HIV-exposed uninfected children. A systematic review on psychological well-being and association with school performances in Africa

There is a growing number of children affected by HIV in Africa. Research on HIV-exposed uninfected children (HEU) is also growing. This systematic review focuses on the psychological well-being of HEU and its association with school intervention, outcomes, and enrollment in the African context, which is where the rate of HIV reaches its highest levels. Research on public databases was conducted according to PRISMA standards. Only studies on HEU primary school children in Africa, both quantitative and qualitative, were included. Out of 1510 papers retrieved, 50 met the inclusion criteria. These studies demonstrate that HEU children are more likely to perform worse in school compared to their counterparts who were not exposed to HIV and to show poorer concentration in the classroom. Children with parents suffering from AIDS are worried for them and have to take household responsibility, resulting in school dropouts, juvenile work, and risky behaviors. Few interventions have been conducted in the school environment with some of them being successful; therefore, future research should involve schools to create an inclusive environment where HEU children could enhance their potential and improve their psychological health

The peopling of the last Green Sahara revealed by high-coverage resequencing of trans-Saharan patrilineages

Little is known about the peopling of the Sahara during the Holocene climatic optimum, when the desert was replaced by a fertile environment

Human papillomavirus prevalence among unvaccinated young female college students in Botswana: A cross-sectional study

Background. Human papillomavirus (HPV) is a sexually transmitted infection and a causative agent of cervical cancer. It is common in adolescent girls and young women, and the majority of infections are transient and asymptomatic. In Botswana, there are currently no data on the HPV prevalence against which the impact of prophylactic HPV vaccines can be measured.Objectives. To establish a baseline HPV prevalence in an unvaccinated cohort of young women.Methods. Women aged ≥18 years were recruited from the University of Botswana between September 2016 and May 2020. Demographic and behavioural characteristics of participants were collected. Subsequently, cervicovaginal swabs were obtained and tested for HPV using polymerase chain reaction-restriction fragment length polymorphism. We determined the prevalent HPV types, and evaluated the risk factors associated with HPV positivity.Results. A total of 978 young women were recruited. Overall, there were 589 (60.2%) participants with HPV infection and 12 (1.2%) with HIV. The median (interquartile range) age of the study participants was 19 (18 - 20) years. Multivariate logistic regression analysis showed that significant factors associated with HPV positivity were sexual activity (adjusted odds ratio (aOR) 2.06; 95% confidence interval (CI) 1.49 - 2.63; p<0.001), number of sex partners ≥3 (aOR 2.10; 95% CI 1.39 - 3.18; p<0.001), and smoking (aOR 2.00; 95% CI 1.26 - 3.20; p=0.004).Conclusion. Our results demonstrate for the first time the prevalence of HPV in unvaccinated young women in Botswana. We found a high prevalence of HPV infection, with statistical differences with different risk factors. This finding supports the need for HPV vaccination strategies for females prior to sexual debut to reduce the future burden of cervical cancer in Botswana

A Sub-Microscopic Gametocyte Reservoir Can Sustain Malaria Transmission

Novel diagnostic tools, including PCR and high field gradient magnetic fractionation (HFGMF), have improved detection of asexual Plasmodium falciparum parasites and especially infectious gametocytes in human blood. These techniques indicate a significant number of people carry gametocyte densities that fall below the conventional threshold of detection achieved by standard light microscopy (LM).To determine how low-level gametocytemia may affect transmission in present large-scale efforts for P. falciparum control in endemic areas, we developed a refinement of the classical Ross-Macdonald model of malaria transmission by introducing multiple infective compartments to model the potential impact of highly prevalent, low gametocytaemic reservoirs in the population. Models were calibrated using field-based data and several numerical experiments were conducted to assess the effect of high and low gametocytemia on P. falciparum transmission and control. Special consideration was given to the impact of long-lasting insecticide-treated bed nets (LLIN), presently considered the most efficient way to prevent transmission, and particularly LLIN coverage similar to goals targeted by the Roll Back Malaria and Global Fund malaria control campaigns. Our analyses indicate that models which include only moderate-to-high gametocytemia (detectable by LM) predict finite eradication times after LLIN introduction. Models that include a low gametocytemia reservoir (requiring PCR or HFGMF detection) predict much more stable, persistent transmission. Our modeled outcomes result in significantly different estimates for the level and duration of control needed to achieve malaria elimination if submicroscopic gametocytes are included.It will be very important to complement current methods of surveillance with enhanced diagnostic techniques to detect asexual parasites and gametocytes to more accurately plan, monitor and guide malaria control programs aimed at eliminating malaria

