World Health Organization Threshold Research Articles

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.

Enhanced arsenite removal from water using zirconium-ferrocene MOFs coupled with peroxymonosulfate:oxidation and multi-sites adsorption mechanism

The efficient removal of arsenite (As(III)) poses a significant challenge to traditional water treatment technologies due to its high toxicity and mobility. In this work, multifunctional Zirconium-Ferrocene Metal Organic Framework (ZrFc-MOF) fabricated with redox-active 1,1-ferrocene dicarboxylic acid ligands and Zr4+ precursors were elaborated to achieve remarkably enhanced As(III) removal via activation by peroxymonosulfate (PMS). The adsorption affinity coefficient increased from 0.097 to 2.035 L mg−1 and the maximum adsorption capacity increased from 59.79 to 111.34 mg g−1 compared with that without PMS. Besides the conventional homogeneous PMS oxidation and the following adsorption through Zr–O clusters of ZrFc-MOFs, the enhanced As(III) removal synergistic combines the oxidation mechanism of As(III) by reactive oxygen species (•OH, SO4•−, O2•− and 1O2) formed in Ferrocene (Fc) activating PMS process with the simultaneous formed extra adsorption sites of Ferrocenium (Fc+). PMS also help ZrFc-MOF to avoid destruction in harsh alkaline condition, making the effluent in this advanced treatment meet the World Health Organization (WHO) threshold of 10 μg L−1 over a wide range of initial pH (2−11) with high selectivity and durability. These results indicate that this novel Fc-based MOFs activating PMS system has potential applicability for As(III) in oxidation and selectively capturing in the water environment.

Precision mapping of schistosomiasis and soil-transmitted helminthiasis among school age children at the coastal region, Kenya

Accurate mapping of schistosomiasis (SCH) and soil transmitted helminths (STH) is a prerequisite for effective implementation of the control and elimination interventions. A precision mapping protocol was developed and implemented in the coastal region of Kenya by applying the current World Health Organization (WHO) mapping guide at a much lower administrative level (ward). A two-stage cluster survey design was undertaken, with 5 villages in each ward selected. From within each village 50 households were randomly selected, and a single child between the ages of 8 and 14 sampled following appropriate assent. The prevalence and intensity of infection of Schistosoma mansoni and STH were determined using the Kato-Katz method (single stool, duplicate slides) and urine filtration for S. haematobium. Of the 27,850 school age children sampled, 6.9% were infected with at least one Schistosoma species, with S. haematobium being the most common 6.1% (95% CI: 3.1-11.9), and Tana River County having highest prevalence 19.6% (95% CI: 11.6-31.3). Prevalence of any STH infection was 5.8% (95% CI: 3.7-8.9), with Lamu County having the highest prevalence at 11.9% (95% CI: 10.0-14.1). The most prevalent STH species in the region was Trichuris trichiura at 3.1% (95% CI: 2.0-4.8). According to the WHO threshold for MDA implementation, 31 wards (in 15 sub-Counties) had a prevalence of ≥10% for SCH and thus qualify for annual MDA of all age groups from 2 years old. On the other hand, using the stricter Kenya BTS MDA threshold of ≥2%, 72 wards (in 17 sub-Counties) qualified for MDA and were targeted for treatment in 2021. The precision mapping at the ward level demonstrated the variations of schistosomiasis prevalence and endemicity by ward even within the same sub-counties. The data collected will be utilized by the Kenyan Ministry of Health to improve targeting.

Catastrophic Health Expenditure in Patients with Lower-Extremity Orthopaedic Trauma.

Health-care expenditures are a leading contributor to financial hardship in the United States. Traumatic orthopaedic injuries are unpredictable and result in substantial expense. Our objectives were to quantify the catastrophic health expenditure (CHE) risk of patients with orthopaedic trauma and to examine the impact of insurance status, socioeconomic status, sex, and race on CHE. We identified all isolated lower-extremity orthopaedic trauma cases at a safety-net, Level-1 trauma center from 2018 to 2020. We queried an institutional charge database to obtain total hospital charges, insurance status, and ZIP Code to determine out-of-pocket (OOP) expenditures. To evaluate financial hardship, we calculated the CHE risk as defined by the World Health Organization's threshold of OOP expenditures, ≥40% of estimated household post-subsistence income. In our cohort of 2,535 patients, 33% experienced a risk of CHE. A risk of CHE was experienced by 99% of patients who were uninsured, 35% of patients with private insurance, 2% of patients with Medicare, and 0% of patients with Medicaid. Multivariable regression modeling showed that patients who were uninsured were significantly more likely to experience a risk of CHE compared with patients with private insurance (odds ratio, 107.68 [95% confidence interval, 37.20 to 311.68]; p < 0.001). One-third of patients with lower-extremity orthopaedic trauma experience a risk of CHE, with patients who are uninsured facing a disproportionately higher risk of CHE compared with patients who are insured. Our results suggest that the expansion of public insurance options may provide substantial financial protection for those at the greatest risk for CHE. Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Principal Component Analysis (PCA)–Geographic Information System (GIS) Modeling for Groundwater and Associated Health Risks in Abbottabad, Pakistan

