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PubMed1995

Effect of resistant starch on fecal bulk and fermentation-dependent events in humans.

This study investigated the effect of two diets, which differed in resistant starch (RS) concentration, on fecal bulk and fermentation-dependent events in 11 humans. Amounts of RS consumed were 5.0 +/- 0.4 and 39.0 +/- 3.0 g/d (mean +/- SEM) for the low- and high-RS diets, respectively. The two diets were fed for 3 wk each in a randomized crossover design. Fecal collections were made in the third week of each study period. The high-RS diet produced an increase (P < 0.01) in total fecal output (from 138 +/- 22 to 197 +/- 37 g/d) and lowered fecal pH (6.9 +/- 0.1 to 6.3 +/- 0.1). There were significant increases (P < 0.05) in the fecal concentrations and daily excretion of butyrate (+38% and +100%, respectively) and acetate (+26% and +72%, respectively) during the high-RS period. The fecal excretion (g/d) of nonstarch polysaccharides (NSP) also rose by 50% during the high-RS diet, suggesting that the presence of starch in the colon may affect the fermentation of NSP. Subjects reported an increase in flatulence and easier defecation. These results demonstrate that RS has a significant impact on putative markers of colonic health in humans.

Acetates↗

PubMedDate not supplied

Transmission of viral infections by the water route: implications for developing countries.

The "enteric" virus group comprises greater than 100 different viruses. These viruses typically infect the cell lining of the alimentary canal and are discharged in very large numbers in the feces of infected persons. Contamination of water supplies by enteric viruses represents an important source of viral infection. Many communities, particularly in developing countries, depend on sewage-polluted sources for their recreational and drinking water. Because conventional methods of sewage and water treatment have proved inefficient in the removal and inactivation of most enteric viruses, great concern has been raised over the impact of waterborne infection on the health of such communities. Current evidence implicating drinking and recreational water supplies in the transmission of nonbacterial gastroenteritis and hepatitis A virus and adenovirus infections is overwhelming. Water-borne transmission of other enteric viruses is also possible. Effective antiviral drugs are generally unavailable, and current vaccines can control only a limited number of viral infections; therefore, provision of uncontaminated water is a basic requirement in raising the standard of health in affected communities.

Acute Disease↗

PubMed2004

Effect of Bifidobacterium longum ingestion on experimental salmonellosis in mice.

AIMS: The effect of lactic acid bacteria on the immune system is well established under normal conditions and generally by in vivo determinations, but few data are available, in vivo, during an infectious challenge. The objective of this study was to obtain data on the putative protective role of bifidobacteria upon challenge with an intestinal pathogen. METHODS AND RESULTS: The effect of oral treatment with Bifidobacterium longum Bb46 on intragastric challenge with Salmonella Typhimurium was studied. Faecal bacterial levels were determined in gnotobiotic (GN) mice and mortality, histopathology (intestines, liver), immunoglobulin levels (IgM, IgG, IgG1, IgG2a) and cytokine production (IFN-gamma, IL-10) were determined in conventional (CV) mice. Conventional mice received 0.1 ml probiotic milk (10(8) CFU) daily, 10 days before the oral pathogenic challenge (10(2) CFU). Then, probiotic treatment was continued until the end of the experiment. Probiotic treatment in germ-free mice consisted of a single dose at the beginning of the experiment. Control groups were treated with sterile skim milk and submitted to the same procedure. A higher survival (40%) was observed for probiotic-treated animals when compared with the control group (0%). This protective effect was confirmed by the histopathological and morphometric data. However, S. Typhimurium population levels in the faeces were similar among control and probiotic-treated groups. During the challenge with S. Typhimurium, a decrease in IFN-gamma and IgG2a productions was observed in probiotic-treated mice. CONCLUSIONS: The protective effect against the pathogenic challenge may be due to a reduced inflammatory response, mediated by the probiotic treatment, but not to a population antagonism. SIGNIFICANCE AND IMPACT OF THE STUDY: Results suggest that dietary supplementation with B. longum could provide benefits against enteric infection.

Animals↗

PubMed1993

Recent trends in the prevalence and distribution of schistosomiasis in the Nile delta region.

