Harare Institute of Technology

A Fe2O3–biochar nano-composite (Fe2O3–BC) was prepared from FeCl3-impregnated pulp and paper sludge (PPS) by pyrolysis at 750 °C. The characteristics and methyl orange (MO) adsorption capacity of Fe2O3–BC were compared to that of unactivated biochar (BC). X-ray diffraction (XRD) and scanning electron microscopy (SEM) confirmed the composite material was nano-sized. Fourier transform infrared (FTIR) spectroscopy revealed the presence of hydroxyl and aromatic groups on BC and on Fe2O3–BC, but Brunauer–Emmett–Teller (BET) surface area and Barrett–Joyner–Halenda (BJH) porosity were lower for Fe2O3–BC than BC. Despite the lower BET surface area and porosity of Fe2O3–BC, its MO adsorption capacity was 52.79 % higher than that of BC. The equilibrium adsorption data were best represented by the Freundlich model with a maximum adsorption capacity of 20.53 mg g−1 at pH 8 and 30 min contact time. MO adsorption obeyed pseudo-second-order kinetics for both BC and Fe2O3–BC with R 2 values of 0.996 and 0.999, respectively. Higher MO adsorption capacity for Fe2O3–BC was attributed to the hybrid nature of the nano-composites; adsorption occurred on both biochar matrix and Fe2O3 nanocrystals. Gibbs free energy calculations confirmed the adsorption is energetically favourable and spontaneous with a high preference for adsorption on both adsorbents. The nano-composite can be used for the efficient removal of MO (>97 %) from contaminated wastewater.

In this review, the role of surface modification of nanoparticles to enhance their performance as adsorbents was explored. Performance was assessed by comparisons on adsorption capacities of differently modified nanoparticles (silica, iron, and alumina based nanoparticles) on different heavy metal ions (Cu, Cd, Co, Ni, Pb, As, Cr, Zn, Mn, and Hg). A comparison of pure and modified materials revealed that the modified materials gave superior adsorption capacities. A close relationship was observed between the various modification methods and the adsorption capacities of particles synthesized by hydrothermal methods giving the highest adsorption capacities. Surface modification also had a direct effect on the specific surface area which decreased with the degree of functionalization. The adsorption capacity was however generally observed to increase with the degree of functionalization.

Food security is one of the priorities of every country in the World. However, different factors are making it difficult to meet global targets on food security. Some unprecedented shocks are encumbering food security at the global level. Various interventions have been applied toward food security and artificial intelligence is one of the modern methods that is being used in various stages of the food system. In this paper, the application of artificial intelligence in the whole food production ecosystem ranging from crop production, livestock production, harvesting/slaughtering, postharvest management, food processing, food distribution, food consumption and food waste management is assessed. The objective of this research is to assess the application of artificial intelligence systems in all the stages of food systems. A systematic review was conducted by analyzing 110 articles after the screening of 450 articles based on the inclusion and exclusion criteria. The results indicated that various artificial intelligence algorithms are being applied to all the stages of the food system from crop/livestock production up to food or agro-waste management.

With the continuous advancement of electronic devices, lightweight, flexible, and easily processable materials have gained substantial techno-commercial importance. Most electronic devices must possess a lightweight, high conductivity, high dielectric permittivity, low dielectric loss, and high breakdown strength. Hence, polymer-based piezoelectric materials are in great demand for design and development in energy storage, electromagnetic interference (EMI) shielding, and ultrafiltration applications. Among the piezoelectric polymers, poly(vinylidene fluoride) (PVDF) with a predominantly polar β-phase is the most important. However, the main drawbacks of the PVDF matrix are its relatively low electrical conductivity and dielectric permittivity, and poor energy harvesting and EMI shielding performance. In this context, the incorporation of conductive nanofillers such as reduced graphene oxides, graphene quantum dots, and carbon nanotubes in the PVDF matrix has attracted considerable interest owing to their extraordinary properties. The final properties of these piezoelectric composites depend on the preparation methods, structural conformation, processing conditions, dispersion of nanofillers in the matrix, surface modification of fillers, and specific or nonspecific interaction of the fillers with the PVDF matrix. Herein, we have critically reviewed the formation mechanism of the electroactive β-phase in PVDF, the effects of nanofillers on the phase transformation of PVDF (dispersion and specific interaction), and the correlation of β-phase PVDF piezoelectric and dielectric properties with energy harvesting, EMI shielding, and membrane applications.

