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1.
Immun Inflamm Dis ; 12(6): e1329, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-39031850

RESUMO

BACKGROUND: Toxoplasma gondii is an obligate intracellular protozoan parasite that can invade all mammalian cells. It is well established that natural killer (NK) cells have critical protective roles in innate immunity during infections by intracellular pathogens. In the current study, we conducted an in vitro experiment to evaluate NK cell differentiation and activation from human umbilical cord blood mononuclear cells (UCB-MNCs) after infection with T. gondii tachyzoites. METHODS: UCB-MNCs were infected by fresh tachyzoites of type I (RH) or type II (PTG) strains of T. gondii pre-expanded in mesenchymal stem cells for 2 weeks in a medium enriched with stem cell factor, Flt3, IL-2, and IL-15. Flow cytometry analysis and western blot analysis were performed to measure the CD57+, CD56+, and Granzyme A (GZMA). RESULTS: Data revealed that incubation of UCB-MNCs with NK cell differentiation medium increased the CD57+, CD56+, and GZMA. UCB-MNCs cocultured with PTG tachyzoites showed a significant reduction of CD56+ and GZMA, but nonsignificant changes, in the levels of CD56+ compared to the control UCB-MNCs (p > .05). Noteworthy, 2-week culture of UCB-MNCs with type I (RH) tachyzoites significantly suppressed CD57+, CD56+, and GZMA, showing reduction of NK cell differentiation from cord blood cells. CONCLUSION: Our findings suggest that virulent T. gondii tachyzoites with cytopathic effects inhibit NK cell activation and eliminate innate immune responses during infection, and consequently enable the parasite to continue its survival in the host body.


Assuntos
Diferenciação Celular , Sangue Fetal , Células Matadoras Naturais , Toxoplasma , Humanos , Células Matadoras Naturais/imunologia , Sangue Fetal/citologia , Sangue Fetal/imunologia , Sangue Fetal/parasitologia , Diferenciação Celular/imunologia , Toxoplasma/imunologia , Células Cultivadas , Toxoplasmose/imunologia , Toxoplasmose/parasitologia , Imunidade Inata , Ativação Linfocitária/imunologia , Leucócitos Mononucleares/imunologia
2.
Biomed Res Int ; 2021: 2754407, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34917681

RESUMO

BACKGROUND: Malaria is one of the leading causes of morbidity and mortality especially in pregnant women and under-five-year-old children. However, data on the prevalence among delivering mothers, potential fetal transmission, and associated birth outcomes is lacking in Ethiopia. OBJECTIVE: To assess the prevalence of Plasmodium infection from peripheral, placental, and cord blood samples among delivering mothers in Kuch health center, Northwest Ethiopia. METHODS: An institution-based cross-sectional study was conducted among 218 delivering mothers from February to May 2021 in Kuch health center. Data on sociodemographic characteristics and clinical and obstetric history of mothers were collected using a structured questionnaire. Giemsa stained blood films from maternal capillary and placental and umbilical cord blood were examined for plasmodium infection. Data were analyzed using Statistical Package for the Social Sciences version 23 software package. RESULTS: The prevalence of maternal, placental, and umbilical cord malaria was 6.4% (14/218), 2.3% (5/218), and 0.5% (1/218), respectively. Plasmodium falciparum and Plasmodium vivax accounted 3.7% (8/218) and 2.8% (6/218), respectively, in maternal peripheral blood but only Plasmodium falciparum was detected in placental and umbilical cord blood samples. Maternal malaria had significant association with primigravida (χ 2 = 12.611, p = 0.002) and low birth weight (χ 2 = 8.381, p = 0.004). Placental malaria was also significantly associated with low birth weight (χ 2 = 32.255, p ≤ 0.001). CONCLUSION: The prevalence of malaria among delivering mothers was considerable. Maternal peripheral malaria had a significant association with gravidity and birth weight. Placental and umbilical cord malaria also had a significant association with birth weight. Pregnant mothers should be examined for malaria and receive appropriate treatment to prevent adverse birth outcomes.


Assuntos
Malária/epidemiologia , Mães/estatística & dados numéricos , Adulto , Peso ao Nascer/fisiologia , Estudos Transversais , Etiópia/epidemiologia , Feminino , Sangue Fetal/parasitologia , Feto/parasitologia , Número de Gestações/fisiologia , Instalações de Saúde/estatística & dados numéricos , Humanos , Placenta/parasitologia , Plasmodium falciparum/patogenicidade , Plasmodium vivax/patogenicidade , Gravidez , Complicações na Gravidez/parasitologia , Cuidado Pré-Natal/estatística & dados numéricos , Prevalência , Cordão Umbilical/parasitologia , Adulto Jovem
3.
J Trop Pediatr ; 66(4): 428-434, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31951264

