Healthcare personnel with laboratory-confirmed mpox in California during the 2022 outbreak.

The California Department of Public Health (CDPH) reviewed 109 cases of healthcare personnel (HCP) with laboratory-confirmed mpox to understand transmission risk in healthcare settings. Overall, 90% of HCP with mpox had nonoccupational exposure risk factors. One occupationally acquired case was associated with sharps injury while unroofing a patient's lesion for diagnostic testing.

Sexual Exposures Associated With Mpox Infection: California, November 2022 to June 2023.

BACKGROUND: Exposures associated with mpox infection remain imperfectly understood. METHODS: We conducted a case-control study enrolling participants who received molecular tests for mpox/orthopoxvirus in California from November 2022 through June 2023. We collected data on behaviors during a 21-day risk period before symptom onset or testing among mpox case patients and test-negative controls. RESULTS: Thirteen of 54 case patients (24.1%) and 5 of 117 controls (4.3%) reported sexual exposure to individuals they identified as potential mpox case patients ("index contacts"; odds ratio [OR], 7.7 [95% confidence interval (CI), 2.5-19.3] relative to individuals who did not report exposure to potential mpox case patients). Among these participants, 10 of 13 case patients (76.9%) and 2 of 5 controls (40.0%) reported that their index contacts were not experiencing symptoms visible to participants during sex (OR, 14.9 [95% CI, 3.6-101.8]). Only 3 of 54 case patients (5.6%) reported exposure to symptomatic index contacts. Case patients reported more anal/vaginal sex partners than did controls (adjusted OR, 2.2 [95% CI, 1.0-4.8] for 2-3 partners and 3.8 [1.7-8.8] for ≥4 partners). Male case patients with penile lesions more commonly reported insertive anal/vaginal sex than those without penile lesions (adjusted OR, 9.3 [95% CI, 1.6-54.8]). Case patients with anorectal lesions more commonly reported receptive anal sex than those without anorectal lesions (adjusted OR, 14.4 [95% CI, 1.0-207.3]). CONCLUSIONS: Sexual exposure to contacts known or suspected to have experienced mpox was associated with increased risk of infection, often when index contacts lacked apparent symptoms. Exposure to more sex partners, including those whom participants did not identify as index contacts, was associated with increased risk of infection in a site-specific manner. While participants' assessment of symptoms in partners may be imperfect, these findings suggest that individuals without visibly prominent mpox symptoms transmit infection.

Reduced Odds of Mpox-Associated Hospitalization Among Persons Who Received JYNNEOS Vaccine - California, May 2022-May 2023.

The effectiveness of 1 dose of JYNNEOS vaccine (modified vaccinia Ankara vaccine, Bavarian Nordic) against hospitalization for mpox (caused by Monkeypox virus), has been demonstrated; however, the impact of 2 doses on hospitalization risk, especially among persons infected with HIV, who are at higher risk for severe disease, is an important factor in evaluating vaccine effectiveness against mpox disease severity and Monkeypox virus infection. Surveillance data collected by the California Department of Public Health were used to evaluate whether receipt of 2 doses of JYNNEOS vaccine reduced the odds of hospitalization among persons with mpox. The odds of hospitalization among persons with mpox who had received 1 or 2 JYNNEOS doses were 0.27 (95% CI = 0.08-0.65) and 0.20 (95% CI = 0.01-0.90), respectively, compared with unvaccinated mpox patients. In mpox patients with HIV infection, the odds of hospitalization among those who had received 1 JYNNEOS vaccine dose was 0.28 (95% CI = 0.05-0.91) times that of those who were unvaccinated. No mpox-associated hospitalizations were identified among persons infected with HIV who had received 2 JYNNEOS vaccine doses. To optimize durable immunity, all eligible persons at risk for mpox, especially those infected with HIV, should complete the 2-dose JYNNEOS series.

Comparing 7-Day Versus 6-8-Day Penicillin Treatment Intervals Among Pregnant People With Syphilis of Late or Unknown Duration: No Difference Found in Incidence of Congenital Syphilis.

