Estimating the Prevalence of Toxic Waste Sites in Low- and Middle-Income Countries

BackgroundExposure to heavy metals at contaminated industrial and mining sites, known also as hot spots, is a significant source of toxic exposure and adverse health outcomes in countries around the world. The Toxic Sites Identification Program (TSIP) developed by Pure Earth, a New York–based nongovernmental organization, is the only systematic effort to catalogue contaminated sites globally. To date, TSIP has identified and catalogued 3282 sites in low- and middle-income countries. The TSIP methodology is not designed to survey all contaminated sites in a country. Rather sites are prioritized based on their perceived impact on human health, and only a limited number of the most highly hazardous sites are surveyed. The total number of contaminated sites globally and the fraction of contaminated sites captured by TSIP is not known.ObjectiveTo determine the TSIP site capture rate, the fraction of contaminated sites in a country catalogued by TSIP.MethodsGhana was selected for this analysis because it is a rapidly industrializing lower middle income country with a heterogeneous industrial base, a highly urban population (51%), and good public records systems. To develop an estimate of the fraction of sites in Ghana captured by TSIP, assessors targeted randomly selected geographic quadrats for comprehensive assessment using area and population statistics from the Ghana Statistical Service. Investigators physically walked all accessible streets in each quadrat to visually identify all sites. Visual identification was supplemented by field-based confirmation with portable x-ray fluorescence instruments to test soils for metals. To extrapolate from survey findings to develop a range of estimates for the entire country, the investigators used 2 methodologies: a “bottom-up” approach that first estimated the number of waste sites in each region and then summed these regional subtotals to develop a total national estimate; and a “top-down” method that estimated the total number of sites in Ghana and then allocated these sites to each region. Both methods used cluster random sampling principles.FindingsThe investigators identified 72 sites in the sampled quadrats. Extrapolating from these findings to the entire country, the first methodology estimated that there are 1561 sites contaminated by heavy metals in Ghana (confidence interval [CI]: 1134-1987), whereas the second estimated 1944 sites (CI: 812-3075). The estimated total number of contaminated sites in Ghana is thus 7-9 times the number of sites captured through TSIP. On a population basis, it was estimated that there are between 31 and 115 contaminated sites per million inhabitants in Ghana.ConclusionsThe findings of this study indicate that the TSIP methodology provides a sound statistical basis for policy formulation. The statistical approaches used in this study can be replicated in other countries to improve estimates of the prevalence of contaminated sites. This information provides important input to calculations of the global burden of disease attributable to hazardous exposures at contaminated sites

SARS-CoV-2 infections among asymptomatic individuals contributed to COVID-19 cases: A cross-sectional study among prospective air travelers from Ghana

BackgroundThe spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by asymptomatic individuals has been reported since the early stages of the coronavirus disease 2019 (COVID-19) outbreak in various parts of the world. However, there are limited data regarding SARS-CoV-2 among asymptomatic individuals in Ghana. The aim of the study was to use test data of prospective travelers from Ghana as a proxy to estimate the contribution of asymptomatic cases to the spread of COVID-19.MethodsThe study analyzed the SARS-CoV-2 PCR test data of clients whose purpose for testing was classified as “Travel” at the COVID-19 walk-in test center of the Noguchi Memorial Institute for Medical Research (NMIMR) from July 2020 to July 2021. These individuals requesting tests for travel generally had no clinical symptoms of COVID-19 at the time of testing. Data were processed and analyzed using Microsoft Excel office 16 and STATA version 16. Descriptive statistics were used to summarize data on test and demographic characteristics.ResultsOut of 42,997 samples tested at the center within that period, 28,384 (66.0%) were classified as “Travel” tests. Of these, 1,900 (6.7%) tested positive for SARS-CoV-2. The majority (64.8%) of the “Travel” tests were requested by men. The men recorded a SARS-CoV-2 positivity of 6.9% compared to the 6.4% observed among women. Test requests for SARS-CoV-2 were received from all regions of Ghana, with a majority (83.3%) received from the Greater Accra Region. Although the Eastern region recorded the highest SARS-CoV-2 positivity rate of 8.35%, the Greater Accra region contributed 81% to the total number of SARS-CoV-2 positive cases detected within the period of study.ConclusionOur study found substantial SARS-CoV-2 positivity among asymptomatic individuals who, without the requirement for a negative SARS-CoV-2 result for travel, would have no reason to test. These asymptomatic SARS-CoV-2-infected individuals could have traveled to other countries and unintentionally spread the virus. Our findings call for enhanced tracing and testing of asymptomatic contacts of individuals who tested positive for SARS-CoV-2

Prevalence of Leishmania infection in three communities of Oti Region, Ghana.

