Browsing by Subject "Toxoplasma gondii"

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    A systematic review and meta-analysis of the serological diagnosis of Toxoplasma gondii infection highlight the lack of a One Health integrative research
    (Elsevier, 2023-01-10) Huertas López, Ana; Álvarez García, Gema; Sánchez Sánchez, Roberto; Cantos Barreda, Ana; Ibáñez López, Francisco José; Martínez Subiela, Silvia; Cerón Madrigal, José Joaquín; Martínez-Carrasco Pleite, Carlos; Sanidad Animal; Facultades de la UMU::Facultad de Veterinaria
    Toxoplasma gondii is a globally distributed food-borne zoonotic parasite with numerous infection sources. The control of this zoonosis requires a One Health response that partially depends on serological monitoring in humans and animals. Herein, a systematic review and a meta-analysis were performed to analyse and compare the transdisciplinary and integrative research under the One Health approach. We searched for articles published between January 1st 2014 and September 5th 2022, focused on the development and evaluation of serological techniques for the diagnosis of T. gondii infection in humans and animals. After an exhaustive search on three scientific databases, a quality assessment was performed on 291 articles by QUADAS-2 tool, and 113 articles were finally selected. A total of 18 variables were extracted and analysed, including bibliometric characteristics, study aims and methodology. Remarkably, none of the studies included in the meta-analysis explicitly quoted the words “One Health”, and only 23.9% of them alluded to the principles underlying the One Health approach; in particular, none were conducted by physician-only teams, with the majority of these studies involving interdisciplinary research teams, followed by veterinarians and by non-physician or non-veterinarian researchers. The One Health approach followed in the serodiagnosis of T. gondii still needs further integration among scientific disciplines, which is essential to design effective control strategies.
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    A time-resolved fluorescence immunoassay for the detection of anti-Neospora caninum antibodies in sheep
    (Elsevier, 2019-11-18) Huertas López, Ana; Huertas-López, Ana; Martínez-Carrasco Pleite, Carlos; Cerón Madrigal, José Joaquín; Sánchez-Sánchez, Roberto; Vázquez-Calvo, Ángela; Álvarez-García, Gema; Martínez Subiela, Silvia; Sanidad Animal; Facultad de Veterinaria
    Neospora caninum is a protozoan parasite (Phylum Apicomplexa) that has been recently suggested as a relevant cause of reproductive disorders in small ruminants. The aim of the present study is to develop and validate a new serological test based on time resolved fluorescency using N. caninum GRA7 recombinant antigen (GRA7-TRFIA) for the detection of N. caninum antibodies in sheep. A total of 346 serum samples (208 from experimentally infected sheep, 117 from a dairy farm with a previous history of Neospora-associated abortion, and 21 negative sera) were used. The validation of the new assay was performed by the evaluation of assay precision, analytical sensitivity (Se), accuracy and cross reactivity. In the experimentally infected sheep, antibody kinetics was compared between GRA7-TRFIA and an in house N. caninum tachyzoite soluble extract-based ELISA (NcSALUVET ELISA) by Wilcoxon matched-pairs signed rank test. The cut-off and diagnostic Se and specificity (Sp) of GRA7-TRFIA was estimated by ROC analysis with field samples. In addition, concordance and correlation between GRA7-TRFIA and a commercial ELISA and NcSALUVET ELISA were assessed by kappa value and Spearman correlation coefficient, respectively. Overall, GRA7-TRFIA showed an adequate precision, analytical Se and accuracy to detect anti-N. caninum antibodies in ovine serum, and no cross reactivity with the closely related protozoan Toxoplasma gondii. In naturally infected sheep, 100% Se and 95.35% Sp were obtained for a cut-off point of 62.68 Units of Fluorometry for N. caninum (UFN). Moreover, GRA7-TRFIA allowed earlier detection of N. caninum infection than NcSALUVET ELISA in experimentally infected sheep.
