Distribution of hepatitis B infection in Brazil: the epidemiological situation at the beginning of the 21 st century

Abstract Brazil was formerly considered a country with intermediate hepatitis B endemicity, with large heterogeneity between Brazilian regions and areas of high prevalence, especially in the Amazon basin. Systematic vaccination of children was initiated in 1998. Between 2004 and 2009, a large population-based study reported decreased prevalence in all regions of Brazil. This review analyzed the current hepatitis B epidemiological situation in Brazil through a systematic search of the scientific literature in MEDLINE, LILACS, and CAPES thesis database, as well as disease notifications to the Information System for Notifiable Diseases. The search strategy identified 87 articles and 13 theses, resulting in 100 total publications. The most recent results indicate reduced hepatitis B prevalence nationwide, classifying Brazil as having low endemicity. Most studies showed HBV carrier prevalence less than 1%. However, there are still isolated regions with increased prevalence, particularly the Amazon, as well as specific groups, such as homeless people in large cities and isolated Afro-descendant communities in the center of the country. This review alsao detected successful vaccination coverage reported in a few studies around the country. The prevalence of anti-HBs alone ranged from 50% to 90%. However, isolated and distant localities still have low coverage rates. This review reinforces the downward trend of hepatitis B prevalence in Brazil and the need to intensify vaccination strategies for young people and adults in specific regions with persisting higher HBV infection prevalence.

Vaccination against Taenia solium cysticercosis

Taenia solium is a parasite that causes human cysticercosis. Its life cycle includes the adult stage, the egg and the larval stage. Human cysticercosis is a disease related to underdevelopment, the main clinical manifestation is neurocysticercosis. Control measures include mass cestocidal treatment aimed to cure possible taeniosis cases. Although useful it has certain disadvantages, such as the generation of symptomatology in occult neurocysticercosis. Alternatively, health education has been shown to be highly effective since people become aware of the importance of human and porcine cysticercosis and the possibility of eliminating it. Nevertheless it has to be implemented by knowledgeable people. On the other hand, the life cycle can be controlled by avoiding swine cysticercosis. This review describes the studies performed to vaccinate pigs against T. solium and indicate that short time perspectives are very encouraging for the production of an optimal vaccine.

Polio inactivated vaccine costs into routine childhood immunization in Brazil

OBJECTIVE To analyze the costs of vaccination regimens for introducing inactivated polio vaccine in routine immunization in Brazil.METHODS A cost analysis was conducted for vaccines in five vaccination regimens, including inactivated polio vaccine, compared with the oral polio vaccine-only regimen. The costs of the vaccines were estimated for routine use and for the “National Immunization Days”, during when the oral polio vaccine is administered to children aged less than five years, independent of their vaccine status, and the strategic stock of inactivated polio vaccine. The presented estimated costs are of 2011.RESULTS The annual costs of the oral vaccine-only program (routine and two National Immunization Days) were estimated at US$19,873,170. The incremental costs of inclusion of the inactivated vaccine depended on the number of vaccine doses, presentation of the vaccine (bottles with single dose or ten doses), and number of “National Immunization Days” carried out. The cost of the regimen adopted with two doses of inactivated vaccine followed by three doses of oral vaccine and one “National Immunization Day” was estimated at US$29,653,539. The concomitant replacement of the DTPw/Hib and HepB vaccines with the pentavalent vaccine enabled the introduction of the inactivated polio without increasing the number of injections or number of visits needed to complete the vaccination.CONCLUSIONS The introduction of the inactivated vaccine increased the annual costs of the polio vaccines by 49.2% compared with the oral vaccine-only regimen. This increase represented 1.13% of the expenditure of the National Immunization Program on the purchase of vaccines in 2011.

