Maternal red blood cell alloimmunization prevalence in the United States.

Hemolytic disease of fetus and newborn (HDFN) is a life-threatening disease mediated by maternal alloimmunization to red blood cell (RBC) antigens. Studies of maternal alloimmunization prevalence in the United States (U.S.) lack national data. This study describes prevalence and trends in alloimmunization in pregnancy in the U.S. RBC antibodies (abs) were identified in a large, nationwide, commercial laboratory database from 2010-2021. The cohort comprised pregnancies for which the year of lab collection and patient's state of residence were available. Data were normalized based on U.S. Centers for Disease Control and Prevention estimates of live births and weighted by year and U.S. Census Division. Cochrane-Armitage tests assessed temporal trends of alloimmunization. Of 9,876,196 pregnancies, 1.5% (147,262) screened positive for RBC abs, corresponding to an estimated prevalence of 1,518/100,000 pregnancies. Of identified RBC abs, anti-D comprised 64.1% (586/100,000 pregnancies). Prevalence of other high-risk RBC abs for HDFN included anti-K (68/100,000) and anti-c (29/100,000). Incidence of all three high-risk abs increased from 2010-21 (all p<0.001). Among almost 10 million pregnancies in the US, comprising an estimated 14.4% of all pregnancies, 1.5% screened positive for RBC abs. Almost three-quarters (74.3%; 683/100,000) of RBC abs identified were high-risk for HDFN. Though prevalence of anti-D is difficult to interpret without the ability to distinguish alloimmunization from passive immunity, it remains problematic in HDFN, ranking second only to anti-K in critical titers. Given the sequelae of HDFN, new initiatives are required to reduce the incidence of alloimmunization in patients of reproductive potential.

Chlamydia trachomatis and Neisseria gonorrhoeae in Pregnancy: Trends in United States, 2010 to 2018.

BACKGROUND: Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) case surveillance relies on reported positive laboratory results. Changes in reported cases may represent changes in testing practice or infection prevalence. This study evaluated changes over time for CT and NG positivity and testing rates of pregnant persons. METHODS: Prenatal testing results from persons aged 16 to 40 years tested by a national reference clinical laboratory were analyzed for CT and NG testing and positivity from 2010 to 2018 (n = 3,270,610). RESULTS: Testing rates increased among pregnant persons for CT (from 56.3% in 2010 to 64.1% in 2018, P < 0.001) and NG (from 55.6% to 63.2%, P < 0.001). Higher CT testing rates were found in Black non-Hispanic (adjusted odds ratio [AOR], 1.58; 95% confidence interval [CI], 1.57-1.60) and Hispanic (AOR, 1.19; 95% CI, 1.18-1.20) persons. NG and CT testing rates were virtually identical. Significant increasing trends in CT positivity were observed for each age group studied (P < 0.001 for all): 16-19 (from 11.7% to 13.0%), 20-24 (from 6.4% to 6.7%), 25-30 (from 1.9% to 2.4%), and 31-40 years (from 0.76% to 0.92%). Black non-Hispanic persons had the highest positivity for CT (AOR, 2.52; 95% CI, 2.46-2.57) and NG (AOR, 5.42; 95% CI, 5.05-5.82). CONCLUSIONS: Testing and adjusted positivity for both CT and NG among pregnant persons increased from 2010 to 2018. Higher testing rates were observed in Black non-Hispanic and Hispanic persons (even in persons younger than 25 years), suggesting some testing decisions may have been based on perceived risk, in contrast to many guidelines recommending screening all pregnant persons younger than 25 years.

Impact of the COVID-19 Pandemic on Chlamydia and Gonorrhea Screening in the U.S.

INTRODUCTION: This study evaluates the impact of the COVID-19 pandemic on testing for common sexually transmitted infections. Specifically, changes are measured in chlamydia and gonorrhea testing and case detection among patients aged 14-49 years during the COVID-19 pandemic. METHODS: U.S. chlamydia and gonorrhea testing and positivity were analyzed on the basis of >18.6 million tests (13.6 million tests for female patients and 4.7 million tests for male patients) performed by a national reference clinical laboratory from January 2019 through June 2020. RESULTS: Chlamydia and gonorrhea testing reached a nadir in early April 2020, with decreases (relative to the baseline level) of 59% for female patients and 63% for male patients. Declines in testing were strongly associated with increases in weekly positivity rates for chlamydia (R2=0.96) and gonorrhea (R2=0.85). From March 2020 through June 2020, an expected 27,659 (26.4%) chlamydia and 5,577 (16.5%) gonorrhea cases were potentially missed. CONCLUSIONS: The COVID-19 pandemic impacted routine sexually transmitted infection services, suggesting an increase in syndromic sexually transmitted infection testing and missed asymptomatic cases. Follow-up analyses will be needed to assess the long-term implications of missed screening opportunities. These findings should serve as a warning for the potential sexual and reproductive health implications that can be expected from the overall decline in testing and potential missed cases.

Chlamydia and Gonorrhea: Shifting Age-Based Positivity Among Young Females, 2010-2017.

