Microbial source tracking and antimicrobial resistance in one river system of a rural community in Bahia, Brazil

Use of antibiotics inevitably leads to antimicrobial resistance. Selection for resistance occurs primarily within the gut of humans and animals as well as in the environment through natural resistance and residual antibiotics in streams and soil. We evaluated antimicrobial resistance in Gram negative bacteria from a river system in a rural community in Bahia, Brazil. Water was collected from the Jiquiriçá and Brejões rivers and the piped water supply. Additionally, stools were collected from a random sample of residents, cows, pigs and horses near the river. The samples were screened for bacteria resistant to ciprofloxacin, cefotaxime, and meropenem and identified biochemically at the genus and species levels. Microbial source tracking demonstrated that ruminant and human fecal contamination increased as the rivers neared the village center and decreased after the last residence. Antibiotic bacteria were identified from all samples (n = 32). No bacteria were resistant to carbapenems, but the majority of the enterobacteria were resistant to ciprofloxacin, even though this class of antibiotics is not commonly used in food animals in this region. Considering these facts, together with the pattern of human fecal contamination, a human source was considered most likely for these resistant isolates.

Prevalence of hepatitis C virus (HCV) infection and HCV genotypes of hemodialysis patients in Salvador, Northeastern Brazil

Hepatitis C virus (HCV) infection has been identified as the major cause of chronic liver disease among patients on chronic hemodialysis (HD), despite the important reduction in risks obtained by testing candidate blood donors for anti-HCV antibodies and the use of recombinant erythropoietin to treat anemia. A cross-sectional study was performed to estimate the prevalence of HCV infection and genotypes among HD patients in Salvador, Northeastern Brazil. Anti-HCV seroprevalence was determined by ELISA in 1243 HD patients from all ten different dialysis centers of the city. HCV infection was confirmed by RT-PCR and genotyping was performed by restriction fragment length polymorphism. Anti-HCV seroprevalence among HD patients was 10.5% (95% CI: 8.8-12.3) (Murex anti-HCV, Abbott Murex, Chicago, IL, USA). Blood samples for qualitative HCV detection and genotyping were collected from 125/130 seropositive HD patients (96.2%). HCV-RNA was detected in 92/125 (73.6%) of the anti-HCV-positive patients. HCV genotype 1 (77.9%) was the most prevalent, followed by genotype 3 (10.5%) and genotype 2 (4.6%). Mixed infections of genotypes 1 and 3 were found in 7.0% of the total number of patients. The present results indicate a significant decrease in anti-HCV prevalence from 23.8% detected in a study carried out in 1994 to 10.5% in the present study. The HCV genotype distribution was closely similar to that observed in other hemodialysis populations in Brazil, in local candidate blood donors and in other groups at risk of transfusion-transmitted infection.

Microsatellite analysis of pooled Schistosoma mansoni DNA: an approach for studies of parasite populations

Human parasites are often distributed in metapopulations, which makes random sampling for genetic epidemiology difficult. The typical approach to sampling Schistosoma mansoni involves laboratory passage to obtain individual worms with small sample size and selection bias as a consequence. By contrast, the naturally pooled samples from egg output in stool or urine directly represent the genetic composition of current populations. To test whether pooled samples could be used to estimate population allele frequencies, DNA from individual cloned parasites was pooled and amplified by PCR for 7 microsatellites. By polyacrylamide gel analysis, the relative band intensities of the products from the major alleles in the pooled samples differed by 0-6% from the summed intensities of the individual clones (mean = 2.1%+/-2.1% S.D.). The number of PCR cycles (25-40) did not influence the accuracy of the estimate. Varying the frequency of 1 allele in pooled samples from 32 to 69% likewise did not affect accuracy. Allele frequency estimates from aggregate samples such as eggs will be a better foundation for studies of parasite population dynamics as well as the basis for large-scale association studies of host and parasite characteristics.

