Systematic review and meta-analysis of maternal and fetal outcomes among pregnant women with bacterial vaginosis.

BACKGROUND: Women of childbearing age are commonly affected by bacterial vaginosis (BV). Maternal-fetal outcomes associated with BV during pregnancy can be fatal for both the mother and the newborn. AIM: To identify maternal and fetal outcomes in pregnant women with BV encountered globally, highlight their prevalence, and identify maternal-fetal outcomes associated with BV. METHODS: The databases Embase, PubMed, Web of Science and Global Index Medicus were searched from inception until December 2022. No restrictions on time or geographical location were imposed when searching for published articles that examined maternal-fetal outcomes in pregnant women with BV. A random effects model was used to perform the meta-analysis. Sources of heterogeneity were investigated using subgroup analysis, and publication bias was assessed using funnel plots and Egger tests. FINDINGS: In total, 26 of the 8983 articles retrieved from the databases met the inclusion criteria and were included in this study. Twenty-two maternal outcomes and 22 fetal outcomes were recorded among pregnant women with BV worldwide. This study determined the prevalence of maternal-fetal outcomes reported in three or more studies. Among fetal outcomes, preterm birth (PTB) had the highest prevalence [17.9%, 95% confidence interval (CI) 13-23.3%], followed by mechanical ventilation (15.2%, 95% CI 0-45.9%), low birth weight (LBW) (14.2%, 95% CI 9.1-20.1%) and neonatal intensive care unit admission (11.2%, 95% CI 0-53.5%). BV was associated with PTB [odds ratio (OR) 1.76, 95% CI 1.32-2.35], LBW (OR 1.73, 95% CI 1.41-2.12) and birth asphyxia (OR 2.90, 95% CI 1.13-7.46). Among maternal outcomes, premature rupture of membranes (PROM) had the highest prevalence (13.2%, 95% CI 6.1-22.3%). BV was associated with the following maternal outcomes: intrauterine infection (OR 2.26, 95% CI 1.44-3.56), miscarriage (OR 2.34, 95% CI 1.18-4.64) and PROM (OR 2.59, 95% CI 1.39-4.82). Maternal and fetal outcomes were most prevalent in women whose BV was diagnosed using the Amsel criteria (37.2%, 95% CI 23-52.6%) and in the third trimester (29.6%, 95% CI 21.2-38.8%). Although reported in fewer than three studies, some maternal-fetal outcomes are highly prevalent, such as respiratory distress (76.67%, 95% CI 57.72-90.07%), dyspareunia (68.33%, 95% CI 55.04-79.74%) and malodorous discharge (85.00%, 95% CI 73.43-92.90%). CONCLUSION: BV has been associated with several adverse maternal-fetal outcomes around the world. While BV is a common vaginal infection, the types of maternal-fetal outcomes from pregnant women with BV vary by country.

Expression profiles of miR3181 and miR199a in plasma and placenta of virally suppressed HIV-1 infected Cameroonian pregnant women at delivery.

Human immunodeficiency virus (HIV)-1 infection during pregnancy reduces the transplacental transfer of protective maternal antibodies needed to confer immunity during early postnatal life. However, the mediation of MicroRNA in this dysregulation is not well understood MicroRNAs 3181 and 199a have been shown to mediate neonatal Fc receptor (FcRn)-like transmembrane antibody transfer and endocytosis respectively but their expression levels in the placenta and plasma in women living with HIV have not been extensively investigated. The objective of this study was to determine how the expression levels of miR-3181 and miR-199a in the placenta and plasma are affected in women chronically infected with HIV who are on antiretroviral therapy (ART) and are virally suppressed at delivery. In this pilot case-control study, plasma and placenta biopsies were obtained from 36 (18 HIV+ and 18 HIV-) Cameroonian women at delivery. MicroRNAs 3181 and 199a expression levels were measured using RT-qPCR, data was analyzed using SPSS22.0 and R 3.60, and p values below 0.05 were considered statistically significant. All the HIV-infected women were on known ART regimens and were virally suppressed. There was no significant difference in the levels of miR-3181 (p>0.05) in the placenta and plasma amongst HIV-infected and HIV uninfected women. The expression levels of miR-199a were significantly greater in the plasma compared to the placenta of HIV+ (p = 0.00005) and HIV- (p = 0.027) women. Moreover, there was a significantly higher (p = 0.02) level of miR-199a in the plasma of women with HIV and their uninfected counterparts. Linear regression models adjusted for systolic pressure showed no significant difference (p>0.05) in the levels of miR-199a and miR-3181 in both the placenta and plasma due to HIV infection. Our findings suggest that even though ART uptake and viral suppression might help in maintaining miR3181 and miR199a levels in the placenta of women with HIV at comparative levels to those of their HIV negative counterparts, the significantly higher levels of miR-199a in the plasma of women with HIV compared to the placenta might highlight lurking systemic dangers and requires further investigation.

