Predicting peripartum infection in laboring patients at high risk in Cameroon, Africa

OBJECTIVE

To develop a predictive model for peripartum infection among high risk laboring patients in Cameroon, Africa.

STUDY DESIGN

We conducted a secondary analysis of the Cameroon Antibiotic Prophylaxis Trial (NCT03248297), a multicenter 3-arm double-blind randomized controlled trial of oral azithromycin ± amoxicillin among term pregnancies with prolonged labor or rupture of membranes in Cameroon 1/2018-5/2020. Patients with chorioamnionitis prior to randomization, study drug contraindications, or planned cesarean were excluded. The outcome of interest was a composite of maternal peripartum infection (chorioamnionitis, endometritis, sepsis by World Health Organization criteria, wound infection/abscess) diagnosed up to 6 weeks postpartum. Potential predictors were compared between patients with and without the composite outcome, and evaluated at a 0.05 alpha level. Statistically significant exposures were analyzed using multivariable regression (to generate adjusted odds ratios and 95 % confidence intervals) with backwards selection to generate a parsimonious model. Receiver operating characteristic curves with associated area under the curve assessed the model's predictive ability. A nomogram based on the final best fit multivariable model was constructed.

RESULTS

Of 756 patients in the parent trial, 652 were analyzed: 45 (7 %) had peripartum infection. Those with infection were more likely to be nulliparous, lower education level, higher gestational age, receive antibiotics per hospital protocols, and undergo cesarean. In our best-fit multivariable model, none/primary education (vs university), cesarean birth, and antibiotic receipt per physician discretion (vs for cesarean prophylaxis) were significantly associated with increased infection risk. This model was moderately predictive (AUC = 0.75, 95 % CI 0.67-0.82). When using this 3 factor model, for a patient with a cesarean birth, receipt of antibiotics per physician discretion, and university education, the probability of peripartum infection was 35 % (95 % CI 0.11-0.73).

CONCLUSIONS

While several variables such as parity are associated with infectious morbidity within 6 weeks among high risk laboring patients in Cameroon, only education level, antibiotic indication, and cesarean birth were independently associated, and a model including these 3 factors was moderately predictive. Validation of our findings in a larger population is warranted.

Disparities in Hypertension Prevalence, Awareness, Treatment, and Control Among Women Living With and Without HIV in the US South

Background

Hypertension-related diseases are major causes of morbidity among women living with HIV. We evaluated cross-sectional associations of race/ethnicity and HIV infection with hypertension prevalence, awareness, treatment, and control.

Methods

Among women recruited into Southern sites of the Women's Interagency HIV Study (2013-2015), hypertension was defined as (1) systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg according to clinical guidelines when data were collected, (2) self-report of hypertension, or (3) use of antihypertensive medication. Awareness was defined as self-report of hypertension, and treatment was self-report of any antihypertensive medication use. Blood pressure control was defined as <140/90 mm Hg at baseline. Prevalence ratios for each hypertension outcome were estimated through Poisson regression models with robust variance estimators adjusted for sociodemographic, behavioral, and clinical risk factors.

Results

Among 712 women, 56% had hypertension and 83% were aware of their diagnosis. Of those aware, 83% were using antihypertensive medication, and 63% of those treated had controlled hypertension. In adjusted analyses, non-Hispanic White and Hispanic women had 31% and 48% lower prevalence of hypertension than non-Hispanic Black women, respectively. Women living with HIV who had hypertension were 19% (P = .04) more likely to be taking antihypertension medication when compared with women living without HIV.

Conclusions

In this study population of women living with and without HIV in the US South, the prevalence of hypertension was lowest among Hispanic women and highest among non-Hispanic Black women. Despite similar hypertension prevalence, women living with HIV were more likely to be taking antihypertensive medication when compared with women living without HIV.

Prevalence and Predictors of Oral Treponema pallidum Detection by qPCR in Early Syphilis

BACKGROUND

Treponema pallidum (T. pallidum) prevalence and burden at oral and lesion sites in adults with early syphilis were assessed by qPCR. Factors associated with oral shedding were also examined.

METHODS

Pre-treatment oral and lesion swabs were collected from adults with early syphilis in a US multicenter syphilis treatment trial. Oral swabs were collected in the presence and absence of oral lesions. Following DNA extraction, qPCR and whole genome sequencing (WGS) were performed to assess burden and strain variability.