ROTAVIRUS GENOTYPES CIRCULATING IN BRAZIL, 2007-2012: IMPLICATIONS FOR THE VACCINE PROGRAM

SUMMARY Regarding public health in Brazil, a new scenario emerged with the establishment of universal rotavirus (RV) vaccination programs. Herein, the data from the five years of surveillance (2007-2012) of G- and P-type RV strains isolated from individuals with acute gastroenteritis in Brazil are reported. A total of 6,196 fecal specimens were investigated by ELISA and RT-PCR. RVs were detected in 19.1% (1,181/6,196). The peak of RV incidence moved from June-August to September. RV was detected less frequently (19.5%) among children ≤ 5 years than in older children and adolescents (6-18 years) (40.6%). Genotype distribution showed a different profile for each year: G2P[4] strains were most prevalent during 2007-2010, G9P[8] in 2011, and G12P[8] in 2012. Mixed infections (G1+G2P[4], G2+G3P[4]+P[8], G2+G12P[8]), unusual combinations (G1P[4], G2P[6]), and rare strains (G3P[3]) were also identified throughout the study period. Widespread vaccination may alter the RV seasonal pattern. The finding of RV disease affecting older children and adolescents after vaccine implementation has been reported worldwide. G2P[4] emergence most likely follows a global trend seemingly unrelated to vaccination, and G12, apparently, is emerging in the Brazilian population. The rapidly changing RV genotype patterns detected during this study illustrate a dynamic population of co-circulating wildtype RVs in Brazil.

Evaluation of local immune response to Fasciola hepatica experimental infection in the liver and hepatic lymph nodes of goats immunized with Sm14 vaccine antigen

Protection against Fasciola hepatica in goats immunized with a synthetic recombinant antigen from Schistosoma mansoni fatty acid-binding protein 14 (rSm14) was investigated by assessing worm burdens, serum levels of hepatic enzymes, faecal egg count and hepatic damage, which was evaluated using gross and microscopic morphometric observation. The nature of the local immune response was assessed by examining the distribution of CD2+, CD4+, CD8+ and γ´+ T lymphocytes along with IgG+, IL-4+ and IFN-γ+ cells in the liver and hepatic lymph nodes (HLN). The goats used consisted of group 1 (unimmunized and uninfected), group 2 [infected control - immunized with Quillaia A (Quil A)] and group 3 (immunized with rSm14 in Quil A and infected), each containing seven animals. Immunization with rSm14 in Quil A adjuvant induced a reduction in gross hepatic lesions of 56.6% (p < 0.001) and reduced hepatic and HLN infiltration of CD2+, CD4+, CD8+ and γ´+ T lymphocytes as well as IL-4+ and IFN-γ+ cells (p < 0.05). This is the first report of caprine immunization against F. hepatica using a complete rSm14 molecule derived from S. mansoni. Immunization reduced hepatic damage and local inflammatory infiltration into the liver and HLN. However, considering that Quil A is not the preferential/first choice adjuvant for Sm14 immunization, further studies will be undertaken using the monophosphoryl lipid A-based family of adjuvants during clinical trials to facilitate anti-Fasciolavaccine development.

Immune response to the mumps component of the MMR vaccine in the routine of immunisation services in the Brazilian National Immunisation Program

A non-controlled longitudinal study was conducted to evaluate the combined vaccine against measles, mumps and rubella (MMR) immunogenicity in 150 children vaccinated in the routine of three health units in the city of Rio de Janeiro, Brazil, 2008-2009, without other vaccines administered during the period from 30 days before to 30 days after vaccination. A previous study conducted in Brazil in 2007, in 1,769 children ranging from 12-15 months of age vaccinated against yellow fever and MMR simultaneously or at intervals of 30 days or more between doses, had shown low seroconversion for mumps regardless of the interval between administration of the two vaccines. The current study showed 89.5% (95% confidence interval: 83.3; 94.0) seroconversion rate for mumps. All children seroconverted for measles and rubella. After revaccination, high antibody titres and seroconversion rates were achieved against mumps. The results of this study and others suggest that two MMR doses confer optimal immunoresponses for all three antigens and the possible need for additional doses should be studied taking into account not only serological, but also epidemiological data, as there is no serological correlate of protection for mumps.

