RESUMO
BACKGROUND: Cohort and case-crossover studies were conducted to evaluate whether new Helicobacter pylori infections are followed by increased diarrhea. METHODS: Participants were 6-month-old to 12-year-old shantytown residents living near Lima, Peru. Baseline data were collected from community households. Health interviews were completed daily, and sera, drawn every 4 months, were tested for H pylori immunoglobulin G. Diarrhea rates among newly H pylori-infected (seroconverting) children were compared with rates among persistently uninfected and infected children using cohort and case-crossover analyses. RESULTS: Sera were obtained from 345 children from January 1, 1995, through September 1, 1997. H pylori incidence was 12% per year (36 H pylori infections in 109 866 seronegative days). In adjusted cohort analyses, seroconverters had more diarrhea days (rate ratio: 2.0; 95% confidence interval: 1.6-2.4), episodes, and sick days in the year after infection than did uninfected children; and more diarrhea days and sick days than did persistently infected children. This effect was strongest in the first 2 months. Case-crossover analyses supported these findings. CONCLUSION: Preventing H pylori infection may help reduce pediatric diarrheal disease.
Assuntos
Diarreia/microbiologia , Infecções por Helicobacter/complicações , Helicobacter pylori , Doença Aguda , Algoritmos , Análise de Variância , Anticorpos Antibacterianos/sangue , Criança , Pré-Escolar , Estudos de Coortes , Estudos Cross-Over , Diarreia/epidemiologia , Infecções por Helicobacter/epidemiologia , Helicobacter pylori/imunologia , Humanos , Incidência , Lactente , Peru/epidemiologia , Áreas de Pobreza , Fatores de RiscoRESUMO
The Helicobacter pylori stool antigen enzyme immunoassay (HpSA) was evaluated during posttreatment follow-up of patients in a country with a very high prevalence of H. pylori infection. From among 273 dyspeptic individuals (18 to 55 years) initially recruited from a shantytown in Lima, Peru, 238 participants who met the inclusion criteria and were suspected to be H. pylori positive based on (14)C urea breath test (UBT) results underwent endoscopy. Participants with endoscopy-proven infections received standard eradication therapy and were monitored by UBT and HpSA at 1 month following treatment and at 3-month intervals for 9 months posttreatment. A second endoscopy was performed if UBT results showed evidence of treatment failure or H. pylori recurrence. Biopsy results were considered the "gold standard" in all analyses. Among patients who underwent endoscopy, HpSA had a pretreatment sensitivity of 93%. Two-hundred thirty patients completed the treatment regimen, of whom 201 (93%) were considered to have had successful treatment outcomes based on a negative follow-up UBT. Thirty-two patients with UBT-defined treatment failures or H. pylori recurrences at any point during the 9-month follow-up underwent a second endoscopy. In the posttreatment setting, HpSA had an overall sensitivity of 73% and a specificity of 67%. Agreement between UBT and HpSA diminished throughout the follow-up. Among 14 participants in whom HpSA remained positive at 1 month following treatment despite UBT evidence of treatment success, 12 (86%) became HpSA negative within 3 months posttreatment. Although this study confirmed the validity of the HpSA in the initial assessment of dyspeptic patients, the test demonstrated a reduced overall accuracy in the detection of treatment failures and H. pylori recurrences during 9 months of posttreatment follow-up. Furthermore, in some patients it may take up to 3 months after successful eradication for antigen shedding to diminish to levels within the negative HpSA range.
