World Health Organization Threshold Research Articles

Extending intervention window from 1000 to 8000 first day of life: how can it boost the stunting reduction program?

Stunting is one of the triple malnutrition burdens in Indonesia, beside obesity and micronutrient deficiency. Stunting is a reflection of long-term undernourishment which resulted in stunted growth. National Health Survey Data showed the reduction of stunting rate among under-five children in Indonesia from 37.2% in 2013 to 30.4% in 2018 and 21.5% in 2023. Despite this decreasing trend, the national stunting rate was still above the World Health Organization threshold of 20%. There is also a wide discrepancy between provinces in Indonesia with stunting rate ranges from 7.2% in Bali to 39.2% in Papua. Back in 2011, there was a movement by 28 countries including Indonesia regarding the 1000 first day of life (1000-days) program. This was an approach targeting children during their 1000 first day of life through specific and sensitive nutritional interventions. The 1000-days is started during pregnancy until the child is two years old. This movement involved related stakeholders from national and sub-national level including ministries, community organization, private sectors, professional organization, academics and others.

P-357 Exposure to bleomycin in vitro reduces biomarkers of human male gamete competence

Abstract Study question Does male human sperm exposure to bleomycin in vitro affect their aptitude to breed? Summary answer Bleomycin, an antitumor antibiotic, adversely impacts human male gamete morphology and functionality, thus potentially compromising male fertility. What is known already Bleomycin is a chemotherapeutic agent used to treat a number of tumors that affect males of reproductive age. Hitherto, its effect on human male reproductive capacity alone has not been previously shown. The little information available on this subject relates to in vivo animal studies and supports the feasibility of this study. Study design, size, duration Between November 2022 and June 2023, individuals of reproductive age were enrolled in this study and had their clinical semen analyzed. The remaining ejaculate was supplied by 45 participants with sperm concentration above the World Health Organization (WHO) threshold for scientific purposes. Sperm were isolated from seminal plasma in the ejaculate of each individual, diluted to a concentration of 16 X 106 sz/mL (raw). Participants/materials, setting, methods In vitro incubation was performed in sperm preparation medium (SPM; control) or bleomycin (100 µg/mL; exposed) augmented for two hours at 37oC and 5% CO2. The results of exposed group were compared to raw and control. To evaluate the competence of human sperm, markers such as acrosome and DNA integrity, mitochondrial membrane potential, sperm motility, vitality, and oxidative stress were evaluated. Ultrastructural data from transmission electron microscopy was also obtained and correlated with functional experiments. Main results and the role of chance The participants were all of reproductive age (median age of 36 years old). The raw sperm parameters fulfilled the normozoospermia threshold set by the WHO, 2021. Prior to the current trial, none of the participants had been diagnosed with cancer or had received chemotherapy, radiation therapy, or both. Bleomycin exposure for two hours in vitro significantly (P < 0.001) reduced sperm motility, vitality, and chromatin condensation as compared to raw and control sperm. Moreover, bleomycin significantly (P < 0.001) increased the percentage of sperm with DNA fragmentation (sDNAfrag) and low mitochondrial membrane potential (MMP). Broad strands were significantly (P < 0.001) attained by bleomycin-induced breaks in the sperm DNA (Head staining pattern), which were succeeded by histone-rich areas (PAR-post-acrossomic region staining pattern). Additionally, bleomycin significantly (P < 0.05) delayed the acrossomic response, but had no significantly influence on the generation of extracellular and intracellular reactive oxygen species or in its reconstitution. Modifications in ultrastructural morphology caused by bleomycin corroborate the results obtained by functional tests. Limitations, reasons for caution Bleomycin impact on male fertility competence in vivo remains crucial. Increased sample sizes, including prepubertal subjects, are needed to pinpoint the precise bleomycin’s mechanism to cause oxidative stress, apoptosis, and sDNAfrag. Long-term implications on fertility and reproductive health, besides methods to lessen or offset bleomycin’s effects, should also be pursued. Wider implications of the findings Bleomycin adversely affects male gamete competence in humans. Along with its accompanying lung toxicity, healthcare practitioners should actively monitor and further investigate bleomycin’s gonadotoxicity in males. It is advised that all cancer patients undergoing chemotherapy treatments that contain bleomycin be provided with a fertility preservation plan in the meantime. Trial registration number not applicable

Onchocerciasis in the Cameroon–Chad border area after more than 20 years of annual mass ivermectin distribution