In 1983, a survey of 71 villages in the Nile delta demonstrated that the overall prevalence of Schistosoma mansoni and S. haematobium infections was 39% and 5%, respectively. Recent increased availability of praziquantel, combined with Egyptian Ministry of Health-sponsored media efforts to educate the public about schistosomiasis, prompted us to determine the current status of S. mansoni and S. haematobium infections in the delta and evaluate any changes that may have occurred since the previous survey. The same villages that participated in the 1983 survey were resampled in 1990. Stool and urine samples were requested from all occupants over the age of two years in a 5% sample of houses within each village. Stool (Kato) thick smears and urine sediments were read qualitatively at the rural health station. Field-prepared Kato smears and a 20% sample of urine specimens were forwarded to the Ministry of Health Laboratory, where quantitative readings were also performed. Analysis of samples obtained from 17,310 persons revealed that S. mansoni prevalence had decreased to 23% and that S. haematobium prevalence had decreased to 3% (P < 0.001). The highest levels of schistosome infection were found in governates located in the eastern section of the delta. The observed changes in the prevalence of S. mansoni and S. haematobium suggest that control measures are having a favorable impact on schistosomiasis transmission in this region.

Adolescent↗

PubMed2002

The influence of colostrum on early Schistosoma mattheei infections in calves.

The study investigated whether the susceptibility of calves to an early Schistosoma mattheei infection may be modified by intake of colostrum from infected cows. Twelve calves born to non-infected mothers were randomly divided into 2 groups of 6. The animals from group 1 were fed colostrum originating from a pool collected from non-infected cows, the calves from group 2 received colostrum from a pool collected from cows infected with S. mattheei. One month after birth all calves were infected by exposure to 1000 cercariae of a local strain of S. mattheei, and perfused 12 weeks later to determine the worm- and tissue egg counts. IgG(H+L), IgG1, IgG2 and IgA levels against soluble adult worm antigen preparation of S. bovis (SWAP bovis) were analysed in both colostrum pools and in the serum from the calves collected during the study before and after receiving colostrum, then on days 7, 30, 73 and 122. Faecal egg counts were determined from day 73 onwards. The IgG(H+L), IgG1 and IgA levels of the positive colostrum pool were higher than those of the negative pool. Calves of group 2 showed significantly higher levels of IgG(H+L) and IgG1 until day 73, to reach equal levels at necropsy. Calves of group 2 showed significant reductions of 42, 28 and 42% in total worm counts, female worm counts, and tissue egg counts, respectively, and a reduction of 25% in cumulative faecal egg counts. These findings indicate that there was a significant impact of colostrum on the parasitological and serological course of early S. mattheei infections.

Animals↗

PubMed1995

Bioavailability of arsenic in soil and house dust impacted by smelter activities following oral administration in cynomolgus monkeys.

This study was conducted to determine the extent of arsenic (As) absorption from soil and house dust impacted by smelter activities near Anaconda, Montana. Female cynomolgus monkeys were given a single oral administration via gelatin capsules of soil (0.62 mg As/kg body wt) or house dust (0.26 mg As/kg body wt), or soluble sodium arsenate by the gavage or intravenous route of administration (0.62 mg As/kg body wt) in a crossover design with a minimum washout period of 14 days. Urine, feces, and cage rinse were collected at 24-hr intervals for 168 hr. Blood was collected at specified time points and area under the curves (AUCs) was determined. Arsenic concentrations for the first 120 hr, representing elimination of greater than 94% of the total administered dose for the three oral treatment groups, were < 0.021 to 4.68 micrograms/ml for the urine and < 0.24 to 31.1 micrograms/g for the feces. In general, peak concentrations of As in the urine and feces were obtained during the collection intervals of 0-24 and 24-72 hr, respectively. The main pathway for excretion of As for the intravenous and gavage groups was in the urine, whereas for the soil and dust groups, it was in the feces. Mean absolute percentage bioavailability values based on urinary excretion data were 68, 19, and 14% for the gavage, house dust, and soil treatments, respectively, after normalization of the intravenous As recovery data to 100%. Corresponding absolute bioavailability values based on blood were 91, 10, and 11%. The bioavailability of soil and house dust As relative to soluble As (by gavage) was between 10 and 30%, depending upon whether urinary or blood values were used. These findings suggest that risks associated with the ingestion of As in soil or dust will be reduced compared to ingestion of comparable quantities of As in drinking water.

Administration, Oral↗

PubMed1993

Bioavailability of arsenic in soil impacted by smelter activities following oral administration in rabbits.