Uniformity of liquid distribution in the canopy of the bean plant, using the spectrophotometric analysis

Fungal diseases are important factors limiting common bean yield. White mold is one of the main diseases caused by soil pathogens. The objective of this study was to quantify the distribution of a fungicide solution sprayed into the canopy of bean plants by spectrophotometry, using a boom sprayer with and without air assistance. The experiment was arranged in a 2 x 2 x 2 factorial (two types of nozzles, two application rates, and air assistance on and off) randomized block design with four replications. Air assistance influenced the deposition of solution on the bean plant and yield increased significantly with the increased rate of application and air assistance in the boom sprayer.

An optimal level of technology reliance on foreign partners in a global sourcing partnership: components procurement, technology management and market performance

Existing studies on global sourcing strategy have implicitly adopted a cJosed-systems perspective in which sourcing activities are managed within a multinational company across national boundaries. Produd and process innovations and components procurement that are jointly managed by a consortium of cooperating firms have not been examined. In this paper, we empiricallyexamine the issues concerning sourcing partnerships in an open-systems perspective. Findings suggest that even in a sourcing partnership arrangement with a foreign supplier, the principal firm's ability to procure and control the supply of major components has a positive bearing on its market performance.

Dengue in the South-eastern region of Brazil: historical analysis and epidemiology

The aim of the study is an historical analysis of the work undertaken by the Public Health organizations dedicated to the combat of the Aedes aegypti, as well as an epidemiolocal study of persons with unexplained fever, with a view to evaluating the ocurrence of dengue within the population. The Mac-Elisa, Gac-Elisa, hemaglutination inhibition, isolation and typage tests were used. Organophosphate intoxication in agricultural workers was also assessed by measuring concentrations of serie cholinesterase. A sera samples of 2,094 were collected in 23 towns, and the type 1 dengue virus was detected in 17 towns and autochthony was confirmed in 12 of them. The cholinesterase was measured in 2,391 sera samples of which 53 cases had abnormal levels. Poisoning was confirmed in 3 cases. Results reveal an epidemic the gravity of which was not officially know. The relationshipe between levels of IgM and IgG antibodies indicates the outbreak tendency. The widespread distribution of the vector is troubling because of the possibility of the urbanization of wild yellow fever, whereas the absence of A. aegypti in 2 towns with autochthony suggests the existence of another vector. Since there is no vaccine against dengue, the combat of the vector is the most efficient measure for preventing outbreaks. The eradication of the vector depends on government decisions which depend, for their execution, on the organization of the Health System and the propagation of information concerning the prevention of the disease using all possible means because short and long term results depend on the education and the active participation of the entire population.

Seroprevalence of human parvovirus B19 in a suburban population in São Paulo, Brazil

OBJECTIVE: To analyze the prevalence of IgG antibodies to human parvovirus B19. METHODS: Cross-sectional study in a suburban community in São Paulo, Southeastern Brazil, between November 1990 and January 1991. Randomly selected (N=435) representative samples of sera were collected from healthy children older than 15 days old and adults up to 40 years old. IgG antibodies were detected using ELISA. RESULTS: High prevalence of IgG antibodies to B19 parvovirus was found in 87% of newborns. The prevalence of maternally derived IgG antibodies exponentially plunged up to the 19th month of age. Low prevalence of antibodies was found in the first 4 years of life, increasing up to 72% in those aged 31-40 years. It was estimated that the average age of first infection in this population is 21 ± 7 years old and the optimal age for vaccination with a hypothetical vaccine would be 1 year of age. CONCLUSIONS: Parvovirus B19 IgG antibody prevalence was high in newborns and those aged 31-40 years. The analysis by age groups showed a pattern similar to that found in previous studies, i.e., low prevalence of infection in children that increases with age.