RESUMO

Diagnosis of congenital malaria is complicated by the low density of the parasite circulating in the cord blood and/or the peripheral blood of the newborns. Molecular techniques are significantly more sensitive than blood smears in detecting low-level parasitemia. This study investigated the prevalence of congenital malaria by the use of the real-time polymerase chain reaction (real-time PCR) in 102 babies born to mothers with microscopically confirmed infected placenta from Blue Nile state, Sudan. At delivery time, placental, maternal peripheral and cord blood samples in addition to samples collected from the newborns' peripheral blood were examined for malaria infection using Giemsa-stained thick smear and parasite DNA detection by real-time PCR. The overall prevalence of congenital malaria includes the total babies with cord blood parasitaemia and peripheral blood parasitaemia was 18.6 and 56.8% using microscopy and real-time PCR, respectively. Even though all the neonates were aparasitaemic by microscopy, 19 (18.6%) of the babies had congenital malaria detected by real-time PCR, 15 (25.9%) of the babies with congenital malaria were born to mothers with both placental and peripheral blood malaria infections detected using the two techniques. Congenital malaria was significantly associated with cord blood malaria infections, maternal age and maternal haemoglobin level (p < 0.001). This first study investigating congenital malaria in Blue Nile state, Sudan shows that malaria-infected placenta resulted in infant and cord blood infections.


Assuntos
Sangue Fetal/parasitologia , Malária/congênito , Placenta/parasitologia , Plasmodium/genética , Complicações Parasitárias na Gravidez/diagnóstico , Adulto , Estudos Transversais , Feminino , Humanos , Recém-Nascido , Transmissão Vertical de Doenças Infecciosas , Malária/sangue , Malária/diagnóstico , Malária/epidemiologia , Masculino , Idade Materna , Mães , Parasitemia/epidemiologia , Plasmodium/classificação , Plasmodium/isolamento & purificação , Gravidez , Complicações Parasitárias na Gravidez/sangue , Complicações Parasitárias na Gravidez/epidemiologia , Prevalência , Estudos Prospectivos , Reação em Cadeia da Polimerase em Tempo Real , Sudão/epidemiologia
4.
Am J Trop Med Hyg ; 101(6): 1350-1358, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31595866

RESUMO

Congenital infection with Trypanosoma cruzi remains a major route for Chagas disease transmission in endemic and non-endemic regions. We evaluated an intervention strategy aimed to detect congenital Chagas disease cases at a major hospital in the Ecuadorian Amazon via cord blood analysis at the time of delivery. All women giving birth at the hospital during the study period (191) were invited to participate. Among them, two (1.0%) did not adjust to the inclusion criteria and four (2.1%) declined to participate in the study, showing the intervention had good acceptability among the mothers. It was possible to obtain cord blood samples during 146 of the deliveries, and only one woman was found to be seropositive, without evidence of transmission to the newborn at delivery or 8 months later. In addition, sociodemographic and economic characterization of the study population revealed that few women had previous knowledge about Chagas disease (16.1%) whereas more than half (62.5%) recognized the vector. Recognizing the vector and having seen it indoors were associated with women from rural families, involved in agriculture, and hunting in the forest. Interestingly, most women (87.3%) reported having easy access to Ecuador's national health system, suggesting serological screening during prenatal visits would be of value in this province. With a proper prenatal screening system in place, cord blood screening would allow for timely detection of T. cruzi infection in newborns from both seropositive women and the minority (2.1%) of women who do not comply with prenatal care visits.


Assuntos
Doença de Chagas/congênito , Doença de Chagas/epidemiologia , Transmissão Vertical de Doenças Infecciosas , Adolescente , Adulto , Animais , Doença de Chagas/prevenção & controle , Estudos Transversais , Vetores de Doenças , Equador/epidemiologia , Feminino , Sangue Fetal/parasitologia , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Recém-Nascido , Mães , Gravidez , Diagnóstico Pré-Natal , Fatores de Risco , População Rural , Inquéritos e Questionários , Adulto Jovem
5.
Acta Trop ; 199: 105127, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31394076

RESUMO

OBJECTIVES: Congenital Chagas Disease (CCD) has become a global health problem. Early diagnosis and treatment is essential for the cure of the disease. Our aim was to evaluate techniques and samples used for the diagnosis of CCD in order to improve diagnostic strategies. METHODS: A total of 181 children born in Spain from Latin American Chagas-infected mothers were consecutively enrolled and studied by microhematocrit, PCR and serology tests at 0-2, 6 and 9-12 months of age and followed up when it was required. Samples of cord blood and peripheral blood were collected for T. cruzi detection by PCR. Parasite culture was performed in patients with a positive PCR. RESULTS: Of 181 children, 7 children (3.9%) were lost to follow-up. A total of 174 children completed follow-up, 12 were diagnosed with CCD (6.9%) and 162 (93.1%) as uninfected children (negative serology tests at the end of the follow-up). Traditional parasitological diagnosis by microhematocrit had a poor performance (sensitivity was 10%), while PCR in peripheral blood showed high sensitivity (90.9%) and specificity (100%), allowing the early diagnosis of 9 infected children during the first 6-months-old. In the other 3 congenital cases, diagnosis was only possible at 12 months by serological and molecular techniques. However, PCR in cord blood showed low sensitivity (33.3%) and less specificity (96.4%) for the diagnosis. CONCLUSION: PCR in peripheral blood has proven to be the most adequate strategy for the diagnosis of CCD, allowing an early and reliable diagnosis.