HEV, TTV and GBV-C/HGV markers in patients with acute viral hepatitis

The aim of the present study was to evaluate the prevalence of HEV, TTV and GBV-C/GBV-C/HGV in patients with acute viral hepatitis A, B and non-A-C. We evaluated sera of 94 patients from a sentinel program who had acute hepatitis A (N = 40), B (N = 42) and non-A-C (N = 12); 71 blood donors served as controls. IgM and anti-HEV IgG antibodies were detected by enzyme immunoassay using commercial kits. TTV and GBV-C/HGV were detected by nested PCR; genotyping was done by sequencing and phylogenetic analysis. Anti-HEV IgG was present in 38, 10 and 17% of patients with hepatitis A, B and non-A-C. Four patients with hepatitis A and 1 with non-A-C hepatitis also had anti-HEV IgM detected in serum. TTV was detected in 21% of patients with acute hepatitis and in 31% of donors. GBV-C/HGV was detected in 9% of patients with hepatitis, and in 10% of donors. We found TTV isolates of genotypes 1, 2, 3, and 4 and GBV-C/HGV isolates of genotypes 1 and 2. Mean aminotransferase levels were lower in patients who were TTV or GBV-C/HGV positive. In conclusion, the detection of anti-HEV IgM in some acute hepatitis A cases suggests co-infection with HEV and hepatitis E could be the etiology of a few cases of sporadic non-A-C hepatitis in Salvador, Brazil. TTV genotype 1, 2, 3 and 4 isolates and GBV-C/HGV genotype 1 and 2 strains are frequent in the studied population. TTV and GBV-C/HGV infection does not appear to have a role in the etiology of acute hepatitis.

Comparative study of Hepatitis C virus genotypes 1 and 3 in Salvador, Bahia

Hepatitis C virus displays a high degree of genetic mutation, with considerable heterogeneity, motivating clinical and biomolecular investigations. It is necessary to understand the effects of genotypes on the course of the disease, as well as their peculiarities at the regional level.

OBJECTIVE

The study objective was to compare epidemiological, biochemical and histological aspects of hepatitis C virus genotypes 1 and 3 in Salvador, Bahia.

STUDY DESIGN

Data were collected retrospectively from outpatient medical records.

MATERIALS AND METHODS

127 patients with positive anti-HCV results were selected, based on detectable RNA-HCV (RT-PCR) of genotypes 1a, 1b and 3a.

RESULTS

Thirty-nine (30.7%) individuals were infected by subtype 1a, 45 (35.4%) by subtype 1b and 43 (33.9%) by subtype 3a. Most (73.2%) patients were male, with an average age of 47.8 years. The subtype 1b-infected patients had the highest average age (512 +/-11.17; P=0.09). The use of illicit injected drugs was more frequent among subtype 3a infected individuals when compared with genotype 1 (6/43; 14% and 3/84; 3.6%, respectively; P=0,06). No significant differences were found for other epidemiological characteristics. Average values for GT, AST, ALT and ferritin did not differ between the groups (64, 78, 109, 276, respectively). Thyroid dysfunction occurred in 7/30 (23.3%) of those infected by genotype 3 (P=0.05). Cryoglobulinemia was also more frequent in this group (5/13, 38%, P=0.02). Most patients presented limited necro-inflammatory activity, stages 2 and 3 by the METAVIR Classification. In some cases, dissociation was noticed between inflammatory activity and fibrosis. No significant differences were found in the histopathological findings of the various genotypes. Younger patients had a significantly smaller degree of necrosis in stomatocytosis (P=0.032) and fibrosis (P=0.012). Intense parenchymatous activity and lymphoid follicles were more frequent among alcohol consumers (P=0.06 and P=0.04, respectively).

CONCLUSIONS

In Bahia, genotype 3 dissemination seems to be associated with illicit drug use. The disease evolution depends on a function of complex interactions between virus and host. Age and alcohol consumption stand out as important variables in the development of cirrhosis.

Hepatitis C virus genotypes in a northeastern area of Brazil

We used a reverse transcription-polymerase chain reaction (RT-PCR) to obtain the genotypes of circulating hepatitis C virus (HCV) in patients from a Gastro-Hepatology Unit in the city of Salvador (Bahia State) in northeastern Brazil. Viral RNA was detected in 83 (65.4%) of 127 anti-HCV seropositive serum samples. Positivity was significantly associated with alterations in levels of aspartate aminotransferase and alanine aminotransferase (P < 0.05). Genotyping of HCV was performed by RT-PCR using genotype-specific primers from the core region: 24.1% were infected with subtype 1a, 38.6% with 1b, 3.6% with 2, 21.7% with 3a, and 12.0% with a mixed genotype. There was no difference in genotype distribution when compared with results from other Brazilian locations. Surprisingly, the high frequency of genotype 3 in Brazilian samples continues to be different from that reported around the world and warrants further investigation.

