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Objective:To describe the genomic analysis and epidemiologic response related to a slow and prolonged methicillin-resistant Staphylococcus aureus (MRSA) outbreak.Design:Prospective observational study.Setting:Neonatal intensive care unit (NICU).Methods:We conducted an epidemiologic investigation of a NICU MRSA outbreak involving serial baby and staff screening to identify opportunities for decolonization. Whole-genome sequencing was performed on MRSA isolates.Results:A NICU with excellent hand hygiene compliance and longstanding minimal healthcare-associated infections experienced an MRSA outbreak involving 15 babies and 6 healthcare personnel (HCP). In total, 12 cases occurred slowly over a 1-year period (mean, 30.7 days apart) followed by 3 additional cases 7 months later. Multiple progressive infection prevention interventions were implemented, including contact precautions and cohorting of MRSA-positive babies, hand hygiene observers, enhanced environmental cleaning, screening of babies and staff, and decolonization of carriers. Only decolonization of HCP found to be persistent carriers of MRSA was successful in stopping transmission and ending the outbreak. Genomic analyses identified bidirectional transmission between babies and HCP during the outbreak.Conclusions:In comparison to fast outbreaks, outbreaks that are “slow and sustained” may be more common to units with strong existing infection prevention practices such that a series of breaches have to align to result in a case. We identified a slow outbreak that persisted among staff and babies and was only stopped by identifying and decolonizing persistent MRSA carriage among staff. A repeated decolonization regimen was successful in allowing previously persistent carriers to safely continue work duties.

Citrus leprosis diseased caused by citrus leprosis virus (CiLV) is considered one of the most destructive diseases of citrus. The putative vectors (Brevipalpus spp.) are present in the major citrus producing states in the U.S.A. Recently, Citrus leprosis virus C2 (CiLV-C2) Hibiscus strain, a virus with a high degree of homology with CiLV, was found infecting hibiscus in Florida and Hawaii. Hibiscus is an important ornamental plant generating over $21 billion (2010–2015) for the Florida nursery industry. We studied the presence of the CiLV-C2 vector Brevipalpus yothersi on hibiscus hedges located in south Florida to determine if hibiscus could be a reservoir for leprosis vectors and if predators and environmental conditions affect the population dynamics of the vector. For two years, samples were taken monthly from 3 hibiscus hedges. All Brevipalpus mites and known predatory mites were counted from three locations in the canopy (top, middle and bottom). Weather data was collected from local weather stations. Brevipalpus mites were always found on hibiscus but in very low numbers. The populations of B. yothersi were similar in all areas of the canopy but were different at the three locations. Humidity and precipitation did not explain changes in B. yothersi populations. Brevipalpus yothersi growth rate increased with temperature with a predicted peak at 26.1°C. Predators populations increased with increases in B. yothersi population. Hibiscus hedges appear to serve as a reservoir for predators. Higher temperatures that could occur with climate change could lead to an exponential increase in the abundance of B. yothersi.