BackgroundThe main vectors of onchocerciasis in Africa are Simulium damnosum sensu lato, which transmit the causative agent Onchocerca volvulus. The force of transmission is driven by the vector density, hence influencing the disease prevalence and intensity. Onchocerciasis is currently targeted for elimination using mass drug administration (MDA) of ivermectin, a potent microfilaricide. MDA in Cameroon began in 1987 in the Vina Valley, an endemic cross-border area with Chad, known for high vector densities and precontrol endemicity. Evaluations in 2008–2010 in this area showed ongoing transmission, while border areas in Chad were close to interrupting transmission. This study aimed to evaluate transmission in this area after several rounds of MDA since the last evaluation surveys.MethodsBlack flies were collected by human landing catches at seven border sites in Cameroon, twice a week, from August 2021 to March 2022. A fraction of the flies was dissected for parity assessment and identification of Onchocerca larval stages. The transmission indices were estimated. Black fly larvae were also collected from the breeding sites at the fly catching sites and identified to species level by cytotaxonomy.ResultsA total of 14,303 female flies were collected, and 6918 were dissected. Of these, 4421 (64.0%) were parous. The total biting rates were high, reaching up to 16,407 bites/person/study period, and transmission potential (third-stage larvae (L3) from head/all L3) were 367/702, 146/506, 51/55, 20/32, 0/3, 0/0, and 0/0 infective larvae/person, respectively, for Mbere-Tchad, Babidan, Hajam/V5, Gor, Djeing, Touboro, and Koinderi. Infectivity rates (L3 from head) were 16.00, 12.75, 5.15, and 4.07 infective females (L3H)/1000 parous flies for Haijam, Mbere-Tchad, Babidan, and Gor, respectively. These values exceed the World Health Organization (WHO) thresholds of ≤ 20 annual transmission potential (ATP) or < 1 infective female/1000 parous females. The major vectors identified were Simulium damnosum sensu stricto, S. squamosum, and for the first time in the area, S. yahense.ConclusionsMore than 20 years of MDA has not eliminated onchocerciasis in the study area; hence, this area is a potential source of reintroduction of onchocerciasis in Chad and would require alternative treatment strategies. Many factors such as MDA efficiency, effectiveness of ivermectin, and cytospecies composition may be contributing to transmission persistence.Graphical

Harnessing overlapped temperature-salinity gradient in solar-driven interfacial seawater evaporation for efficient steam and electricity generation

Solar-driven interfacial water evaporation (SIWE) offers a superb way to leverage concentrated solar heat to minimize energy dissipation during seawater desalination. It also engenders overlapped temperature-salinity gradient (TSG) between water-air interface and adjacent seawater, affording opportunities of harnessing electricity. However, the efficiency of conventional SIWE technologies is limited by significant challenges, including salt passivation to hinder evaporation and difficulties in exploiting overlapped TSG simultaneously. Herein, we report self-sustaining hybrid SIWE for not only sustainable seawater desalination but also efficient electricity generation from TSG. It enables spontaneous circulation of salt flux upon seawater evaporation, inducing a self-cleaning evaporative interface without salt passivation for stable steam generation. Meanwhile, this design enables spatial separation and simultaneous utilization of overlapped TSG to enhance electricity generation. These benefits render a remarkable efficiency of 90.8% in solar energy utilization, manifesting in co-generation of solar steam at a fast rate of 2.01 kg m−2 h−1 and electricity power of 1.91 W m−2 with high voltage. Directly interfacing the hybrid SIWE with seawater electrolyzer constructs a system for water-electricity-hydrogen co-generation without external electricity supply. It produces hydrogen at a rapid rate of 1.29 L h−1 m−2 and freshwater with 22 times lower Na+ concentration than the World Health Organization (WHO) threshold.

An evaluation of LLIN physical integrity and population attitudes towards net use, care and handling during the Magude project in southern Mozambique