BackgroundLeishmaniasis is a neglected tropical disease caused by parasites of the genus Leishmania and is transmitted by various species of female phlebotomine sand flies. The first report of cutaneous leishmaniasis (CL) in Ghana refer to a cluster of cases in 1999-2003 in the Ho municipality of the Volta Region. We conducted an epidemiological assessment in the Oti Region, encouraged by recent reports of potential cases of CL.Methodology/principal findingsUsing a cross-sectional study design, the exposure to Leishmania was investigated in three communities of the Oti Region based on the leishmanin skin test (LST). LST results for 3,071 participants comprising 1091, 848, and 1132 persons from the communities of Ashiabre, Keri, and Sibi Hilltop, indicated an overall prevalence of exposure to Leishmania infection of 41.8% and individual community prevalence of 39.4%, 55.1%, and 34.2% respectively. Being male [AOR = 1.27; CI: 1.09, 1.49], and living in Keri [AOR = 1.83; CI: 1.43, 2.34] were associated with an increase in the odds of exposure to Leishmania. Being 5-10 years old [AOR = 1.48; CI: 1.06, 2.05], 11-17 years old [AOR = 2.03; CI: 1.45, 2.85], 18-40 years old [AORR = 2.83; CI: 1.81, 4.43] and 41-65 years old [AOR = 5.08; CI: 2.98, 8.68] were also significantly associated with increased odds of being exposed to Leishmania.Conclusions/significanceThis study demonstrated exposure to Leishmania in the study communities and also identified associated factors. Future efforts aimed at reducing exposure to Leishmania infection in the study area should take the associated factors into consideration

Submicroscopic placental infection by non-<i>falciparum Plasmodium</i> spp.

<div><p>Background</p><p>Among the <i>Plasmodium</i> species that infect humans, adverse effects of <i>P</i>. <i>falciparum</i> and <i>P</i>. <i>vivax</i> have been extensively studied and reported with respect to poor outcomes particularly in first time mothers and in pregnant women living in areas with unstable malaria transmission. Although, other non-<i>falciparum</i> malaria infections during pregnancy have sometimes been reported, little is known about the dynamics of these infections during pregnancy.</p><p>Methods and findings</p><p>Using a quantitative PCR approach, blood samples collected from Beninese pregnant women during the first antenatal visit (ANV) and at delivery including placental blood were screened for <i>Plasmodium</i> spp. Risk factors associated with <i>Plasmodium spp</i>. infection during pregnancy were assessed as well as the relationships with pregnancy outcomes.</p><p><i>P</i>. <i>falciparum</i> was the most prevalent <i>Plasmodium</i> species detected during pregnancy, irrespective either of parity, of age or of season during which the infection occurred. Although no <i>P</i>. <i>vivax</i> infections were detected in this cohort, <i>P</i>. <i>malariae</i> (9.2%) and <i>P</i>. <i>ovale</i> (5.8%) infections were observed in samples collected during the first ANV. These non-<i>falciparum</i> infections were also detected in maternal peripheral blood (1.3% for <i>P</i>. <i>malariae</i> and 1.2% for <i>P</i>. <i>ovale</i>) at delivery. Importantly, higher prevalence of <i>P</i>. <i>malariae</i> (5.5%) was observed in placental than peripheral blood while that of <i>P</i>. <i>ovale</i> was similar (1.8% in placental blood). Among the non-<i>falciparum</i> infected pregnant women with paired peripheral and placental samples, <i>P</i>. <i>malariae</i> infections in the placental blood was significantly higher than in the peripheral blood, suggesting a possible affinity of <i>P</i>. <i>malariae</i> for the placenta. However, no assoctiation of non-<i>falciparum</i> infections and the pregnancy outcomes was observed</p><p>Conclusions</p><p>Overall this study provided insights into the molecular epidemiology of <i>Plasmodium</i> spp. infection during pregnancy, indicating placental infection by non-<i>falciparum Plasmodium</i> and the lack of association of these infections with adverse pregnancy outcomes.</p></div

Risk factors for <i>P</i>. <i>falciparum</i> malaria infections at enrolment.

<p>Risk factors for <i>P</i>. <i>falciparum</i> malaria infections at enrolment.</p

Association of <i>Plasmodium</i> spp. infections at enrolment with pregnancy outcomes.

<p>Association of <i>Plasmodium</i> spp. infections at enrolment with pregnancy outcomes.</p

Risk factors for <i>P</i>. <i>falciparum</i> and non-<i>falciparum</i> malaria mixed infections at enrolment.

<p>Risk factors for <i>P</i>. <i>falciparum</i> and non-<i>falciparum</i> malaria mixed infections at enrolment.</p

Parasite load of infections detected by microscopy and PCR.

<p>Parasite load of infections detected by microscopy and PCR.</p

Detection of cutaneous leishmaniasis in three communities of Oti Region, Ghana.

BackgroundCutaneous leishmaniasis (CL) is the most common type of leishmaniasis, a neglected tropical disease caused by parasites of the genus Leishmania. In Ghana, some studies in the Volta region have detected Leishmania parasites among persons with skin ulcers.Methodology/principal findingsUsing a cross-sectional study design, the prevalence of CL in three communities of the Oti Region of Ghana was investigated. Demographic and epidemiological data were obtained by a structured interviewer administered questionnaire. A total of 426 (12.4%) out of 3,440 participants screened had at least one skin ulcer. Of 595 skin ulcers sampled and tested by PCR for Leishmania infection, 150 (25.2%) ulcers from 136 individuals tested positive, accounting for an overall CL prevalence of 31.9% among persons with skin ulcers. Individual community CL prevalence of 23.2%, 29.8%, and 36.8% was observed in Ashiabre, Keri, and Sibi Hilltop respectively among persons with skin ulcers.Conclusions/significanceConfirmation of CL in the study area suggests an active cycle of transmission of Leishmania infection. The observation of skin ulcers which tested negative to Leishmania infection suggests a need to test for additional causes of skin ulcers such as Treponema pallidum pertenue and Mycobacterium ulcerans in the study area

Paired peripheral and placental samples of mono-infection of <i>P</i>. <i>malariae</i>.

<p>Paired peripheral and placental samples of mono-infection of <i>P</i>. <i>malariae</i>.</p