Assuntos
Doença de Chagas/diagnóstico , Complicações Parasitárias na Gravidez/diagnóstico , Adolescente , Adulto , Doença de Chagas/congênito , Doença de Chagas/parasitologia , Feminino , Sangue Fetal/parasitologia , Seguimentos , Saúde Global , Hematócrito , Humanos , Lactente , Recém-Nascido , Estudos Longitudinais , Masculino , Reação em Cadeia da Polimerase/métodos , Gravidez , Complicações Parasitárias na Gravidez/parasitologia , Sensibilidade e Especificidade , Testes Sorológicos , Espanha , Trypanosoma cruzi/genética , Trypanosoma cruzi/imunologia , Trypanosoma cruzi/isolamento & purificação , Adulto Jovem
6.
Transpl Infect Dis ; 21(4): e13117, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31102567

RESUMO

BACKGROUND: Human umbilical cord blood has proven to be a successful alternate source of hematopoietic stem cells for pediatric patients with major hematologic disorders. Toxoplasma gondii is a global opportunistic protozoan which cause fatal complications in immunocompromised individuals. AIM: Our goal is to study the prevalence of toxoplasmosis in umbilical cord blood (UCB) and to assess the sensitivity of ELISA and PCR for Toxoplasma infection screening. MATERIAL AND METHODS: One hundred cord blood samples were collected immediately after delivery. Anti-Toxoplasma IgG and IgM antibodies were determined using ELISA method; Toxoplasma DNA was detected using nested PCR technique. Total nucleated cells (TNC) and HB were also determined. Demographic data and risk factors data related to the transmission of toxoplasmosis, were collected from mothers. RESULTS: Among 100 cord blood samples, 36 (36%) were positive for anti-Toxoplasma IgG antibodies and 6 (6%) were positive for anti-Toxoplasma IgM antibodies. The nested PCR showed 11 (11%) samples containing Toxoplasma DNA from which, 6 (55%) samples were IgM positive. There was no significant association between the risk of Toxoplasma transmission and cord blood positivity for toxoplasmosis. CONCLUSION: Owing to the prevalence of toxoplasmosis, its rapid progression and its fatal outcome in immunocompromised patients, cord blood screening for toxoplasmosis with nested PCR should be incorporated into cord blood bank screening protocols.


Assuntos
Anticorpos Antiprotozoários/sangue , Sangue Fetal/parasitologia , Técnicas de Diagnóstico Molecular/normas , Testes Sorológicos/normas , Toxoplasmose/diagnóstico , Adulto , DNA de Protozoário/genética , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Reação em Cadeia da Polimerase , Gravidez , Prevalência , Fatores de Risco , Sensibilidade e Especificidade , Toxoplasma/genética , Toxoplasma/imunologia , Adulto Jovem
7.
Am J Trop Med Hyg ; 100(5): 1158-1163, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30860019

RESUMO

Despite recent large-scale investments, malaria remains a major public health concern. Few studies have examined congenital malaria, defined as the presence of malaria parasitemia within the first 7 days of life, in endemic areas. This study aimed to determine the prevalence, to describe the clinical presentation, and to examine factors associated with congenital malaria in newborns aged up to 7 days attending Tororo General Hospital in Uganda. A total of 261 mother/baby pairs were recruited in this cross-sectional study. Giemsa-stained thick blood smears for malaria parasites and rapid malaria diagnostic tests were performed on capillary blood samples from all newborns and mothers, as well as on placental and cord samples from newborns delivered in the hospital. The prevalence of congenital malaria in the newborns was 16/261 (6.1%). No single clinical feature was associated with congenital malaria. However, there were associations between congenital malaria and maternal parasitemia (P < 0.001), gravidity of one (P = 0.03), maternal age < 19 years (P = 0.01), cord blood parasitemia (P = 0.01), and placental malaria (P = 0.02). In conclusion, congenital malaria is not rare in Uganda and there are no obvious clinical features associated with it in the newborn. Based on these findings, we recommend strengthening malaria prevention during pregnancy to reduce the occurrence of congenital malaria in newborns.