Forest and wildlife resources are indispensable for the provision of ecosystem goods and services; as well as spiritual and cultural values in rural areas. In most unprotected areas, these resources are increasingly under threat prompting indigenous communities to apply their local knowledge in an effort to conserve them. Therefore, this study documents how the Nharira community of Chikomba district, Zimbabwe is using indigenous knowledge to conserve forest and wildlife resources. Qualitative methods involving interviews and focus group discussions with villagers were used to gather data. The participants were purposively selected by the traditional leaders on the basis of their rich indigenous knowledge and participation in cultural ceremonies and rituals. The study found wide use of (a) customary rules and regulations, (b) customs and rituals, (c) taboos and totems, and (d) metaphors and proverbs applied in forest and wildlife resource conservation. These forms of indigenous knowledge constitute the social and religious values of the Nharira community that are used in conserving the human-environment system.

Ovarian cancer ranks as the fifth leading cause of cancer-related mortality in women. Late-stage diagnosis (stages III and IV) is a major challenge due to the often vague and inconsistent initial symptoms. Current diagnostic methods, such as biomarkers, biopsy, and imaging tests, face limitations, including subjectivity, inter-observer variability, and extended testing times. This study proposes a novel convolutional neural network (CNN) algorithm for predicting and diagnosing ovarian cancer, addressing these limitations. In this paper, CNN was trained on a histopathological image dataset, divided into training and validation subsets and augmented before training. The model achieved a remarkable accuracy of 94%, with 95.12% of cancerous cases correctly identified and 93.02% of healthy cells accurately classified. The significance of this study lies in overcoming the challenges associated with the human expert examination, such as higher misclassification rates, inter-observer variability, and extended analysis times. This study presents a more accurate, efficient, and reliable approach to predicting and diagnosing ovarian cancer. Future research should explore recent advances in this field to enhance the effectiveness of the proposed method further.

Abstract Owing to their competitive price, ease of processability, and rust resistance, polymers are the most extensively used materials in everyday life. However, consistent exposure to ultraviolet (UV) radiation can lead to the degradation and discoloration of polymeric materials. Various polymer composites containing inorganic and organic nanoparticles (NPs) have been developed to improve the UV‐shielding properties of neat polymers. However, the most used UV‐shielding inorganic NPs are prone to photocatalytic processes, leading to further polymer chain degradation. To overcome this challenge, organic NPs have been used; however, they easily agglomerate, decreasing the UV‐shielding performance of the polymer composites. Herein, we critically report the fundamentals of the UV‐shielding mechanism and the synthesis methods, surface modification, and characterization of the most important inorganic and organic UV‐shielding NPs. We then summarize the various processing techniques used to disperse NPs in polymer matrices to obtain polymer composites with improved UV‐shielding properties. Finally, we propose a broader understanding of how the NP characteristics, their interaction with polymer matrices, and the various processing methods affect the UV‐shielding performance of the obtained polymer composites. In addition, various applications of inorganic and organic NPs‐containing UV‐shielding polymer composites have been reported.

