Methods and challenges for the health impact assessment of vaccination programs in Latin America

ABSTRACT OBJECTIVE To describe methods and challenges faced in the health impact assessment of vaccination programs, focusing on the pneumococcal conjugate and rotavirus vaccines in Latin America and the Caribbean. METHODS For this narrative review, we searched for the terms "rotavirus", "pneumococcal", "conjugate vaccine", "vaccination", "program", and "impact" in the databases Medline and LILACS. The search was extended to the grey literature in Google Scholar. No limits were defined for publication year. Original articles on the health impact assessment of pneumococcal and rotavirus vaccination programs in Latin America and the Caribbean in English, Spanish or Portuguese were included. RESULTS We identified 207 articles. After removing duplicates and assessing eligibility, we reviewed 33 studies, 25 focusing on rotavirus and eight on pneumococcal vaccination programs. The most frequent studies were ecological, with time series analysis or comparing pre- and post-vaccination periods. The main data sources were: health information systems; population-, sentinel- or laboratory-based surveillance systems; statistics reports; and medical records from one or few health care services. Few studies used primary data. Hospitalization and death were the main outcomes assessed. CONCLUSIONS Over the last years, a significant number of health impact assessments of pneumococcal and rotavirus vaccination programs have been conducted in Latin America and the Caribbean. These studies were carried out few years after the programs were implemented, meet the basic methodological requirements and suggest positive health impact. Future assessments should consider methodological issues and challenges arisen in these first studies conducted in the region.

Use of MAC-ELISA for evaluation of yellow fever vaccination

An evaluation of the IgM antibody immune response against yellow fever using strain 17D was carried out by MAC-ELISA and PRNT. The results showed an agreement of 97% between both tests and the authors conclude that MAC-ELISA can be used as a specific and sensitive asssay to replace the PRNT for detecting yellow fever antibodies in human sera, after vaccination programs.

Bone mineral density of rat femurs after hindlimb unloading and different physical rehabilitation programs

Bone weakening can occur due to the absence of load on the skeleton or even short periods of decreased physical activity. Therefore, musculoskeletal diseases that involve temporary immobilization by casts, inactivity or tension increases the risk of fractures. Physical activity is the most studied procedure both to prevent damage and to restore bone structure. The present study aimed at evaluating, by bone densitometry on rat femurs, the influence of hindlimb unloading and later running activity on treadmill or free movement. Sixty-four Wistar rats were used, aged 65 days with a mean corporal mass of 316.11g, randomly divided into eight experimental groups: group 1, the suspended control with seven animals under hindlimb unloading regimen for 28 days, then euthanized; groups 2 and 3, the trained suspended comprising of 7 and five animals, respectively, subjected to hindlimb unloading for 28 days, followed by treadmill exercise for 28 days (group 2) or 56 days (group 3), then euthanized; groups 4 and 5, designated free suspended, comprised of 7 animals each under hindlimb unloading regimen for 28 days followed by free activity in cages for 28 days (group 4) or 56 days (group 5), then euthanized; groups 6, 7 and 8, negative controls, each with 8 animals allowed to free activity in cages and euthanized at the ages of 93, 121 and 149 days, respectively. Bone mineral density (BMD) of the left femur was analyzed by bone densitometry. Unloading by tail-suspension decreased BMD while treadmill training and free activity in cages promoted its recovery in a similar way and over time.

Long-term outcomes of school-based treatment for control of urinary schistosomiasis: a review of experience in Coast Province, Kenya

Urinary schistosomiasis remains a significant burden for Africa and the Middle East. The success of population-based control programs will depend on their impact, over many years, on Schistosoma haematobium reinfection and associated disease. In a multi-year (1984-1992) control program in Kenya, we examined risk for S. haematobium reinfection and late disease during and after annual school-based treatment. In this setting, long-term risk of new infection was independently associated with location, age, hematuria, and incomplete treatment, but not with sex or frequency of water contact. Thus, very local environmental features and age-related factors played an important role in S. haematobium transmission, such that population-based control programs should optimally tailor their efforts to local conditions on a village-by-village basis. In 2001-2002, the late benefits of earlier participation in school-based antischistosomal therapy were estimated in a cohort of formerly-treated adult residents compared to never-treated adults from the same villages. Among age-matched subjects, current infection prevalence was lower among those who had received remote therapy. In addition, prevalence of bladder abnormality was lower in the treated group, who were free of severe bladder disease. Treatment of affected adults resulted in rapid resolution of infection and any detectable bladder abnormalities. We conclude that continued treatment into adulthood, as well as efforts at long-term prevention of infection (transmission control) are necessary to achieve optimal morbidity control in affected communities.

