations in the csrRS genes were not associated with invasive GAS soft-tissue infection. There has been an increase in the number of cases of invasive GAS soft-tissue infections in IDUs in Barcelona, which seems to be related to drug users' habits and their socioeconomic status. Clonality (emm 25.2) but not mutations in the csrRS genes was associated with more severe GAS soft-tissue infections.
AB - An unexplained resurgence of Group A streptococci (GAS) infections has been observed since the mid-1980s in the United States and Europe, particularly among intravenous drug users (IDUs). Several risk factors have been identified. Mutations in the capsule synthesis regulator genes (csrRS) have been associated with an increase in virulence. From January 1998 to December 2003, we conducted a prospective and retrospective descriptive analysis of invasive GAS soft-tissue infections in IDUs in Barcelona, Spain. Clinical features were collected, and we conducted a surveillance study to identify risk factors associated with GAS soft-tissue infections. We analyzed chromosomal DNA by low cleavage restriction enzymes and used pulsed-field gel electrophoresis (PFGE) and variable gene sequence typing (VGST) of the emm gene to disclose the epidemiologic relationship between the strains. We analyzed the influence of clonality (M-type) and mutations in csrRS genes of these strains on clinical features. We identified 44 cases, all of which were grouped in 3 clusters: fall 2000, fall 2002, and fall 2003. Cellulitis with or without abscesses (75%) and fever (90.9%) were the most common clinical manifestations. Distant septic complications were infrequent (18.2%). Although all patients had severe infections (mainly bacteremic needle abscesses), their outcome with antibiotic therapy, usually β-lactam, was successful in all cases. However, surgery was needed in 40.9% of patients.Through the surveillance study we found that infected patients had a higher number of drug injections per day (odds ratio [OR], 18.84; 95% confidence interval [CI], 4.83-79.4; p < 0.00001), shared paraphernalia for drug use more frequently (OR, 11.11; 95% CI, 3.24-39.04; p < 0.0001), were in a higher proportion both currently unemployed and homeless (OR, 4.22; 95% CI, 1.5-12.15; p < 0.0001), were not in a methadone maintenance program (OR, 0.03; 95% CI, 0-0.19; p < 0.00001), and more often bought drugs at a specific site (OR, 33.92; 95% CI, 7.44-174.93; p < 0.00001) and from a specific dealer (OR, 72; 95% CI, 8-3090; p < 0.00001), compared with patients not infected. The fall 2000 cluster was polyclonal, whereas the other 2 clusters were mainly due to the same strain of GAS (emm 25.2), and were defined as epidemic outbreaks. Clinically, the cases due to the clonal strain presented abscesses and needed surgery more frequently (p < 0.001 and p ≤ 0.005, respectively). On the other hand, mutations in the csrRS genes were not associated with invasive GAS soft-tissue infection. There has been an increase in the number of cases of invasive GAS soft-tissue infections in IDUs in Barcelona, which seems to be related to drug users' habits and their socioeconomic status. Clonality (emm 25.2) but not mutations in the csrRS genes was associated with more severe GAS soft-tissue infections.
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U2 - 10.1097/01.md.0000224707.24392.52
DO - 10.1097/01.md.0000224707.24392.52
M3 - Article
C2 - 16721256
AN - SCOPUS:33744828954
SN - 0025-7974
VL - 85
SP - 139
EP - 146
JO - Medicine (United States)
JF - Medicine (United States)
IS - 3
ER -