Pattern of blood concentrations of 47 elements in two populations from the same geographical area but with different geological origin and lifestyles: Canary Islands (Spain) vs. Morocco.

The Canary Islands are one of the outermost regions of the European Union (EU), which are located barely 100 km from the coasts of Morocco. Although these islands are located in Africa, the degree of socioeconomic development and lifestyle in this archipelago is comparable to that of any other region of Europe. It is well established that the main determinants of human exposure to elements have to do both, with their place of residence and with habits related to their lifestyle. For this reason, we wanted to study the pattern of contamination by elements of these two populations so geographically close, but so different both in their lifestyle, and the geological origin of the territory where they live. Thus, we have determined the blood concentrations of 47 elements (including 25 rare earth elements (REE) and other minority elements (ME) widely employed in the hi-tech industry) in a paired sample of Moroccans (n = 124) and Canary Islands inhabitants (n = 120). We found that the levels of iron, selenium, zinc, arsenic, cadmium, strontium, and specially lead, were significantly higher in Moroccans than in Canarians, probably due to the intensive mining activity in this country. We also found significantly higher levels of the sum of REE and ME in Moroccans than in Canarians, possibly related to the inappropriate management of e-waste in this country. On the other hand, in the inhabitants of the Canary Islands we found higher levels of manganese, probably related to a higher degree of exposure to heavy traffic and exposure to Saharan dust of the people living in this region, and niobium and bismuth, probably related to the higher economic development in these islands. Our results indicate that the vicinity of both territories is not a major determinant of each other's contamination.

Outbreak and Eradication of Tropical Rat Mite (Acari: Macronyssidae) in a European Animal Facility.

A zoonotic, opportunistic out-break of tropical rat mite Ornithonyssus bacoti [Acari: Macronyssidae; Ornithonyssus bacoti (Hirst)] in an animal facility, is described. Immunocompetent mice [Mus musculus (Linnaeus)] and rat [Rattus norvegicus (Berkenhout)] strains in a conventional health status facility suffered from scratching and allopecia and staff members suffered from pruritic, erythemato-papular lesions, presumed to be allergic in origin. O. bacoti was identified and treatment with a 0.1% ivermectin solution led to its complete erradication. Safety assessment revealed no signs of acute toxicity in any animal strain. Following this inexpensive strategy, 7 wk after the initial dose, samples were negative for the presence of acari. At the time of this report, 26 months after diagnosis, O. bacoti remains undetected.

Blood levels of toxic metals and rare earth elements commonly found in e-waste may exert subtle effects on hemoglobin concentration in sub-Saharan immigrants.

Pollution by heavy metals and more recently by rare earth elements (REE) and other minor elements (ME) has increased due in part to their high use in technological and electronic devices. This contamination can become very relevant in those sites where e-waste is improperly processed, as it is the case in many countries of the African continent. Exposure to some toxic elements has been associated to certain hematological disorders, specifically anemia. In this study, the concentrations of 48 elements (including REE and other ME) were determined by ICP-MS in whole blood samples of sub-Saharan immigrants with anemia (n=63) and without anemia (n=78). We found that the levels of Fe, Cr, Cu, Mn, Mo, and Se were significantly higher in the control group than in the anemia group, suggesting that anemia was mainly due to nutritional deficiencies. However, since other authors have suggested that in addition to nutritional deficiency, exposure to some elements may influence hemoglobin levels, we wanted to explore the role of a broad panel of toxic and "emerging" elements in hemoglobin deficiency. We found that the levels of Ag, As, Ba, Bi, Ce, Eu, Er, Ga, La, Nb, Nd, Pb, Pr, Sm, Sn, Ta, Th, Tl, U and V were higher in anemic participants than in controls. For most of these elements an inverse correlation with hemoglobin concentration was found. Some of them also correlated inversely with blood iron levels, pointing to the possibility that a higher rate of intestinal uptake of these could exist in relation to a nutritional deficiency of iron. However, the higher levels of Pb, and the group of REE and other ME in anemic participants were independent of iron levels, pointing to the possibility that these elements could play a role in the development of anemia.

Study of the influencing factors of the blood levels of toxic elements in Africans from 16 countries.