Occupational accidents among middle and high school students of the state of São Paulo, Brazil

OBJECTIVES: To estimate the prevalence of occupational injuries and identify their risk factors among students in two municipalities. METHODS: A cross-sectional survey was conducted in public schools of the municipalities of Santo Antonio do Pinhal and Monteiro Lobato, Brazil. A stratified probabilistic sample was drawn from public middle and high schools of the study municipalities. A total of 781 students aged 11 to 19 years participated in the study. Students attending middle and high school answered a comprehensive questionnaire on living and working conditions, as well as aspects of work injuries, and health conditions. Multiple logistic regression models were fitted to estimate risk factors of previous and present occupational injuries. RESULTS: Of 781 students, 604 previously had or currently have jobs and 47% reported previous injuries. Among current workers (n=555), 38% reported injuries on their current job. Risk factors for work injuries with statistically significant odds ratio >2.0 included attending evening school, working as a housekeeper, waiter or brickmaker, and with potentially dangerous machines. CONCLUSIONS: The study results reinforce the need of restricting adolescent work and support communities to implement social promotion programs.

Shiftworking families: parents' working schedule and sleep patterns of adolescents attending school in two shifts

OBJECTIVE: To explore whether parents' engagement in shift work affects the sleep habits of their adolescent children who attend school in two shifts. METHODS: The data were drawn from an extensive survey of sleep and daytime functioning of adolescents attending school one week in the morning and the other in the afternoon. The participants were 1,386 elementary and high school students (11-18 years old) whose parents were both employed. The data were analyzed using MANOVA, with parents' work schedule, adolescents' gender and type of school as between-subject factors. RESULTS: Parents' working schedule significantly affected the sleep patterns of high school adolescents. When attending school in the morning, adolescents whose parents were both day workers woke up somewhat later than adolescents with one shiftworking parent. In addition, they slept longer than adolescents whose parents were both shift workers. On weekends, adolescents whose parents both worked during the day went to bed earlier than adolescents whose parents were both shiftworkers. They also had smaller bedtime delay on weekends with respect to both morning and afternoon shifts than adolescents for whom one or both parents worked shifts. A significant interaction between parents' working schedule, adolescents' gender and type of school was found for sleep extension on weekends after afternoon shift school. CONCLUSIONS: Parental involvement in shift work has negative effects on the sleep of high school adolescents. It contributes to earlier wake-up time and shorter sleep in a week when adolescents attend school in the morning, as well as to greater bedtime irregularity.

Determinants of vaccination after the Colombian health system reform

OBJECTIVE: To assess the effects of individual, household and healthcare system factors on poor children's use of vaccination after the reform of the Colombian health system. METHODS: A household survey was carried out in a random sample of insured poor population in Bogota, in 1999. The conceptual and analytical framework was based on the Andersen's Behavioral Model of Health Services Utilization. It considers two units of analysis for studying vaccination use and its determinants: the insured poor population, including the children and their families characteristics; and the health care system. Statistical analysis were carried out by chi-square test with 95% confidence intervals, multivariate regression models and Cronbach's alpha coefficient. RESULTS: The logistic regression analysis showed that vaccination use was related not only to population characteristics such as family size (OR=4.3), living area (OR=1.7), child's age (OR=0.7) and head-of-household's years of schooling (OR=0.5), but also strongly related to health care system features, such as having a regular health provider (OR=6.0) and information on providers' schedules and requirements for obtaining care services (OR=2.1). CONCLUSIONS: The low vaccination use and the relevant relationships to health care delivery systems characteristics show that there are barriers in the healthcare system, which should be assessed and eliminated. Non-availability of regular healthcare and deficient information to the population are factors that can limit service utilization.