BackgroundThe Magude Project assessed the feasibility of eliminating malaria in Magude district, a low transmission setting in southern Mozambique, using a package of interventions, including long-lasting insecticidal nets (LLINs). As the efficacy of LLINs depends in part on their physical integrity, this metric was quantified for Olyset® Nets post mass-distribution, in addition to net use, care and handling practices and other risk factors associated with net physical integrity.MethodsNets were collected during a cross-sectional net evaluation, nine months after the Magude project commenced, which was 2 years after the nets were distributed by the National Malaria Control Programme (NMCP). The physical integrity of the nets was assessed by counting and sizing the holes at different positions on each net. A structured questionnaire was administered to assess how the selected net was used and treated (care, wash and repair). Net bio-efficacy was assessed following the standard World Health Organization (WHO) cone bioassay procedures.ResultsOut of the 170 Olyset® Nets included in the analysis, 63.5% had been used the night before. The main reason for not using a net was the notion that there were no mosquitoes present. The average number of people using each net was 1.79. Two thirds of the nets had only been washed once or twice since distribution. Most nets (80.9%) were holed and 18% were torn, but none of the risk factors were significantly associated with net integrity, except for presence of mice in the household. Less than half of the participants noticed holes in holed nets, and of those only 38.6% attempted to repair those. None of the six nets that were tested for bio-efficacy passed the WHO threshold of 80% mosquito mortality.ConclusionOverall the majority of Olyset® Nets were in serviceable condition two years post-distribution, but their insecticidal effect may have been lost. This study—together with previous evidence on suboptimal access to and use of LLINs in Magude district—highlights that LLINs as an intervention could have been optimized during the Magude project to achieve maximum intervention impact.

Updated threshold, renewed problems: should the diagnostic criteria of polycythemia vera be reconsidered? A retrospective cross-sectional cohort study.

This aim of this study was to evaluate hemoglobin and hematocrit values of polycythemia vera and secondary polycythemia patients with updated World Health Organization thresholds. In addition, by determining our own threshold values, we aimed to demonstrate the necessity of bone marrow biopsy and genetic analysis to be used for further diagnosis in patients with high-normal hematocrit and hemoglobin values. A cross-sectional and retrospective study was performed with the medical records of patients from Eskisehir City Hospital hematology clinics and outpatient clinics between July 1, 2019 and July 1, 2020. The study included patients with polycythemia, divided into two groups according to polycythemia vera and secondary polycythemia. A bone marrow biopsy was performed on patients with either Janus kinase mutation positivity and/or subnormal erythropoietin levels. Receiver operating characteristics analysis was used to find threshold values, and the diagnostic efficiency of these values in differentiating World Health Organization thresholds in 2008 and 2016 was evaluated. A total of 73 patients were included. The median age was 43.5 years (min: 18; max: 84). The hematocrit value of 54.1 was predicted to diagnose polycythemia vera with a sensitivity of 45% and a specificity of 80%. Subsequent analysis revealed that an hemoglobin value of 17.7 was indicative of diagnosing polycythemia vera with a sensitivity of 60% and a specificity of 63%. The mean follow-up length was 6.4 months (2-12). Our study demonstrated that modified World Health Organization criteria might lead to unnecessary additional tests for polycythemia vera patients with high-normal hemoglobin and hematocrit values.

The Financial Burden of Guideline-recommended Cancer Medications for Metastatic Urothelial Carcinoma

Bladder cancer is a significant global health concern owing to its prevalence, negative impact on quality of life, and high treatment costs. Treatment for metastatic urothelial carcinoma (mUC) traditionally relies on platinum-based chemotherapy regimens. However, clinical trial results have led to the approval of immune checkpoint inhibitors (ICIs) as viable treatment options. We assessed the escalating costs and economic viability of mUC treatment guidelines in Europe. We used a pragmatic approach that involved: (1) collection of the costs of the recommended medications in the five most populous European countries; (2) conversion of the costs into international dollars to account for differences in purchasing power parity among countries; (3) evaluation of the cost trends over time; and (4) comparison of the medication costs to World Health Organization thresholds. Introduction of ICIs in European guidelines substantially increased the cost of medications for mUC. Intriguingly, important differences across European countries emerged: the annual cost of medications was twofold higher in Italy than in France and the UK. Despite limitations, our study sheds light on the escalating costs and economic challenges of mUC treatment, and highlights the need for assessments of sustainable and cost-effective management approaches. Patient summaryWe looked at the costs of treatments for metastatic bladder cancer and found that costs have been rising over time, especially with the introduction of new immune therapies, with notable differences among European countries. While these new treatments improve patient outcomes, they also come with a high price tag, which could strain health care budgets. Our results suggest that cost-effectiveness studies will be essential in determining the best and most sustainable treatment strategies in the future.

Mercury distribution in fish organs sampled along the Mauritanian Atlantic coast and their potential human health risks

This paper aimed at assessing total mercury concentration in seven common fish species (Auxis rochei, Caranx rhonchus, Sardina pilchardus, Sardinella aurita, Sardinella maderensis, Scomber colias and Trachurus trecae) and a relationship between Hg organotropism and food regimes along the Mauritanian Atlantic coast. Results show that total mercury concentration in fish collected along five sites ranged from 0.027 to 0.533 mg/kg dry weight. Significant differences were observed among species depending on feeding behavior. Muscle tissues of carnivorous fish presented significantly higher levels of total mercury than that of omnivorous fish, except for Scomber colias, suggesting mercury biomagnification through the food chain. Significant differences in mercury concentrations were observed between muscle tissues and liver, for Auxis rochei, Trachurus trecae, and Caranx rhonchus.The mean concentrations in the different species are however low and none of the concentration values exceed the World Health Organization's threshold for human consumption.

