zithromax and Fasciitis--Necrotizing

In 2016, we detected an outbreak of group A Streptococcus (GAS) invasive infections among the estimated 1000 persons experiencing homelessness (PEH) in Anchorage, Alaska. We characterized the outbreak and implemented a mass antibiotic intervention at homeless service facilities.. We identified cases through the Alaska GAS laboratory-based surveillance system. We conducted emm typing, antimicrobial susceptibility testing, and whole-genome sequencing on all invasive isolates and compared medical record data of patients infected with emm26.3 and other emm types. In February 2017, we offered PEH at 6 facilities in Anchorage a single dose of 1 g of azithromycin. We collected oropharyngeal and nonintact skin swabs on a subset of participants concurrent with the intervention and 4 weeks afterward.. From July 2016 through April 2017, we detected 42 invasive emm26.3 cases in Anchorage, 35 of which were in PEH. The emm26.3 isolates differed on average by only 2 single-nucleotide polymorphisms. Compared to other emm types, infection with emm26.3 was associated with cellulitis (odds ratio [OR], 2.5; P = .04) and necrotizing fasciitis (OR, 4.4; P = .02). We dispensed antibiotics to 391 PEH. Colonization with emm26.3 decreased from 4% of 277 at baseline to 1% of 287 at follow-up (P = .05). Invasive GAS incidence decreased from 1.5 cases per 1000 PEH/week in the 6 weeks prior to the intervention to 0.2 cases per 1000 PEH/week in the 6 weeks after (P = .01).. In an invasive GAS outbreak in PEH in Anchorage, mass antibiotic administration was temporally associated with reduced invasive disease cases and colonization prevalence.

Topics: Adolescent; Adult; Alaska; Anti-Bacterial Agents; Azithromycin; Bacterial Outer Membrane Proteins; Disease Outbreaks; Epidemiological Monitoring; Fasciitis, Necrotizing; Female; Humans; Ill-Housed Persons; Incidence; Male; Mass Drug Administration; Medical Records; Middle Aged; Polymorphism, Single Nucleotide; Prevalence; Streptococcal Infections; Streptococcus pyogenes; Whole Genome Sequencing; Young Adult

The ability of azithromycin, erythromycin, clarithromycin, or cefuroxime to modify the course of group A streptococcus (GAS) or Staphylococcus aureus soft-tissue infection was compared in a mouse model. In GAS-infected mice given azithromycin, fewer demonstrated dermonecrosis (P = 0.0004); the average weight gain was greater (P < 0.05) and the latency to sustained weight gain was shorter (P < 0.05) than for animals given other antibiotics. All antibiotics were effective against S. aureus infections, with no significant differences among treatments in parameters evaluated. The effectiveness of azithromycin in GAS-infected mice may be related to the high and sustained tissue concentrations achieved with this antibiotic.

Topics: Analysis of Variance; Animals; Anti-Bacterial Agents; Azithromycin; Cefuroxime; Clarithromycin; Disease Models, Animal; Erythromycin; Fasciitis, Necrotizing; Mice; Mice, Hairless; Skin Diseases; Staphylococcal Infections; Staphylococcus aureus; Streptococcus pyogenes

If the demonstration of the interest to treat beta-haemolytic streptococcal pharyngitis is not to be done, the recommended antibiotics, most of the time, display the drawback of a treatment with one to three intakes daily for 10 days. The azithromycin, with its numerous properties, allows for the required treatment duration, to decrease the intakes number, thus facilitating the compliance. Its in vitro activity is very good on streptococci with a MIC90 of 0.06 mg/l. Its in vivo activity in animal, with experimental Streptococcus pyogenes infection models is identical to the amoxicillin activity, and better than those of other tested macrolides. One of the major characteristics of azithromycin in man is its most peculiar pharmacokinetic with an extended half life and very high tonsillar concentrations, for at least 10 days after the administration of the product at the 1.5 g dose regimen over 3 days. In streptococcal acute tonsillitis clinical studies, with a 1.5 g dose regimen over 5 days, clinical results and bacterial eradication are identical to those obtained in the Penicillin V groups. This administration facility should greatly improve the treatment compliance and lower the risks of a prematurely discontinued treatment.

Topics: Animals; Anti-Bacterial Agents; Azithromycin; Disease Models, Animal; Fasciitis, Necrotizing; Female; Humans; Male; Mice; Penicillins; Skin Diseases, Infectious; Streptococcal Infections; Streptococcus pyogenes; Tonsillitis