RESUMEN
Enteric fever remains a major public health problem in the developing world. With the emergence of antimicrobial resistance, disease prevention is becoming essential. There is evidence that improvement of contextual factors, such as socioeconomic development and water supply and sanitation, reduce the burden of this disease. However, such positive results are not universal. This study describes enteric fever trends in Bangladesh along with these factors' progress between 1990 and 2014. Retrospective enteric fever data were collected from Dhaka Shishu (children) Hospital (DSH), Shishu Shasthya Foundation Hospital (SSFH), International Center for Diarrheal Disease Research, Bangladesh, and Popular Diagnostic Center (PDC). Contextual factors data were gathered from relevant organizations and their websites and plotted against time to see trends. During 2001-2014, data for a total of 131,449 blood cultures were available at DSH, SSFH, and PDC. Of those, 7,100 (isolation rate 5.4%) yielded either Salmonella enterica serovar Typhi or Salmonella enterica serovar Paratyphi growth without visible change in isolation rate trends. Contextual factors data were reported from 1990 to 2014. There were significant developments for sanitation facilities, drinking water supply, female literacy, and reduction in poverty head count ratio. During this time period, population density also increased significantly. Despite improvements in these contextual factors in Bangladesh, the enteric fever trend seems steady, possibly because of high population density and unplanned development of water supply and sewerage system. Although proper development of these two factors is important, immunization with an effective vaccine is instrumental to prevent this disease immediately in endemic countries such as Bangladesh, specifically to overcome the challenge of emerging resistance to available antibiotics.
Asunto(s)
Fiebre Paratifoidea/epidemiología , Fiebre Tifoidea/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Bangladesh/epidemiología , Niño , Preescolar , Humanos , Lactante , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Factores de Tiempo , Adulto JovenRESUMEN
Confirmative diagnosis of visceral leishmaniasis (VL) is still a challenge at the primary health care facilities in most of the rural areas of endemicity in the Indian subcontinent. Conventional methods for parasitological confirmation are risky and require skilled personnel, and hence they are unavailable to the poor people in the regions of endemicity. Buffy coat smear microscopy, as a minimally invasive, simple alternative for the parasitological diagnosis of VL, was evaluated in this prospective study. One hundred twelve VL patients were enrolled in this study. The buffy coat was separated from peripheral blood of all enrolled subjects using Histopaque-1119 solution. Leishman-stained buffy coat smears were examined for Leishmania donovani bodies, and buffy coat was also utilized for detection of parasite DNA by Leishmania nested PCR (LnPCR) for all cases. Concomitant splenic smears could be examined for L. donovani bodies in 66 cases, and the parasite load was graded on a scale of 1+ to 6+ for L. donovani-positive smears. All splenic smear-positive cases were also found to be positive by LnPCR. Of 112 enrolled VL cases, 103 (92%) were found to be positive for L. donovani bodies in buffy coat smear microscopy, which is promising as a confirmative diagnosis tool. We have also found a significant association of the buffy coat smear positivity with parasitic burden in the spleen smear. In this preliminary observation in Bangladesh, buffy coat smear microscopy has been found to be very simple, minimally invasive, and risk-free method of parasitological diagnosis of VL with a good diagnostic accuracy and potential for field use.
Asunto(s)
Capa Leucocitaria de la Sangre/parasitología , Técnicas de Laboratorio Clínico/métodos , Leishmania donovani/citología , Leishmaniasis Visceral/diagnóstico , Microscopía/métodos , Parasitología/métodos , Adolescente , Adulto , Bangladesh , Niño , ADN Protozoario/genética , ADN Protozoario/aislamiento & purificación , Femenino , Humanos , Leishmania donovani/genética , Masculino , Reacción en Cadena de la Polimerasa/métodos , Estudios Prospectivos , Adulto JovenRESUMEN
During March and April 2002, a resurgence of Vibrio cholerae O139 occurred in Dhaka and adjoining areas of Bangladesh with an estimated 30,000 cases of cholera. Patients infected with O139 strains were much older than those infected with O1 strains (p<0.001). The reemerged O139 strains belong to a single ribotype corresponding to one of two ribotypes that caused the initial O139 outbreak in 1993. Unlike the strains of 1993, the recent strains are susceptible to trimethoprim, sulphamethoxazole, and streptomycin but resistant to nalidixic acid. The new O139 strains carry a copy of the Calcutta type CTX(Calc) prophage in addition to the CTX(ET) prophage carried by the previous strains. Thus, the O139 strains continue to evolve, and the adult population continues to be more susceptible to O139 cholera, which suggests a lack of adequate immunity against this serogroup. These findings emphasize the need for continuous monitoring of the new epidemic strains.