Killer-Cell Immunoglobulin-Like Receptors (KIR) in HIV-Exposed Infants in Cameroon.

The biological reason(s) behind persistent mother-to-child transmission (MTCT) of HIV (albeit at reduced rate compared to the preantiretroviral therapy era) in spite of the successful implementation of advanced control measures in many African countries remains a priority concern to many HIV/AIDS control programs. This may be partly due to differences in host immunogenetic factors in highly polymorphic regions of the human genome such as those encoding the killer-cell immunoglobulin-like receptor (KIR) molecules which modulate the activities of natural killer cells. The primary aim of this study was to determine the variants of KIR genes that may have a role to play in MTCT in a cohort of infants born to HIV-infected mothers in Yaoundé, Cameroon. We designed a cross-sectional study to molecularly determine the frequencies of 15 KIR genes in 14 HIV-exposed infected (HEI), 39 HIV-exposed/uninfected (HEU), and 27 HIV-unexposed/uninfected (HUU) infants using the sequence specific primer polymerase chain reaction (PCR-SSP) method. We found that all 15 KIR genes were present in our cohort. The frequency of KIR2DL1 was significantly higher in the unexposed (control) group than in the HIV-exposed group (OR = 0.22, P = 0.006). Stratifying analysis by infection status but focusing only on exposed infants revealed that KIR2DL5, KIR2DS1, and KIR2DS5 were significantly overrepresented among the HIV-exposed/uninfected compared to infected infants (OR = 0.20, P = 0.006). Similarly, the frequencies of KIR2DS1, KIR2DS5, and KIR2DL5 were significantly different between infants perinatally infected with HIV (HIV+ by 6 months of age) and HIV-negative infants. Our study demonstrates that KIR genes may have differential effects with regard to MTCT of HIV-1.

Case Definitions of Clinical Malaria in Children from Three Health Districts in the North Region of Cameroon.

Malaria endemicity in Cameroon greatly varies according to ecological environment. In such conditions, parasitaemia, which is associated with fever, may not always suffice to define an episode of clinical malaria. The evaluation of malaria control intervention strategies mostly consists of identifying cases of clinical malaria and is crucial to promote better diagnosis for accurate measurement of the impact of the intervention. We sought out to define and quantify clinical malaria cases in children from three health districts in the Northern region of Cameroon. A cohort study of 6,195 children aged between 6 and 120 months was carried out during the raining season (July to October) between 2013 and 2014. Differential diagnosis of clinical malaria was performed using the parasite density and axillary temperature. At recruitment, patients with malaria-related symptoms (fever [axillary temperature ≥ 37.5°C], chills, severe malaise, headache, or vomiting) and a malaria positive blood smear were classified under clinical malaria group. The malaria attributable fraction was calculated using logistic regression models. Plasmodium falciparum was responsible for over 91% of infections. Children from Pitoa health district had the highest number of asymptomatic infections (45.60%) compared to those from Garoua and Mayo Oulo. The most suitable cut-off for the association between parasite densities and fever was found among children less than 24 months. Overall, parasite densities that ranged above 3,200 parasites per µl of blood could be used to define the malaria attributable fever cases. In groups of children aged between 24 and 59 months and 60 and 94 months, the optimum cut-off parasite density was 6,400 parasites per µl of blood, while children aged between 95 and 120 months had a cut-off of 800 parasites per µl of blood. In the same ecoepidemiological zone, clinical malaria case definitions are influenced by age and location (health district) and this could be considered when evaluating malaria intervention strategies in endemic areas.

Impact of HIV-1 infection on the IGF-1 axis and angiogenic factors in pregnant Cameroonian women receiving antiretroviral therapy.