Informing ASR Treatment Practices in a Florida Aquifer through a Human Health Risk Approach.

Aquifer storage and recovery (ASR) can augment water supplies and hydrologic flows under varying climatic conditions. However, imposing drinking water regulations on ASR practices, including pre-treatment before injection into the aquifer, remains arguable. Microbial inactivation data-Escherichia coli, Pseudomonas aeruginosa, poliovirus type 1 and Cryptosporidium parvum-were used in a human health risk assessment to identify how the storage time of recharged water in the Floridan Aquifer enhances pathogen inactivation, thereby mitigating the human health risks associated with ingestion. We used a quantitative microbial risk assessment to evaluate the risks for a gastrointestinal infection (GI) and the associated disability-adjusted life years (DALYs) per person per year. The risk of developing a GI infection for drinking water no longer exceeded the suggested annual risk threshold (1 × 10-4) by days 31, 1, 52 and 80 for each pathogen, respectively. DALYs per person per year no longer exceeded the World Health Organization threshold (1 × 10-6) by days 27, <1, 43 and 72. In summary, storage time in the aquifer yields a significant reduction in health risk. The findings emphasize that considering microbial inactivation, caused by storage time and geochemical conditions within ASR storage zones, is critical for recharge water treatment processes.

The Prevalence of Trachomatous Trichiasis in People Aged 15 Years and Over in Six Evaluation Units of Gaoual, Labé, Dalaba and Beyla Districts, Guinea

ABSTRACT Purpose Trachoma is a public health problem in 42 countries. Inflammation associated with repeated ocular infection with Chlamydia trachomatis can cause the eyelid to scar and turn inwards, resulting in the eyelashes rubbing against the eyeball, known as trachomatous trichiasis (TT). In Guinea, baseline surveys conducted in 2013 reported inflammatory trachoma prevalences below the World Health Organization (WHO) threshold for elimination, but TT prevalences above threshold. Given this epidemiological context and time since baseline survey, TT-only surveys were conducted in selected districts to determine current TT prevalence. The results of this study provide critical data for assessing Guinea’s achievement of trachoma elimination targets. Methods Four health districts, consisting of six evaluation units (EU), were surveyed. In each EU, field teams visited 29 clusters with a minimum 30 households included in each. Participants aged≥15 years were examined by certified graders trained to identify TT and determine whether management had been offered. Results A total of 22,476 people were examined, with 48 TT cases across the six EUs identified. Five of six EUs had an age-and-gender adjusted TT-prevalence unknown to the health system less than 0.2%, whereas one EU, Beyla 2, had an adjusted TT prevalence of 0.24%. Conclusion These TT-only surveys, along with findings from other trachoma interventions, suggest that Guinea is close to achieving elimination of trachoma as a public health problem. This study demonstrates the value of undertaking TT-only surveys in settings where baseline surveys indicated active trachoma prevalences below WHO elimination threshold, but TT prevalences above it.