Assuntos
Malária/congênito , Malária/epidemiologia , Parasitemia/congênito , Parasitemia/epidemiologia , Complicações Parasitárias na Gravidez/epidemiologia , Adolescente , Estudos Transversais , Feminino , Sangue Fetal/parasitologia , Hospitais Gerais , Humanos , Recém-Nascido , Doenças do Recém-Nascido/epidemiologia , Doenças do Recém-Nascido/parasitologia , Malária/sangue , Idade Materna , Mães/estatística & dados numéricos , Placenta/parasitologia , Gravidez , Complicações Parasitárias na Gravidez/prevenção & controle , Prevalência , Uganda , Adulto Jovem
8.
Acta Trop ; 193: 142-147, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30836060

RESUMO

In malaria-endemic areas, most pregnant women are susceptible to asymptomatic Plasmodium falciparum infections. We present here the results of a cross-sectional study conducted in Madibou, a southern district of Brazzaville in the Republic of Congo, between March 2014 and April 2015. The main aim was to characterize P. falciparum infections. Blood samples corresponding to peripheral, placental and cord from 370 asymptomatic malaria women at delivery were diagnosed for plasmodium infection by thick blood smears (microscopic infection). Sub-microscopic infection was detected by PCR, using the MSP-2 gene as marker. Microscopic infections were detected in peripheral, placental and cord blood samples with a prevalence of respectively 7.3% (27/370), 2.7% (10/370) and 0%. The negative samples were submitted to sub-microscopic detection, with respective prevalence of 25.4% (87/343), 16.7% (60/360) and 9.4% (35/370) (P < 0.001). We further investigated the genetic diversity of the parasite by characterizing MSP2 allelic families 3D7 (24 distinct alleles) and FC27 (20 distinct alleles). The total number of alleles for these two families were 31, 25 and 19 in peripheral, placental and cord samples respectively. The 3D7 MSP-2 was the predominant allelic family. The multiplicity of infections (MOI) in peripheral (mean 1.4 ± 0.01; range 1-4), placental (mean 1.2 ± 0.01; range 1-3) and cord samples (1.4 ± 0.01; range 1-3) were similar (P = 0.9) and are unaffected by age, gravidity or sulfadoxine-pyrimethamine. These results shown a high prevalence of sub-microscopic infection and a high genetic diversity of Plasmodium falciparum strains in Congo. Age, gravidity and doses of preventive treatment based on sulfadoxine-pyrimethamine do not interfere with the multiplicity of infections.


Assuntos
Sangue Fetal/parasitologia , Malária Falciparum/epidemiologia , Placenta/parasitologia , Plasmodium falciparum/genética , Plasmodium falciparum/isolamento & purificação , Proteínas de Protozoários/genética , Adulto , Alelos , Doenças Assintomáticas/epidemiologia , Congo/epidemiologia , Estudos Transversais , Feminino , Variação Genética , Humanos , Malária Falciparum/sangue , Malária Falciparum/parasitologia , Gravidez , Prevalência , Adulto Jovem
9.
Parasitol Int ; 68(1): 48-52, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30304711

RESUMO

Toxoplasmosis, a worldwide distributed zoonosis, can be transmitted congenitally affecting fetuses and developing variable clinical signs. Different Toxoplasma gondii genotypes and infective dose are related factors with different clinical manifestations. Several studies indicate that atypical strains could produce more severe clinical manifestations compared to typical strains. Umbilical cord blood (n = 37) and placenta (n = 19) were collected at birth from women with acute T. gondii infection and processed for isolation by mice bioassay. Six isolates were obtained and identified as TgHm14-4Arg, TgHm15-02Arg, TgHm16-01Arg, TgHm16-02Arg, TgHm17-01Arg and TgHm17-02Arg. Three genotypes described previously on Toxo-DB were identified: #138 identified in chickens from Brazil, #182 isolated from eared doves from Brazil, #14 from wallaby kangaroos and chickens from Argentina, chickens from Brazil, Colombia, Chile and Venezuela, cats and dogs from Brazil and Colombia and also coyotes from USA indicating worldwide distribution of these genotypes. Two new allele combinations were obtained showing high genotypes diversity in Argentina. Four of the isolates (TgHm14-4Arg, TgHm15-02Arg, TgHm16-01Arg, TgHm16-02Arg) and two of them (TgHm17-01Arg, TgHm17-02Arg) produced chronic and acute infections in mice, respectively. Until now, seven T. gondii isolates have been obtained from humans in Argentina, and all were atypical or non-clonal genotypes. The identification of atypical strains causing congenital toxoplasmosis and circulating in our region, make important to perform the serological screenings according Argentine Consensus of Toxoplasmosis and to apply and monitoring treatments earlier in pregnancy. To achieve this aim, it is necessary to inform general population about T. gondii infection, diagnostics and control measures. These results should serve to generate awareness about congenital toxoplasmosis in South America.