This study determined the extent of arsenic (As) absorption from soil from Anaconda, Montana. Prepubescent male and female SPF New Zealand White rabbits (5/sex/group) were given a single oral (capsule) administration of soil (3900 ppm As) at three different dose levels (0.2, 0.5, and 1.0 g of soil/kg, corresponding to 0.78, 1.95, and 3.9 mg As/kg, respectively). Standard groups included untreated controls, an intravenous sodium arsenate group (1.95 mg As/kg), and a gavage sodium arsenate group (1.95 mg As/kg). Urine, cage rinse, and feces were collected at 24-hr intervals for 5 days and were analyzed for total As concentration. Clinical signs, body weights, and food consumption for treated animals were similar to controls. Maximum As concentrations were obtained over the initial 24-hr collection interval. A dose-dependent delay in urinary As excretion, the major elimination pathway, was observed in the oral soil group compared to that in the gavage group. For the animals in the soil groups, approximately 80% of the administered As dose was eliminated in the feces compared to approximately 10 and 50% for the intravenous and oral gavage groups, respectively. The relative oral bioavailabilities (+/- SD) of As in the gavage and test soil groups based on comparison with excreta data from the intravenous group were approximately 50 +/- 5.7 and 24 +/- 3.2%, respectively (after normalization of intravenous group's As recovery data to 100%). These results indicated that As in the soil was probably in a less soluble and therefore a less absorbable form than sodium arsenate.

Absorption↗

PubMed2004

Fasting and postprandial lipid response to the consumption of modified milk fats by guinea pigs.

The objective of the present study was to investigate the effect of three modified milk fats with different melting profiles on fasting and postprandial lipid responses and on fecal fat content in guinea pigs. We hypothesized that the consumption of modified milk fat with a high m.p. results in reduced fasting and postprandial lipid responses compared with that of modified milk fat fractions with lower m.p. To test this hypothesis, male Hartley guinea pigs were fed isoenergetic diets containing 110 g of fat/kg, either from one of the three modified milk fats with high (HMF), medium (MMF), or low melting profiles (LMF), or from one of the two reference fats as whole milk fat (MF) or a fat blend similar to that of nonhydrogenated soft margarine (MA) for 28 d. Food intake (P < 0.05) and body weight gain (P < 0.05) were reduced in the animals fed the HMF diet compared with the other groups. In the fasting state, plasma LDL cholesterol was highest in animals fed the LMF diet, intermediary in those fed the MMF and MF diets, and lowest in those fed the HMF and MA diets (P< 0.05). Postprandially, the areas under the 0- to 3-h curves for the changes in plasma TG were lower in the HMF group than in the MA- and LMF-fed guinea pigs (P< 0.05). The fecal fat content was higher (P< 0.05) in the HMF group compared to the other milk fat groups. The present results suggest that modified milk fats can impact food intake, body weight gain, fasting cholesterolemia, and postprandial triglyceridemia, and these changes may be attributed to an altered fat absorption.

Animals↗

PubMed2006

Adjusting worm egg counts for faecal moisture in sheep.

The number of eggs from gastrointestinal nematodes per gram of faeces (worm egg count WEC) is commonly used to determine the need for anti-parasite treatments and the breeding value of animals when selecting for worm resistance. Diarrhoea increases faecal moisture and may dilute the number of worm eggs observed. To quantify this effect, egg counts in sheep at pasture were simulated by dosing 15 animals with chromic oxide particles. The simulated WEC diminished as faecal moisture increased. When faeces were dried, simulated WEC per unit dry matter was not influenced by the amount of faecal moisture present prior to drying. The results suggest that adjustment for faecal moisture may provide an improved estimate of FEC. Drying faeces to calculate the WEC per unit dry matter would provide such an adjustment but may not be practical for industry application. In the past, the CSIRO McMaster Laboratory has used an adjustment factor developed by Gordon based on the classification of faecal consistency derived from the morphology of faeces. To examine the utility of an adjustment factor based on faecal consistency score (FCS), the relationships between FCS and simulated WEC and dry matter were examined. Dry matter and simulated WEC exhibited an exponential decline as FCS increased. The relationship between FCS and dry matter was further examined in 368 samples collected over 12 months from sheep at pasture, where it was observed that dry matter showed a linear decline as FCS increased. Adjustment factors based on dry matter were similar to those proposed by Gordon however adjustment factors predicted from simulated WEC diverged from the remainder for FCS>4. As no samples scored FCS 5 in the study of simulated FEC, the adjustment factors based on the larger study that included samples with FCS 5 was therefore considered more robust. Adjustment factors were given by the equation: WEC(estimated)=(WEC(observed)/(34.21-5.15 FCS))x29.06. This equation estimates for samples with FCS>1 the WEC that would be expected if the samples were FCS 1, the faecal consistency score for normal faeces. The impact of adjustment of observed WEC for faecal moisture predicted by FCS on decision points for treatment and on estimated breeding values requires further examination.