Africa's economy is growing faster than any other continent and it has been estimated that the middle class in Africa now exceeds 350 million people. This has meant a parallel increase in the importation of consumer goods and in the implementation of communication and information technologies (ICT), but also in the generation of large quantities of e-waste. However, inadequate infrastructure development remains a major constraint to the continent's economic growth and these highly toxic residues are not always adequately managed. Few studies have been conducted to date assessing the possible association between socioeconomic development factors, including e-waste generation, and blood levels of inorganic elements in African population. To disclose the role of geographical, anthropogenic, and socioeconomic development determinants on the blood levels of Ag, Al, As, Be, Cd, Co, Cr, Hg, Ni, Pb, Sb, and V -all of them frequently found in e-waste-, an immigrant population-based study was made including a total of 245 subjects from 16 countries recently arrived to the Canary Islands (Spain). Women presented higher levels of blood elements than men, and Northern Africans (Moroccans) were the most contaminated. People from low-income countries exhibited significantly lower blood levels of inorganic elements than those from middle-income countries. We found a significant association between the use of motor vehicles and the implementation of information and communication technologies (ICT) and the level of contamination. Immigrants from the countries with a high volume of imports of second-hand electronic equipment, telephone and internet use had higher levels of inorganic elements. In general terms, the higher level of economic development the higher the blood levels of inorganic pollutants, suggesting that the economic development of Africa, in parallel to e-waste generation and the existence of informal recycling sites, have directly affected the level of contamination of the population of the continent.

Different pattern of contamination by legacy POPs in two populations from the same geographical area but with completely different lifestyles: Canary Islands (Spain) vs. Morocco.

The archipelago of the Canary Islands is one of the so-called ultra-peripheral territories of the European Union due to its geographical location away from the continent. Although the level of socioeconomic development and lifestyle of this region is comparable to that of any other of the European Union, it is just 100 km off the coast of Morocco, in the African continent. The population of the Canaries has been extensively studied with respect to their levels of POPs, and it has been described that their levels are relatively high compared to other European regions. It has been speculated with that the proximity to Africa may be associated with this level of contamination, but so far this theory has not been verified. This paper describes for the first time the levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in a sample of the population of Morocco (n = 131), which were compared with those of a similar sample of the population of permanent residents in the Canary Islands (n = 100) in order to check this hypothesis. Our results showed that Moroccans have higher median values of OCPs than the residents in the Canaries (∑ OCP = 150.2 ng/g lw vs. 83.4 ng/g lw, p = 0.0001). Regarding the PCBs, although recent studies have reported that new environmental sources of PCBs exist in several African countries (including Morocco), the plasma levels of most congeners were significantly higher in Canarians than in Moroccans, especially for the dioxin-like PCBs (median = 7.3 ng/g lw vs. 0.0 ng/g lw, p = 0.0001). The detailed analysis of our results suggests that the levels of these pollutants in the Canarian people are more influenced by their lifestyle and the previous use of these chemicals in the archipelago than by its geographical vicinity with Morocco.

Relationship of polychlorinated biphenyls (PCBs) with parasitism, iron homeostasis, and other health outcomes: Results from a cross-sectional study on recently arrived African immigrants.

Polychlorinated biphenyls (PCBs) are toxic and persistent chemicals produced between 1930s and 1980s, which accumulate in humans and wildlife. Although a decreasing trend of PCB levels in humans has been described in developed countries, mainly as a consequence of strict regulations and remediation plans, an inverse trend has been recently reported in people from developing countries. We had the opportunity of sampling a series of African immigrants recently arrived to the Spanish archipelago of the Canary Islands, in which high levels of PCBs have been described, and we studied the relationships between their level of contamination and health status. A total of 570 subjects who underwent a complete medical examination and a face-to-face interview were recruited for this study. Hematological and biochemical parameters (blood and urine) were determined in all participants. Serology for the diagnostic of infectious diseases was also performed, and direct identification of parasites was performed in feces, urine or blood samples when appropriate. It is remarkable that up to 26.0% of the population had intestinal parasites, and we found an inverse relationship between PCB levels and parasitism and parasitic diseases: median values of PCBs were lower in parasitized subjects than in subjects without parasites in stool (237.6ng/g fat vs. 154.4ng/g fat for marker PCBs, p=0.015) and median values of dioxin-like PCBs were lower in subjects carrying pathogen parasites than among subjects showing non-pathogen parasites in stool (0.0 ng/g fat vs. 13.1ng/g fat, respectively; p=0.001). Although this inverse association had been described in some vertebrates this is the first study reporting such an association in humans. Furthermore, it has been also recently described that PCBs may disrupt iron metabolism, and we found a direct relationship between serum iron and total PCBs burden (r=0.231, p=0.025), suggesting that PCBs, although at subclinical level, could play a role on iron homeostasis. Although the role of PCBs in parasitism and in the iron metabolism needs future research, our findings may help to understand the adverse health outcomes associated to environmental exposure to PCBs and they might be used in exposed populations as indicators of subtle effects due to environmental insult.

[Microbiological diagnosis of imported malaria]. / Diagnóstico microbiológico de la malaria importada.