Asunto(s)
Cólera/epidemiología , Enfermedades Transmisibles Emergentes/epidemiología , Brotes de Enfermedades , Vibrio cholerae O139/genética , Adolescente , Bangladesh/epidemiología , Preescolar , Femenino , Genes de ARNr/genética , Genotipo , Humanos , Masculino , Reacción en Cadena de la Polimerasa , Vibrio cholerae O139/clasificación , Vibrio cholerae O139/aislamiento & purificaciónRESUMEN
Rotavirus-specific subclass antibody responses and cytokines, tumour necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), interleukin-8 (IL-8), and IL-10, were measured in children 7-24 months of age with rotavirus diarrhoea (n = 29); the responses were compared with children with watery diarrhoea from whom no enteric pathogens were isolated (controls; n = 11). All children had diarrhoea for < 5 days and were enrolled from the Dhaka Hospital of the Centre for Health and Population Research. Samples of blood and stools were collected on the day of enrollment and 18-21 days after the onset of diarrhoea. Children showing a > or = 4-fold rise in antibody titre between the acute and convalescent stages were considered to have a response. The numbers of children with rotavirus-specific IgA and IgA1 responses in stool were similar in the two groups of children. In the plasma, more children with rotavirus diarrhoea had rotavirus-specific IgA, IgA1, IgG, IgG1, and IgG3 responses than did control children (P = 0.049, 0.007, 0.001, 0.002, and 0.012, respectively). IgA2 was not detectable. Among cytokines measured in supernatants from peripheral blood mononuclear cells (PBMCs) cultured for 6 and 24 hr, IFN-gamma was the only cytokine that was higher in children with rotavirus diarrhoea compared with controls (P = 0.013). Severity of illness did not correlate with nutritional status or antibody titres, but severity did correlate with TNF-alpha during the acute stage of illness. IFN-gamma correlated positively with IgG1 titres. These findings suggest a role for IFN-gamma in the pathogenesis of rotavirus infection, but this needs confirmation by other studies. The immune responses described are relevant to future vaccine trials, as immune responses in vaccinees should mimic those in natural infection.
Asunto(s)
Anticuerpos Antivirales/sangre , Especificidad de Anticuerpos , Diarrea/inmunología , Diarrea/virología , Rotavirus/inmunología , Bangladesh , Preescolar , Citocinas/metabolismo , Heces/virología , Humanos , Inmunoglobulina A , Inmunoglobulina G , Lactante , Rotavirus/clasificación , Infecciones por Rotavirus/inmunología , Infecciones por Rotavirus/virología , Índice de Severidad de la EnfermedadRESUMEN
The chemokine stromal-cell derived factor-1 (SDF-1) controls maturation, trafficking, and homing of certain subsets, lymphoid cells including immunogenic B and T cells, as a ligand of the CXCR4 chemokine receptor. Insulin-dependent diabetes mellitus (IDDM) and Sjögren's syndrome (SS), both highly regulated autoimmune diseases, develop spontaneously in non-obese diabetic (NOD) mice. To investigate the role of SDF-1 in the development of autoimmune diseases, we injected groups of NOD female mice with antibodies to SDF-1 (anti-SDF-1), which resulted in a 30% reduction of diabetes up to 30 weeks of age, delayed average diabetes onset by 10 weeks, and suppressed insulitis. Autoimmune sialoadenitis was evident in anti-SDF-1-injected mice (SDF-1-Ig group) at the same level as in all groups of mice, whether injected with non-specific antibodies or not. In addition, in the SDF-1-Ig group, a greater number of immunoglobulin M (IgM)- IgD- B220(low) CD38+ CD43+ CD23- progenitor B cells and IgM+ IgD+ B220(high) CD43- CD38+ CD24+ CD23+ mature B cells remained in the bone marrow, whereas infiltration of mature IgM+ B cells was less extensive in peripheral tissues. Our results suggested that anti-SDF-1 antibodies injection was effective in inhibiting diabetes and insulitis without affecting autoimmune sialoadenitis or SS in NOD mice. SDF-1 may be an essential chemokine for trafficking and migration of autoreactive B cells in the development of diabetes.
Asunto(s)
Enfermedades Autoinmunes/inmunología , Quimiocinas CXC/inmunología , Diabetes Mellitus Experimental/inmunología , Animales , Anticuerpos Monoclonales/inmunología , Antígenos de Superficie/metabolismo , Enfermedades Autoinmunes/patología , Linfocitos B/inmunología , Células de la Médula Ósea/inmunología , Quimiocina CXCL12 , Quimiotaxis de Leucocito/inmunología , Diabetes Mellitus Experimental/patología , Femenino , Células Madre Hematopoyéticas/inmunología , Macrófagos/inmunología , Ratones , Ratones Endogámicos NOD , Sialadenitis/inmunología , Sialadenitis/patología , Subgrupos de Linfocitos T/inmunologíaRESUMEN
NOD/LtSz-prkdc(scid)/prkdc(scid) (non-obese diabetic-severe combine immunodeficiency; NOD-scid) mice grafted with human peripheral blood lymphoid cells have been used as an in vivo humanized mouse model in various studies. However, cytotoxic human T cells are induced in this model during immune responses, which gives misleading results. To assist in grafting of human lymphocytes without the induction of cytotoxic human T cells, we investigated the effects of T helper type 1 (Th1) and Th2 cytokines on human lymphocyte grafting and migration, as well as the production of immunoglobulin deposited in glomeruli and human immunodeficiency virus-1 (HIV-1) infection using NOD-scid mice. Administration of interleukin-18 (IL-18) and IL-12 enhanced the grafting of human CD4+ and CD8+ T cells in the mice, whereas co-administration prevented grafting due to interferon-gamma-dependent apoptosis. Immunoglobulin A (IgA) deposits were observed in mice treated with IL-18 alone, but not in those given phosphate-buffered saline, IL-12 alone, or IL-18 + IL-12. A high rate of HIV infection was also observed in the IL-18-treated group. Together, these results indicate that IL-18 may be effective for the grafting and migration of CD4+ and CD8+ T cells, except for the induction of apoptosis and regulation of class-switching IgA. IL-18-administered NOD-scid mice provide a useful small humanized model for the study of HIV infection and IgA nephropathy.