Assuntos
Genótipo , Toxoplasma/genética , Toxoplasmose Congênita/epidemiologia , Toxoplasmose Congênita/parasitologia , Doença Aguda/epidemiologia , Animais , Anticorpos Antiprotozoários/sangue , Argentina/epidemiologia , Bioensaio , Doenças do Gato/epidemiologia , Doenças do Gato/parasitologia , Gatos , Galinhas , DNA de Protozoário/genética , Doenças do Cão/epidemiologia , Doenças do Cão/parasitologia , Cães , Feminino , Sangue Fetal/parasitologia , Humanos , Recém-Nascido , Camundongos , Placenta/parasitologia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição/genética , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/parasitologia , Gravidez , América do Sul/epidemiologia , Toxoplasma/imunologia , Toxoplasma/isolamento & purificação , Toxoplasmose Animal/parasitologia , Toxoplasmose Congênita/sangue
10.
Parasite Immunol ; 41(3): e12540, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-29888463

RESUMO

Congenital transmission of leishmaniasis is recognized in cases detected by passive surveillance. Most cases are from low-resource countries, limiting the study of several important aspects of this route of infection, including the offspring's immune response. Studies on natural and experimentally infected animals suggest that parasites might be transmitted to the embryo or foetus at any time during pregnancy. As immune system undergoes sequential stages of development, an infection before the time of self-recognition could lead to central tolerance, making an individual specifically tolerant and susceptible to infection. In the alternative scenario, infection after self-recognition would allow the proper development of T-lymphocyte clones in response to Leishmania antigens, providing resistance to the disease. Newborns undergo a transient period of low expression of several immune surface molecules and a naïve adaptive immune response with no memory, which together might contribute to slow elimination of the parasite over several months. This insight is a proposed independent mechanism of the previously proven T-cell exhaustion and must be investigated. Analyses of infected placenta, cord blood and infant immunity are required for a better understanding of immunity in congenital leishmaniasis infection.


Assuntos
Tolerância Imunológica/imunologia , Transmissão Vertical de Doenças Infecciosas , Leishmania/imunologia , Leishmaniose/imunologia , Linfócitos T/imunologia , Feminino , Sangue Fetal/parasitologia , Humanos , Recém-Nascido , Placenta/parasitologia , Gravidez
11.
Rev Argent Microbiol ; 51(2): 157-163, 2019.
Artigo em Espanhol | MEDLINE | ID: mdl-30541666

RESUMO

The etiology leading to neonatal damage is multifactorial, being genital infections one of the causes. The objective of the study was to identify microorganisms of the maternal genital tract that are associated with neonatal damage, in order to prevent future perinatal complications. Seven hundred and eleven pregnant patients attended their prenatal control during the period January 2010-July 2013. Ureaplasma urealyticum and Mycoplasma hominis presence was investigated in umbilical cord blood by metabolic substrates (Micofast-Biomerieux) and that of T.vaginalis, by PCR using specific primers. The microbiological study of the vaginal contents of 288 pregnant patients at weeks 35 to 37 was performed by conventional methods, adding the modified thioglycolate culture for T.vaginalis. GroupB streptococcus (GBS) was investigated in anorectal and vaginal introitus swabs, using selective broth enrichment and subsequent isolation in chromogenic medium. The χ2 Yates test and Fisher's test were used for independent samples. A p value <0.05 was considered statistically significant. The pathogens significantly related to neonatal damage were M.hominis (p=0.03), T.vaginalis (p=0.03), and BV (p=0.02). Main complications were preterm birth, premature rupture of membranes (PRM), low weight and Apgar score ≤7. U.urealyticum (p=0.35), Candidaspp. (p=0.94) and GBS (p=0.18) were not related to neonatal damage. Since different microorganisms of the maternal genital tract were related to neonatal damage, it is very important to perform the microbiological study of vaginal contents during pregnancy to prevent possible maternal and perinatal complications.


Assuntos
Sangue Fetal/microbiologia , Sangue Fetal/parasitologia , Doenças do Recém-Nascido/microbiologia , Mycoplasma hominis/isolamento & purificação , Complicações Infecciosas na Gravidez/microbiologia , Complicações Infecciosas na Gravidez/parasitologia , Trichomonas vaginalis/isolamento & purificação , Ureaplasma urealyticum/isolamento & purificação , Vagina/microbiologia , Vagina/parasitologia , Feminino , Humanos , Recém-Nascido , Gravidez , Estudos Prospectivos
13.
Sci Rep ; 8(1): 10860, 2018 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-30022038

RESUMO

Using a well-designed longitudinal cohort, we aimed to identify cytokines that were protective against malaria and to explore how they were influenced by genetic and immunological factors. 349 Mozambican pregnant women and their newborn babies were recruited and followed up for malaria outcomes until 24 months of age. Six Th1 cytokines in cord blood were screened for correlation with malaria incidence, of which IL-12 was selected for further analyses. We genotyped IL-12 polymorphisms in children/mothers and evaluated the genotype-phenotype associations and genetic effects on IL-12 levels. Maternal IL-12 concentrations were also investigated in relation to Plasmodium infections and cord blood IL-12 levels. Our data showed that high background IL-12 levels were prospectively associated with a low incidence of clinical malaria, while IL-12 production after parasite stimulation had the opposite effect on malaria incidence. IL-12 genotypes (IL-12b rs2288831/rs17860508) and the haplotype CGTTAGAG distribution were related to malaria susceptibility and background IL-12 levels. Maternal genotypes also exhibited an evident impact on host genotype-phenotype associations. Finally, a positive correlation in background IL-12 levels between maternal and cord blood was identified. Thus, cord blood background IL-12 concentrations are important for protecting children from clinical malaria, likely mediated by both genotypes (children&mothers) and maternal immunity.