Animals↗

PubMed2001

Antibiotic resistance in Escherichia coli isolates obtained from animals, foods and humans in Spain.

Antibiotic resistance was investigated in 474 Escherichia coli isolates recovered from animal faeces (broilers, pigs, pets, bulls and horses), human faeces (patients and healthy volunteers) and food products of animal origin. E. coli isolates (3260) recovered from human significant infectious samples were also included. There was a high frequency of nalidixic acid, ciprofloxacin and gentamicin resistance in E. coli isolates from broilers (88, 38 and 40%, respectively), and from foods (53, 13 and 17%). High levels of resistance to trimethoprim-sulphamethoxazole and tetracycline have been found in E. coli isolates from broilers, pigs and foods. These data raise important questions about the potential impact of antibiotic use in animals and the possible entry of resistant pathogens into the food chain.

Animals↗

PubMed2000

Effect of forage legumes containing condensed tannins on lungworm (Dictyocaulus sp.) and gastrointestinal parasitism in young red deer (Cervus elaphus).

To investigate the effect of feeding forage legumes containing condensed tannins (CT) on internal parasitism, red deer calves were fed either lucerne (Medicago sativa; 0.1 per cent CT), birdsfoot trefoil (Lotus corniculatus; 1.9 per cent CT) or sulla (Hedysarum coronarium; 3.5 per cent CT) and trickle-infected with deer-origin gastrointestinal nematode and lungworm (Dictyocaulus sp.) larvae for 5 weeks, then slaughtered at 7 weeks. There was a significant negative linear relationship between dietary CT concentration and abomasal nematode burdens. No significant differences in faecal egg counts, lungworm burdens or voluntary feed intake were found. Deer fed sulla had higher liveweight gain, carcass weight and carcass dressing-out percentage, higher serum total protein and albumin concentration and lower serum gastrin concentration and faecal lungworm larval count, compared with lucerne-fed deer. Inclusion of sulla in diets for young red deer may reduce the impact of internal parasites and/or reduce the dependence on anthelmintic treatment.

Animal Feed↗

PubMed1997

Effects of experimentally-impaired reticular contractions on digesta passage in sheep.

The aim of the study was to evaluate the functional role of reticular contractions for digesta passage in sheep. Feed intake, mean retention time of fluid and plastic particles in the reticulo-rumen, rumen fluid volume, forestomach motility and particle size distribution in the faeces were determined in five rumen-fistulated sheep fed on hay ad libitum (Expt 1). The same variables were determined when reticular movements were impaired for 10 d by introducing a silicone-covered lead weight (500 g) into the reticulum (Expt 2). As feed intake dropped in Expt 2 by 27% compared with Expt 1, the sheep received in an additional experiment exactly the amount of feed which had been consumed during Expt 2 and measurements were repeated without impairing reticular movements (Expt 3). The introduction of the weight did not affect the frequency of A- or B-cycles, but elevation of the reticular floor in a cranio-dorsal direction during the biphasic contraction was markedly reduced. The pattern of marker excretion indicated a drastically changed composition of reticular outflow in Expt 2 compared with Expts 1 and 3. During Expt 2, rumen fluid volume was similar to that in Expt 1 but about 25% higher than that in Expt 3; the amount of large feed particles in the faeces was increased compared with Expt 1 (+49%) and Expt 3 (+76%). In at least two sheep, abomasal emptying was inhibited during Expt 2, as indicated by an enlarged impacted abomasum. In conclusion, the results emphasize the central role of reticular motility for the separation of particles in the forestomach, the outflow of digesta from the reticulo-rumen and transpyloric digesta flow.

Abomasum↗

PubMed2005

Species-specific oligonucleotide probes for the detection and identification of Lactobacillus isolated from mouse faeces.