Assuntos
Antígenos de Bactérias/análise , Infecções por Helicobacter/microbiologia , Helicobacter pylori/isolamento & purificação , Adolescente , Adulto , Antígenos de Bactérias/imunologia , Fezes/microbiologia , Seguimentos , Infecções por Helicobacter/diagnóstico , Infecções por Helicobacter/epidemiologia , Infecções por Helicobacter/imunologia , Helicobacter pylori/imunologia , Humanos , Imunoensaio/métodos , Pessoa de Meia-Idade , Peru/epidemiologiaRESUMO
The protective efficacy of an oral inactivated whole cell Vibrio cholerae plus recombinant B subunit cholera vaccine was determined against El Tor cholera among Peruvian children and adults (2-65 years old) in a randomized, double-blind manner. Study subjects received 2 doses of vaccine or placebo 2 weeks apart, followed by a booster dose 10 months later. Surveillance for cholera was performed actively, with 2 visits per week to each household, and passively, at a local hospital. Stool samples were collected during diarrhea episodes and were cultured for V. cholerae. A total of 17,799 persons received 2 doses of vaccine or placebo, and 14,997 of these persons received the booster dose. After 2 doses (first surveillance period), V. cholerae biotype O1 was isolated from 17 vaccinees and 16 placebo recipients, demonstrating vaccine efficacy (VE) of -4%. After 3 doses (second surveillance period), V. cholerae O1 was isolated from 13 vaccinees and 32 placebo recipients, demonstrating VE of 61% (95% confidence interval ¿CI, 28%-79%). In the second surveillance period, the VE for illness requiring hospitalization was 82% (95% CI, 27%-96%). VE was also higher for persons >15 years old (VE, 72%; 95% CI, 28%-89%).
Assuntos
Toxina da Cólera/imunologia , Vacinas contra Cólera , Cólera/imunologia , Cólera/prevenção & controle , Vacinas Sintéticas/administração & dosagem , Administração Oral , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Cólera/epidemiologia , Toxina da Cólera/administração & dosagem , Vacinas contra Cólera/administração & dosagem , Diarreia/virologia , Fezes/microbiologia , Humanos , Pessoa de Meia-Idade , Peru/epidemiologia , Vigilância da População , Vibrio cholerae/imunologia , Vibrio cholerae/isolamento & purificação , Eliminação de Partículas ViraisRESUMO
To evaluate enteropathogens and other factors associated with severe disease in children with diarrhea, 381 children <5 years of age with diarrhea and moderate to severe dehydration (in-patients) and 381 age-, sex-, and date-of-visit-matched children with mild diarrhea (out-patients) presenting to a hospital in Peru, were studied. Rotavirus was detected in 52% of the in-patients and 35% of the out-patients (odds ratio [OR]=2.3, 95% confidence interval [95% CI]= 1.6-3.2); 95% of the rotaviruses among in-patients were of serotypes G1-G4. The risk of severe diarrhea was particularly great in children who were not exclusively breast-fed in early infancy and who also lacked piped water in their homes (for children with both characteristics OR=6.8, 95% CI=3.6-12.8). The high prevalence of rotavirus and its association with severe diarrhea underscores the need for rotavirus vaccines. Interventions to educate mothers and improve access to safe water should augment the impact of rotavirus vaccines in preventing severe diarrhea.