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    Comparative performance of five recombinant and chimeric antigens in a time resolved fluorescence immunoassay for detection of Toxoplasma gondii infection in cats
    (Elsevier, 2022-03-28) Huertas López, Ana; Contreras Rojo, Marinela; Sukhumavasi, Woraporn; Martínez Subiela, Silvia; Álvarez García, Gema; López Ureña, Nadia María; Cerón Madrigal, José Joaquín; Martínez-Carrasco Pleite, Carlos; Sanidad Animal; Facultades de la UMU::Facultad de Veterinaria
    Felids are definitive hosts of Toxoplasma gondii, being the only hosts that can spread the infection through oocyst shedding in their feces. The elevated presence of this parasite in the domestic cat (Felis catus), and its close contact with humans, make it necessary to obtain reliable diagnostic methods to detect positive animals as a public health measure. For this reason, in this study, the diagnostic performance of five different recombinant antigen-based techniques was assessed to diagnose T. gondii infection in cat blood plasma samples. Specifically, four T. gondii recombinant antigens (GRA7, truncated GRA7, SAG2, and truncated SAG2) and a chimeric antigen (SAG1-GRA8) were used. A time-resolved fluorescence immunoassay (TRFIA) was developed for each antigen, and the results of each of these techniques were compared with those obtained by a commercial enzyme-linked immunoassay (ELISA) and a modified agglutination test (MAT) as reference techniques. The TRFIA based on SAG1-GRA8 antigen showed better discrimination between seropositive and seronegative cats (p < 0.001), as well as a better area under the curve (0.95), sensitivity (93.6%), and specificity (89.5%) values for the optimal cut-off, versus the other TRFIAs. In addition, SAG1-GRA8 TRFIA showed substantial agreement (kappa value =0.78) and a oderate significant correlation (Spearman’s correlation: r = 0.62, p < 0.001) compared with the reference techniques. On the other hand, since plasma samples were obtained from 101 cats in Bangkok city and four of them were Neospora caninum seropositive by indirect immunofluorescence assay (IFAT), this is the first time that anti-N. caninum antibodies are detected in cats in Thailand. In conclusion, our study highlights that the TRFIA with TgSAG1-GRA8 antigen is an accurate and recommended diagnostic technique for detecting anti-T. gondii antibodies in cats.
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    Contribution of the dopaminergic system in toxoplasmic encephalitis neuroimmunopathogenesis
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2025) Anteplıoğlu, Tuğçe; Dincel, Gungor Cagdas; Alçiğir, Mehmet Eray; Türkmen, Merve Bışkın; Yapic, Tilbe Su; Kul, Oguz; Al Olayan, Ebtsam; Alshahrani, Mohammad Y.; El Ashram, Saeed; Biología Celular e Histología
    Toxoplasma gondii (T. gondii), a parasitic intracellular protozoan, can establish a chronic infection in the host brain and cause significant neuropathology. The current study aimed to determine the role of Tyrosine Hydroxylase (TH), Dopamine Receptor D1 (D1R), Nuclear Receptor Related-1 (Nurr1), and Dopamine Transporter (DAT) expression in the neuroimmunopathogenesis of toxoplasmic encephalitis (TE) at 15, 30, 45, and 60 days after infection with T. gondii. Additionally, the study investigated whether there was a correlation between the markers on these critical days, which had yet to be explored. The results showed that TH expression in brain tissue of BALB/c mice was significantly increased in all infected groups compared with healthy controls (p<0.05). However, other striking findings of the study were that D1R, DAT, and Nurr1 expression were significantly decreased in all infected groups compared with healthy controls, in contrast to TH expression (p<0.05). Study findings regarding behavioral changes in chronic T. gondii-infected laboratory animals and humans with TE provide important evidence of the relationship between neuropsychiatric diseases and T. gondii infection. By elucidating the pathogenesis of the disease in detail, treatment protocols that consider these coordinated changes in expression that vary from day to day can be developed.