Drinking water quality is a major problem in Pakistan, especially in the Abbottabad region of Pakistan. The main objective of this study was to use a Principal Component Analysis (PCA) and integrated Geographic Information System (GIS)-based statistical model to estimate the spatial distribution of exceedance levels of groundwater quality parameters and related health risks for two union councils (Mirpur and Jhangi) located in Abbottabad, Pakistan. A field survey was conducted, and samples were collected from 41 sites to analyze the groundwater quality parameters. The data collection includes the data for 15 water quality parameters. The Global Positioning System (GPS) Essentials application was used to obtain the geographical coordinates of sampling locations in the study area. The GPS Essentials is an android-based GPS application commonly used for collection of geographic coordinates. After sampling, the laboratory analyses were performed to evaluate groundwater quality parameters. PCA was applied to the results, and the exceedance values were calculated by subtracting them from the World Health Organization (WHO) standard parameter values. The nine groundwater quality parameters such as Arsenic (As), Lead (Pb), Mercury (Hg), Cadmium (Cd), Iron (Fe), Dissolved Oxygen (DO), Electrical Conductivity (EC), Total Dissolved Solids (TDS), and Colony Forming Unit (CFU) exceeded the WHO threshold. The highly exceeded parameters, i.e., As, Pb, Hg, Cd, and CFU, were selected for GIS-based modeling. The Inverse Distance Weighting (IDW) technique was used to model the exceedance values. The PCA produced five Principal Components (PCs) with a cumulative variance of 76%. PC-1 might be the indicator of health risks related to CFU, Hg, and Cd. PC-2 could be the sign of natural pollution. PC-3 might be the indicator of health risks due to As. PC-4 and PC-5 might be indicators of natural processes. GIS modeling revealed that As, Pb, Cd, CFU, and Hg exceeded levels 3, 4, and 5 in both union councils. Therefore, there could be greater risk for exposure to diseases such as cholera, typhoid, dysentery, hepatitis, giardiasis, cryptosporidiosis, and guinea worm infection. The combination of laboratory analysis with GIS and statistical techniques provided new dimensions of modeling research for analyzing groundwater and health risks.

Evaluation of the resistance of Mycobacterium tuberculosis to rifampicin at the regional hospital center of Maradi, Niger Republic.

According to the World Health Organization (WHO) data, 600,000 cases of rifampicin-resistant tuberculosis (TB) have been reported worldwide, including 490,000 cases of multidrug-resistant TB. Thus, through the present study, we proposed to evaluate the resistance of Mycobacterium tuberculosis to rifampicin in the regional hospital of Maradi. Our study involved 887 sputum samples that were GeneXpert tested from January 2016 to December 2020. These data were collected from the laboratory records of the Maradi Regional Hospital and analyzed with SPSS and Excel 2013 software. In total, more than half of the patients were male, i.e., a sex ratio of 3.03. The average age was 41 years. The rate of detection of M. tuberculosis by GeneXpert was 42% and the frequency of resistance to rifampicin was 20%. However, treatment failure and relapse were associated with this monoresistance in 53.95% and 30.26% of cases, respectively. The present study shows a fairly high prevalence of rifampicin resistance in the Maradi region, corresponding to twice the WHO threshold. The vast majority of these cases presented either a therapeutic failure or a relapse. Urgent and effective actions must be taken to significantly reduce the rates of treatment failure and relapse to decrease the rate of monoresistance and thus avoid the emergence of multidrug-resistant strains.

The interruption of transmission of onchocerciasis in Kaduna, Kebbi and Zamfara states, Nigeria: another milestone achievement.