Assuntos
Diarreia/etiologia , Infecções por Rotavirus/epidemiologia , Animais , Pré-Escolar , Diarreia/microbiologia , Diarreia/parasitologia , Diarreia/virologia , Eucariotos/isolamento & purificação , Fezes/microbiologia , Fezes/parasitologia , Fezes/virologia , Bactérias Gram-Negativas/isolamento & purificação , Infecções por Bactérias Gram-Negativas/diagnóstico , Infecções por Bactérias Gram-Negativas/epidemiologia , Infecções por Bactérias Gram-Negativas/microbiologia , Humanos , Lactente , Recém-Nascido , Análise por Pareamento , Peru/epidemiologia , Infecções por Protozoários/diagnóstico , Infecções por Protozoários/epidemiologia , Infecções por Protozoários/parasitologia , Fatores de Risco , Rotavirus/isolamento & purificação , Infecções por Rotavirus/diagnóstico , Infecções por Rotavirus/virologiaRESUMO
To provide optimum protection against classical and El Tor biotypes of Vibrio cholerae O1, a single-dose, oral cholera vaccine was developed by combining two live, attenuated vaccine strains, CVD 103-HgR (classical, Inaba) and CVD 111 (El Tor, Ogawa). The vaccines were formulated in a double-chamber sachet; one chamber contained lyophilized bacteria, and the other contained buffer. A total of 170 partially-immune American soldiers stationed in Panama received one of the following five formulations: (a) CVD 103-HgR at 10(8) CFU plus CVD 111 at 10(7) CFU, (b) CVD 103-HgR at 10(8) CFU plus CVD 111 at 10(6) CFU, (c) CVD 103-HgR alone at 10(8) CFU, (d) CVD 111 alone at 10(7) CFU, or (e) inactivated Escherichia coli placebo. Among those who received CVD 111 at the high or low dose either alone or in combination with CVD 103-HgR, 8 of 103 had diarrhea, defined as three or more liquid stools. None of the 32 volunteers who received CVD 103-HgR alone or the 35 placebo recipients had diarrhea. CVD 111 was detected in the stools of 46% of the 103 volunteers who received it. About 65% of all persons who received CVD 103-HgR either alone or in combination had a fourfold rise in Inaba vibriocidal titers. The postvaccination geometric mean titers were comparable among groups, ranging from 450 to 550. Ogawa vibriocidal titers were about twice as high in persons who received CVD 111 as in those who received CVD 103-HgR alone (600 versus 300). The addition of CVD 111 improved the overall seroconversion rate and doubled the serum Ogawa vibriocidal titers, suggesting that the combination of an El Tor and a classical cholera strain is desirable. While CVD 111 was previously found to be well tolerated in semiimmune Peruvians, the adverse effects observed in this study indicate that this strain requires further attenuation before it can be safely used in nonimmune populations.
Assuntos
Vacinas contra Cólera/imunologia , Cólera/prevenção & controle , Militares , Qualidade de Produtos para o Consumidor , Humanos , Panamá , Estados Unidos , Vacinas Atenuadas/imunologiaRESUMO
OBJECTIVE: Lactobacillus GG (L-GG), an acid- and bile-resistant strain that colonizes the intestinal mucosa, has been used to manage diarrhea in children. Our objective was to evaluate the prophylactic use of L-GG to prevent diarrhea in children at high risk from a developing country in a randomized, placebo-controlled trial. STUDY DESIGN: Two hundred four undernourished children 6 to 24 months old from an indigent peri-urban Peruvian town received either L-GG or placebo in flavored gelatin once daily, 6 days a week, for 15 months. Episodes of diarrhea were documented by daily home visits, and diagnostic studies were done in a subset of cases. Recovery of L-GG in stool from subjects and from family contacts was examined. RESULTS: Subjects in the L-GG group had significantly fewer episodes of diarrhea (5.21 episodes diarrhea/child/year ['ecy'] L-GG group, 6. 02 ecy placebo group; P =.028). The decreased incidence of diarrhea in the L-GG group was greatest in the 18- to 29-month age group (P =. 004) and was largely limited to nonbreastfed children (Breastfed: 6. 59 ecy L-GG, 6.32 ecy placebo, P =.7; Nonbreastfed: 4.69 ecy L-GG, 5. 86 ecy placebo, P =.005). The duration of diarrhea episodes and the causes of diarrhea were similar in both groups, except adenovirus was more common in the placebo group. CONCLUSION: L-GG supplementation may be useful as a prophylactic measure to control diarrhea in undernourished children at increased risk, especially nonbreastfed children in the toddler age group.
PIP: This article features a placebo-controlled trial of Lactobacillus GG (L-GG) for diarrhea prevention in undernourished children in Peru. The purpose of the study was to evaluate the use of L-GG as prophylactic treatment for diarrhea. The study population included 204 undernourished children aged 6-24 months, 99 of which were on L-GG and 105 on placebo. Subjects were followed by daily home visits to document diarrhea episodes and diagnostic studies were conducted. Results revealed that children receiving L-GG experienced fewer episodes of diarrhea, which were more pronounced among 18-29 month old children and largely limited to non-breast-fed children. Moreover, the duration of diarrhea episodes and its causes were similar in both groups, except that adenovirus was detected more frequently in the placebo group. In conclusion, L-GG supplementation would decrease diarrhea incidence in high-risk children.