Although mother-to-child transmission of HIV has dramatically declined, the number of in utero HIV-exposed, uninfected infants is on the increase. HIV-exposed infants are at an increased risk of mortality, morbidity and slower early growth than their non-HIV exposed counterparts. Maternal HIV increases the risk of having preterm deliveries, intrauterine growth restriction and low birth weight babies. However, the mechanism underlying dysregulation of fetal growth in HIV-infected pregnant women is unknown. We sought to determine whether maternal HIV is associated with dysregulation of the insulin-like growth factor (IGF) axis, some angiogenic factors or other related biomarkers that regulate fetal growth. A total of 102 normotensive pregnant women were enrolled in a small cross-sectional study. Amongst these were thirty-one HIV-1 positive women receiving combination antiretroviral therapy (cART) (Mean age: 30.0 ± 5.1 years; % on ART: 83.9%; median plasma viral load: 683 copies/ml; median CD4 count: 350 cells/ul) and 71 HIV uninfected women (mean age: 27.3 ± 5.8) recruited at delivery. A panel of biomarkers including IGF1 and IGF binding proteins (IGFBP1, IGFBP3), angiopoietins (ANG) 1 and 2, matrix metalloproteinases (MMP) 2 and 9, and galectin 13, was measured in plasma collected from the placental intervillous space. The levels of IGF1, IGFBP1, ANG1, ANG2, MMP2, MMP9 and Gal-13 were not affected by maternal HIV, even when adjusted for maternal factors in linear regression models (all p>0.05). It was observed that HIV-infection in pregnancy did not significantly affect key markers of the IGF axis and angiogenic factors. If anything, it did not affect women. These findings highlight the importance of the use of ART during pregnancy, which maintains factors necessary for fetal development closer to those of healthy women. However, decrease in IGF1 levels might be exacerbated in women con-infected with HIV and malaria.

A comparison of thick-film microscopy, rapid diagnostic test, and polymerase chain reaction for accurate diagnosis of Plasmodium falciparum malaria.

BACKGROUND: Accurate diagnosis of malaria is important for effective disease management and control. In Cameroon, presumptive clinical diagnosis, thick-film microscopy (TFM), and rapid diagnostic tests (RDT) are commonly used to diagnose cases of Plasmodium falciparum malaria. However, these methods lack sensitivity to detect low parasitaemia. Polymerase chain reaction (PCR), on the other hand, enhances the detection of sub-microscopic parasitaemia making it a much-needed tool for epidemiological surveys, mass screening, and the assessment of interventions for malaria elimination. Therefore, this study sought to determine the frequency of cases missed by traditional methods that are detected by PCR. METHODS: Blood samples, collected from 551 febrile Cameroonian patients between February 2014 and February 2015, were tested for P. falciparum by microscopy, RDT and PCR. The hospital records of participants were reviewed to obtain data on the clinical diagnosis made by the health care worker. RESULTS: The prevalence of malaria by microscopy, RDT and PCR was 31%, 45%, and 54%, respectively. However, of the 92% of participants diagnosed as having clinical cases of malaria by the health care worker, 38% were malaria-negative by PCR. PCR detected 23% and 12% more malaria infections than microscopy and RDT, respectively. A total of 128 (23%) individuals had sub-microscopic infections in the study population. The sensitivity of microscopy, RDT, and clinical diagnosis was 57%, 78% and 100%; the specificity was 99%, 94%, and 17%; the positive predictive values were 99%, 94%, and 59%; the negative predictive values were 66%, 78%, and 100%, respectively. Thus, 41% of the participants clinically diagnosed as having malaria had fever caused by other pathogens. CONCLUSIONS: Malaria diagnostic methods, such as TFM and RDT missed 12-23% of malaria cases detected by PCR. Therefore, traditional diagnostic approaches (TFM, RDT and clinical diagnosis) are not adequate when accurate epidemiological data are needed for monitoring malaria control and elimination interventions.

PCR-based detection of Plasmodium falciparum in saliva using mitochondrial cox3 and varATS primers.