Incidence of Neonatal Hypothermia in the Newborn Nursery and Associated Factors

Thermoregulation is a key component of well-newborn care. There is limited epidemiologic data on hypothermia in late preterm and term infants admitted to the nursery. Expanding on these data is essential for advancing evidence-based care in a population that represents more than 3.5 million births per year in the US. To examine the incidence and factors associated with hypothermia in otherwise healthy infants admitted to the newborn nursery following delivery. A retrospective cohort study using electronic health record data from May 1, 2015, to August 31, 2021, was conducted at a newborn nursery at a university-affiliated children's hospital. Participants included 23 549 infants admitted to the newborn nursery, from which 321 060 axillary and rectal temperature values were analyzed. Infant and maternal clinical and demographic factors. Neonatal hypothermia was defined according to the World Health Organization threshold of temperature less than 36.5 °C. Hypothermia was further classified by severity (mild: single episode, temperature 36.0-36.4 °C; moderate/severe: persistent or recurrent hypothermia and/or temperature <36.0 °C) and timing (early: all hypothermic episodes occurred within the first 24 hours after birth; late: any episode extended beyond the first 24 hours). Of 23 549 included infants (male, 12 220 [51.9%]), 5.6% were late preterm (35-36 weeks' gestation) and 4.3% were low birth weight (≤2500 g). The incidence of mild hypothermia was 17.1% and the incidence of moderate/severe hypothermia was 4.6%. Late hypothermia occurred in 1.8% of infants. Lower birth weight and gestational age and Black and Asian maternal race and ethnicity had the highest adjusted odds across all classifications of hypothermia. The adjusted odds ratios of moderate/severe hypothermia were 5.97 (95% CI 4.45-8.00) in infants with a birth weight less than or equal to 2500 vs 3001 to 3500 g, 3.17 (95% CI 2.24-4.49) in 35 week' vs 39 weeks' gestation, and 2.65 (95% CI 1.78-3.96) in infants born to Black mothers and 1.94 (95% CI 1.61-2.34) in infants born to Asian mothers vs non-Hispanic White mothers. In this cohort study of infants in the inpatient nursery, hypothermia was common, and the incidence varied by hypothermia definition applied. Infants of lower gestational age and birth weight and those born to Black and Asian mothers carried the highest odds of hypothermia. These findings suggest that identifying biological, structural, and social determinants of hypothermia is essential for advancing evidence-based equitable thermoregulatory care.

Prevalence and associated factors of active trachoma among 1-9 years of age children in Andabet district, northwest Ethiopia, 2023: A multi-level mixed-effect analysis.

Trachoma is the chief cause of preventable blindness worldwide and has been earmarked for elimination as a public health problem by 2030. Despite the five-year Surgery, Antibiotics, Facial cleanliness, and Environmental improvement (SAFE)-based interventions in the Andabet district, the prevalence of trachomatous follicular (TF) was 37%. With such a high prevalence of TF, the determinant factors were not revealed. Besides, there were no reports on the overall prevalence of active trachoma (i.e.TF and or trachomatous intense (TI)). To determine the prevalence and associated factors of active trachoma among 1-9 years of age children in the Andabet district. A community-based cross-sectional study was conducted among children aged under nine years from March 1-30, 2023 in Andabet district, Northwest Ethiopia. Multi-stage systematic random sampling was employed to reach 540 children. A multilevel mixed-effect logistic regression analysis was employed to assess factors associated with active trachoma. We fitted both random effect and fixed effect analysis. Finally, variables with p<0.05 in the multivariable multilevel analysis were claimed to be significantly associated with active trachoma. In this study, the overall prevalence of active trachoma was 35.37% (95% CI: 31.32%, 39.41%). The prevalence of TF and TI was 31.3% and 4.07% respectively. In the multilevel logistic regression analysis ocular discharge, fly-eye contact, latrine utilization, and source of water were significantly associated with the prevalence of active trachoma. In this study, the prevalence of active trachoma was much higher than the World Health Organization (WHO) threshold prevalence. Ocular discharge, fly-eye contact, latrine utilization, and source of water were independent determinants of active trachoma among children (1-9 years). Therefore, paying special attention to these high-risk groups could decrease the prevalence of a neglected hyperendemic disease, active trachoma.

Cost-Effectiveness of Four Tobacco Control Interventions in Mongolia.

The aim of this study is to quantify the cost-effectiveness of four tobacco control interventions: Tobacco taxation, mass media campaigns, school programs, and cessation support, and to illustrate how available evaluation tools can be adapted to the local setting. We used the dynamic population health modeling-health impact assessment tool to project the future smoking prevalence associated with the interventions and to simulate the resulting smoking-related disease burden over time. Applying the most recent available national Mongolian data as input, the costs and effects of four interventions were compared to a business-as-usual scenario, resulting in costs per life year gained and per disability-adjusted life years (DALYs) averted. Three years after implementation, all interventions reduce the prevalence of current smoking, with the strongest reduction observed with the increase in tobacco tax (5.1% points), followed by mass media campaigns (1.6% points), school programs (1.3% points), and cessation support interventions (0.6% points). School programs were a cost-saving tobacco control intervention compared to current practice in Mongolia, while the other programs resulted in additional costs compared to business as usual. Compared to the World Health Organization (WHO) thresholds, all interventions would be considered "very cost-effective" in terms of cost per DALY averted (below US$ 4295 per DALY averted) in Mongolia. Large-scale interventions such as taxation and mass media campaigns result in both cost-effectiveness and important health benefits in relation to intervention costs. Reducing the prevalence of smoking among the male population would be particularly worthwhile in Mongolia. This study shows that in Mongolia school programs were a cost-saving intervention, while the cost-effectiveness ratios were US$ 25 per disability-adjusted life year (DALY) averted for mass media campaigns, US$ 74 for taxation, and US$ 1961 for cessation support interventions. Compared to the WHO thresholds, all interventions would be considered "very cost-effective" in terms of expenses per DALY averted (<US$ 4295 per DALY averted), making it beneficial to scale up the WHO-Monitor tobacco use and prevention, Protect people from smoke, Offer help to quit smoking, Warn about the danger, Enforce bans, and Raise taxes (MPOWER) interventions to reduce the burden from smoking in Mongolia.