Assuntos
Diarreia/prevenção & controle , Lactobacillus , Aleitamento Materno , Transtornos da Nutrição Infantil , Pré-Escolar , Diarreia/epidemiologia , Diarreia/microbiologia , Método Duplo-Cego , Fezes/microbiologia , Feminino , Humanos , Incidência , Lactente , Modelos Lineares , Masculino , Estado Nutricional , Peru/epidemiologia , Vigilância da População , ProbióticosRESUMO
To assess the safety, immunogenicity, and lot stability of the whole cell/recombinant B subunit cholera vaccine, 2 lots manufactured in June 1991 and February 1992 were tested in January 1995. Two oral doses of vaccine or placebo given 2 weeks apart were given with buffer to 216 Peruvian adults and children. Symptoms were elicited for 3 days after each dose. Serum and plasma specimens obtained from each volunteer before vaccination and 10-14 days after the second dose were tested for vibriocidal and anti-cholera toxin antibodies. The vaccine was well-tolerated. Nearly half of the 100 vaccinees had pre-vaccination vibriocidal titers > or = 1:40. Elevated titers were observed in 22% of 37 children 2-5 years of age compared with 66% of 63 vaccinees 6-65 years (P < 0.001). A > or =2-fold serum vibriocidal response was observed in 55% of 100 vaccinees and 6% of 32 placebo recipients. An elevated pre-vaccination titer (< or =1:40) did not change the proportion of vaccinees who responded with a > or =2-fold increase in vibriocidal titer (51% versus 59%, difference not significant), but did change the proportion responding with a > or =4-fold increase (41% versus 22%; P < 0.05). The vibriocidal seroconversion rate was lowest in children 2-5 years old despite low pre-vaccination titers. Two-fold or greater serum antitoxic responses in IgA and IgG were observed in >90% of the vaccinees; > or =4-fold responses were seen in 65-70% of the vaccinees with a 6-8-fold increase over baseline. Plasma specimens were as good as sera for determining anti-toxic antibodies by ELISA, but were less satisfactory for determining vibriocidal antibody titers.
Assuntos
Toxina da Cólera/imunologia , Vacinas contra Cólera/efeitos adversos , Vacinas contra Cólera/imunologia , Cólera/prevenção & controle , Vibrio cholerae/imunologia , Administração Oral , Adolescente , Adulto , Fatores Etários , Idoso , Anticorpos Antibacterianos/sangue , Criança , Pré-Escolar , Vacinas contra Cólera/administração & dosagem , Método Duplo-Cego , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Peru , Valores de Referência , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/efeitos adversos , Vacinas Sintéticas/imunologia , Vibrio cholerae/isolamento & purificaçãoRESUMO
Diarrhea and wasting are among the most debilitating and deadly manifestations of AIDS, yet only limited information is available regarding the etiology, clinical consequences, and immunologic effects of infection with diarrheal agents. Peruvian AIDS patients presenting with and without diarrhea were followed prospectively to examine the relations among diarrheal pathogens, clinical presentations, CD4 lymphocyte count, weight loss, and survival. Patients with chronic diarrhea had lower CD4 lymphocyte counts (P = .001) and lost more weight (P < .001). Weight loss and a decreased CD4 lymphocyte count were associated with increased mortality (P = .011 and P = .003, respectively). Mean CD4 lymphocyte count varied significantly by diarrheal agent. Clostridium difficile was the most prevalent pathogen and was associated with significantly increased mortality before and after adjustment for coinfection, length of follow-up, CD4 lymphocyte count, and weight loss (P = .006). C. difficile may be a more important and more prevalent etiologic agent in AIDS than previously recognized and may represent a preventable cause of death in patients with immunosuppression.