Background: Guidelines recommend that pregnant patients with syphilis of late/unknown duration be treated with benzathine penicillin G, dosed as 3 weekly intramuscular injections (BPGx3) given ideally at strict 7-day intervals. Given limited pharmacokinetic data, it is unknown whether more flexible BPG treatment intervals might be effective in preventing congenital syphilis (CS). Methods: We used California surveillance data to identify birthing parent/infant dyads wherein the pregnant parent had syphilis of late/unknown duration between January 1, 2016 - June 30, 2019. We divided the dyads into 3 groups based on prenatal treatment: (1) BPGx3 at strict 7-day intervals, (2) BPGx3 at 6-8 day intervals, and (3) no/inadequate treatment. We then compared CS incidence among infants in each group. Results: We analyzed 1,092 parent/infant dyads: 607 (55.6%) in the 7-day treatment group, 70 (6.4%) in the 6-8 day treatment group, and 415 (38.0%) in the no/inadequate treatment group. The incidence proportion of infants meeting CS criteria in each group was, respectively, 5.6%, 5.7%, and 36.9%. Compared with BPGx3 at 7-day intervals, the odds of CS were 1.0 [95% CI 0.4-3.0] in the 6-8 day group and 9.8 [95% CI 6.6-14.7] in the no/inadequate treatment group. Conclusions: Prenatal BPGx3 at 6-8 days was no more likely to lead to CS in infants than 7-days. These findings hint that 6-8-day intervals might be adequate to prevent CS among pregnant people with syphilis of late/unknown duration. Consequently, it is possible that CS evaluation beyond an RPR at delivery may be unnecessary in asymptomatic infants whose parents received BPGx3 at 6-8 days.

HIV and Sexually Transmitted Infections Among Persons with Monkeypox - Eight U.S. Jurisdictions, May 17-July 22, 2022.

High prevalences of HIV and other sexually transmitted infections (STIs) have been reported in the current global monkeypox outbreak, which has affected primarily gay, bisexual, and other men who have sex with men (MSM) (1-5). In previous monkeypox outbreaks in Nigeria, concurrent HIV infection was associated with poor monkeypox clinical outcomes (6,7). Monkeypox, HIV, and STI surveillance data from eight U.S. jurisdictions* were matched and analyzed to examine HIV and STI diagnoses among persons with monkeypox and assess differences in monkeypox clinical features according to HIV infection status. Among 1,969 persons with monkeypox during May 17-July 22, 2022, HIV prevalence was 38%, and 41% had received a diagnosis of one or more other reportable STIs in the preceding year. Among persons with monkeypox and diagnosed HIV infection, 94% had received HIV care in the preceding year, and 82% had an HIV viral load of <200 copies/mL, indicating HIV viral suppression. Compared with persons without HIV infection, a higher proportion of persons with HIV infection were hospitalized (8% versus 3%). Persons with HIV infection or STIs are disproportionately represented among persons with monkeypox. It is important that public health officials leverage systems for delivering HIV and STI care and prevention to reduce monkeypox incidence in this population. Consideration should be given to prioritizing persons with HIV infection and STIs for vaccination against monkeypox. HIV and STI screening and other recommended preventive care should be routinely offered to persons evaluated for monkeypox, with linkage to HIV care or HIV preexposure prophylaxis (PrEP) as appropriate.

Epidemiologic and environmental characterization of the Re-emergence of St. Louis Encephalitis Virus in California, 2015-2020.

St. Louis encephalitis virus (SLEV) is an endemic flavivirus in the western and southeastern United States, including California. From 1938 to 2003, the virus was detected annually in California, but after West Nile virus (WNV) arrived in 2003, SLEV was not detected again until it re-emerged in Riverside County in 2015. The re-emerging virus in California and other areas of the western US is SLEV genotype III, which previously had been detected only in Argentina, suggesting a South American origin. This study describes SLEV activity in California since its re-emergence in 2015 and compares it to WNV activity during the same period. From 2015 to 2020, SLEV was detected in 1,650 mosquito pools and 26 sentinel chickens, whereas WNV was detected concurrently in 18,108 mosquito pools and 1,542 sentinel chickens from the same samples. There were 24 reported human infections of SLEV in 10 California counties, including two fatalities (case fatality rate: 8%), compared to 2,469 reported human infections of WNV from 43 California counties, with 143 fatalities (case fatality rate: 6%). From 2015 through 2020, SLEV was detected in 17 (29%) of California's 58 counties, while WNV was detected in 54 (93%). Although mosquitoes and sentinel chickens have been tested routinely for arboviruses in California for over fifty years, surveillance has not been uniform throughout the state. Of note, since 2005 there has been a steady decline in the use of sentinel chickens among vector control agencies, potentially contributing to gaps in SLEV surveillance. The incidence of SLEV disease in California may have been underestimated because human surveillance for SLEV relied on an environmental detection to trigger SLEV patient screening and mosquito surveillance effort is spatially variable. In addition, human diagnostic testing usually relies on changes in host antibodies and SLEV infection can be indistinguishable from infection with other flaviviruses such as WNV, which is more prevalent.