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    Development and validation of a time-resolved fluorescence immunoassay for the detection of anti-Toxoplasma gondii antibodies in goats
    (Elsevier, 2021-04-21) Huertas López, Ana; Martínez Subiela, Silvia; Cerón, Jose J.; Vázquez Calvo, Ángela; Pazmiño Bonilla, Elvis Danilo; López Ureña, Nadia María; Martínez Carrasco, Carlos; Álvarez García, Gema; Medicina y Cirugía Animal
    Toxoplasma gondii is a worldwide distributed parasite causing abortions and fetal malformations in small ruminants. The aim of this study was to design and validate a new immunoassay based on the use of TgSAG1-GRA8 chimeric antigen for the detection of anti-T. gondii antibodies in serum of goats. First, a time-resolved fluorescence immunoassay (TgSAG1-GRA8-TRFIA) was developed. In addition, the diagnostic performance of TgSAG1-GRA8-TRFIA was compared with an optimized enzyme-linked immunosorbent assay (TgSALUVET-ELISA) and a Western Blot (WB), both based on whole T. gondii tachyzoite antigenic extract. The TgSAG1-GRA8-TRFIA has shown a high intra- and inter-assay precision, analytical sensitivity and accuracy. The ROC analysis of this assay showed an optimal cut-off of 217.4 Units of Fluorometry for T. gondii (UFT), with 92 % of sensitivity and 90.48 % of specificity. A positive and statistically significant Spearman’s correlation with TgSALUVET-ELISA was detected, and kappa value was 0.83, presenting high agreement with both methods. However, TgSAG1-GRA8 protein showed cross-reactivity with specific anti-Neospora caninum antibodies. Thus, TgSAG-1-GRA8 chimeric antigen seems not to be an ideal option for the serodiagnosis of T. gondii infection in goats unless combined with the serodiagnosis of N. caninum infection in parallel. In the light of the results obtained, a comprehensive study on the existence of cross-reactivities between T. gondii antigens used in serological tests employed in animal health and specific antibodies directed against Toxoplasmatinae parasites should be performed.
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    Experimental toxoplasmosis in red-legged partridges (Alectoris rufa) fed Toxoplasma gondii oocysts
    (Elsevier, 2005-03-09) Martínez-Carrasco Pleite, Carlos; Bernabé Salazar, Antonio; Ortiz Sánchez, Juana María; Alonso de Vega, Francisco-Domingo; Sanidad Animal; Facultades de la UMU::Facultad de Veterinaria
    Thirty red-legged partridges (Alectoris rufa), 5-month-old, were orally inoculated with oocysts of the OV-51/95 strain of Toxoplasma gondii. Birds were distributed into five groups and received, respectively, 10 (group A, 4 birds), 50 (group B, 14 birds), 100 (group C, 4 birds), 1000 (group D, 4 birds) and 10,000 (group E, 4 birds) oocysts. One partridge from group B and one from group E died suddenly of acute toxoplasmosis at 7 day after inoculation (DAI) with demonstrable T. gondii in several tissues. The rest of birds remained clinically normal until killed at 44, 58, 65, 72, 79 or 100 DAI. Brain, heart, liver and skeletal muscle from these partridges were bioassayed individually in mice; T. gondii was demonstrated in all these tissues, except in heart of three birds inoculated, respectively, with 10, 50 and 100 oocysts. Lesions were not seen in histologic sections of tissues from surviving partridges. These results suggest that red-legged partridges are resistant to clinical toxoplasmosis.
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    Lesiones asociadas a una toxoplasmosis aguda en perdices rojas (alectoris rufa) infectadas experimentalmente
    (Murcia: Universidad de Murcia, Servicio de Publicaciones, 2006) Martínez-Carrasco Pleite, Carlos; Bernabé Salazar, Antonio; Ortiz Sánchez, Juana; Alonso de Vega, Francisco; Facultad de Veterinaria
    En el presente trabajo se describen las lesiones asociadas a una toxoplasmosis aguda en perdices rojas (Alectoris rufa) infectadas experimentalmente con ooquistes de Toxoplasma gondii. Para ello, treinta perdices rojas de cinco meses de edad fueron infectadas por vía oral con ooquistes de la cepa OV-51/95 de T. gondii. Las aves fueron distribuidas en cinco lotes, que recibieron unas dosis infectantes de 10, 50, 100, 1000 y 10000 ooquistes, respectivamente. Sólo dos aves, inoculadas con 50 y 10000 ooquistes, murieron por toxoplasmosis aguda al cabo de 7 días postinoculación. Macroscópicamente se apreció hepatomegalia, esplenomegalia y congestión vascular del intestino delgado. Las lesiones microscópicas más características consistieron en una enteritis y focos de necrosis en el bazo y el hígado. Se observaron taquizoítos en los cortes histológicos de estos tejidos, y además en pancreas, pulmón, riñón, tejido muscular esquelético y cardíaco, proventrículo, molleja y bolsa de Fabricio.