RESULTS

All 32 participants were male, mean age was 35, and 90.6% were living with HIV. T. pallidum oral PCR positivity varied by stage: 16.7% primary, 44.4% secondary, and 62.5% in early latent syphilis. Median oral T. pallidum burden was highest in secondary syphilis at 63.2 copies/µL. Lesion PCR positivity was similar in primary (40.0%) and secondary syphilis (38.5%). Age 18-29 years was significantly associated with oral shedding (vs age 40+) in adjusted models. WGS identified two distinct strains.

CONCLUSION

T. pallidum DNA was directly detected at oral and lesion sites in a high proportion of men with early syphilis. Younger age was associated with oral shedding. Ease of oral specimen collection and increased PCR availability suggest opportunities to improve syphilis diagnostic testing.

Chlamydia trachomatis -Specific Antibody Responses in Women in Cameroon With Secondary Infertility

ABSTRACT

The contribution of chlamydia to secondary infertility in women is poorly understood. Among 404 female participants enrolled in a previous study in Cameroon, 142 had secondary infertility (cases) and 262 were pregnant with no history of infertility (controls) , Chlamydia trachomatis seropositivity was 92%. Seropositivity did not significantly differ by case/control status.

Association of marijuana, tobacco and alcohol use with estimated glomerular filtration rate in women living with HIV and women without HIV

OBJECTIVE

Marijuana, tobacco and alcohol use are prevalent among people with HIV and may adversely affect kidney function in this population. We determined the association of use of these substances with estimated glomerular filtration rate (eGFR) among women with HIV (WWH) and women without HIV.

DESIGN

We undertook a repeated measures study of 1043 WWH and 469 women without HIV within the United States Women's Interagency HIV Study, a multicenter, prospective cohort of HIV-seropositive and HIV-seronegative women.

METHODS

We quantified substance exposures using semi-annual questionnaires. Using pooled eGFR data from 2009 to 2019, we used linear regression models with multivariable generalized estimating equations to ascertain associations between current and cumulative substance use exposures with eGFR, adjusting for sociodemographics, chronic kidney disease risk factors and HIV-related factors.

RESULTS

Marijuana use of 1-14 days/month versus 0 days/month was associated with 3.34 ml/min per 1.73 m 2 [95% confidence interval (CI) -6.63, -0.06] lower eGFR and marijuana use of >0.02-1.6 marijuana-years versus 0-0.2 marijuana-years was associated with 3.61 ml/min per 1.73 m 2 (95% CI -5.97, -1.24) lower eGFR. Tobacco use was not independently associated with eGFR. Alcohol use of seven or more drinks/week versus no drinks/week was associated with 5.41 ml/min per 1.73 m 2 (95% CI 2.34, 8.48) higher eGFR and alcohol use of >0.7-4.27 drink-years and >4.27 drink-years versus 0-0.7 drink-years were associated with 2.85 ml/min per 1.73 m 2 (95% CI 0.55, 5.15) and 2.26 ml/min per 1.73 m 2 (95% CI 0.33, 4.20) higher eGFR, respectively.

CONCLUSION

Among a large cohort of WWH and women without HIV, marijuana use was associated with a lower eGFR while alcohol use was associated with a higher eGFR.

Sub-microscopic Plasmodium falciparum parasitaemia, dihydropteroate synthase (dhps) resistance mutations to sulfadoxine-pyrimethamine, transmission intensity and risk of malaria infection in pregnancy in Mount Cameroon Region

BACKGROUND

Plasmodium falciparum resistance to intermittent preventive treatment with sulfadoxine-pyrimethamine (IPTp-SP) continues to spread throughout sub-Saharan Africa. This study assessed the occurrence of microscopic and sub-microscopic P. falciparum parasitaemia, dihydropteroate synthase mutations associated with resistance to SP and maternal anaemia in the Mount Cameroon area.

METHODS

Consenting pregnant women living in semi-rural and semi-urban/urbanized settings were enrolled in this cross-sectional study. Socio-demographic, antenatal and clinical data were documented. Microscopic and sub-microscopic parasitaemia were diagnosed using peripheral blood microscopy and nested polymerase chain reaction (PCR) respectively. The dhps mutations were genotyped by restriction fragment length polymorphism analysis. The presence of A437G, K540E, and A581G was considered a marker for high-level resistance. Haemoglobin levels and anaemia status were determined.