Evaluation of the effectiveness of the California mosquito-borne virus surveillance & response plan, 2009-2018.

Local vector control and public health agencies in California use the California Mosquito-Borne Virus Surveillance and Response Plan to monitor and evaluate West Nile virus (WNV) activity and guide responses to reduce the burden of WNV disease. All available data from environmental surveillance, such as the abundance and WNV infection rates in Culex tarsalis and the Culex pipiens complex mosquitoes, the numbers of dead birds, seroconversions in sentinel chickens, and ambient air temperatures, are fed into a formula to estimate the risk level and associated risk of human infections. In many other areas of the US, the vector index, based only on vector mosquito abundance and infection rates, is used by vector control programs to estimate the risk of human WNV transmission. We built models to determine the association between risk level and the number of reported symptomatic human disease cases with onset in the following three weeks to identify the essential components of the risk level and to compare California's risk estimates to vector index. Risk level calculations based on Cx. tarsalis and Cx. pipiens complex levels were significantly associated with increased human risk, particularly when accounting for vector control area and population, and were better predictors than using vector index. Including all potential environmental components created an effective tool to estimate the risk of WNV transmission to humans in California.

Geospatial Social Determinants of Health Correlate with Disparities in Syphilis and Congenital Syphilis Cases in California.

Syphilis and congenital syphilis (CS) are increasing in California (CA). From 2015 through 2019, for example, CA cases of early syphilis among reproductive-age females (15−44) and CS each increased by >200%. Certain populations­including people experiencing homelessness, using drugs, and/or belonging to certain racial/ethnic groups­have been disproportionately impacted. We hypothesized that geospatial social determinants of health (SDH) contribute to such health inequities. To demonstrate this, we geospatially described syphilis in CA using the Healthy Places Index (HPI). The HPI is a composite index that assigns a score to each CA census tract based on eight socioeconomic characteristics associated with health (education, housing, transportation, neighborhood conditions, clean environment, and healthcare access as well as economic and social resources). We divided CA census tracts into four quartiles based on HPI scores (with the lowest quartile having the least healthy socioeconomic and environmental conditions), then used 2013−2020 CA sexually transmitted diseases surveillance data to compare overall syphilis (among adults and adolescents) and CS case counts, incidence rates (per 100,000 population or live births), and incidence rate ratios (IRRs) among these quartiles. From 2013 to 2020, across all stages of syphilis and CS, disease burden was greatest in the lowest HPI quartile and smallest in the highest quartile (8308 cases (representing 33.2% of all incidents) versus 3768 (15.1%) for primary and secondary (P&S) syphilis; 5724 (31.6%) versus 2936 (16.2%) for early non-primary non-secondary (NPNS) syphilis; 11,736 (41.9%) versus 3026 (10.8%) for late/unknown duration syphilis; and 849 (61.9%) versus 57 (4.2%) for CS; all with p < 0.001). Using the highest HPI quartile as a reference, the IRRs in the lowest quartile were 17 for CS, 4.5 for late/unknown duration syphilis, 2.6 for P&S syphilis, and 2.3 for early NPNS syphilis. We thus observed a direct relationship between less healthy conditions (per HPI) and syphilis/CS in California, supporting our hypothesis that SDH correlate with disparities in syphilis, especially CS. HPI could inform allocation of resources to: (1) support communities most in need of assistance in preventing syphilis/CS cases and (2) reduce health disparities.

Noncommunicable Disease and Health Care-Seeking Behavior Among Urban Camp-Dwelling Syrian Refugees in Lebanon: A Preliminary Investigation.