Microplastics are discharged into the environment through human activities and are persistent in the environment. With the prevalent use of plastic-based personal protective equipment in the prevention of the spread of the COVID-19 virus, the concentration of microplastics in the environment is envisaged to increase. Potential ecological and health risks emanate from their potential to adsorb and transport toxic chemicals, and ease of absorption into the cells of living organisms and interfering with physiological processes. This review (1) discusses sources and pathways through which microplastics enter the environment, (2) evaluates the fate and behavior of microplastics, (3) discusses microplastics in African aquatic systems, and (4) identifies research gaps and recommends remediation strategies. Importantly, while there is significant microplastics pollution in the aquatic environment, pollution in terrestrial systems are not widely studied. Besides, there is a dearth of information on microplastics in African aquatic systems. The paper recommends that the governments and non-governmental organizations should fund research to address knowledge gaps, which include: (1) the environmental fate of microplastics, (2) conducting toxicological studies under environmentally relevant conditions, (3) investigating toxicity mechanisms to biota, and developing mitigation measures to safeguard human health, and (4) investigating pollutants transported by microplastics. Moreover, regulatory measures, along with the circular economy strategies, may help reduce microplastic pollution.

BACKGROUND: Traditional medicine plays an important role in health care provision in the developing world. A number of cancer patients have been found to be using traditional medicine as primary therapy and/or as complementary medicine. Cancer is one of the leading causes of morbidity and mortality globally among the non-communicable diseases. The aim of this study was to identify the plants used by traditional medicine practitioners (TMPs) in Zimbabwe to treat cancer. METHODS: A structured questionnaire was used to interview consenting registered TMPs on ethnomedicinal plants they use to treat cancer. A review of published literature on the cited plants was also carried out. The practitioners were asked about the plants that they use to treat cancer, the plant parts used, type of cancer treated, other medicinal uses of the plants and preparation and administration of the plant parts. RESULTS: Twenty (20) TMPs took part in the study. A total of 18 medicinal plant species were cited. The commonly treated types of cancer were breast, prostate, colon, skin and blood cancers with most plants being used to treat skin, blood and breast cancers, respectively. Of the medicinal plants cited, 44.4% were used to treat all cancer types. The most used plant parts were the roots (72.2%) and leaves (72.2%) followed by the bark (38.9%). The medicinal plants were used for multiple ailments. The most common plant preparation methods were infusion (72.2%) and decoction (66.7%) and the oral route of administration, as extracts and powder put in tea and porridge, was the most used. CONCLUSION: The frequently used plant parts were leaves and roots. The traditional uses of the medicinal plants cited in this study resonate well with their reported uses from other ethnopharmacological studies done in other parts of the world. The plants used by TMPs to treat cancer in Zimbabwe, if adequately explored, can be instrumental in the discovery and development of cancer drugs.

= 266.89 mg/g and b = 0.89 L/mg). The adsorption process was both endothermic (ΔH = 97 kJ/mol) and spontaneous (ΔG = -22 kJ/mol). We can conclude that we were able to successfully synthesize NSHS, use them to remove lead (II) ions and the produced NSHS have a capacity that is higher than most other adsorbents investigated by other researchers.

BACKGROUND: There is scanty or inconclusive evidence on which cervical cancer screening tool is effective and suitable for human immunodeficiency virus (HIV)-seropositive women. The aim of this review was to assess, synthesise and document published evidence relating to the available cervical cancer screening modalities for HIV-seropositive women in developing countries. This paper did not review the issue of human papillomavirus (HPV) prophylactic vaccine on HIV-seropositive women. METHODS: Five electronic databases were systematically searched from inception to January 2018 for relevant published original research examining cervical cancer prevention modalities for HPV infection, abnormal cytology and direct visualisation of the cervix amongst HIV-seropositive women in developing countries. Extra studies were identified through reference list and citation tracking. RESULTS: Due to methodological and clinical heterogeneity, a narrative synthesis was presented. Of the 2559 articles, 149 underwent full-text screening and 25 were included in the review. Included studies were of moderate quality, and no exclusions were made based on quality or bias. There is no standard cervical cancer screening test or programme for HIV-seropositive women and countries screening according to available resources and expertise. The screening methods used for HIV-seropositive women are the same for HIV-negative women, with varying clinical performance and accuracy. The main cervical cancer screening methods described for HIV-seropositive women are HPV deoxyribonucleic acid/messenger RNA (DNA/mRNA) testing (n = 16, 64.0%), visual inspection with acetic acid (VIA) (n = 13, 52.0%) and Pap smear (n = 11, 44.0%). HPV testing has a better accuracy/efficiency than other methods with a sensitivity of 80.0-97.0% and specificity of 51.0-78.0%. Sequential screening using VIA or visual inspection with Lugol's iodine (VILI) and HPV testing has shown better clinical performance in screening HIV-seropositive women. CONCLUSION: Although cervical cancer screening exists in almost all developing countries, what is missing is both opportunistic and systematic organised population-based screenings. Cervical cancer screening programmes need to be integrated into already existing HIV services to enable early detection and treatment. There is a need to offer opportunistic and coordinated screening programmes that are provider-initiated to promote early identification of cervical precancerous lesions. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42018095702.