AIMS: To develop species-specific monitoring techniques for rapid detection and identification of Lactobacillus isolated from mouse faeces. METHODS AND RESULTS: The specificity of oligonucleotide probes was evaluated by dot blot hybridization to 16S rDNA and 23S rDNA amplified by PCR from 12 Lactobacillus type strains and 100 strains of Lactobacillus isolated from mouse faeces. Oligonucleotide probes specific for each Lactobacillus species hybridized only with targeted rDNA. The Lactobacillus strains isolated from mouse faeces were identified mainly as Lactobacillus intestinalis, L. johnsonii, L. murinus and L. reuteri using species-specific probes. 16S rDNA of eight unidentified isolates were sequenced and two new probes were designed. Four of eight strains of unhybridized Lactobacillus were identified as L. johnsonii/gasseri group, and the remaining four strains as L. vaginalis. CONCLUSIONS: The species-specific probe set of L. intestinalis, L. johnsonii, L. murinus, L. reuteri and L. vaginalis in this study was efficient for rapid identification of Lactobacillus isolated from mouse faeces. SIGNIFICANCE AND IMPACT OF THE STUDY: The oligonucleotide probe set for Lactobacillus species harboured in the mouse intestine, can be used for rapid identification of lactobacilli and monitoring of the faecal Lactobacillus community.

Animals↗

PubMed2006

Detection of norovirus capsid proteins in faecal and food samples by a real time immuno-PCR method.

AIMS: To develop a sensitive real time immuno-polymerase chain reaction (rtI-PCR) method for detecting norovirus (NV) capsid protein in food samples. METHODS AND RESULTS: The viral antigens were captured by two polyclonal antisera against recombinant Norwalk viral-like particles (rNVLPs). Biotin-conjugated antibodies, avidin and biotin-conjugated DNA reporter were used to convert the protein signals into DNA signals. The reporter DNA was then amplified by addition of primers and PCR. A real time PCR method was used in order to perform a quantitative post-PCR analysis. One hundred rNVLPs (10 fg) and a NV sample containing 660 rNVLPs equivalent particle units (66 fg) could be detected by this method. CONCLUSION: The PCR inhibitors present in the food samples had minimal effect on antigen capture and were removed by multiple wash steps during the rtI-PCR procedure. The sensitivity of rtI-PCR was >1000-fold higher than the standard enzyme-linked immunosorbent assay and approximately 10 times higher than reverse transcription PCR in detection of NV capsid protein in stool and food samples. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report of a rtI-PCR method to detect NV in contaminated food samples without concentration or purification of the virus.

Animals↗

PubMed2006

The effect of prebiotics on production of antimicrobial compounds, resistance to growth at low pH and in the presence of bile, and adhesion of probiotic cells to intestinal mucus.

AIMS: Screening of five bile salt-resistant and low pH-tolerant lactic acid bacteria for inhibitory activity against lactic acid bacteria and bacterial strains isolated from the faeces of children with HIV/AIDS. Determining the effect of prebiotics and soy milk-base on cell viability and adhesion of cells to intestinal mucus. METHODS AND RESULTS: Lactobacillus plantarum 423, Lactobacillus casei LHS, Lactobacillus salivarius 241, Lactobacillus curvatus DF 38 and Pediococcus pentosaceus 34 produced the highest level of antimicrobial activity (12,800 AU ml(-1)) when grown in MRS broth supplemented with 2% (m/v) dextrose. Growth in the presence of Raftilose Synergy1, Raftilose L95 and Raftiline GR did not lead to increased levels of antimicrobial activity. Cells grown in the presence of Raftilose Synergy1 took longer to adhere to intestinal mucus, whilst cells grown in the absence of prebiotics showed a linear rate of binding. CONCLUSIONS: A broad range of gram-positive and gram-negative bacteria were inhibited. Dextrose stimulated the production of antimicrobial compounds. Adhesion to intestinal mucus did not increase with the addition of prebiotics. SIGNIFICANCE AND IMPACT OF THE STUDY: The strains may be incorporated in food supplements for HIV/AIDS patients suffering from gastro-intestinal disorders.

Anti-Bacterial Agents↗

PubMed2006

Fecal contamination of agricultural soils before and after hurricane-associated flooding in North Carolina.