Purpose: Syrian refugees (SRs) in Lebanon are often relegated to informal camps with poor living conditions and substandard access to health care. This study examined the unique condition of urban camp-dwelling SRs in Lebanon. This population is rarely studied as they are marginalized and difficult to access. We sought to assess the prevalence of noncommunicable diseases (NCDs) and health care-seeking behaviors within this population. Methods: A randomized group of urban camp-dwelling SR participants completed a survey on disease burden, health care-seeking patterns, and attitudes toward care. A second group completed interviews regarding health care experiences. We present descriptive population and epidemiologic measures to quantify NCD burden and health care-seeking behaviors. Results: Of 101 participants, 39% reported arthritis, 25% skin infection, 24% high blood pressure, 16% chronic lung conditions, 16% eye disease, and 15% diabetes. Major themes from interviews with SRs included poor living conditions, high cost of health care services, and perceived discrimination by health care workers (HCWs). The major theme from interviews with HCWs was a perception that SRs received health care services similar to members of surrounding communities. Discussion: In this population, we found a higher prevalence of NCDs at younger ages than in the general SR population. We described perceived barriers to accessing health care, including the noteworthy finding of perceived discrimination by HCWs in a linguistically and culturally related host community. We discussed social determinants of health within the camp and refugees' ability to access health care services.

Characterizing Areas with Increased Burden of West Nile Virus Disease in California, 2009-2018.

West Nile virus (WNV) is a mosquito-borne flavivirus that can cause severe neurological disease in humans, for which there is no treatment or vaccine. From 2009 to 2018, California has reported more human disease cases than any other state in the United States. We sought to identify smaller geographic areas within the 10 California counties with the highest number of WNV cases that accounted for disproportionately large numbers of human cases from 2009 to 2018. Eleven areas, consisting of groups of high-burden ZIP codes, were identified in nine counties within southern California and California's Central Valley. Despite containing only 2% of California's area and 17% of the state's population, these high-burden ZIP codes accounted for 44% of WNV cases reported and had a mean annual incidence that was 2.4 times the annual state incidence. Focusing mosquito control and public education efforts in these areas would lower WNV disease burden.

West Nile Virus-Associated Hospitalizations, California, 2004-2017.

BACKGROUND: West Nile virus (WNV) is the most commonly reported mosquito-borne disease in the USA. California reports more WNV disease than any other state. METHODS: We identified WNV-associated hospitalizations from 2004 through 2017 in California and estimated hospitalization incidence using Patient Discharge Data. We described demographic, geographic, and clinical characteristics of WNV hospitalizations; identified risk factors for in-hospital death; and tabulated hospitalization charges. RESULTS: From 2004 through 2017, 3109 Californians were hospitalized with WNV (median, 214 patients/year; range, 72-449). The majority were male (1983; 63.8%) and aged ≥60 years (1766; 56.8%). The highest median annual hospitalization rate (0.88 hospitalizations/100 000 persons) was in the Central Valley, followed by southern California (0.59 hospitalizations/100 000 persons). Most patients (2469; 79.4%) had ≥1 underlying condition, including hypertension, cardiovascular disease, diabetes, chronic kidney disease, or immunosuppression due to medications or disease. Median hospitalization length of stay was 12 days (interquartile range, 6-23 days). During hospitalization, 1317 (42%) patients had acute respiratory failure and/or sepsis/septic shock, 772 (24.8%) experienced acute kidney failure, and 470 (15.1%) had paralysis; 272 (8.8%) patients died. Nearly 47% (1444) of patients were discharged for additional care. During these 14 years, $838 680 664 (mean $59.9 million/year) was charged for WNV hospitalizations, 73.9% through government payers at a median charge of $142 321/patient. CONCLUSIONS: WNV-associated hospitalizations were substantial and costly in California. Hospitalization incidence was higher in males, elderly persons, and patients with underlying conditions. WNV persists as a costly and severe public health threat in California.

West Nile virus in California, 2003-2018: A persistent threat.