Failure to detect Plasmodium vivax in West and Central Africa by PCR species typing

<p>Abstract</p> <p>Background</p> <p><it>Plasmodium vivax </it>is estimated to affect 75 million people annually. It is reportedly absent, however, from west and central Africa due to the high prevalence of the Duffy negative phenotype in the indigenous populations. Despite this, non-African travellers consistently return to their own countries with <it>P. vivax </it>malaria after visiting this region. An attempt was made, therefore, to detect the presence of <it>P. vivax </it>parasites in blood samples collected from the indigenous populations of west and central Africa.</p> <p>Methods</p> <p>Parasite species typing (for all four human malaria parasites) was carried out by PCR on 2,588 blood samples collected from individuals from nine African malaria-endemic countries.</p> <p>Results</p> <p>Most infections (98.5%) were <it>Plasmodium falciparum</it>, <it>Plasmodium malariae </it>was identified in 8.5% of all infections, and <it>Plasmodium ovale </it>in 3.9%. The prevalence of both parasites varied greatly by country. Only one case of <it>P. vivax </it>was detected from Sao Tome, an island off the west coast of Africa, confirming the scarcity of this parasite in Africa.</p> <p>Conclusion</p> <p>The prevalence of <it>P. vivax </it>in local populations in sub-Saharan Africa is very low, despite the frequent identification of this parasite in non-African travellers.</p

Biotransformation of Metal-Rich Effluents and Potential Recycle Applications

In this chapter, it was introduced about the metallurgic effluents, and their potential to be converted into some feasible coproducts for industries. Some possibilities to introduce circular economy in the context of metallurgic effluents, and in the same way, some techniques to promote bioremediation using microorganisms and products from them were also described. Reported studies, as well as some perspectives to use metal-rich effluents in agriculture and soil quality improvement, were also shown. Copper effluents were kept as the main candidate for sustainable use, as a potentially interesting material for circular economy approaches

Plasmodium falciparum: Differential Selection of Drug Resistance Alleles in Contiguous Urban and Peri-Urban Areas of Brazzaville, Republic of Congo

The African continent is currently experiencing rapid population growth, with rising urbanization increasing the percentage of the population living in large towns and cities. We studied the impact of the degree of urbanization on the population genetics of Plasmodium falciparum in urban and peri-urban areas in and around the city of Brazzaville, Republic of Congo. This field setting, which incorporates local health centers situated in areas of varying urbanization, is of interest as it allows the characterization of malaria parasites from areas where the human, parasite, and mosquito populations are shared, but where differences in the degree of urbanization (leading to dramatic differences in transmission intensity) cause the pattern of malaria transmission to differ greatly. We have investigated how these differences in transmission intensity affect parasite genetic diversity, including the amount of genetic polymorphism in each area, the degree of linkage disequilibrium within the populations, and the prevalence and frequency of drug resistance markers. To determine parasite population structure, heterozygosity and linkage disequilibrium, we typed eight microsatellite markers and performed haplotype analysis of the msp1 gene by PCR. Mutations known to be associated with resistance to the antimalarial drugs chloroquine and pyrimethamine were determined by sequencing the relevant portions of the crt and dhfr genes, respectively. We found that parasite genetic diversity was comparable between the two sites, with high levels of polymorphism being maintained in both areas despite dramatic differences in transmission intensity. Crucially, we found that the frequencies of genetic markers of drug resistance against pyrimethamine and chloroquine differed significantly between the sites, indicative of differing selection pressures in the two areas