Current diagnosis of malaria is based on the combined and sequential use of rapid antigen detection tests (RDT) of Plasmodium and subsequent visualization of the parasite stained with Giemsa solution in a thin and thick blood smears. If an expert microscopist is not available, should always be a sensitive RDT to rule out infection by Plasmodium falciparum, output the result immediately and prepare thick smears (air dried) and thin extensions (fixed with methanol) for subsequent staining and review by an expert microscopist. The RDT should be used as an initial screening test, but should not replace microscopy techniques, which should be done in parallel. The diagnosis of malaria should be performed immediately after clinical suspicion. The delay in laboratory diagnosis (greater than 3 hours) should not prevent the initiation of empirical antimalarial treatment if the probability of malaria is high. If the first microscopic examination and RDT are negative, they must be repeated daily in patients with high suspicion. If suspicion remains after three negative results must be sought the opinion of an tropical diseases expert. Genomic amplification methods (PCR) are useful as confirmation of microscopic diagnosis, to characterize mixed infections undetectable by other methods, and to diagnose asymptomatic infections with submicroscopic parasitaemia.

Diagnóstico microbiológico de la malaria importada / Microbiological diagnosis of imported malaria

El diagnóstico actual de la malaria se basa en el uso combinado y secuencial de los tests rápidos de detección de antígenos de Plasmodium y la visualización posterior del parásito teñido con solución de Giemsa en un frotis y una gota gruesa en muestras de sangre total capilar o venosa. Si no se dispone de un microscopista experto debe realizarse siempre un test rápido de detección de antígenos muy sensible para descartar la infección por Plasmodium falciparum, emitir inmediatamente el resultado y preparar gotas gruesas (secadas al aire) y extensiones finas (fijadas con metanol) para su posterior tinción y revisión por un microscopista experto del propio laboratorio o de un laboratorio de referencia. Los tests rápidos de detección de antígenos deben utilizarse como prueba inicial de cribado, pero no deben sustituir a las técnicas de microscopia, las cuales deben hacerse en paralelo. El diagnóstico de la malaria debe ser realizado inmediatamente tras la sospecha clínica. El retraso en el diagnóstico de laboratorio (demora mayor de 3 h) no debe impedir el inicio de tratamiento antimalárico empírico si la probabilidad de malaria es alta. Si el primer examen microscópico y el test rápido de detección de antígenos son negativos, estos deben repetirse diariamente en pacientes con alta sospecha. Si esta sospecha permanece tras 3 resultados negativos debe solicitarse la opinión de un experto en enfermedades tropicales. Los métodos de amplificación genómica (reacción en cadena de la polimerasa) son útiles como confirmación del diagnóstico microscópico, para caracterizar infecciones mixtas no detectables por otros métodos y para caracterizar infecciones asintomáticas por debajo del nivel de detección microscópica

Current diagnosis of malaria is based on the combined and sequential use of rapid antigen detection tests (RDT) of Plasmodium and subsequent visualization of the parasite stained with Giemsa solution in a thin and thick blood smears. If an expert microscopist is not available, should always be a sensitive RDT to rule out infection by Plasmodium falciparum, output the result immediately and prepare thick smears (air dried) and thin extensions (fixed with methanol) for subsequent staining and review by an expert microscopist. The RDT should be used as an initial screening test, but should not replace microscopy techniques, which should be done in parallel. The diagnosis of malaria should be performed immediately after clinical suspicion. The delay in laboratory diagnosis (greater than 3 hours) should not prevent the initiation of empirical antimalarial treatment if the probability of malaria is high. If the first microscopic examination and RDT are negative, they must be repeated daily in patients with high suspicion. If suspicion remains after three negative results must be sought the opinion of an tropical diseases expert. Genomic amplification methods (PCR) are useful as confirmation of microscopic diagnosis, to characterize mixed infections undetectable by other methods, and to diagnose asymptomatic infections with submicroscopic parasitaemia

Socioeconomic development as a determinant of the levels of organochlorine pesticides and PCBs in the inhabitants of Western and Central African countries.

Several studies of environmental samples indicate that the levels of many persistent organic pollutants (POPs) are increasing in Africa, but few studies have been conducted in humans. Simultaneously, many African countries are experiencing a rapid economic growth and implementing information and communication technologies (ICT). These changes have generated high amounts of electronic waste (e-waste) that have not been adequately managed. We tested the hypothesis that the current levels of two main classes of POPs in Western and Central African countries are affected by the degree of socioeconomic development. We measured the levels of 36 POPs in the serum of recent immigrants (N=575) who came from 19 Sub-Saharan countries to the Canary Islands (Spain). We performed statistical analyses on their anthropometric and socioeconomic data. High median levels of POPs were found in the overall sample, with differences among the countries. Organochlorine pesticide (OCP) and polychlorinated biphenyl (PCB) levels increased with age. People from low-income countries had significantly higher OCP levels and much lower PCB levels than those from high-income countries. We found a significant association between the implementation of ICT and PCB contamination. Immigrants from the countries with a high volume of imports of second-hand electronic equipment had higher PCB levels. The economic development of Africa and the e-waste generation have directly affected the levels of POPs. The POP legacies of these African populations most likely are due to the inappropriate management of the POPs' residues.