The California Arbovirus Surveillance Program was initiated over 50 years ago to track endemic encephalitides and was enhanced in 2000 to include West Nile virus (WNV) infections in humans, mosquitoes, sentinel chickens, dead birds and horses. This comprehensive statewide program is a function of strong partnerships among the California Department of Public Health (CDPH), the University of California, and local vector control and public health agencies. This manuscript summarizes WNV surveillance data in California since WNV was first detected in 2003 in southern California. From 2003 through 2018, 6,909 human cases of WNV disease, inclusive of 326 deaths, were reported to CDPH, as well as 730 asymptomatic WNV infections identified during screening of blood and organ donors. Of these, 4,073 (59.0%) were reported as West Nile neuroinvasive disease. California's WNV disease burden comprised 15% of all cases that were reported to the U.S. Centers for Disease Control and Prevention during this time, more than any other state. Additionally, 1,299 equine WNV cases were identified, along with detections of WNV in 23,322 dead birds, 31,695 mosquito pools, and 7,340 sentinel chickens. Annual enzootic detection of WNV typically preceded detection in humans and prompted enhanced intervention to reduce the risk of WNV transmission. Peak WNV activity occurred from July through October in the Central Valley and southern California. Less than five percent of WNV activity occurred in other regions of the state or outside of this time. WNV continues to be a major threat to public and wild avian health in California, particularly in southern California and the Central Valley during summer and early fall months. Local and state public health partners must continue statewide human and mosquito surveillance and facilitate effective mosquito control and bite prevention measures.

Thermal thresholds heighten sensitivity of West Nile virus transmission to changing temperatures in coastal California.

Temperature is widely known to influence the spatio-temporal dynamics of vector-borne disease transmission, particularly as temperatures vary across critical thermal thresholds. When temperature conditions exhibit such 'transcritical variation', abrupt spatial or temporal discontinuities may result, generating sharp geographical or seasonal boundaries in transmission. Here, we develop a spatio-temporal machine learning algorithm to examine the implications of transcritical variation for West Nile virus (WNV) transmission in the Los Angeles metropolitan area (LA). Analysing a large vector and WNV surveillance dataset spanning 2006-2016, we found that mean temperatures in the previous month strongly predicted the probability of WNV presence in pools of Culex quinquefasciatus mosquitoes, forming distinctive inhibitory (10.0-21.0°C) and favourable (22.7-30.2°C) mean temperature ranges that bound a narrow 1.7°C transitional zone (21-22.7°C). Temperatures during the most intense months of WNV transmission (August/September) were more strongly associated with infection probability in Cx. quinquefasciatus pools in coastal LA, where temperature variation more frequently traversed the narrow transitional temperature range compared to warmer inland locations. This contributed to a pronounced expansion in the geographical distribution of human cases near the coast during warmer-than-average periods. Our findings suggest that transcritical variation may influence the sensitivity of transmission to climate warming, and that especially vulnerable locations may occur where present climatic fluctuations traverse critical temperature thresholds.

Quantifying sociodemographic heterogeneities in the distribution of Aedes aegypti among California households.

The spread of Aedes aegypti in California and other regions of the U.S. has increased the need to understand the potential for local chains of Ae. aegypti-borne virus transmission, particularly in arid regions where the ecology of these mosquitoes is less understood. For public health and vector control programs, it is helpful to know whether variation in risk of local transmission can be attributed to socio-demographic factors that could help to target surveillance and control programs. Socio-demographic factors have been shown to influence transmission risk of dengue virus outside the U.S. by modifying biting rates and vector abundance. In regions of the U.S. where Ae. aegypti have recently invaded and where residential areas are structured differently than those in the tropics where Ae. aegypti are endemic, it is unclear how socio-demographic factors modify the abundance of Ae. aegypti populations. Understanding heterogeneities among households in Ae. aegypti abundance will provide a better understanding of local vectorial capacity and is an important component of understanding risk of local Ae. aegypti-borne virus transmission. We conducted a cross-sectional study in Los Angeles County, California during summer 2017 to understand the causes of variation in relative abundance of Ae. aegypti among households. We surveyed 161 houses, representing a wide range of incomes. Surveys consisted of systematic adult mosquito collections, inspections of households and properties, and administration of a questionnaire in English or Spanish. Adult Ae. aegypti were detected at 72% of households overall and were found indoors at 12% of households. An average of 3.1 Ae. aegypti were collected per household. Ae. aegypti abundance outdoors was higher in lower-income neighborhoods and around older households with larger outdoor areas, greater densities of containers with standing water, less frequent yard maintenance, and greater air-conditioner use. We also found that Ae. aegypti abundance indoors was higher in households that had less window and door screening, less air-conditioner usage, more potted plants indoors, more rain-exposed containers around the home, and lower neighborhood human population densities. Our results indicate that, in the areas of southern California studied, there are behavioral and socio-demographic determinants of Ae. aegypti abundance, and that low-income households could be at higher risk for exposure to Ae. aegypti biting and potentially greater risk for Zika, dengue, and chikungunya virus transmission if a local outbreak were to occur.