[Assessment of quality of obstetric hospital care: use of corticoid in preterm labor]

This study aimed to assess quality of obstetric care for preterm labor patients, using referents, indicators, and standards derived from scientific evidence, focusing on antenatal corticotherapy. Available meta-analyses and randomized controlled trials were examined to establish referents, defining indicators and estimating process and outcome standards for the present study. Data from hospital discharge summaries of seven public maternity hospitals in Rio de Janeiro were analyzed. The standard of process used was 100%. It was not possible to estimate outcome standards, since the necessary adjustment for gestational age was not feasible. Utilization of antenatal corticotherapy in the present study was very low, about 4% and 2%, considering patients up to 33 weeks and 6 days and 36 weeks and 6 days, respectively. Failure to use antenatal corticotherapy when formally indicated deserves attention by health planners and managers, considering: a) the ease in incorporating such a technology, in contrast to the adequate incorporation of special/intensive neonatal care; b) benefits and costs associated with this technology compared to those of delivering neonatal care to premature babies.

[Analysis of adequacy and effectiveness in the use of tocolytics in preterm labor]

The objective of this study was to assess quality of care for premature labor at public maternity facilities in Rio de Janeiro, Brazil, using referents, indicators, and standards of care derived from scientific evidence. The standard utilized in the process analysis for use of betamimetic tocolytics was 100%, considering the related referents. For outcome analysis, the standard applied was the occurrence of premature delivery in 11% of patients within 24 h and in 24% of patients (referent) within 48 h of hospital admission. Use of tocolytics was observed in 18.7% of patients admitted in premature labor. At gestational age from 28 weeks to 33 weeks and 6 days, especially critical for neonatal survival, tocolytics were used in 32.6% of patients. Premature birth occurred in 59% of patients within 24 h and in 64% within 48 h. These outcomes were consistent with the low rate of utilization of tocolytics. Effectiveness of care for preterm labor measured by rate of premature birth was low. Results of the corresponding process and outcomes analysis were consistent.

A flow cytometric assay for the detection of antiphospholipid antibodies

The data and the results obtained at the above symposium show that the flow cytometric method closely correlates with the standardized aCL bench ELISA and with the APhL ELISA kit. The aCL/aPS FACS kit is comparable in sensitivity to the APhL ELISA kit and standard aCL bench ELISA, but the aCL/aPS FACS kit is more specific than the standard anticardiolipin assay (particularly for the determination of aPS). In summary, the aCL/aPS FACS kit enables rapid (total run time < or = 1 hr) and simultaneous determination of aCL (aCL) and anti-PS antibodies of the IgG and IgM classes and combines good sensitivity and specificity in a single assay. The method is reproducible (intraassay variations < 5%). Furthermore, it is easy to transform into a partially or fully mechanized process and is well suited for laboratories that test large numbers of samples daily. The assay promises to be useful not only for detecting positive APS sera, but also in evaluating the significance of phospholipid specificity and antibody isotypes in patients with APS.

Validation of outcomes through the analysis of the process-outcome relation: limitations

Validation of outcomes of different levels of neonatal care through the analysis of the relationship between process and outcome of care was attempted as part of an effectiveness study and quality assurance programme. Adequacy rates and outcome measures were calculated for second- and third-level units and centres according to the babies' level of risk. Differences in adequacy rates were apparently influenced by the differential distribution of babies by care level sectors among maternity centres. The comparison of mortality rates for "treated" and "untreated" subgroups did not show higher mortality rates for the "untreated" subgroups. This finding could be related to the phenomenon of "confounding by indication". Consistency of differences in average rates of adequacy with differences in general outcomes was observed for most subgroups analysed; lack of consistency could be related to low effectiveness. Indications of low effectiveness related to secondary and more so to tertiary level technologies were observed. The study approach was found more useful for comparisons made at the level of maternity services as a whole, where "confounding by indication" does not operate than at the level of sectors.

[Underreporting of maternal mortality in Rio de Janeiro, Brazil: comparison of 2 information systems]

Two notification systems were compared to estimate maternal death underreporting for 1988 in eight public maternity clinics of Rio de Janeiro. The death rates obtained were compared with the corrected maternal death rate (13.9 per 10,000 live births), which represented all deaths validated by either system. The system based on hospital discharge records yielded a maternal death-rate of 11.6 per 10,000 live births, or 16% underreporting when compared with the corrected death rate. Error was due to system failure in processing the discharge forms, and also to the transfer of patients to nonmonitored hospitals. The system based on death certificates, including "presumed" maternal deaths, presented a rate of 6.6 per 10,000 live births, with 52% underreporting in relation to the corrected rate. The official death rate, based on maternal deaths as declared in death certificates, underreported by 60% compared to the corrected death rate. When the two systems were compared with each other, the one based on death certificates showed 62% underreporting in relation to that based on hospital discharge forms. In order to minimize underreporting of maternal deaths and to broaden the knowledge on circumstances relating to those deaths, it is suggested (a) that a perinatal information system be introduced in all obstetric service units, and (b) to monitor the final outcome of patients transferred to tertiary units.