Pertussis booster vaccine for adolescents and young adults in São Paulo, Brazil

OBJECTIVE: To develop a model to assess different strategies of pertussis booster vaccination in the city of São Paulo. METHODS: A dynamic stationary age-dependent compartmental model with waning immunity was developed. The "Who Acquires Infection from Whom" matrix was used to modeling age-dependent transmission rates. There were tested different strategies including vaccine boosters to the current vaccination schedule and three of them were reported: (i) 35% coverage at age 12, or (ii) 70% coverage at age 12, and (iii) 35% coverage at age 12 and 70% coverage at age 20 at the same time. RESULTS: The strategy (i) achieved a 59% reduction of pertussis occurrence and a 53% reduction in infants while strategy (ii) produced 76% and 63% reduction and strategy (iii) 62% and 54%, respectively. CONCLUSION: Pertussis booster vaccination at age 12 proved to be the best strategy among those tested in this study as it achieves the highest overall reduction and the greatest impact among infants who are more susceptible to pertussis complications.

Temporal trends and spatial distribution of unsafe abortion in Brazil, 1996-2012

OBJECTIVE To analyze temporal trends and distribution patterns of unsafe abortion in Brazil. METHODS Ecological study based on records of hospital admissions of women due to abortion in Brazil between 1996 and 2012, obtained from the Hospital Information System of the Ministry of Health. We estimated the number of unsafe abortions stratified by place of residence, using indirect estimate techniques. The following indicators were calculated: ratio of unsafe abortions/100 live births and rate of unsafe abortion/1,000 women of childbearing age. We analyzed temporal trends through polynomial regression and spatial distribution using municipalities as the unit of analysis. RESULTS In the study period, a total of 4,007,327 hospital admissions due to abortions were recorded in Brazil. We estimated a total of 16,905,911 unsafe abortions in the country, with an annual mean of 994,465 abortions (mean unsafe abortion rate: 17.0 abortions/1,000 women of childbearing age; ratio of unsafe abortions: 33.2/100 live births). Unsafe abortion presented a declining trend at national level (R2: 94.0%, p < 0.001), with unequal patterns between regions. There was a significant reduction of unsafe abortion in the Northeast (R2: 93.0%, p < 0.001), Southeast (R2: 92.0%, p < 0.001) and Central-West regions (R2: 64.0%, p < 0.001), whereas the North (R2: 39.0%, p = 0.030) presented an increase, and the South (R2: 22.0%, p = 0.340) remained stable. Spatial analysis identified the presence of clusters of municipalities with high values for unsafe abortion, located mainly in states of the North, Northeast and Southeast Regions. CONCLUSIONS Unsafe abortion remains a public health problem in Brazil, with marked regional differences, mainly concentrated in the socioeconomically disadvantaged regions of the country. Qualification of attention to women’s health, especially to reproductive aspects and attention to pre- and post-abortion processes, are necessary and urgent strategies to be implemented in the country.

Temporal evolution and spatial distribution of maternal death

OBJECTIVE To analyze the temporal evolution of maternal mortality and its spatial distribution.METHODS Ecological study with a sample made up of 845 maternal deaths in women between 10 and 49 years, registered from 1999 to 2008 in the state of Rio Grande do Sul, Southern Brazil. Data were obtained from Information System on Mortality of Ministry of Health. The maternal mortality ratio and the specific maternal mortality ratio were calculated from records, and analyzed by the Poisson regression model. In the spatial distribution, three maps of the state were built with the rates in the geographical macro-regions, in 1999, 2003, and 2008.RESULTS There was an increase of 2.0% in the period of ten years (95%CI 1.00;1.04; p = 0.01), with no significant change in the magnitude of the maternal mortality ratio. The Serra macro-region presented the highest maternal mortality ratio (1.15, 95%CI 1.08;1.21; p < 0.001). Most deaths in Rio Grande do Sul were of white women over 40 years, with a lower level of education. The time of delivery/abortion and postpartum are times of increased maternal risk, with a greater negative impact of direct causes such as hypertension and bleeding.CONCLUSIONS The lack of improvement in maternal mortality ratio indicates that public policies had no impact on women’s reproductive and maternal health. It is needed to qualify the attention to women’s health, especially in the prenatal period, seeking to identify and prevent risk factors, as a strategy of reducing maternal death.