Antimicrobial Drug-Resistant Gram-Negative Saprophytic Bacteria Isolated from Ambient, Near-Shore Sediments of an Urbanized Estuary: Absence of ß-Lactamase Drug-Resistance Genes.

We assessed the prevalence of antimicrobial resistance and screened for clinically relevant ß-lactamase resistance determinants in Gram-negative bacteria from a large urbanized estuary. In contrast to the broad literature documenting potentially hazardous resistance determinants near wastewater treatment discharge points and other local sources of aquatic pollution, we employed a probabilistic survey design to examine ambient, near-shore sediments. We plated environmental samples from 40 intertidal and shallow subtidal areas around San Francisco Bay (California, USA) on drug-supplemented MacConkey agar, and we tested isolates for antimicrobial resistance and presence of clinically relevant ß-lactamase resistance determinants. Of the 74 isolates identified, the most frequently recovered taxa were Vibrio spp. (40%), Shewanella spp. (36%), Pseudomonas spp. (11%), and Aeromonas spp. (4%). Of the 55 isolates tested for antimicrobial resistance, the Vibrio spp. showed the most notable resistance profiles. Most (96%) were resistant to ampicillin, and two isolates showed multidrug-resistant phenotypes: V. alginolyticus (cefotaxime, ampicillin, gentamicin, cefoxitin) and V. fluvialis (cefotaxime, ampicillin, cefoxitin). Targeted testing for class 1 integrons and presence of ß-lactam-resistance gene variants TEM, SHV, OXA, CTX-M, and Klebsiella pneumonia carbapenemase (KPC) did not reveal any isolates harboring these resistance determinants. Thus, while drug-resistant, Gram-negative bacteria were recovered from ambient sediments, neither clinically relevant strains nor mobile ß-lactam resistance determinants were found. This suggests that Gram-negative bacteria in this well-managed, urbanized estuary are unlikely to constitute a major human exposure hazard at this time.

Identification and Monitoring of International Travelers During the Initial Phase of an Outbreak of COVID-19 - California, February 3-March 17, 2020.

The threat of introduction of coronavirus disease 2019 (COVID-19) into the United States with the potential for community transmission prompted U.S. federal officials in February 2020 to screen travelers from China, and later Iran, and collect and transmit their demographic and contact information to states for follow-up. During February 5-March 17, 2020, the California Department of Public Health (CDPH) received and transmitted contact information for 11,574 international travelers to 51 of 61 local health jurisdictions at a cost of 1,694 hours of CDPH personnel time. If resources permitted, local health jurisdictions contacted travelers, interviewed them, and oversaw 14 days of quarantine, self-monitoring, or both, based on CDC risk assessment criteria for COVID-19. Challenges encountered during follow-up included errors in the recording of contact information and variation in the availability of resources in local health jurisdictions to address the substantial workload. Among COVID-19 patients reported to CDPH, three matched persons previously reported as travelers to CDPH. Despite intensive effort, the traveler screening system did not effectively prevent introduction of COVID-19 into California. Effectiveness of COVID-19 screening and monitoring in travelers to California was limited by incomplete traveler information received by federal officials and transmitted to states, the number of travelers needing follow-up, and the potential for presymptomatic and asymptomatic transmission. More efficient methods of collecting and transmitting passenger data, including electronic provision of flight manifests by airlines to federal officials and flexible text-messaging tools, would help local health jurisdictions reach out to all at-risk travelers quickly, thereby facilitating timely testing, case identification, and contact investigations. State and local health departments should weigh the resources needed to implement incoming traveler monitoring against community mitigation activities, understanding that the priorities of each might shift during the COVID-19 pandemic.

Genotypic distribution of Staphylococcus aureus colonizing children and adolescents in daycare centers, an outpatient clinic, and hospitals in a major Brazilian urban setting.