Assuntos
Infecções Oportunistas Relacionadas com a AIDS/microbiologia , Clostridioides difficile/isolamento & purificação , Diarreia/etiologia , Enterocolite Pseudomembranosa/microbiologia , Infecções Oportunistas Relacionadas com a AIDS/epidemiologia , Infecções Oportunistas Relacionadas com a AIDS/imunologia , Adulto , Contagem de Linfócito CD4 , Clostridioides difficile/imunologia , Infecção Hospitalar/microbiologia , Enterocolite Pseudomembranosa/epidemiologia , Enterocolite Pseudomembranosa/imunologia , Feminino , Humanos , América Latina/epidemiologia , Masculino , Estudos Prospectivos , Taxa de Sobrevida , Redução de PesoRESUMO
Vibrio cholerae induces massive intestinal fluid secretion that continues for the life of the stimulated epithelial cells. Enhanced regional blood flow and peristalsis are required to adapt to this obligatory intestinal secretory challenge. Nitric oxide (NO) is a multifunctional molecule that modulates blood flow and peristalsis and possesses both cytotoxic and antibacterial activity. We demonstrate that, compared with those in asymptomatic control subjects, levels of stable NO metabolites (NO2-/NO3-) are significantly increased in sera from acutely ill Peruvian patients with natural cholera infection as well as from symptomatic volunteers from the United States infected experimentally with V. cholerae. In a rabbit ileal loop model in vivo, cholera toxin (CT) elicited fluid secretion and dose-dependent increases in levels of NO2-/NO3- in the fluid (P < 0.01). In contrast, lipopolysaccharide (LPS) elicited no such effects when applied to the intact mucosa. NO synthase (NOS) catalytic activity also increased in toxin-exposed tissues (P < 0.05), predominantly in epithelial cells. The CT-induced NOS activity was Ca2+ dependent and was not suppressed by dexamethasone. In conclusion, symptomatic V. cholerae infection induces NO production in humans. In the related animal model, CT, but not LPS, stimulated significant production of NO in association with increases in local Ca(2+)-dependent NOS activity in the tissues.
Assuntos
Cólera/metabolismo , Intestino Delgado/metabolismo , Óxido Nítrico Sintase/metabolismo , Óxido Nítrico/biossíntese , Adulto , Idoso , Animais , Cólera/fisiopatologia , Toxina da Cólera/farmacologia , Diarreia/etiologia , Diarreia/fisiopatologia , Di-Hidrolipoamida Desidrogenase/análise , Inibidores Enzimáticos/farmacologia , Feminino , Humanos , Íleo/enzimologia , Intestino Delgado/efeitos dos fármacos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Molsidomina/análogos & derivados , Molsidomina/farmacologia , Músculo Liso/enzimologia , Nitritos/metabolismo , Peru , Coelhos , Valores de Referência , Fatores de Tempo , Estados Unidos , Vibrio cholerae/efeitos dos fármacosRESUMO
During a cholera surveillance programme, Vibrio furnissii was isolated in late January and early February 1994 from stool samples collected from 14 persons of whom six had diarrhoea. The remaining eight persons were healthy family members or neighbours to cholera cases. No common source of infection was found. Strains isolated from stool samples each showed typical biochemical reactions of V. furnissii including gas production. Each isolate, except one, agglutinated O-antisera yielding a total of eight different serotypes. Most isolates were sensitive to 10 antibiotics tested, except to ampicillin and the vibriostatic agent O/129 (10 micrograms). Eight of 14 (57%) strains carried plasmids in the size range 2.6-88 kb, however, no correlation was found between antibiotic susceptibility patterns and plasmid content. Altogether, seven closely related HindIII ribotypes were observed among the 14 V. furnissii isolates studied. V. furnissii strains isolated from family members and other persons living close together often showed different ribotypes suggesting that the isolation was not associated with neighbourhood. Serotyping, plasmid profiling and ribotyping revealed a high strain diversity within V. furnissii, however, the importance of V. furnissii as an enteric pathogen remains to be elucidated.