The Zn(2+) and Ni(2+) adsorption capacities of six biosorbents derived from water hyacinth (Eichhornia crassipes) (WH) and sawdust (SD) were investigated, with activated carbon as the control. The biosorbents were raw biomass (WH, SD), charred WH (BWH) and SD and sulphonated bio-chars of WH and SD. The effect of the initial solution pH and Zn(2+) and Ni(2+) concentrations on adsorption capacity was studied, and adsorption isotherms for Zn(2+) and Ni(2+) evaluated. The initial solution pH significantly influenced adsorption (p < 0.05) but the relationship was generally nonlinear. Zn(2+) suppressed Ni(2+) adsorption on all biosorbents. The adsorption capacities of the biosorbents were statistically (p ≤ 0.05) similar to or higher than that of activated carbon. The effects of pyrolysis and bio-char sulphonation on adsorption were inconsistent and dependent on biomass type; in most cases bio-char was a better biosorbent than the original biomass, while sulphonation resulted in less or comparable adsorption. Adsorption data obeyed at least one of three isotherms (linear, Langmuir and Freundlich) (r(2) = 0.90-0.995, p < 0.05). The study revealed that low-cost biosorbents may be used as alternatives to activated carbon in applications including selective separation of Zn(2+) from multi-metal ion solutions containing Ni(2+), and water and wastewater treatment.

The aim of this study was to prepare activated carbon from tobacco stalks using microwave heating. The prepared activated carbon was applied as an adsorbent in methylene blue (MB) removal from water. The optimum conditions for activated carbon preparation were a radiation power of 280 W for a period of 6 minutes after the impregnation of the precursor material with 30% ZnCl2 for 24 hours. The activated carbon yield and iodine number were 49.43% and 1,264.51 mg/g respectively. The activated carbon also had a point of zero charge of 5.81 with an adsorption capacity of 123.45 mg/g for MB. The optimum conditions for MB adsorption were a pH of 6.5 with an adsorbent dosage of 0.2 g/50 mL at 25 °C. The MB adsorption kinetics followed the pseudo second order kinetic model with the intra-particle diffusion model suggesting a two-step adsorption mechanism. The adsorption data also fitted well within the Langmuir adsorption isotherm model. Tobacco stalks can successfully be turned into an economically important product.

While much emphasis has been placed on involving men in AIDS prevention in sub-Saharan Africa, there remain few rigorously evaluated interventions in this area. A particularly appealing point of intervention is the sexual risk behavior associated with men's alcohol consumption. This article reports the outcomes of The Sahwira HIV Prevention Program, a male-focused, peer-based intervention promoting the idea that men can assist their friends in avoiding high-risk sexual encounters associated with alcohol drinking. The intervention was evaluated in a randomized, controlled trial (RCT) implemented in 24 beer halls in Harare, Zimbabwe. A cadre of 413 male beer hall patrons (~20% of the patronage) was trained to assist their male peers within their friendship networks. Activities included one-on-one interactions, small group discussions, and educational events centering on the theme of men helping their male friends avoid risk. Venues were randomized into 12 control versus 12 intervention beer halls with little cross-contamination between study arms. The penetration and impact of the intervention were assessed by pre- and post-intervention cross-sectional surveys of the beer hall patronage. The intervention was implemented with a high degree of fidelity to the protocol, with exposure to the intervention activities significantly higher among intervention patrons compared to control. While we found generally declining levels of risk behavior in both study arms from baseline to post-intervention, we found no evidence of an impact of the intervention on our primary outcome measure: episodes of unprotected sex with non-wife partners in the preceding 6 months (median 5.4 episodes for men at intervention beer halls vs. 5.1 among controls, P = 0.98). There was also no evidence that the intervention reduced other risks for HIV. It remains an imperative to find ways to productively engage men in AIDS prevention, especially in those venues where male bonding, alcohol consumption, and sexual risk behavior are intertwined.

