RESUMO
To better understand underlying causes of lower rotavirus vaccine effectiveness in low-middle income countries (LMICs), we measured innate antiviral factors in Nicaraguan mothers' milk and immune response to the first dose of the pentavalent rotavirus vaccine in corresponding infants. No relationship was found between concentrations of innate factors and rotavirus vaccine response.
Assuntos
Vacina contra Difteria, Tétano e Coqueluche/imunologia , Vacinas Anti-Haemophilus/imunologia , Imunidade Inata/imunologia , Leite Humano/imunologia , Vacina Antipólio de Vírus Inativado/imunologia , Países em Desenvolvimento , Vacina contra Difteria, Tétano e Coqueluche/administração & dosagem , Feminino , Vacinas Anti-Haemophilus/administração & dosagem , Humanos , Imunogenicidade da Vacina/imunologia , Lactente , Masculino , Nicarágua , Vacina Antipólio de Vírus Inativado/administração & dosagem , Resultado do Tratamento , Vacinas Combinadas/administração & dosagem , Vacinas Combinadas/imunologiaRESUMO
We examined potential risk factors on vaccine virus shedding and antibody seroresponse to human rotavirus vaccine (Rotarix) in Mexican infants. Two doses of Rotarix were administered to infants during the first two visits for their routine childhood immunization (â¼8 and 15weeks of age) in Mexico City. Infant's characteristics and socioeconomic indicators were obtained, including history of long-term feeding practices (exclusively/predominantly breastfed and exclusively/predominantly non-breastfed). Two serum specimens were collected, one during the second rotavirus vaccine visit and one 7weeks later. Stool specimens were collected between days 4-7 after each of the two rotavirus vaccine doses. Rotavirus IgA and IgG titers in serum were determined by enzyme immunoassays (EIA) and rotavirus shedding in stool was assessed by EIA and confirmed by RT-PCR. The overall rotavirus IgA geometric mean titers (GMT) increased significantly post dose 2 from post dose 1 [176 (95%CI: 113-273) to 335 (238-471); p=0.020). Infants who were exclusively/predominantly breastfed were less likely to shed vaccine virus in stool than those who were formula-fed (22% vs. 43%, p=0.016). Infants who were breastfed had lower rotavirus IgA titers than those who were formula-fed after dose 1 [GMT: 145 (84-250) vs. 267 (126-566) p=0.188] and dose 2 [236 (147-378) vs.578 (367-910), p=0.007]. Infants who shed vaccine virus post dose 1 had significantly higher serum IgA GMT than those who did not shed [425 (188-965) vs. 150 (84-266), p=0.038]. Breastfeeding was linked with the reduction of both stool vaccine shedding, and IgA seroresponse. The reduced rotavirus replication in the gut and shedding after dose 1 may explain in part the lower IgA response in serum.
Assuntos
Anticorpos Antivirais/sangue , Aleitamento Materno , Imunoglobulina A/sangue , Vacinas contra Rotavirus/imunologia , Rotavirus/imunologia , Rotavirus/fisiologia , Eliminação de Partículas Virais , Fezes/virologia , Feminino , Humanos , Imunização , Técnicas Imunoenzimáticas , Imunogenicidade da Vacina , Lactente , Masculino , México , Leite Humano/imunologia , Rotavirus/isolamento & purificação , Infecções por Rotavirus/prevenção & controle , Vacinas contra Rotavirus/administração & dosagem , Vacinas contra Rotavirus/efeitos adversos , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/efeitos adversos , Vacinas Atenuadas/imunologia , Replicação ViralRESUMO
Much debate exists regarding the need, acceptability, and value of humanitarian medical assistance. We conducted a cross-sectional study on 457 children under 5 years from four remote riverine communities in the Peruvian Amazon and collected anthropometric measures, blood samples (1-4 years), and stool samples. Focus groups and key informant interviews assessed perspectives regarding medical aid delivered by foreigners. The prevalence of stunting, anemia, and intestinal parasites was 20%, 37%, and 62%, respectively. Infection with multiple parasites, usually geohelminths, was detected in 41% of children. The prevalence of intestinal parasites both individual and polyparasitism increased with age. Participants from smaller communities less exposed to foreigners expressed lack of trust and fear of them. However, participants from all communities were positive about foreigners visiting to provide health support. Prevalent health needs such as parasitic infections and anemia may be addressed by short-term medical interventions. There is a perceived openness to and acceptability of medical assistance delivered by foreign personnel.