Hurricane Floyd and other storms in 1999 caused widespread and extensive flooding of eastern North Carolina and environmental contamination with fecal wastes from municipal wastewater and livestock operations. Because wastewater contains high levels of pathogenic micro-organisms, principal health risks to humans from flooding are consumption of crops grown in fecally contaminated soil and ingestion of contaminated water. Flood waters polluted with microbial and other contaminants also may be detrimental to the health of livestock and plant crops. In the present study, agricultural soils impacted by flood waters were analyzed for bacterial and viral indicators of fecal contamination. Total coliforms, fecal coliforms, Escherichia coli, spores of Clostridium perfringens, and both male specific (F+) and somatic coliphages were recovered from soil and assayed in liquid culture media. A number of samples were positive for the presence of fecal coliforms, E. coli, and coliphages, indicating the presence of human or animal feces. Most samples were positive for total coliforms, and almost all samples contained high levels of Cl. perfringens spores. The levels of Cl. perfringens spores were significantly (P < 0.001) higher in flooded soil (post-Hurricane Floyd) compared to pre-flood soil. Persistent fecal contamination of soil, as demonstrated by the high levels of Cl. perfringens spores, suggests the need for additional or alternative measures to protect crop-growing areas, including prospective microbiological monitoring and improved protection of watersheds from incidents capable of releasing fecal material.

Agriculture↗

PubMed1995

Effect of aging on animal response to chronic fluoride exposure.

This study was conducted to test the hypothesis that physiological changes which occur during aging increase the biological impact of fluoride and reduce the threshold of safe fluoride exposure. Four groups of rats were fed a low-fluoride diet (< 1.2 ppm) ad libitum and received 0, 5, 15, or 50 ppm fluoride in their drinking water. Animals were killed after three, six, 12, or 18 months of treatment. Blood and urine were monitored for biochemical markers of tissue function, and plasma, urine, feces, and representative tissues were analyzed for fluoride. In addition, bone marrow cells from animals killed after 18 months of treatment were examined for frequency of sister chromatid exchange (SCE), a marker of genetic damage. Study results indicated that, within treatment groups, fluoride intake, excretion, and retention did not change significantly between three and 18 months. Fluoride concentration in soft tissues did not change with treatment duration in the fluoride-treated animals. Mineralized tissue fluoride concentration and the total fluoride in the carcasses increased continually as the animals aged. In spite of significant, dose-related differences in tissue fluoride levels which occurred in all age groups in this study, there were no indications that increased fluoride in the tissues caused any adverse physiological or genotoxic effects. None of the monitored clinical "wellness" markers of tissue integrity and function was altered by fluoride in a clinically significant manner. Therefore, there was no evidence from this study that aging reduces the threshold of safe chronic fluoride exposure.

Age Factors↗

PubMed1995

Comparative evaluation of immunization with live attenuated and inactivated poliovirus vaccines.

The development of serum and nasopharyngeal antibody response, as well as the magnitude and temporal pattern of fecal shedding of vaccine and revertant polio-viruses, have been examined in infants previously immunized with one or more doses of orally administered live attenuated poliovaccine, enhanced potency inactivated polio-vaccine, or both. The nature of serum immune response appears to be similar after either immunization schedule, although the antibody titers are quantitatively higher after two doses of EP-IPV than those observed after a similar schedule with OPV. Highest antibody activity is generally detected in subjects immunized with a combination of EP-IPV followed by OPV. ELISA antibody activity in the nasopharynx was regularly detected after either form of immunization. However, neutralizing and VP3 poliovirus virion protein-specific antibody responses in the nasopharynx were consistently observed in subjects immunized with OPV or EP-IPV followed by OPV. Subjects immunized with EP-IPV alone exhibit significantly lower or absent neutralizing or VP3-specific responses. The nucleic acid sequences of the purified RNA obtained from all virus isolates have also been examined in the 5' noncoding region by dideoxy-sequencing to determine whether the viruses shed represent revertants (vaccine), non-revertants, or both. The frequency and duration of vaccine virus shedding appears to be similar in both immunization schedules. Revertant virus shedding was not demonstrated 30 days after immunization with OPV alone. However, shedding of revertants was detected for as long as 60 days in some subjects previously immunized with EP-IPV. The duration of shedding of revertant virus differed with different serotypes and different immunization regimens. Prior immunization with one or more doses of OPV reduced the length of shedding of revertant virus. Significantly, however, prior immunization with one or more doses of EP-IPV was not associated with reduced shedding of revertant virus types. Based on these observations and a number of other epidemiologic data summarized in this review, it is clear that both OPV and EP-IPV when used alone are highly effective and safe in inducing effective immunity to polio-virus and in the eradication of poliomyelitis. While the combination schedule employing EP-IPV followed by OPV should result in a decline of vaccine-associated paralytic (VAP) disease in OPV recipients, such immunization schedules may have little or no impact on the development of VAP in susceptible contacts. Furthermore, the logistics and the cost of combination schedules must be considered before current recommendations based on the use of OPV or EP-IPV alone are revised.

Antibodies, Viral↗