The multifunctional properties of biochar make it a promising adsorbent of heavy metals for environmental bioremediation. Pyrolytic temperature is a key factor that impacts the properties, performance, and mechanisms of agro-wastes-derived biochar because of the physiochemical transformation of its structural composition. It has been deliberated that increased pyrolysis temperatures strongly enhance specific surface area, pH, and high microporosity as well as carbon and ash content with low cation exchange capacity and volatiles content. The reason for different properties from different pyrolysis is related to the variations in the lignin-cellulose structures as well as moistures in different agro-waste biomasses. Biochar has been considered a low-cost material that has shown its convenient applicability in rural areas of developing countries where environmental contamination of heavy metals is emerging. A wide range of pyrolytic temperatures has shown distinctive properties and characteristics of biochar from different biomass and their capacities to remove heavy metals. Higher pyrolysis temperatures can exhibit higher specific surface areas, enhanced functional groups, and stability than modified biochar. Different pyrolysis temperatures exhibited diverse adsorption capacities on biomass such as rice husk and corncob, as efficiency increases with temperatures on selective heavy metals such as hexavalent chromium [Cr(VI)], cadmium [Cd(II)] and zinc [Zn(II)]. This review aimed to understand the physiochemical and structural properties, the transformation of pristine biochar that can enhance the environmental bioremediation of heavy metals. It deliberated on the mechanisms of diverse biomasses obtained from different pyrolysis for decision making process as well as production costs. The authors propose future investigations on heavy metal immobilization to unlock the full potential of biochar in environmental bioremediation.

In this study distillery wastewater was treated using the vermifiltration technology in a bid to reduce downstream contamination by the effluent. 10 kg of Eisenia fetida earthworms were used as the vermifiltration media in a 0.5 m × 0.5 m x 0.3 m vermifiltration bed over a 40 h period cycle. The distillery effluent physicochemical parameters which included pH, total Kjeldahl nitrogen (TKN), biological oxygen demand (BOD), total dissolved solids (TDS), total suspended solids (TSS) and the chemical oxygen demand (COD) were measured every 5 days. The vermicompost which was produced as a result of the vermifiltration process's nitrogen, phosphorous and potassium composition was also determined. The distillery effluent pH changed from acidic to neutral whilst a decrease of 94.9% was observed for the TKN, 91.1% for the BOD, 91.9% for the TDS, 92.4% for the TSS and 89.4% for the COD upon treatment with vermifiltration. The vermicompost, a by-product of the vermifiltration process had a nitrogen, phosphorous and potassium composition of 1.87%, 0.87% and 0.66% respectively. Keywords: Distillery effluent, Eisenia fetida, BOD, COD, TDS, TSS, Vermifiltration, Vermicompost