BACKGROUND: Sampling of saliva for diagnosing Plasmodium falciparum infections is a safe, non-invasive alternative to sampling of blood. However, the use of saliva presents a challenge because lower concentrations of parasite DNA are present in saliva compared to peripheral blood. Therefore, a sensitive method is needed for detection of parasite DNA in saliva. This study utilized two recently reported "ultra-sensitive" PCR assays based on detection of the P. falciparum mitochondrial cox3 gene and the multi-copy nuclear varATS gene. The ultra-sensitive assays have an advantage over standard 18S rRNA gene-based PCR assay as they target genes with higher copy numbers per parasite genome. Stored saliva DNA samples from 60 Cameroonian individuals with infections previously confirmed by 18S rRNA gene PCR in peripheral blood were tested with assays targeting the cox3 and varATS genes. RESULTS: Overall, the standard 18S rRNA gene-based PCR assay detected P. falciparum DNA in 62% of the stored saliva DNA samples, whereas 77 and 68% of the samples were positive with assays that target the cox3 and varATS genes, respectively. Interestingly, the ultra-sensitive assays detected more P. falciparum infections in stored saliva samples than were originally detected by thick-film microscopy (41/60 = 68%). When stratified by number of parasites in the blood, the cox3 assay successfully detected more than 90% of infections using saliva when individuals had > 1000 parasites/µl of peripheral blood, but sensitivity was reduced at submicroscopic parasitemia levels. Bands on electrophoresis gels were distinct for the cox3 assay, whereas faint or non-specific bands were sometimes observed for varATS and 18S rRNA that made interpretation of results difficult. Assays could be completed in 3.5 and 3 h for the cox3 and varATS assays, respectively, whereas the 18S rRNA gene assays required at least 7 h. CONCLUSIONS: This study demonstrates that a PCR assay targeting the cox3 gene detected P. falciparum DNA in more saliva samples than primers for the 18S rRNA gene. Non-invasive collection of saliva in combination with the proposed cox3 primer-based PCR assay could potentially enhance routine testing of P. falciparum during disease surveillance, monitoring, and evaluation of interventions for malaria elimination.

Detection of Plasmodium falciparum DNA in saliva samples stored at room temperature: potential for a non-invasive saliva-based diagnostic test for malaria.

BACKGROUND: Current malaria diagnostic methods require blood collection, that may be associated with pain and the risk of transmitting blood-borne pathogens, and often create poor compliance when repeated sampling is needed. On the other hand, the collection of saliva is minimally invasive; but saliva has not been widely used for the diagnosis of malaria. The aim of this study was to evaluate the diagnostic performance of saliva collected and stored at room temperature using the OMNIgene®â€¢ORAL kit for diagnosing Plasmodium falciparum malaria. METHODS: Paired blood and saliva samples were collected from 222 febrile patients in Cameroon. Saliva samples were collected using the OMNIgene®â€¢ORAL (OM-501) kit and stored at room temperature for up to 13 months. Thick blood film microscopy (TFM) was used to detect P. falciparum blood-stage parasites in blood. Detection of P. falciparum DNA in blood and saliva was based on amplification of the multi-copy 18 s rRNA gene using the nested-polymerase chain reaction (nPCR). RESULTS: Prevalence of malaria detected by TFM, nPCR-saliva and nPCR-blood was 22, 29, and 35%, respectively. Using TFM as the gold standard, the sensitivity of nPCR-saliva and nPCR-blood in detecting P. falciparum was 95 and 100%, respectively; with corresponding specificities of 93 and 87%. When nPCR-blood was used as gold standard, the sensitivity of nPCR-saliva and microscopy was 82 and 68%, respectively; whereas, the specificity was 99 and 100%, respectively. Nested PCR-saliva had a very good agreement with both TFM (kappa value 0.8) and blood PCR (kappa value 0.8). At parasitaemia > 10,000 parasites/µl of blood, the sensitivity of nPCR-saliva was 100%. Nested PCR-saliva detected 16 sub-microscopic malaria infections. One year after sample collection, P. falciparum DNA was detected in 80% of saliva samples stored at room temperature. CONCLUSIONS: Saliva can potentially be used as an alternative non-invasive sample for the diagnosis of malaria and the OMNIgene®â€¢ORAL kit is effective at transporting and preserving malaria parasite DNA in saliva at room temperature. The technology described in this study for diagnosis of malaria in resource-limited countries adds on to the armamentarium needed for elimination of malaria.