Impact of vaccine effectiveness and coverage on preventing large mumps outbreaks on college campuses: Implications for vaccination strategy.

Recent mumps outbreaks among highly vaccinated populations, including college students, have called into question the vaccine effectiveness (VE) of routine two-dose measles, mumps, and rubella (MMR2) immunization. We aimed to estimate the VE required for a novel vaccination strategy (e.g., MMR booster dose, novel vaccine) to prevent large mumps outbreaks on college campuses. Using mumps college outbreak data reported to the U.S. Centers for Disease Control and Prevention during 2016-2017, we estimated current MMR2 VE using the screening method and implemented a compartmental model of mumps transmission. We performed 2000 outbreak simulations, following introduction of an infectious person to a population of 10,000, over ranges of MMR2 vaccine coverage (VC) and VE (30.0-99.0%). We compared the impact of varying VC and VE on mumps and mumps orchitis case counts and determined VE thresholds that ensured < 5.0% and < 2.0% of the outbreak simulations exceeded 20 and 100 mumps cases. Median estimated MMR2 VE in reported mumps outbreaks was 60.5% and median reported MMR2 VC was 97.5%. Simulated mumps case count was more sensitive to changes in VE than in VC. The opposite was true for simulated mumps orchitis case count, though orchitis case count was small (mean <10 cases across simulations for VE near 60.5% and VC near 97.5%). At 97.5% VC, 73.1% and 78.2% VE were required for < 5.0% and < 2.0% of outbreaks, respectively, to exceed 100 mumps cases. Maintaining 97.5% VC, 82.4% and 85.9% VE were required for < 5.0% and < 2.0% of outbreaks, respectively, to exceed 20 cases. We conclude that maintaining current levels of MMR2 VC, a novel vaccination strategy aimed at reducing mumps transmission must achieve at least 73.1-85.9% VE among young adults to prevent large mumps outbreaks on college campuses.

Differences in gram-positive bacterial colonization and antimicrobial resistance among children in a high income inequality setting.

BACKGROUND: Staphylococcus aureus and beta-hemolytic streptococci (BHS) diseases disproportionately affect populations in middle/low-income countries. To assess if this disparity is reflected in colonization by these organisms, we compared their colonization frequency among children from different socioeconomic status (SES) communities in a city with high income inequality. METHODS: Between May-August 2014, we collected nasal and throat swabs to investigate S. aureus and BHS colonization among children who attended private and public pediatric clinics. Patients were classified as high SES, middle/low SES, and slum residents. We investigated the antimicrobial resistance profile, the SCCmec types and the presence of PVL genes among methicillin-resistant S. aureus (MRSA). We also examined the antimicrobial resistance profile and serogroups of BHS. RESULTS: Of 598 children, 221 (37%) were colonized with S. aureus, of which 49 (22%) were MRSA. MRSA colonization was higher in middle/low SES (n = 18; 14%) compared with high SES (n = 17; 6%) and slum (n = 14; 8%) residents (p = 0.01). All MRSA strains were susceptible to clindamycin, nitrofurantoin, and rifampin. The highest non-susceptibility frequency (42.9%) was observed to erythromycin. SCCmec type V was only found in isolates from high SES children; types I and II were found only in middle/low SES children. Ten (20%) MRSA isolates carried PVL genes. Twenty-four (4%) children were BHS carriers. All BHS (n = 8) found in high SES children and six (67%) isolates from slum patients belonged to group A. All group B streptococci were from middle/low SES children, corresponding to five (71%) of the seven BHS isolated in this group. BHS isolates were susceptible to all drugs tested. CONCLUSIONS: Children from different SES communities had distinct bacterial colonization profiles, including MRSA carriage. Public health officials/researchers should consider SES when assessing disease transmission and control measures.

High prevalence of Staphylococcus aureus and methicillin-resistant S. aureus colonization among healthy children attending public daycare centers in informal settlements in a large urban center in Brazil.

BACKGROUND: In the past decade methicillin-resistant Staphylococcus aureus (MRSA) has become increasingly prevalent in community settings. Attending a daycare center (DCC) is a known risk factor for colonization with MRSA. Brazil operates free, public DCCs for low-income families, some of which are located in census tracts defined by the Brazilian Census Bureau as informal settlements (aglomerados subnormais, AGSN). Physical and demographic characteristics of AGSNs suggest that S. aureus colonization prevalence would be higher, but little is known about the prevalence of MRSA in these settings. METHODS: We conducted a cross-sectional study to assess risk factors for S. aureus and MRSA colonization among children attending DCCs located in AGSN vs non-AGSN. Nasal swabs were collected from children aged three months to six years in 23 public DCCs in Niterói, Brazil between August 2011 and October 2012. RESULTS: Of 500 children enrolled in the study, 240 (48%) were colonized with S. aureus and 31 (6.2%) were colonized with MRSA. Children attending DCCs in AGSNs were 2.32 times more likely to be colonized with S. aureus (95% CI: 1.32, 4.08), and 3.27 times more likely to be colonized with MRSA than children attending non-AGSN DCCs (95% CI: 1.52, 7.01), adjusted for confounding variables. CONCLUSION: S. aureus and MRSA colonization prevalence among children attending DCCs in informal settlement census tracts was higher than previously reported in healthy pre-school children in Latin America. Our data suggest that transmission may occur more frequently in DCCs rather than at home, highlighting the importance of DCCs in AGSNs as potential MRSA reservoirs. This finding underscores the importance of local epidemiologic surveillance in vulnerable AGSN communities.

Risk factors for Staphylococcus aureus and methicillin-resistant S aureus colonization among health care workers in pediatrics departments.

Risk factors for Staphylococcus aureus and methicillin-resistant S aureus (MRSA) were evaluated for 178 health care workers from a public hospital pediatrics department in Brazil. Colonization rates were 33.1% for S aureus and 5.1% for MRSA. Risk factors for S aureus colonization differed from those for MRSA. Results suggest nurses with prolonged pediatric patient contact in inpatient units are at higher risk for MRSA colonization.

Divergent profile of emerging cutaneous leishmaniasis in subtropical Brazil: new endemic areas in the southern frontier.

BACKGROUND: Although known to be highly endemic in the Amazon regions of Brazil, the presence of cutaneous leishmaniasis (CL) in the subtropical southern part of the country has largely been ignored. This study was conducted to demonstrate CL is emerging in the Brazilian state of Santa Catarina, as well as to characterize the epidemiological profile and Leishmania species involved. METHODOLOGY/PRINCIPAL FINDINGS: For this cross-sectional study, data from all CL cases from Santa Catarina, Brazil, reported to the Brazilian National Notifiable Diseases Information System from 2001 to 2009 were investigated. Amplification of the kDNA minicircle conserved region followed by restriction fragment length polymorphism (PCR-RFLP) was conducted to screen for Leishmania species present in patient biopsy. Overall, 542 CL cases were reported, with majority resulting from autochthonous transmission (n = 401, 73.99%) and occurring in urban zones (n = 422, 77.86%). Age, gender, zone of residence, origin of case, clinical form and case outcome were found to differ significantly by region. Imported cases were over seven times more likely to relapse (95% CI 2.56-21.09). Mapping of cases revealed new endemic areas in northeastern Santa Catarina with two species present. With the exception of three L. (Leishmania) amazonensis cases (1.20%), majority of PCR positive samples were found to be L. (Viannia) braziliensis (n = 248, 98.80%). CONCLUSIONS/SIGNIFICANCE: CL is now endemic in the state of Santa Catarina, Brazil, with case profiles varying significantly by region. L. (V.) braziliensis has been identified as the predominant species in the region.