Staphylococcus aureus nasal colonization is a major risk factor for infection. Studies have suggested an epidemiologic shift in the methicillin-resistant S. aureus (MRSA) strains that circulate in Brazil. We conducted cross-sectional studies of MRSA carriage among 1) children and adolescents in community daycare centers, 2) an outpatient clinic, and 3) hospitals in a large Brazilian metropolitan setting. There were 1.500 study subjects, 500 from each locale: 768 (51.2%) carried S. aureus whereas 150 (10%) of these were colonized with MRSA. The most common lineages were the Southwest Pacific (SWP) and the Pediatric clones in all three groups. Roughly 50% of SWP carried Panton-Valentine leukocidin (PVL) (p < 0.01) genes while 63.3% of the Pediatric clones were resistant or intermediately resistant to erythromycin (p < 0.01). This study describes a clonal change of the Brazilian epidemic clone (BEC) to the Pediatric and SWP lineages in Brazil. This finding has implications for clinical management of MRSA infections.

Probable transfusion transmission of West Nile virus from an apheresis platelet that screened non-reactive by individual donor-nucleic acid testing.

BACKGROUND: Despite West Nile virus (WNV) blood donation screening using nucleic acid testing (NAT), donors with low viral loads not detected by mini-pool-NAT have led to transfusion transmitted (TT)-WNV infection. We describe a probable case of fatal TT-WNV infection from an individual donor (ID)-NAT non-reactive apheresis platelet donation. STUDY DESIGN AND METHODS: An apheresis platelet donation was WNV ID-NAT reactive and prior donations from the same donor were investigated. A WNV ID-NAT non-reactive apheresis platelet unit collected 26 days earlier was transfused during heart transplantation to a patient who subsequently developed WNV neuroinvasive disease and expired. The source of the recipient's WNV infection was investigated. RESULTS: Twenty-six days after collection of the suspect platelet unit, a donation from the same donor was WNV ID-NAT reactive and WNV IgM and IgG positive. In addition to the suspect platelet unit, the heart transplant recipient who developed WNV infection received 17 blood components from 24 donors. Serologic testing performed on 11 of the remaining 24 donors (46%) was WNV IgM negative. Pre-transplant recipient and heart donor samples tested WNV RNA and IgM negative. CONCLUSION: A probable case of fatal neuroinvasive TT-WNV was linked to an infectious apheresis platelet unit undetected by WNV ID-NAT. It is hypothesized that the suspect unit was collected early in the viremic period when viral RNA was below the limit-of-detection of the ID-NAT assay. Implementation of ID-NAT screening of blood donors has not entirely eliminated the risk of TT-WNV infections, which may best be addressed by pathogen inactivation technologies.

Population structure of Streptococcus pneumoniae colonizing children before and after universal use of pneumococcal conjugate vaccines in Brazil: emergence and expansion of the MDR serotype 6C-CC386 lineage.

Objectives: To determine the population structure and change in drug resistance of pneumococci colonizing children before and after the introduction of the 10-valent and 13-valent pneumococcal conjugate vaccines (PCV10/13) in Brazil. Methods: We used MLST to analyse 256 pneumococcal isolates obtained from children aged <6 years before (2009-10; n = 125) and after (2014; n = 131) the introduction of the PCV10 and PCV13. Antimicrobial susceptibility and capsular types were previously determined. Results: We identified 97 different STs. Ninety (35.2%) isolates were related to international clones. The most frequent lineages were serogroup 6-CC724 (where CC stands for clonal complex) and the MDR serotype 6C-CC386 in the pre- and post-PCV10/13 periods, respectively. Penicillin-non-susceptible pneumococci (PNSP) formed 24% and 38.9% of the pre- and post-PCV10/13 isolates, respectively (P = 0.01). In the pre-PCV10/13 period, serotype 14-ST156 was the predominant penicillin-non-susceptible lineage, but it was not detected in the post-PCV10/13 period. Serotype 14-ST156 and serotype 19A-ST320 complex isolates had the highest penicillin and ceftriaxone MICs in the pre- and post-PCV10/13 periods, respectively. In turn, serotype 6C-CC386 comprised almost 30% of the PNSP and over 40% of the erythromycin-resistant isolates (MIC >256 mg/L) in the post-PCV10/13 period. Conclusions: Although PNSP strains were polyclonal, most resistant isolates belonged to a single genotype from each period. Higher erythromycin resistance prevalence (42%) in the post-PCV10/13 period was mainly attributed to MDR serotype 6C-CC386. Ongoing surveillance of pneumococcal clonal composition is important to evaluate PCV use outcomes and to identify factors other than PCVs that drive pneumococcal drug resistance evolution.