The Cost-Effectiveness of Universal Screening of Healthy Term Newborn Infants for Nasal MRSA Colonization at Birth – 20 months Data

Background: Community-associated Methicillin Resistant Staphylococcus aureus (CA-MRSA) infections are increasing in frequency. The impact of universal screening to detect nasal (N) MRSA colonization (C) among newborns (NBs) is not well characterized.

Objective: To determine the cost-effectiveness of universal nasal MRSA C screening of healthy term NBs at birth.

Methods: All pregnant women admitted to L&D and their NB admitted to the nursery (NBN) from 12/01/07- 08/31/09 were screened for N MRSA C by using the Cepheid GeneXpert rapid PCR. The cost of the MRSA screening test was obtained from the microbiology laboratory. The transmission rate (TR) of MRSA was calculated based on the estimates by Jernigan et al (0.14 patient-per-day for an unrecognized C NB, 0.009 for a recognized NB in isolation precautions). Microbiology laboratory data were also reviewed to detect any MRSA invasive infections in NBs less than 48 hours of age.

Results: A total of 2110 babies were born from 12/07 to 8/09. N MRSA surveillance screens were ordered in 2031 (compliance rate of 96%). 1660 of the total NB’s were admitted to our NBN & 450 to the NICU, however only 1582 NB’s were used in cost benefit analysis as 78 were in the NICU at some point in time. 4 of 2031 (0.2%) NB tested positive for MRSA C. Mothers (M) of 3 of these NBs had positive nasal screen (NS) at admission to L & D and the 4th NB’s M had negative NS but history of perineal abscess one week before delivery. 2 colonized NBs were born at term and the other 2 NBs were preterm (admitted to the NICU & would have been tested for MRSA C under the current mandate ). Thus, only 2 positive tests were used for the cost benefit analysis of NB screening. The total cost of screening for the study period (for the 1582 NB) for our health system (HS) was $ 79,500 ($50/test) & for payers (PY) was $ 318,000 ($200/test). Thus, the cost of detection of a carrier for HS was $39,750 & for PY $159,000. The average length of stay in our NBN is 2.1 days. The two colonized NBs stayed for a total of 3 days in the hospital. If there is no universal screening in effect, according to Jernigan et al TR estimates, 0. 42 days of transmissions of MRSA would have occurred based on the three patient days not spent in isolation during the study period. It would take 7971 patient days (3.99 years) to prevent one MRSA transmission day at the cost of $ 189,800 for our HS & $759,200 for PY. In addition, there were no cases of MRSA bacteremia or invasive disease among NBs admitted to our nursery from 12/07 through 08/09.

Conclusions: Our data indicates that MRSA C/infection of NB at birth is extremely uncommon despite the increasing incidence of CA-MRSA infections. Universal NB screening for MRSA C appears unnecessary and is not cost-effective for HS and PY at this time based on the low incidence, short hospital stay & lack of invasive disease in term NBs. Furthermore our data suggest that maternal C/ disease status is highly predictive of the NB’s status.