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    Serologic response of red-legged partridges (Alectoris rufa) after oral inoculation with Toxoplasma gondii oocysts
    (Elsevier, 2004-05) Martínez-Carrasco Pleite, Carlos; Ortiz, Juana; Bernabé, Antonio; Ruiz de Ybáñez Carnero, María del Rocío; Garijo Toledo, María Magdalena; Alonso, Francisco D.; Sanidad Animal
    Thirty 5-month-old red-legged partridges (Alectoris rufa) reared in battery were divided into five groups: 4 birds in group A, 14 birds in group B, 4 birds in group C, 4 birds in group D and 4 birds in group E, and were inoculated orally with 10, 50, 102, 103 and 104 oocysts of the OV-51/95 strain of Toxoplasma gondii, respectively. During the experiment, blood samples from all birds were drawn every 3–7 days and at necropsy. Serologic response was measured by the modified agglutination test (MAT) and the latex agglutination test (LAT). One bird from each group was killed at 44, 58, 65 and 72 days after inoculation (DAI). From 72 DAI to the end of the experiment, surviving partridges from group B were killed at weekly intervals. The last partridges were sacrified 100 DAI. MAT was the most sensitive and specific test for detecting T. gondii antibodies in the birds. First positive titers were detected by MAT in all sera on 7 DAI, but titers by LAT did not appear until 13 DAI. Antibody titers detected by MAT on 7 DAI were higher in the partridges with the largest inocula (103 or 104 oocysts) than those inoculated with 10, 50 or 102 oocysts. All surviving birds developed a serologic response to T. gondii, with maximum titers of 512–32 768 in the MAT on 13–17 DAI, and positive titers persisted at least until 100 DAI. To the contrary, LAT reveals only very low antibody titers even in partridges inoculated with the highest dose of T. gondii.
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    Seronegativity of Iberian ibex (Capra pyrenaica) against Toxoplasma gondii and Neospora caninum is consistent with eco-epidemiological and environmental features in Mediterranean mountainous areas
    (Elsevier, 2025-01-07) Cano Manuel, Alejandro; Granados, José Enrique; Álvarez García, Gema; Huertas López, Ana; Diezma Díaz, Carlos; Cano Manuel, Francisco Javier; Ortega Mora, Luis Miguel; Fandos, Paulino; Mentaberre, Gregorio; López Olvera, Jorge Ramón; Martínez-Carrasco Pleite, Carlos; Sanidad Animal; Facultades de la UMU::Facultad de Veterinaria
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    Seroprevalence of Toxoplasma gondii in outdoor dogs and cats in Bangkok, Thailand
    (Cambridge University Press, 2021-03-10) Huertas López, Ana; Sukhumavasi, Woraporn; Álvarez-García, Gema; Martínez-Subiela, Silvia; Cano-Terriza, David; Almería, Sonia; Dubey, Jitender P.; García-Bocanegra, Ignacio; Cerón Madrigal, José Joaquín; Martínez-Carrasco Pleite, Carlos; Sanidad Animal; Facultad de Veterinaria
    The aim of this study was to estimate the seroprevalence and risk factors associated with Toxoplasma gondii exposure in dogs and cats from Bangkok, Thailand. Blood samples from 318 dogs and 321 cats were tested for T. gondii antibodies by modified agglutination test (cut-off 1:25). Additionally, 18 dogs and 20 cats were longitudinally sampled for T. gondii antibodies during the same study period, between June and July 2019. The overall seroprevalence in dogs and cats was 7.9% (25/318; 95% CI 4.9–10.8%) and 18.7% (95% CI 14.4–23.0%), respectively. For dogs, risk factors identified were being a mixed-breed animal and living totally outdoors, while increasing age was shown to be a risk factor for cats. Seroconversion was not detected and titres from positive animals remained constant over longitudinal study. The present study indicates that there is a prominent presence of T. gondii in urban and peri-urban areas of Bangkok, suggesting that outdoor dogs and cats should be considered as a possible risk factor for humans.