Investigating water safety in multi-purpose buildings used as an elementary school and plumbing remediation effectiveness

Three buildings that were repurposed for use as an elementary school were shutdown for three months in response to the pandemic. Building cold and hot water quality was monitored before reopening to detect and resolve chemical and microbiological problems. The authors collected first draw pre-flush and post-flush water samples. First draw water samples did not contain detectable disinfectant residual, but nickel and lead sometimes exceeded the health-based action limits for cold water (max. 144 μg Ni/L, 3.4 μg Pb/L). Stagnant cold water at a bathroom sink (188 MPN/100 mL) and drinking water fountain (141.6 MPN/100 mL), in the same building, exceeded theL.pneumophilathresholds advised by the World Health Organization (WHO) (10 CFU/mL) and American Industrial Hygiene Association (AIHA) (100 CFU/mL). Fixture flushing was conducted to remove cold and hot stagnant water and noL.pneumophilawas detected immediately after flushing. Two weeks after no subsequent building water use, chemical and microbiological contaminant levels were found to be similar to levels prior to flushing with one exception. The maximumL.pneumophilalevel (kitchen sink, hot water: 61.1 MPN/100 mL) was found in a different building than the prior maximum detections. No repeat positive locations forL.pneumophilawere found during the second visit, but new fixtures were positive the organism. When this study was conducted no evidence-based guidelines for plumbing recommissioning were available. A single plumbing flush reduced heavy metal andL.pneumophilalevels below WHO and AIHA thresholds in all three buildings. Additional work is needed to examine the role of building size, type and plumbing design on fixture water quality in shutdown buildings.

Nitrogen sources and conversion processes in shallow groundwater around a plain lake (Northwest China): Evidenced by multiple isotopes and water chemistry

The groundwater quality is severely impacted by Nitrate (NO3−-N) pollution worldwide. Effective lake quality management depends on understanding the origin and fate of nitrogen (N) in the groundwater around lakes. This study combined data for multiple stable isotopes (δ2H–H2O and δ18O–H2O, δ15N–NO3 and δ18O–NO3) and hydrochemistry with the hydrodynamic monitoring profile and a Bayesian isotope mixing (MixSIAR) model to clarify the sources and transformation of N within shallow groundwater around Shahu Lake in the arid area plain of Northwest China. In May 2022, multiple water samples were collected from aquifers (n = 33), drainage water (n = 1), channel water (n = 1), and lake water (n = 7). The results showed that 57% of groundwater samples had high NO3−-N concentrations exceeding the World Health Organisation threshold for drinking water (10 mg/L). The high variation in δ15N–NO3 (from −9.21‰ to +27.57‰) and δ18O–NO3 (from −8.32‰ to +19.04‰) revealed multiple N sources and conversion processes. According to nitrate isotopes and the MixSIAR model, N fertilizer, soil organic N and manure, and sewage are the main sources of nitrogen in groundwater and lake water, which account for 40.61%, 35.86%, and 21.55% of groundwater NO3−-N, respectively, and 35.07%, 34.43%, and 27.49% of lake water NO3−-N. Hydrodynamic monitoring combined with water isotopes showed that upper groundwater (5–10 m) within 1.22 km of the adjacent lake shore strongly interacted with the lake. In groundwater, nitrification predominated, while local denitrification remained a possibility. In conclusion, this research offers a comprehensive approach to determining the sources and conversion of N in contaminated groundwater.

Hopes, joys and fears: Meaning and perceptions of viral load testing and low-level viraemia among people on antiretroviral therapy in Uganda: A qualitative study.