INTRODUCTION: This study aims to determine if and how the age distribution of Chlamydia trachomatis and Neisseria gonorrhoeae infections in women evolved from 2010 to 2017, given changes in sexual practices over this time. METHODS: All Chlamydia trachomatis/Neisseria gonorrhoeae co-testing laboratory results from females aged 12-30 years tested at Quest Diagnostics during 2010-2017 (n=17,794,680) were evaluated to assess trends in Chlamydia trachomatis and Neisseria gonorrhoeae positivity over time. Data were collected and analyzed in November 2018. RESULTS: Age-based positivity shifted toward older ages from 2010 to 2017 for both Chlamydia trachomatis and Neisseria gonorrhoeae. There was a declining trend in Chlamydia trachomatis positivity from 2010 to 2017 for the youngest age group (12-17 years; 17% decline, 8.9% to 7.4%, p<0.0001) but increasing trends for both those aged 18-24 years (21% increase, 6.1% to 7.4%, p<0.0001) and 25-30 years (50% increase, 2.2% to 3.3%, p<0.0001). The Chlamydia trachomatis positivity rate for 27-year-olds in 2017 (3.5%) and 24-year-olds in 2010 (3.5%) was the same. Similarly, there was a declining trend in Neisseria gonorrhoeae positivity from 2010 to 2017 for the youngest age group (12-17 years; 14% decline, 1.33% vs 1.17%, p<0.0001) but increasing trends for both those aged 18-24 years (27% increase, 0.79% vs 1.00%, p<0.0001) and 25-30 years (117% increase, 0.29% vs 0.63%, p<0.0001). For Neisseria gonorrhoeae, 30-year-old women tested in 2017 had an identical positivity rate to 23-year-old women tested in 2010, at 0.5%. CONCLUSIONS: Healthcare providers may want to consider this positivity rate age shift in Chlamydia trachomatis and Neisseria gonorrhoeae to inform prevention and control strategies, including considering the potential for increased risk in women aged 25-30 years.

Contributions of Liquid-Based (Papanicolaou) Cytology and Human Papillomavirus Testing in Cotesting for Detection of Cervical Cancer and Precancer in the United States.

OBJECTIVES: Given the recent debate challenging the contribution of cytology in cervical screening, we evaluated results of liquid-based cytology (LBC) and human papillomavirus (HPV) testing in cotesting preceding cervical cancer (CxCa) and precancer diagnoses in a national, heterogeneous population. METHODS: We assessed the results of cotesting, performed by Quest Diagnostics, in 13,633,071 women 30 years and older, tested 2010 to 2018. Cotest results preceding CxCa or precancer diagnoses were analyzed and stratified by histopathology. RESULTS: Among all screening results, 1,615 cotests preceded 1,259 CxCa diagnoses, and 11,164 cotests preceded 8,048 cervical precancer diagnoses. More women who were subsequently diagnosed with CxCa within 1 year were identified by the LBC result than by the HPV result (85.1%, 1,015/1,193 vs 77.5%, 925/1,193). Among all women with CxCa, the overall rate of nondetection was 13.1% (212/1,615) for cotesting results (LBC negative/HPV negative) and this rate increased substantially when testing exceeded 12 months compared to within 1 year prediagnosis of either CxCa or precancer. CONCLUSIONS: Analysis of 9-year cotest results from a national reference laboratory confirms the value of LBC element in cotesting. This supports that LBC/HPV cotesting enhances screening for the identification of CxCa in women 30 years and older, more so than LBC or HPV alone within cotesting.

Prenatal cell-free DNA screening for fetal aneuploidy in pregnant women at average or high risk: Results from a large US clinical laboratory.

BACKGROUND: We evaluated the performance of a cell-free DNA (cfDNA) prenatal screening assay for trisomies 21, 18, and 13, and sex chromosome aneuploidies (SCAs) among a population of pregnant women that included both those at average and high risk. METHODS: Specimen collection, cfDNA extraction, massively parallel sequencing, and bioinformatics analysis were conducted per laboratory protocol. Assay results, concordance with pregnancy outcomes, and performance characteristics were evaluated. RESULTS: A total 75,658 specimens from 72,176 individual pregnant women were received. Technical reasons accounted for 288 (0.4% of all received samples) tests not performed. In the final analysis cohort (N = 69,794), 13% of pregnancies were considered at average risk and 87% at high risk. Mean gestational age at specimen collection was 15.1 weeks. Of the 69,794 unique pregnancies, 1,359 (1.9%) had positive test results. Among the results with confirmed outcomes, PPV for trisomies 21, 18, and 13 was 98.1%, 88.2%, and 59.3%, respectively; the PPV was 69.0% for SCAs and 75.0% for microdeletions. Overall, PPV was 87.2%, sensitivity was 97.9%, and specificity was 99.9%. CONCLUSION: This cfDNA prenatal screening assay provides highly accurate discrimination between affected and unaffected pregnancies among a population of pregnant women at average and high risk for fetal genetic abnormalities.