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    Serosurvey of selected reproductive pathogens in domestic ruminants from Upper Egypt
    (Frontiers Media, 2023-10-23) Farag, Shimaa Ismail; Cano Terriza, David; Gonzálvez Juan, Moisés; Salman, Doaa; Aref, Nasr-Eldin M.; Mubaraki, Murad A.; Jiménez Martín, Débora; García Bocanegra, Ignacio; Elmahallawy, Ehab Kotb; Sanidad Animal; Facultades de la UMU::Facultad de Veterinaria
    Toxoplasmosis, neosporosis, and Q fever are among the most important abortifacient diseases in ruminants worldwide. These diseases result in huge economic losses in livestock besides the fact that some of are of public health concern. The present study aimed to update the data about the current seroepidemiological situation of these diseases in Upper Egypt. A total of 411 blood samples were collected from small and large ruminants and serologically tested against the presence of T. gondii, N. caninum, and C. burnetii. Generalized estimating equation (GEE) models were performed to assess the potential risk factors associated with the exposure to these pathogens. The overall seroprevalence of T. gondii was 47.9% (197/411) with an individual seropositivity of 59.4% (63/106), 58.6% (17/29), 38.8% (54/139) and 46% (63/137) in cattle, buffalo, sheep and goats, respectively. Meanwhile, 9.7% (38/411) of the examined animals were tested positive for anti-N. caninum antibodies, with an individual seropositivity of 13.2% (12/106), 34.5% (10/29), 8.6% (12/139) and 2.9% (4/137) in cattle, buffalo, sheep and goats, respectively. Furthermore, the overall prevalence of antibodies against C. burnetii was 17.3% (63/411), and exposure to this pathogen was detected in 4.7% (5/106) of cattle, 19.3% (20/129) of sheep, 29.2% (38/130) of goats but none of the examined buffalo were found to be seropositive. A total of 12.1% (50/411) of the examined animals showed co-exposure to at least two of the tested pathogens. Regarding the potential risk factors, there were statistically significant differences among species in the frequency of exposure to the three tested pathogens. Age (> 6 months) was also shown to be a significant risk factor associated with T. gondii exposure. The results obtained provided updated information about the occurrence of three of the main reproductive pathogens in Upper Egypt. The high seropositivity values found for the tested zoonotic pathogens in most of the analyzed ruminant species suggest the necessity of performing additional in-depth studies to evaluate the epidemiology of these pathogens in the study area.