We sought to examine the association between maternal erythrocyte omega-3, omega-6 and trans fatty acids and risk of preeclampsia. We conducted a case-control study of 170 women with proteinuric, pregnancy-induced hypertension and 185 normotensive pregnant women who delivered at Harare Maternity Hospital, Harare, Zimbabwe. We measured erythrocyte omega-3, omega-6 and trans fatty acid as the percentage of total fatty acids using gas chromatography. After multivariate adjustment for confounding factors, women in the highest quartile group for total omega-3 fatty acids compared with women in the lowest quartile experienced a 14% reduction in risk of preeclampsia (odds ratio 0.86, 95% confidence interval 0.45 to 1.63). For total omega-6 fatty acids the odds ratio was 0.46 (95% confidence interval 0.23 to 0.92), although there was suggestion of a slight increase in risk of preeclampsia associated with high levels of arachidonic acid. Among women in the highest quartile for arachidonic acid the odds ratio was 1.29 (95% confidence interval 0.66 to 2.54). A strong statistically significant positive association of diunsaturated fatty acids with a trans double bond with risk of preeclampsia was observed. Women in the upper quartile of 9-cis 12-trans octadecanoic acid (C(18:2n6ct)) compared with those in the lowest quartile experienced a 3-fold higher risk of preeclampsia (odds ratio = 3.02, 95% confidence interval 1.41 to 6.45). Among women in the highest quartile for 9-trans 12-cis octadecanoic acid (C(18:2n6tc)) the odds ratio was 3.32 (95% confidence interval 1.55 to 7.13). Monounsaturated trans fatty acids were also positively associated with the risk of preeclampsia, although of much reduced magnitude. We observed a strong positive association of trans fatty acids, particularly diunsaturated trans fatty acids, with the risk of preeclampsia. We found little support for the hypothesized inverse association between omega-3 fatty acids and preeclampsia risk in this population. Polyunsaturated fatty acids, particularly omega-3 fatty acids, were comparatively lower in Zimbabwean than among US pregnant women. Given the limited inter-person variation in omega-3 fatty acids among Zimbabwean women, our sample size may be too small to adequately assess the relation in this population.

BACKGROUND: The rise in cervical cancer trends in the past two decades has coincided with the human immunodeficiency virus (HIV) epidemic especially in the sub-Saharan African region. Young people (15 to 24 years old) are associated with many risk factors such as multiple sexual partners, early sexual debut, and high HIV incidences, which increase the chances of developing cervical cancer. The National Cancer Prevention and Control Strategy for Zimbabwe (2014-2018) highlights that no cancer communication strategy focusing on risk factors as primary cancer prevention. Therefore, the study aims to determine the knowledge, attitude and practices of young people in Zimbabwe on cervical cancer, screening, human papillomavirus (HPV) and vaccination. METHODS: A cross-sectional survey assessing young people's knowledge, attitude and practices concerning cervical cancer was conducted in five provinces in Zimbabwe. A total of 751 young people were recruited through a three-stage cluster design from high schools and universities. Knowledge, attitudes and practices were assessed using questions based and adapted from the concepts of the Health Belief Model (HBM) and the Cervical Cancer Measuring tool kit-United Kingdom (UK). RESULTS: Most young people, 87.47% (656/750) claimed to know what the disease called cervical cancer is, with a mean score of 89.98% [95% CI 73.71.11-96.64] between high school and 86.72% [95% CI 83.48-89.40] among university students. There was no significant difference in mean scores between high school and university students (p = 0.676). A risk factor knowledge proficiency score of ≥13 out of 26 was achieved in only 13% of the high school respondents and 14% of the university respondents with a broad range of misconceptions about cervical cancer risk factors in both females and males. There was not much difference on comprehensive knowledge of cervical cancer and its risk factors between female and male students, with the difference in knowledge scores among high school (p = 0.900) and university (p = 0.324) students not statistically significant. In contrast, 43% of respondents heard of cervical cancer screening and prevention, and 47% knew about HPV transmission and prevention. Parents' educational level, province and smoking, were some of the factors associated with knowledge of and attitude towards cervical among high school and university students. CONCLUSION: This study revealed that young people in Zimbabwe have an idea about cervical cancer and the seriousness thereof, but they lack adequate knowledge of risk factors. Cervical cancer education and awareness emphasising causes, risk factors and care-seeking behaviours should be commissioned and strengthen at the community, provincial and national level. Developing a standard cervical cancer primary prevention tool that can be integrated into schools can be a step towards addressing health inequity.