RESULTS

Among the women, the prevalence of microscopic and sub-microscopic P. falciparum infection were 7.7% (67/874) and 18.6% (93/500) respectively. Predictors of microscopic infection were younger age (< 21 years) (AOR = 2.89; 95% CI 1.29-6.46) and semi-rural settings (AOR = 2.27; 95% CI 1.31-3.96). Determinants of sub-microscopic infection were the rainy season (AOR, 3.01; 95% CI 1.77-5.13), primigravidity (AOR = 0.45; 95% CI 0.21-0.94) and regular ITN usage (AOR = 0.49; 95% CI 0.27-0.90). Of the145 P. falciparum isolates genotyped, 66.9% (97) carried mutations associated with resistance to SP; 33.8% (49), 0%, 52.4% (76) and 19.3% (28) for A437G, K540E, A581G and A437G + A581G respectively. The A581G mutation was associated with ≥ 3 SP doses evident only among sub-microscopic parasitaemia (P = 0.027) and multigravidae (P = 0.009). Women with microscopic infection were more likely from semi-rural settings (AOR = 7.09; 95% CI 2.59-19.42), to report history of fever (AOR = 2.6; 95% CI 1.07-6.31), to harbour parasites with double resistant mutations (AOR = 6.65; 95% CI 1.85-23.96) and were less likely to have received 2 SP doses (AOR = 0.29; 95% CI 1.07-6.31). Microscopic infection decreased Hb levels more than sub-microscopic infection.

CONCLUSION

The occurrence of sub-microscopic P. falciparum parasites resistant to SP and intense malaria transmission poses persistent risk of malaria infection during pregnancy in the area. ITN usage and monitoring spread of resistance are critical.

Global and Rural Health Disparities

Ethn Dis. 2022;32(4):265-268; doi:10.18865/ed.32.4.265

Data-driven commentary on SARS-CoV-2 infection, vaccination, and fertility

A recent study by Wesselink et al. (Am J Epidemiol. 2022 Jan 20;kwac011. doi: 10.1093/aje/kwac011. Online ahead of print) adds to the growing body of research finding that vaccination for coronavirus disease 2019 (COVID-19) is safe for individuals either seeking pregnancy or who are pregnant. The study's authors found no effect of COVID-19 vaccination on fecundity in a population of individuals with no known infertility who were attempting conception. The finding reinforces the messaging of the American Society for Reproductive Medicine COVID-19 Task Force, the aim of which is to provide data-driven recommendations to individuals contemplating pregnancy in the face of the COVID-19 pandemic. As safe and effective COVID-19 vaccines became available, and with an increasing number of studies showing a heightened risk of severe disease during pregnancy, an important role of the Task Force is to encourage vaccination during the preconceptual window and in early pregnancy. The Task Force supports ongoing research to address gaps in knowledge about safe and effective therapies and preventive measures for individuals contemplating pregnancy and during pregnancy. Such research will help optimize care for reproductive-age individuals in the face of current and future health crises.

Data-Driven Commentary on SARS-CoV-2 Infection, Vaccination, and Fertility

A recent study by Wesselink et al. (Am J Epidemiol. 2022;191(8):1383-1395) adds to the growing body of research finding that vaccination for coronavirus disease 2019 (COVID-19) is safe for individuals either seeking pregnancy or who are pregnant. The study's authors found no effect of COVID-19 vaccination on fecundity in a population of individuals with no known infertility who were attempting conception. The finding reinforces the messaging of the American Society for Reproductive Medicine COVID-19 Task Force, the aim of which is to provide data-driven recommendations to individuals contemplating pregnancy in the face of the COVID-19 pandemic. As safe and effective COVID-19 vaccines became available, and with an increasing number of studies showing a heightened risk of severe disease during pregnancy, an important role of the Task Force is to encourage vaccination during the preconceptual window and in early pregnancy. The Task Force supports ongoing research to address gaps in knowledge about safe and effective therapies and preventive measures for individuals contemplating pregnancy and during pregnancy. Such research will help optimize care for reproductive-age individuals in the face of current and future health crises.

Highly confined photon transport in subwavelength metallic slot waveguides

We report experimental realization of subwavelength slot waveguides that exhibit both micrometer-range propagation and high spatial confinement of light. Attention is given to rectangular waveguides with a Si3N4 core and Ag cladding; core thicknesses of 50-100 nm and widths of 250 nm - 10 microm are explored. Propagation lengths of approximately 5lambda are achieved with light confined to lateral and transverse dimensions of approximately lambda/5 and approximately lambda/2, respectively. This unique combination of light localization and propagation is achieved via interacting surface plasmons, which produce short modal wavelengths and strong field confinement at each metal/dielectric interface.