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    A systematic review and meta-analysis of the validation of serological methods for detecting anti-Toxoplasma gondii antibodies in humans and animals
    (Elsevier, 2024-03-21) Huertas López, Ana; Cantos Barreda, Ana; Sánchez Sánchez, Roberto; Martínez-Carrasco Pleite, Carlos; Martínez Subiela, Silvia; Cerón Madrigal, José Joaquín; Ibáñez López, Francisco Javier; Álvarez García, Gema; Facultades, Departamentos, Servicios y Escuelas::Departamentos de la UMU::Sanidad Animal; Sanidad Animal
    Toxoplasma gondii is a paradigmatic zoonotic parasite from the One Health perspective, since it is broadly distributed and virtually infects all warm-blooded species. A wide variety of serological techniques have been developed to detect T. gondii infection in humans and animals. Our aim was to describe and compare the main characteristics of these serological tests and validation processes and to critically analyze whether these tests meet the standards required to ensure an accurate serological diagnosis. The current systematic review and metaanalysis included 134 studies that were published from 2013 to 2023. QUADAS 2 tool was used to evaluate the quality of the included studies. A total of 52 variables related to the characteristics of the techniques and analytical and diagnostic validation parameters were studied. A wider panel of tests was developed for humans, including techniques exclusively developed for humans that involve costly equipment and the measurement of different Ig isotypes that are considered biomarkers of congenital toxoplasmosis. Studies conducted in humans frequently employed commercial techniques as reference tests, measured different immunoglobulin isotypes with a predominance for IgG (>50%) and discriminated between acute and chronic infections. In animals, the most commonly used reference techniques were in-house tests, which almost exclusively detected IgG. Common limitations identified in a large number of studies were some misunderstandings of the terms “gold standard” and “reference test” and the absence of information about the negative and positive control sera used or the exact cutoff employed, which were independent of the quality of the study. There is a lack of analytical validation, with few evaluations of cross-reactivity with other pathogens. Diagnostic odds ratio values showed that indirect ELISA based on native or chimeric antigens performed better than other tests. The reproducibility of serological test results in both humans and animals is not guaranteed due to a lack of relevant information and analytical validation. Thus, several key issues should be considered in the future, including interlaboratory ring trials.
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    Urban landscape and infection risk in free-roaming cats
    (Wiley, 2022-02-07) Fanelli, A.; Carvalho, J.; Serrano, E.; Domenech, G.; Alonso, F.; Martinez-Carrasco, C.; González Candela, M.; Sanidad Animal; Department of Veterinary Medicine, University of Bari, Valenzano, Bari, Italy; Department of Biology & Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Aveiro, Portugal; Wildlife Ecology & Health group (WE&H) and Servei d'Ecopatologia de Fauna Salvatge (SEFaS), Universitat Autònoma de Barcelona, Barcelona, Spain; Department of Food Technology, University of Murcia, Murcia, Spain
    Despite public concern on the role of free-roaming cats as reservoirs of zoonotic agents, little is known about the influence of urban and peri-urban landscapes on the exposure risk. We evaluated the seroprevalence of three zoonotic agents (Chlamydia felis, Coxiella burnetii and Toxoplasma gondii) in domestic cats (Felis catus). Two hundred and ninety-one free-roaming cats were trapped in Murcia municipality (Southeast Spain), and their sera were tested for specific antibodies against T. gondii using a modified agglutination test (MAT), and for C. felis, C. burnetii and feline immunodeficiency virus (FIV) antibodies with ELISA technique. Pathogen seroprevalence at 95% CI was calculated for each sex and age category (up to and over 12 months) and compared with a chi-squared test. The role of human population density and urban landscape characteristics on the risk of pathogen exposure in the cat population was explored using generalized linear models. Seropositivity against a single pathogen was found in 60% of the cats, while 19% was seropositive for two or three pathogens. Seroprevalence of C. felis was 8% (CI95%: 5–11), 37% (CI95%: 31–42) for C. burnetii and 42% (CI95%: 36–47) for T. gondii. In addition to these three pathogens, FIV seropositivity was low (1%, CI95%: −0.1 to 2) and adult cats were more likely to be seropositive to C. burnetii than young individuals (OR: 2.3, CI95%: 1.2–4.2). No sex or age class differences in seroprevalence were observed for the rest of the pathogens. Seropositivity was correlated with water surface areas for C. felis, and not with crop areas. Coxiella burnetii seropositivity was correlated with the percentage of urban areas (continuous with only buildings and discontinuous, that include buildings, parks, and pedestrian and urban green areas), human population size and peri-urban areas with shrubs, and not correlated with other agricultural landscapes (orchards and crop areas). However, the seroprevalence of T. gondii was only associated with agricultural landscapes such as orchards. The detection of hotspot areas of high pathogen exposure risk is the basis for municipal services to implement surveillance and risk factor control campaigns in specific-risk areas, including (a) efficient health management of urban cat colonies by geographical location, population census and health status monitoring of the components of each cat colony, (b) improvement of hygiene and sanitary conditions at the feeding points of the cat colony and (c) free-roaming cat trapping for health monitoring and, in the long term, to know the evolution of the health status of their populations.