Assuntos
Sangue Fetal/imunologia , Interleucina-12/genética , Interleucina-12/imunologia , Leucócitos Mononucleares/imunologia , Malária Falciparum/epidemiologia , Plasmodium falciparum/imunologia , Complicações Parasitárias na Gravidez/imunologia , Estudos de Coortes , Feminino , Sangue Fetal/parasitologia , Genótipo , Haplótipos , Humanos , Lactente , Interleucina-12/sangue , Leucócitos Mononucleares/parasitologia , Malária Falciparum/imunologia , Malária Falciparum/parasitologia , Plasmodium falciparum/patogenicidade , Gravidez , Complicações Parasitárias na Gravidez/parasitologia
14.
Malar J ; 17(1): 177, 2018 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-29743113

RESUMO

BACKGROUND: Increased susceptibility to malaria during pregnancy is not completely understood. Cellular immune responses mediate both pathology and immunity but the effector responses involved in these processes have not been fully characterized. Maternal and fetal cytokine and chemokine responses to malaria at delivery, and their association with pregnancy and childhood outcomes, were investigated in 174 samples from a mother and child cohort from Mozambique. Peripheral and cord mononuclear cells were stimulated with Plasmodium falciparum lysate and secretion of IL-12p70, IFN-γ, IL-2, IL-10, IL-8, IL-6, IL-4, IL-5, IL-1ß, TNF, TNF-ß was quantified in culture supernatants by multiplex flow cytometry while cellular mRNA expression of IFN-γ, TNF, IL-2, IL-4, IL-6, IL-10 and IL-13 was measured by quantitative PCR. RESULTS: Higher concentrations of IL-6 and IL-1ß were associated with a reduced risk of P. falciparum infection in pregnant women (p < 0.049). Pro-inflammatory cytokines IL-6, IL-1ß and TNF strongly correlated among themselves (ρ > 0.5, p < 0.001). Higher production of IL-1ß was significantly associated with congenital malaria (p < 0.046) and excessive TNF was associated with peripheral infection and placental lesions (p < 0.044). CONCLUSIONS: Complex network of immuno-pathological cytokine mechanisms in the placental and utero environments showed a potential trade-off between positive and negative effects on mother and newborn susceptibility to infection.


Assuntos
Citocinas/imunologia , Sangue Fetal/parasitologia , Imunidade Celular , Leucócitos Mononucleares/imunologia , Malária Falciparum/imunologia , Complicações Parasitárias na Gravidez/imunologia , Adolescente , Adulto , Estudos de Coortes , Citocinas/sangue , Feminino , Humanos , Lactente , Recém-Nascido , Malária Falciparum/parasitologia , Moçambique , Plasmodium falciparum/fisiologia , Gravidez , Complicações Parasitárias na Gravidez/parasitologia , Adulto Jovem
15.
Clin Infect Dis ; 67(4): 519-524, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-29438471

RESUMO

Background: Trypanosoma cruzi causes Chagas disease in the Americas. The outcome of infection ranges from lifelong asymptomatic status to severe disease. Relationship between T. cruzi lineage (TcI-TcVI) infection history and prognosis is not understood. We previously described peptide-based lineage-specific enzyme-linked immunosorbent assay (ELISA) with trypomastigote small surface antigen (TSSA). Methods: A novel rapid diagnostic test (RDT; Chagas Sero K-SeT) that incorporates a peptide that corresponds to the TSSA II/V/VI common epitope was developed and validated by comparison with ELISA. Patients from Bolivia and Peru, including individuals with varying cardiac pathology, and matched mothers and neonates, were then tested using Chagas Sero K-SeT. Results: Chagas Sero K-SeT and ELISA results, with a Bolivian subset of cardiac patients, mothers, and neonates, were in accord. In adult chronic infections (n = 121), comparison of severity class A (no evidence of Chagas cardiomyopathy) with class B (electrocardiogram suggestive of Chagas cardiomyopathy) and class C/D (decreased left ventricular ejection fraction; moderate/severe Chagas cardiomyopathy) revealed a statistically significant increase in Chagas Sero K-SeT reactivity with increasing severity (χ2 for trend, 7.39; P = .007). In Peru, Chagas Sero K-SeT detected the sporadic TcII/V/VI infections. Conclusions: We developed a low cost RDT that can replace ELISA for identification of TSSA II/V/VI immunoglobulin G. Most importantly, we show that response to this RDT is associated with severity of Chagas cardiomyopathy and thus may have prognostic value. Repeated challenge with T. cruzi infection may both exacerbate disease progression and boost the immune response to the TSSApep-II/V/VI epitope.