BackgroundMore than 40 million people live in onchocerciasis-endemic areas in Nigeria. For at least 19 y, mass drug administration (MDA) with ivermectin was implemented with at least 65% total population coverage in Kaduna, Kebbi and Zamfara states. Impact surveys done using skin biopsies yielded no infections. Serological and entomological assessments were undertaken to determine if onchocerciasis transmission had been interrupted and MDA could be stopped.MethodsThe presence of onchocerciasis-specific immunoglobulin G4 antibody was measured by enzyme=linked immunosorbent assay conducted on dried blood spots collected from 5- to 9-year-old children resident in each state. O-150 polymerase chain reaction testing of Simulium damnosum s.l. heads for Onchocerca volvulus DNA was done on black flies collected by human landing capture and Esperanza window traps.ResultsA total of 9078 children were surveyed across the three states. A total of 6139 vectors were collected from Kaduna state, 129 from Kebbi state and 2 from Zamfara state; all were negative. Kebbi and Zamfara states did thousands of hours of black fly catching and intensive river prospecting. The resulting low fly catch was due to a low fly population incapable of sustaining transmission.ConclusionOnchocerciasis transmission has been interrupted and the three states meet World Health Organization thresholds: seropositivity in children <0.1% and <1/2000 infective black flies with 95% confidence. The 2.2 million people in Kaduna state and 4 million in Kebbi and Zamfara states no longer need ivermectin for onchocerciasis.

Quality of anthropometric data in India's National Family Health Survey: Disentangling interviewer and area effect using a cross-classified multilevel model

India has adopted a target-based approach to reduce the scourge of child malnourishment. Because the monitoring and evaluation required by this approach relies primarily on large-scale data, a data quality assessment is essential. As field teams are the primary mode of data collection in large-scale surveys, this study attempts to understand their contribution to variations in child anthropometric measures. This research can help disentangle the confounding effects of regions/districts and field teams on the quality of child anthropometric data. The anthropometric z-scores of 2,25,002 children below five years were obtained from the fourth round of India's National Family and Health Survey (NFHS-4), 2015–16. Unadjusted and adjusted standard deviations (SD) of the anthropometric measures were estimated to assess the variations in measurements. In addition, a cross-classified multilevel model (CCMM) approach was adopted to estimate the contribution of geographical regions/districts and teams to variations in anthropometric measures. The unadjusted SDs of the measures of stunting, wasting, and underweight were 1.7, 1.4, and 1.2, respectively. The SD of stunting was above the World Health Organisation threshold (0.8–1.2), as well as the Demographic and Health Survey mark. After adjusting for team-level characteristics, the SDs of all three measures reduced marginally, indicating that team-level workload had a marginal but significant role in explaining the variations in anthropometric z-scores. The CCMM showed that the maximum contribution to variations in anthropometric z-scores came from community-level (Primary Sampling Unit (PSU)) characteristics. Team-level characteristics had a higher contribution to variations in anthropometric z-scores than district-level attributes. Variations in measurement were higher for child height than weight. The present study decomposes the effects of district- and team-level factors and highlights the nuances of introducing teams as a level of analysis in multilevel modelling. Population size, density, and terrain variations between PSUs should be considered when allocating field teams in large-scale surveys.

THE BACKGROUND CONCENTRATION OF SOME HEAVY METALS AT NYSC ORIENTATION CAMP LAYOUT, KATSINA

An anthropogenic activities leads to the presence of heavy metals in an environment which lead to environmental pollution. The area has become gradually engage with various waste such as animal waste, refused dump, spilling of petrol, kerosene, engine oil etc which can introduces the trace heavy metals. The research of background concentration of various heavy metals in soil samples taken from the NYSC orientation camp layout, which is situated in Katsina state, Nigeria, at latitudes of 643.7 m to 798.5 m and longitudes of 18 21I32IIE to 18 28I37II, was conducted. At intervals of 100 m, soil samples were taken from the locations, and each 100 m was divided into 10 m. (A1A10). In order to determine the concentration of the five examined heavy metals, a flame atomic absorption spectrophotometer (FAAS) was used (Co, Cr, Pb, Cd, Cu). The locations have an average heavy metal concentration of:- 0.16009, 0.55449, 0.02804, 0.00231, and 0.10406 ppm Respectively. Significant differences were observed by comparing the mean concentration of the heavy metals in the study areas with world health organization (W.H.O) threshold limit, national and international studies and it was suggested that the samples were not contaminated with the heavy metals. But the metals were detected and there is no need for immediate implementation and remediation measures by the relevant authority. It was and recommended that industries, factories and filling station should not be located at the area in order to minimize human activities so as to maintain stable environment free from pollutants

Measuring, Mapping, and Evaluating Daytime Traffic Noise Levels at Urban Road Intersections in Doha, Qatar

In this study, equivalent hourly traffic noise levels at different intersections in the city of Doha, Qatar were measured and compared to the local and World Health Organization (WHO) thresholds. As part of the study, equivalent sound pressure levels, ambient temperature, humidity, and wind speed were recorded during the morning, afternoon, and evening hours on weekdays and weekends. The results showed that regardless of the day (weekday or weekend), the mean 16-h daytime traffic noise levels at all sites exceeded the local and the WHO’s recommended thresholds. The values of the mean weekday noise levels at the sites ranged between 67.6 dB(A) and 77.5 dB(A), whereas the weekend values ranged between 68.8 dB(A) and 76.9 dB(A). The measured noise levels were also compared with traffic noise levels reported in other countries. Finally, some recommendations to reduce excessive traffic noise levels were suggested. The results of the study could be used as a benchmark of traffic noise levels in the country after the implementation of any countermeasures in the future.

