What underpins the decline in syphilis in Southern and Eastern Africa? An exploratory ecological analysis.

BACKGROUND: AIDS mortality played an important role in the decline in syphilis prevalence in the USA, but its effect on the dramatic reduction in syphilis prevalence in Southern and Eastern Africa has not been explored. In this ecological study, we investigated the extent to which the relationship between syphilis and HIV prevalence at a population level varied between the early and late periods of the HIV epidemic. METHODS: We performed linear regression analysis to measure the association between the national prevalence of syphilis and the peak-HIV prevalence in the early and late phases of the HIV epidemic in 11 countries of Southern and Eastern Africa. RESULTS: Our analysis showed a strong positive association between peak-HIV prevalence and syphilis prevalence early in the HIV epidemic (R(2)=0.59; p=0.006). Although only of borderline statistical significance, this linear relationship between HIV prevalence and syphilis prevalence switched to a negative direction late in the HIV epidemic (R(2)=0.32; p=0.07). CONCLUSIONS: AIDS mortality may have played an important role in the decline in syphilis in this region. Consequently, with AIDS deaths declining in Sub-Saharan Africa, vigilant surveillance of syphilis prevalence will be necessary to detect a potential re-emergence, as has occurred in high-income countries, and to render a timely public health response

Intermittent preventive treatment of malaria in pregnancy and infectious causes of adverse birth outcomes in sub-Saharan Africa

Background: The World Health Organization recommends intermittent preventive treatment of malaria in pregnancy (IPTp) using sulphadoxine-pyrimethamine (SP) during antenatal visits in moderate to high transmission areas. In some areas of Africa, recent efforts to control and eliminate malaria have yielded historic reductions in transmission intensity that have occurred alongside concomitant increases in parasite resistance to SP, compromising the efficacy of IPTp. Nevertheless, IPTp-SP continues to have beneficial effect on birth outcomes, and there is a suspicion that SP may protect against adverse birth outcomes attributable to curable sexually transmitted and reproductive tract infections (STIs/RTIs). This doctoral thesis explores five research questions related to IPTp with methods noted in parentheses. Research questions and methods: 1. In the context of declining malaria transmission, is there a threshold of malaria transmission intensity below which IPTp-SP may no longer protect against the incidence of low birth weight? (Methods: systematic review, meta-analysis, and meta-regression analysis) 2. In the context of declining parasite sensitivity to SP, is there a threshold of the Plasmodium falciparum resistance to SP defined by the prevalence of dhps mutation at codon A581G above which IPTp-SP may no longer protect against the incidence of low birth weight? (Methods: systematic review and meta-analysis) 3. In the context of declining malaria transmission and parasite sensitivity to SP, might protection conferred by IPTp-SP be explained partially by an effect against malaria infection as well as STIs/RTIs? (Methods: descriptive analysis and multivariate logistic regression) 4. In the context of pregnant women attending antenatal care in sub-Saharan Africa, what is the prevalence of malaria infection and curable STIs/RTIs? (Methods: systematic review and meta-analysis) 5. In the context of a high dual burden of malaria infection and curable STIs/RTIs amongst pregnant women in sub-Saharan Africa, would azithromycin be an efficacious drug to be included as part of IPTp? (Methods: systematic review and selected meta-analysis) Results: Evidence suggests that IPTp-SP protects against low birth weight in all gravidae regardless of transmission intensity. This protection persists among primi- and secundigravidae irrespective of the prevalence of the A581G mutation. Protection appears to wane, however, as there is no evidence of protective effect against low birth weight amongst multigravidae where the prevalence of A581G is >10.1%. Despite this finding, data from Zambia suggests that the protective effect of IPTp-SP may safeguard pregnancies against more than just the effects of malaria infection; women who received more doses of IPTp-SP during pregnancy were protected against adverse birth outcomes attributable to co-infection with malaria and several curable STIs/RTIs. Meta-analysis of data from pregnant women attending antenatal care facilities in sub-Saharan Africa suggests that malaria infection and curable STIs/RTIs amongst pregnant women attending antenatal care facilities in sub-Saharan Africa is very high and, when considered collectively, curable STIs/RTIs may be more prevalent than malaria infection during pregnancy. A potential response to this dual burden of disease in pregnancy is to explore combination therapies that address malaria and curable STIs/RTIs jointly and more effectively than IPTp-SP. Research presented in this thesis suggests that curable STIs/RTIs are sensitive to azithromycin and that policymakers need additional evidence to consider adding azithromycin to IPTp regimens. Conclusions: Despite evidence of parasite resistance, IPTp-SP remains protective against the effects of malaria infection in most pregnant women, even where transmission intensities are very low, and may also reduce the burden of curable STIs/RTIs. However, this protection is likely sub-optimal and, given the high prevalence of malaria and curable STIs/RTIs among pregnant women in sub-Saharan Africa, alternative therapies that include azithromycin merit investigation in clinical trials with robust microbiological components

North Country Hard Cider Yeast Investigation

This project worked in collaboration with North Country Hard Cider, a hard cidery established in 2014, to investigate two areas of interest. The first focused on yeast removal and product turbidity based on the flow rate through a centrifuge. Data was collected at various flow rates in order to optimize centrifuge performance. Turbidity and yeast count data for final products were determined to provide a baseline for future product development. The second experiment aimed to identify and create a profile of the various yeast strains found in the different steps of the fermenting process. Yeast strains were identified through DNA isolation, amplification, and sequencing. This information can be used for further product development and improving product consistency at North Country

Factors that influence vaccination decision-making among pregnant women: A systematic review and meta-analysis.

BACKGROUND: The most important factor influencing maternal vaccination uptake is healthcare professional (HCP) recommendation. However, where data are available, one-third of pregnant women remain unvaccinated despite receiving a recommendation. Therefore, it is essential to understand the significance of other factors and distinguish between vaccines administered routinely and during outbreaks. This is the first systematic review and meta-analysis (PROSPERO: CRD 42019118299) to examine the strength of the relationships between identified factors and maternal vaccination uptake. METHODS: We searched MEDLINE, Embase Classic & Embase, PsycINFO, CINAHL Plus, Web of Science, IBSS, LILACS, AfricaWideInfo, IMEMR, and Global Health databases for studies reporting factors that influence maternal vaccination. We used random-effects models to calculate pooled odds ratios (OR) of being vaccinated by vaccine type. FINDINGS: We screened 17,236 articles and identified 120 studies from 30 countries for inclusion. Of these, 49 studies were eligible for meta-analysis. The odds of receiving a pertussis or influenza vaccination were ten to twelve-times higher among pregnant women who received a recommendation from HCPs. During the 2009 influenza pandemic an HCP recommendation increased the odds of antenatal H1N1 vaccine uptake six times (OR 6.76, 95% CI 3.12-14.64, I2 = 92.00%). Believing there was potential for vaccine-induced harm had a negative influence on seasonal (OR 0.22, 95% CI 0.11-0.44 I2 = 84.00%) and pandemic influenza vaccine uptake (OR 0.16, 95% CI 0.09-0.29, I2 = 89.48%), reducing the odds of being vaccinated five-fold. Combined with our qualitative analysis the relationship between the belief in substantial disease risk and maternal seasonal and pandemic influenza vaccination uptake was limited. CONCLUSIONS: The effect of an HCP recommendation during an outbreak, whilst still powerful, may be muted by other factors. This requires further research, particularly when vaccines are novel. Public health campaigns which centre on the protectiveness and safety of a maternal vaccine rather than disease threat alone may prove beneficial