Uganda applies the World Health Organization threshold of 1,000 copies/ml to determine HIV viral non-suppression. While there is an emerging concern of low-level viraemia (≥50 to <1,000 copies/ml), there is limited understanding of how people on antiretroviral therapy perceive viral load testing and low-level viremia in resource-limited settings. This qualitative study used the health belief model to explore the meaning that people living with HIV attach to viral load testing and low-level viraemia in Uganda. We used stratified purposive sampling to select people on antiretroviral therapy from eight high volume health facilities from the Central, Eastern, Northern and Western regions of Uganda. We used an interview guide, based on the health belief model, to conduct 32 in-depth interviews, which were audio-recorded and transcribed verbatim. Thematic analysis technique was used to analyze the data with the help of ATLAS.ti 6. The descriptions of viral load testing used by the participants nearly matched the medical meaning, and many people living with HIV understood what viral load testing was. Perceived benefits for viral load testing were the ability to show; the amount of HIV in the body, how the people living with HIV take their drugs, whether the drugs are working, and also guide the next treatments steps for the patients. Participants reported HIV stigma, lack of transport, lack of awareness for viral load testing, delayed and missing viral load results and few health workers as the main barriers to viral load testing. On the contrary, most participants did not know what low-level viraemia meant, while several perceived it as having a reduced viral load that is suppressed. Many people living with HIV are unaware about low-level viraemia, and hence do not understand its associated risks. Likewise, some people living with HIV are still not aware about viral load testing. Lack of transport, HIV stigma and delayed viral load results are major barriers to viral load testing. Hence, there is an imminent need to institute more strategies to create awareness about both low-level viraemia and viral load testing, manage HIV related stigma, and improve turnaround time for viral load results.

Spatial distribution of radon contamination in hot springs water and its cancer and non-cancer risks in the Hunza-Nagar valley, Pakistan.

Radon (222Rn) is a ubiquitous radioactive gas and could threaten human life due to its potential for cancer and non-cancer risks. This study examined the measurement of 222Rn concentration and associated health risks in the hot springs of Hunza-Nagar valley. For this purpose, the hot springs water of Hunza and Nagar districts and the background sites were analyzed for 222Rn concentration using the RAD7 detector (Durridge Company, USA). The average concentrations of 222Rn were 46.1 ± 0.94, 65.3 ± 0.45, and 5.47 ± 0.25Bq/L in the Hunza district, Nagar district, and background sites, respectively. Results showed that 222Rn concentrations of hot springs water were multifold higher than the background sites. 222Rn concentrations for hot springs water in Hunza-Nagar valley had surpassed the maximum contamination level set by the US environmental protection agency (USEPA). Humans' annual mean exposure dose rates of various age groups were calculated for the estimated lifetime cancer risk (ELCR) and non-cancer risks. The total annual mean exposure doses from 222Rn in water (EwTotal) values were (187 ± 3.80, 265 ± 1.84, and 22.2 ± 1.02μSv/a) for infants (143 ± 2.92, 203 ± 1.40, and 17.0 ± 0.78μSv/a) children, and (138 ± 2.80, 196 ± 1.35, and 16.4 ± 0.76μSv/a) adults in the Hunza district, Nagar district, and background, respectively. Among the age groups of humans, infants showed a higher risk than others. Results showed that hot springs water consumption surpassed the world health organization threshold of 100μSv/y for chronic or non-cancer and USEPA 0.1 × 10-3 for ELCR risks.The concentration of 222Rn showed a positive correlation (> 0.68) with hot springs' water temperature and pH suggesting a common origin.

Analysis of Some Heavy Metal Background Concentration at Dandagoro Quarters, Katsina, Katsina State, Nigeria

Human activities lead to the accumulation of heavy metals in an environment which make environment to be polluted. The research area has become stepwise engage with various waste such as refused dump, animal waste, engine oil, kerosene, spilling of disel etc which can introduce the trace heavy metals. Heavy metals are environmental threat for soils, are also dependent by plant and life of living organism. As the risk of exposure to heavy metals increases for humans directly or indirectly. The study of Analysis of Background Concentration Some Heavy Metals in soil samples extracted from Dandagoro Quarters, Katsina, Katsina State, located at latitude 37˚91ᴵ74ᴵᴵ to 76ᴵᴵE and the longitude 13˚8ᴵ24ᴵᴵN was carried out. At intervals of 100 m, soil samples were collected from the study area, and each 100 m was divided into 10 m. (B1-B10). In order to determine the concentration of the five examined heavy metals (Cr, Cu, Cd, Pb and Co,), a flame atomic absorption spectrophotometer (FAAS) was used. The locations have an average heavy metal concentration of 0.240, 0.110, 0.093, 0.002 and 0.001(ppm) respectively. Differences were seen by comparing the mean concentration of the heavy metals in the target areas with world health organization (W.H.O) threshold limit, national and international related studies and it was reporeted that the samples were not contaminated with the heavy metals. But the metals were presence and there is no need for urgent intervention and remediation measures by the authority. It was recommended that, factories, gas station and manufacturing industries should not be located at or near the area in order to reduced human activities so as to make environment stable and free from pollutants.