Cost-Effectiveness of Lung Cancer Screening Using Low-Dose Computed Tomography Based on Start Age and Interval in China: Modeling Study

BackgroundLung cancer is the most commonly diagnosed cancer and the leading cause of cancer-related death in China. The effectiveness of screening for lung cancer has been reported to reduce lung cancer–specific and overall mortality, although the cost-effectiveness, optimal start age, and screening interval remain unclear.ObjectiveThis study aimed to assess the cost-effectiveness of lung cancer screening among heavy smokers in China by incorporating start age and screening interval.MethodsA Markov state-transition model was used to assess the cost-effectiveness of a lung cancer screening program in China. The evaluated screening strategies were based on a screening start age of 50-74 years and a screening interval of once or annually. Transition probabilities were obtained from the literature and validated, while cost parameters were derived from databases of local medical insurance bureaus. A societal perspective was adopted. The outputs of the model included costs, quality-adjusted life years (QALYs), and lung cancer–specific mortality, with future costs and outcomes discounted by 5%. A currency exchange rate of 1 CNY=0.1557 USD is applicable. The incremental cost-effectiveness ratio (ICER) was calculated for different screening strategies relative to nonscreening.ResultsThe proposed model suggested that screening led to a gain of 0.001-0.042 QALYs per person as compared with the findings in the nonscreening cohort. Meanwhile, one-time and annual screenings were associated with reductions in lung cancer–related mortality of 0.004%-1.171% and 6.189%-15.819%, respectively. The ICER ranged from 119,974.08 to 614,167.75 CNY per QALY gained relative to nonscreening. Using the World Health Organization threshold of 212,676 CNY per QALY gained, annual screening from a start age of 55 years and one-time screening from the age of 65 years can be considered as cost-effective in China. Deterministic and probabilistic sensitivity analyses were conducted.ConclusionsThis economic evaluation revealed that a population-based lung cancer screening program in China for heavy smokers using low-dose computed tomography was cost-effective for annual screening of smokers aged 55-74 years and one-time screening of those aged 65-74 years. Moreover, annual lung cancer screening should be promoted in China to realize the benefits of a guideline-recommended screening program.

Appropriateness of the current parasitological control target for hookworm morbidity: A statistical analysis of individual-level data.

BackgroundSoil-transmitted helminths affect almost 2 billion people globally. Hookworm species contribute to most of the related morbidity. Hookworms mainly cause anaemia, due to blood loss at the site of the attachment of the adult worms to the human intestinal mucosa. The World Health Organization (WHO) aims to eliminate hookworm morbidity by 2030 through achieving a prevalence of moderate and heavy intensity (M&HI) infections below 2%. In this paper, we aim to assess the suitability of this threshold to reflect hookworm-attributable morbidity.Methodology/Principal findingsWe developed a hierarchical statistical model to simulate individual haemoglobin concentrations in association with hookworm burdens, accounting for low haemoglobin values attributable to other causes. The model was fitted to individual-level data within a Bayesian framework. Then, we generated different endemicity settings corresponding to infection prevalence ranging from 10% to 90% (0% to 55% M&HI prevalence), using 1, 2 or 4 Kato-Katz slides. For each scenario, we estimated the prevalence of anaemia due to hookworm. Our results showed that on average, haemoglobin falls below the WHO threshold for anaemia when intensities are above 2000 eggs per gram of faeces. For the different simulated scenarios, the estimated prevalence of anaemia attributable to hookworm ranges from 0% to 30% (95%-PI: 24% - 36%) being mainly associated to the prevalence of M&HI infections. Simulations show that a 2% prevalence of M&HI infections in adults corresponds to a prevalence of hookworm-attributable anaemia lower than 1%.Conclusions/SignificanceOur results support the use of the current WHO thresholds of 2% prevalence of M&HI as a proxy for hookworm morbidity. A single Kato-Katz slide may be sufficient to assess the achievement of the morbidity target. Further studies are needed to elucidate haemoglobin dynamics pre- and post- control, ideally using longitudinal data in adults and children.