Assuntos
Necessidades e Demandas de Serviços de Saúde , Missões Médicas , Aceitação pelo Paciente de Cuidados de Saúde , Fatores Etários , Transtornos da Nutrição Infantil/epidemiologia , Pré-Escolar , Coinfecção , Feminino , Nível de Saúde , Humanos , Lactente , Enteropatias Parasitárias/epidemiologia , Malária/epidemiologia , Masculino , Doenças Parasitárias/epidemiologia , Peru/epidemiologia , Rios , População Rural/estatística & dados numéricosRESUMO
We molecularly characterized samples with Giardia, Cryptosporidium, and soil-transmitted helminths from a facility-based surveillance system for diarrhea in Santa Rosa, Guatemala. The DNA sequence analysis determined the presence of Giardia assemblages A (N = 7) and B (N = 12) and, Cryptosporidium hominis (N = 2) and Cryptosporidium parvum (N = 2), suggestive of different transmission cycles. All 41 samples with soil-transmitted helminths did not have the ß-tubulin mutation described for benzimidazole resistance, suggesting potential usefulness in mass drug administration campaigns.
Assuntos
Cryptosporidium/genética , Giardia/genética , Helmintos/genética , Adolescente , Adulto , Idoso , Animais , Anti-Helmínticos/uso terapêutico , Ascaríase/tratamento farmacológico , Ascaríase/parasitologia , Ascaris lumbricoides/genética , Criança , Pré-Escolar , Criptosporidiose/tratamento farmacológico , Criptosporidiose/parasitologia , Cryptosporidium/fisiologia , Cryptosporidium parvum/genética , Cryptosporidium parvum/fisiologia , Resistência a Medicamentos/genética , Giardia/fisiologia , Giardíase/tratamento farmacológico , Giardíase/parasitologia , Guatemala , Helmintos/fisiologia , Humanos , Lactente , Recém-Nascido , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo Real , Solo/parasitologia , Tricuríase/tratamento farmacológico , Tricuríase/parasitologia , Trichuris/genética , Trichuris/fisiologia , Adulto JovemRESUMO
The guinea pig (Cavia porcellus) is a natural reservoir for Trypanosoma cruzi but has seldom been used as an experimental infection model. We developed a guinea pig infection model for acute and chronic Chagas disease. Seventy-two guinea pigs were inoculated intradermally with 10(4) trypomastigotes of T. cruzi strain Y (experimental group); 18 guinea pigs were used as control group. Eight animals from the experimental group and two from the control group were sacrificed 5, 15, 20, 25, 40, 55, 115, 165, and 365 days after inoculation. During the acute phase (15 to 55 days), we observed parasitemia (with a peak on day 20) and positive IgM and IgG Western blots with anti-shed acute-phase antigen bands. The cardiac tissue showed vasculitis, necrosis (on days 40 to 55), moderate to severe inflammation, and abundant amastigote nests. Smaller numbers of amastigote nests were also present in kidney, brain, and other organs. In the early chronic phase (115 to 165 days), parasitemia disappeared and anti-T. cruzi IgG antibodies were still detectable. In cardiac tissue, the number of amastigote nests and the grade of inflammation decreased. In the chronic phase (365 days), the cardiac tissue showed vasculitis and fibrosis; detectable parasite DNA was associated with higher grades of inflammation. The experimental T. cruzi infection model in guinea pigs shows kinetics and pathologic changes similar to those of the human disease.