Vascular endothelial growth factor (VEGF), a disulphide-linked homodimeric glycoprotein that is selectively mitogenic for endothelial cells, plays an important role in vasculogenesis and angiogenesis. Preeclampsia, a relatively common complication of pregnancy that is characterized by diffuse endothelial dysfunction possibly secondary to impaired trophoblast invasion of the spiral arteries during implantation, has recently been associated with alterations in maternal serum/plasma concentrations of VEGF, and other related growth factors and their receptors. We examined the relationship of maternal plasma VEGF, sVEGF-R1 and PlGF levels to the risk of preeclampsia among women delivering at Harare Maternity Hospital, Zimbabwe. 131 pregnant women with preeclampsia and 175 controls were included in a case-control study. Maternal plasma concentrations of each biomarker were measured using enzymatic methods. We used logistic regression to calculate odds ratios (OR) and 95 % confidence intervals (CI). Preeclampsia risk was inversely related with quartiles of plasma VEGF (OR: 1.0, 1.0, 0.7, and 0.5, with the lowest quartile as reference; p for trend=0.06). We noted a strong positive association between preeclampsia risk and sVEGF-R1 concentrations (OR: 1.0, 6.5, 9.7, 31.6, with the first quartile as the referent group; p for trend<0.001). After adjusting for confounders, we noted that women with sVEGF-R1 concentrations in the highest quartile (>or=496 pg/ml), as compared with those in the lowest quartile (<62 pg/ml) had a 31.6-fold increased risk of preeclampsia (OR=31.6, 95 % CI 7.7-128.9). There was no clear evidence of a linear relation in risk of preeclampsia with PlGF concentrations. In conclusion, plasma VEGF, sVEGF-R1 and PlGF concentrations (measured at delivery) were altered among Zimbabwean women with preeclampsia as compared with normotensive women. Our results are consistent with some, though not all, previous reports. Prospective studies are needed to: 1) identify modifiable determinants of maternal plasma concentrations VEGF, sVEGF-R1, and PlGF; and 2) evaluate the temporal relationship between observed alterations of these biological markers in preeclamptic pregnancies.

INTRODUCTION: As prevalence of undiagnosed HIV declines, it is unclear whether testing programmes will be cost-effective. To guide their HIV testing programmes, countries require appropriate metrics that can be measured. The cost-per-diagnosis is potentially a useful metric. METHODS: We simulated a series of setting-scenarios for adult HIV epidemics and ART programmes typical of settings in southern Africa using an individual-based model and projected forward from 2018 under two policies: (i) a minimum package of "core" testing (i.e. testing in pregnant women, for diagnosis of symptoms, in sex workers, and in men coming forward for circumcision) is conducted, and (ii) core-testing as above plus additional testing beyond this ("additional-testing"), for which we specify different rates of testing and various degrees to which those with HIV are more likely to test than those without HIV. We also considered a plausible range of unit test costs. The aim was to assess the relationship between cost-per-diagnosis and the incremental cost-effectiveness ratio (ICER) of the additional-testing policy. The discount rate used in the base case was 3% per annum (costs in 2018 U.S. dollars). RESULTS: There was a strong graded relationship between the cost-per-diagnosis and the ICER. Overall, the ICER was below $500 per-DALY-averted (the cost-effectiveness threshold used in primary analysis) so long as the cost-per-diagnosis was below $315. This threshold cost-per-diagnosis was similar according to epidemic and programmatic features including the prevalence of undiagnosed HIV, the HIV incidence and a measure of HIV programme quality (the proportion of HIV diagnosed people having a viral load <1000 copies/mL). However, restricting to women, additional-testing did not appear cost-effective even at a cost-per-diagnosis of below $50, while restricting to men additional-testing was cost-effective up to a cost-per-diagnosis of $585. The threshold cost per diagnosis for testing in men to be cost-effective fell to $256 when the cost-effectiveness threshold was $300 instead of $500, and to $81 when considering a discount rate of 10% per annum. CONCLUSIONS: For testing programmes in low-income settings in southern African there is an extremely strong relationship between the cost-per-diagnosis and the cost-per-DALY averted, indicating that the cost-per-diagnosis can be used to monitor the cost-effectiveness of testing programmes.