Assuntos
Cardiomiopatia Chagásica/diagnóstico , Testes Sorológicos/métodos , Índice de Gravidade de Doença , Trypanosoma cruzi/isolamento & purificação , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos de Protozoários/imunologia , Bolívia , Ensaio de Imunoadsorção Enzimática , Feminino , Sangue Fetal/parasitologia , Humanos , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Peru , Testes Sorológicos/economia , Adulto Jovem
16.
Am J Trop Med Hyg ; 98(2): 478-485, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29210352

RESUMO

Compared with South America, there is a lack of epidemiologic studies about the risk of congenital transmission of Trypanosoma cruzi in Central America and Mexico. It has been suggested that T. cruzi genotypes might differ by region and that congenital transmission might vary according to the parasite's genotype. Our objective was to compare T. cruzi congenital transmission rates in three countries. We performed an observational prospective study in 2011-2014 enrolling women at delivery in one hospital in Argentina, two hospitals in Honduras, and two hospitals in Mexico. Congenital T. cruzi infection was defined as the presence of one or more of the following criteria: presence of parasites in cord blood (direct parasitological microscopic examination) with positive polymerase chain reaction (PCR) in cord blood, presence of parasites in infant's blood at 4-8 weeks (direct parasitological microscopic examination), and persistence of T. cruzi-specific antibodies at 10 months, as measured by at least two tests. Among 28,145 enrolled women, 347 had at least one antibody rapid test positive in cord blood and a positive enzyme-linked immunosorbent assay in maternal blood. PCR in maternal blood was positive in 73.2% of the cases, and genotyping identified a majority of non-TcI in the three countries. We found no (0.0%; 95% confidence interval [CI]: 0.0, 2.0) confirmed congenital case in Honduras. Congenital transmission was 6.6% (95% CI: 3.1, 12.2) in Argentina and 6.3% (95% CI: 0.8, 20.8) in Mexico. Trypanosoma cruzi non-TcI predominated and risks of congenital transmission were similar in Argentina and Mexico.


Assuntos
Doença de Chagas/transmissão , Transmissão de Doença Infecciosa/estatística & dados numéricos , Adulto , Doença de Chagas/epidemiologia , Feminino , Sangue Fetal/parasitologia , Honduras/epidemiologia , Humanos , Recém-Nascido , México/epidemiologia , Gravidez , Estudos Prospectivos , Estatísticas não Paramétricas , Trypanosoma cruzi/patogenicidade
17.
Acta Trop ; 174: 38-44, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28610938

RESUMO

Toxoplasmosis is a common zoonotic disease that can also be transmitted from the mother to the embryo, with the risk of congenital infection varying around the world. The aim of this study was to screen pregnant women and their neonates for toxoplasmosis by serologic and molecular methods and assess the impact of risk factors associated with toxoplasmosis on the rate of congenital infection. This study was conducted at a regional maternity hospital in Arak, the capital of the Markazi Province in Iran, during a period of six months. All selected pregnant women (n=261) and the corresponding cord blood samples were serologically screened for toxoplasmosis, with seropositive samples also undergoing molecular testing. Demographic data, as well as information related to the risk factors associated with the transmission of the disease, were collected from mothers and their neonates. The detection of anti-Toxoplasma antibodies and the extraction of DNA from blood samples were conducted using commercial kits. Results showed that the sera of 87 maternal blood samples (33.3%) and 40 cord blood samples (15.3%) were positive for anti-Toxoplasma antibodies (IgG and/or IgM). Molecular screening of the seropositive samples only identified one positive cord blood sample. In other words, the diagnosis of congenital toxoplasmosis was definitive in only one neonate. There was no significant association between the risk of parasite transmission and neonatal seropositivity (p >0.05). Therefore, the results showed that the prevalence of congenital toxoplasmosis in the studied area was consistent with the global rate and suggest that the implementation of newborn screening and follow-up testing could help reduce the disease risk.