Molecular Markers of Sulfadoxine-Pyrimethamine Resistance in Samples from Children with Uncomplicated Plasmodium falciparum at Three Sites in Angola in 2019.

Sulfadoxine-pyrimethamine (SP) is used for prevention of malaria in pregnant women in Angola. We sequenced the Plasmodium falciparum dihydrofolate reductase (pfdhfr) and dihydropteroate synthase (pfdhps) genes, implicated in SP resistance, in samples collected during a 2019 study of artemisinin-based combination therapy efficacy in Benguela, Lunda Sul, and Zaire provinces. A total of 90 day 0 and day of failure samples were individually sequenced, while 508 day 0 samples from participants without recurrent parasitemia were pooled after DNA extraction into 61 pools. The N51I, C59R, and S108N pfdhfr mutations and A437G pfdhps mutations were present at high proportions in all provinces (weighted allele frequencies, 62% to 100%). The K540E pfdhps mutation was present at lower proportions (10% to 14%). The A581G pfdhps mutation was only observed in Zaire, at a 4.6% estimated prevalence. The I431V and A613S mutations were also only observed in Zaire, at a prevalence of 2.8% to 2.9%. The most common (27% to 66%) reconstructed haplotype in all three provinces was the canonical quadruple pfdhfr pfdhps mutant. The canonical quintuple mutant was absent in Lunda Sul and Benguela and present in 7.9% of samples in Zaire. A single canonical sextuple (2.6%) mutant was observed in Zaire Province. Proportions of the pfdhps K540E and A581G mutations were well below the World Health Organization thresholds for meaningful SP resistance (prevalence of 95% for K540E and 10% for A581G). Samples from therapeutic efficacy studies represent a convenient source of samples for monitoring SP resistance markers.

Efficacy and safety of praziquantel preventive chemotherapy in Schistosoma mansoni infected school children in Southern Ethiopia: A prospective cohort study.

Background: The World Health Organization recommends efficacy and safety surveillance of anti-helminths used in mass drug administration campaigns. We evaluated the effectiveness of single-dose praziquantel against Schistosoma mansoni infection, and the safety of praziquantel plus albendazole preventive chemotherapy (PC) in Schistosoma mansoni infected school children (n = 512) in Southern Ethiopia. Method: Stool examinations were done using thick smear Kato-Katz at baseline, week-4, and week-8 of post-Mass drug administration (MDA) to assess praziquantel efficacy. Participants were followed for MDA-associated adverse events up to day 7 of post-MDA. The primary and secondary study outcomes were praziquantel efficacy (parasitological cure and egg reduction rates) and MDA-associated adverse events (AEs), respectively. Result: The overall cure rates at week-4 and week-8 were 89.1% (95%CI = 86.1-91.7) and 87.5% (95%CI = 83.6-90.8), respectively. Cure rates among moderate-to-heavily infected children were significantly lower (p = 0.001) compared to those with light infection at week-4 (84.4% vs. 91.1%, p = 0.03) and week-8 (78.6% vs. 91.9%, respectively). Older children had a higher cure rate than younger ones at week-8 (90.1% vs. 79.5%, p = 0.01). Among those who were Schistosoma egg-free (cured) at week 4, 7.8% became egg-positive at week 8. The overall egg reduction rate (ERR) at week-4 and week-8 were 93.5% and 91.3%, respectively, being lower among the 5-9 years old age groups (p = 0.01) at week-8. The proportion of children who remained schistosoma egg-positive throughout the study follow-up period was 4.6%, and their ERR at week-4 and week-8 was 50% and 51%, respectively, which is below the 90% World Health Organization threshold for efficacy. The incidence of experiencing at least one type of MDA-associated AEs were 17.0% (95%CI = 13.8%-20.5%); abdominal pain, headache, and vomiting were the most common. The proportion of mild, moderate, and severe AEs was 63.2%, 26.3%, and 10.5%, respectively. Females experienced more AEs than males (p = 0.03). Conclusion: Single-dose praziquantel is still effective for the treatment of intestinal schistosomiasis. Praziquantel and albendazole preventive chemotherapy is safe and tolerable, and associated AEs are mostly mild-to-moderate and transient. However, the reduced PZQ effectiveness in moderate-to-heavy infection and observed AEs in about one-fifth of infected children underscores the need for better treatment strategies and surveillance for early detection of parasite resistance and management of AEs.