Recent trends in human Brucella canis infection.

There is little information in the literature regarding the clinical progress of brucellosis in patients affected by other diseases. We report Brucella canis human infection link to Gaucher's disease and Guillain Barré syndrome and discuss complications observed in a case with infective endocarditis. The three cases described came from areas of socio-economic deprivation and scarce epidemiological information where the healthcare personnel did not even consider such diagnosis. The growth of large urban populations deprived from basic services has created a new set of global health challenges. Changes in the urban environment due to slum communities' expansion have resulted in increased dog populations in the peridomiciliary environment. Eleven laboratory employees working with the strains found and their identification were examined. Sanitary authorities should focus on the zoonotic aspect of B. canis considering the dramatic increase of canine roamers near urban centers.

Detection and discrimination of Loa loa, Mansonella perstans and Wuchereria bancrofti by PCR-RFLP and nested-PCR of ribosomal DNA ITS1 region.

The ribosomal deoxyribonucleic acid (DNA) internal transcribed spacer region (ITS1) of two filarial nematodes, Loa loa and Mansonella perstans, was amplified and further sequenced to develop an species-specific polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) protocol for the differentiation of both species from Wuchereria bancrofti, three filarial nematodes with blood circulating microfilariae. The ITS1-PCR product digested with the restriction endonuclease Ase I generated an specific diagnostic pattern for each of the three species. Moreover, three new specific nested-PCRs, targeting the ITS1 region, for differential detection of L. loa, M. perstans and W. bancrofti were developed and used when the ITS1-PCR products were insufficient for the Ase I enzymatic digestion. These filarial species-specific molecular protocols were evaluated in forty blood samples from African adult immigrants attending in the Hospital Insular of Gran Canaria, Canarias, Spain.

Prevalencia de infección por HTLV-1 en inmigrantes subsaharianos asintomáticos recién llegados / HTLV-1 infection prevalence in recently arrived sub-Saharan immigrants

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Application of an ELISA test using Schistosoma bovis adult worm antigens in travellers and immigrants from a schistosomiasis endemic area and its correlation with clinical findings.

We have recently evaluated an ELISA for the diagnosis of human schistosomiasis using S. bovis adult worm antigens (AWA Sb), showing a sensitivity of 94% and a specificity of 97% for patients diagnosed by egg detection. Nevertheless, the comparison of this AWA Sb ELISA with direct parasitological findings as the gold standard could introduce a selection bias, due to the well-known lack of sensitivity of direct methods in the detection of acute schistosomiasis and of low burden infections. The objective of the present work is to compare it with parasitological methods and commercial indirect haemagglutination test using S. mansoni antigens (WA Sm IHA) in 254 immigrants and travellers with different clinical settings; in addition, to find specific bands in the EITB of different phases of schistosomiasis. The AWA Sb ELISA showed 72% of seropositivity in patients with Katayama fever, while patients with eosinophilia and genito-urinary complaints showed 27% and 93%, respectively. The diagnosis yield was globally higher than direct egg detection or WA Sm IHA test with regard to the clinical setting. Finally, the utilization of EITB with S. bovis AWA permits the confirmation of diagnosis in chronic and acute phases of the disease.

Helminth-related Eosinophilia in African immigrants, Gran Canaria.

Of 788 recent African adult immigrants to Las Palmas de Gran Canaria, 213 (27.0%) had eosinophilia. The most frequent causes were filariasis (29.4%), schistosomiasis (17.2%), and hookworm infection (16.8%). Stool microscopy and filarial and schistosomal serologic tests gave the highest diagnostic yield. Country of origin and eosinophil count were associated with specific diagnoses.

Antigens from Ascaris suum trigger in vitro macrophage NO production.

SUMMARY We investigated the in vitro effect of total excretory/secretory and somatic antigens from Ascaris suum adults (ESA and SA) and larvae 3 (ESL3 and SL3), and of 10 purified protein fractions from ESA components on rat alveolar macrophage nitric oxide (NO) production. Our results showed that in vitro incubation of macrophages with SA and SL3 antigens of A. suum did not result in NO release from cells, whereas incubation with ESA or ESL3 antigens resulted in the stimulation of NO production by these cells, both in a specific (inhibited by L-NAME and L-canavanine) and dose-dependent manner. In addition, we could demonstrate that a purified ESA fraction consisting of three Coomassie-stained bands of approximately 37, 44 and 46 kDa is involved in the in vitro triggering of NO production by host cells. These three bands were subjected to MALDI-peptide mass fingerprint, showing similarities with phosphoglycerate kinase, elongation factor Tu and enolase molecules, respectively. Future studies will focus on the characterization of these parasite-derived molecules.