Assuntos
Sangue Fetal/parasitologia , Estudos Soroepidemiológicos , Toxoplasmose Congênita/diagnóstico , Toxoplasmose/sangue , Toxoplasmose/epidemiologia , Adulto , Anticorpos Antiprotozoários/sangue , Feminino , Humanos , Recém-Nascido , Irã (Geográfico) , Gravidez , Complicações Parasitárias na Gravidez/sangue , Complicações Parasitárias na Gravidez/epidemiologia , Prevalência , Fatores de Risco , Toxoplasma/imunologia , Toxoplasmose Congênita/sangue
18.
Sci Rep ; 7(1): 2080, 2017 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-28522856

RESUMO

Congenital malaria diagnosis is challenging due to frequently observed low parasite density infections, while their clinical relevance during early infancy is not well characterized. In Nanoro health district (Burkina Faso), we determined the prevalence of congenital malaria by real-time quantitative PCR and we assessed the performance of rapid diagnosis test (RDT) and light microscopy (LM) to detect Plasmodium falciparum infections in cord-blood samples. In addition, we examined the usefulness of P. falciparum Histidine Rich Protein2 (PfHRP2) as surrogate biomarker of infection and explored association between congenital malaria and clinical outcomes. A prevalence of congenital malaria by qPCR of 4% (16/400) was found, which increased to 10% among newborns from mothers infected at delivery. RDT and LM showed poor performances indicating limited utility for congenital malaria screening in cord blood. Because PfHRP2 detection in cord blood could be affected by transplacental passage of parasite antigens, PfHRP2 might not be used as a surrogate biomarker of congenital malaria infections. There was no evidence of a significant clinical impact of congenital malaria on infant's health from birth to 59 days of life. Case control studies including long-term follow up may provide additional understanding on the relevance of neonatal malaria infections.


Assuntos
Antígenos de Protozoários/genética , Transmissão Vertical de Doenças Infecciosas , Malária/sangue , Técnicas de Diagnóstico Molecular/métodos , Proteínas de Protozoários/genética , Adulto , Feminino , Sangue Fetal/parasitologia , Humanos , Lactente , Recém-Nascido , Malária/congênito , Malária/transmissão , Masculino , Técnicas de Diagnóstico Molecular/normas , Plasmodium falciparum/genética , Plasmodium falciparum/patogenicidade
19.
Trans R Soc Trop Med Hyg ; 110(9): 551-557, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27794096

RESUMO

BACKGROUND: Toxoplasma gondii is a parasite that causes significant disease in humans. Toxoplasmosis is normally asymptomatic, unless associated with congenital transmission, or in immunocompromised people. Congenital transmission generally occurs at low frequencies. In this study, we use PCR to investigate possible congenital transmission of T. gondii during pregnancy in a cohort of mothers from Libya. METHODS: Two hundred and seventy two pregnant women (producing 276 neonates) were recruited to obtain umbilical cord tissue from their neonates at birth; DNA was extracted from that tissue and tested for T. gondii DNA using two specific PCR protocols based on the sag 1 and sag 3 genes. RESULTS: Toxoplasma gondii DNA was detected in the umbilical cord DNA from 27 of the 276 neonates giving a prevalence of 9.9% (95% CI 6.8-13.9%). Compared with more commonly reported rates of congenital transmission of 0.1% of live births, this is high. There was no association of infection with unsuccessful pregnancy. CONCLUSIONS: This study shows a high frequency presence of T. gondii DNA associated with neonatal tissue at birth in this cohort of 276 neonates from Libya. Although PCR cannot detect living parasites, there is the possibility that this indicates a higher than usual frequency of congenital transmission.


Assuntos
DNA de Protozoário/análise , Transmissão Vertical de Doenças Infecciosas/estatística & dados numéricos , Complicações Parasitárias na Gravidez/diagnóstico , Toxoplasma/isolamento & purificação , Toxoplasmose Congênita/congênito , Toxoplasmose Congênita/diagnóstico , Anticorpos Antiprotozoários/sangue , DNA de Protozoário/sangue , Feminino , Sangue Fetal/parasitologia , Humanos , Recém-Nascido , Líbia/epidemiologia , Masculino , Reação em Cadeia da Polimerase , Gravidez , Complicações Parasitárias na Gravidez/epidemiologia , Complicações Parasitárias na Gravidez/parasitologia , Prevalência , Toxoplasma/genética , Toxoplasma/imunologia , Toxoplasmose Congênita/epidemiologia , Toxoplasmose Congênita/parasitologia
20.
Emerg Infect Dis ; 22(8): 1468-70, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27433974

RESUMO

To assess patterns of Chagas disease, we reviewed results of screening umbilical cord blood from a US public cord blood bank during 2007-2014. Nineteen maternal donors tested positive for Trypanosoma cruzi parasites (0.04%). Because perinatal transmission of Chagas disease is associated with substantial illness, targeted prenatal programs should screen for this disease.


Assuntos
Bancos de Sangue , Doença de Chagas/sangue , Sangue Fetal/parasitologia , Trypanosoma cruzi/isolamento & purificação , Adulto , Doadores de Sangue , Doença de Chagas/epidemiologia , Estudos de Coortes , Feminino , Testes de Hemaglutinação , Humanos , Gravidez , Ensaio de Radioimunoprecipitação , Estudos Retrospectivos
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