Decay of antibody isotypes against early developmental stages of Schistosoma mansoni after treatment of schistosomiasis patients

Antibodies to a number of parasite antigens are found in schistosomiasis patients, and antibodies to early developmental stages were demonstrated to be efficient immunologic markers for the diagnosis of schistosomiasis. In the present study, decay patterns of IgM and IgG antibodies against cercariae and schistosomula were investigated, in comparison to antibodies against worms and eggs in schistosomiasis patients after chemotherapy, for an investigation of seroepidemiologic aspects. Data obtained in the study of 359 serum samples from patients with Schistosoma mansoni infection, noninfected individuals, and patients followed-up for a period of 12 to 15 months after treatment provided the basis to postulate a general pattern for the kinetics of antibody decay. Before treatment, the antibody pattern was represented by a unimodal curve, which shifted to a bimodal curve after treatment, and ended with a unimodal curve similar to that for the noninfected group. Different types of antibodies were classified into four categories according to their decay features, and anti-schistosomulum IgM was classified into the moderate-decay caterogy, whereas other antibodies to early parasite stages were classified into the slow-decay category. The present methodology permits the identification of the most suitable antibodies to be detected in field control programs for schistosomiasis or other parasitoses

Acute postsurgical suppurative parotitis: current prevalence at Hospital das Clínicas, São Paulo University Medical School

Postsurgical acute suppurative parotitis is a bacterial gland infection that occurs from a few days up to some weeks after abdominal surgical procedures. In this study, the authors analyze the prevalence of this complication in Hospital das Clínicas/São Paulo University Medical School by prospectively reviewing the charts of patients who underwent surgeries performed by the gastroenterological and general surgery staff from 1980 to 2005. Diagnosis of parotitis or sialoadenitis was analyzed. Sialolithiasis and chronic parotitis previous to hospitalization were exclusion criteria. In a total of 100,679 surgeries, 256 patients were diagnosed with parotitis or sialoadenitis. Nevertheless, only three cases of acute postsurgical suppurative parotitis associated with the surgery were identified giving an incidence of 0.0028%. All patients presented with risk factors such as malnutrition, immunosuppression, prolonged immobilization and dehydration. In the past, acute postsurgical suppurative parotitis was a relatively common complication after major abdominal surgeries. Its incidence decreased as a consequence of the improvement of perioperative antibiotic therapy and postoperative support. In spite of the current low incidence, we believe it is important to identify risks and diagnose as quick as possible, in order to introduce prompt and appropriate therapeutic measures and avoid potentially fatal complications with the evolution of the disease.

Prevalence of pediculosis capitis in children from a rural school in Yucatan, Mexico

We conducted an analytical cross-sectional survey to estimate the prevalence of and factors associated with active head lice infestation. In total 140 children, aged 6 to 16-years, from a public school in rural Yucatan, Mexico, were examined by wet-combing. A structured questionnaire was used to collect information on individuals and the conditions in the surrounding environment. Head lice infestation was found in 19 out of the 140 children tested (13.6%) and this was associated with both lower income (OR 9.9, 95% CI 2.15-45.79, p = 0.003) and a higher frequency of hair washing (OR 8, 95% CI 1.58-50, p = 0.012). Intersectoral control programs that take into account the socioeconomic differences of children should be implemented.

Control of parasitic infections among school children in the peri-urban area of Botucatu, São Paulo, Brazil

Tide prevalence of intestinal parasitosis ivas investigated in a primaiy school located in Rubiâo Júnior, a peri-urban district of Botucatu, São Paulo slate, Brazil, in order to assess the effect of treatment and practical measures of prophylaxis in the control of parasitic infections among 7-to- 18-year-old school children of a low socio-economic status. The first series of parasitological examinations included 219 school children, ef which 123 (56.1 %) were found to be infected with one or more parasite species. Eighty- four children canying pathogenic parasites were submitted to various anti-parasitic treatment schedules. We re-evaluated 15 (89 %) students after 4 to 6 months post- chemotherapy. The results indicate that the combination of treatment with prophylactic measures has been successful in the control of parasitic infections, since reinfection rates were generally low (< 5-3 %), except for Giardia lamblia infections (18.6 %), and a marked reduction oti the prevalence rates was obsewed with a significant percentage of cure (> 73-1 %) in children infected with most parasite species. The reasons for the apparent failure in the control of infections caused by Hymenolepis nana and Strongyloides stercoralis are discussed.

Histopathology of human American cutaneous leishmaniasis before and after treatment

Chemical therapy for the treatment of leishmaniasis is still inadequate, and a number of drugs and therapeutic programs are being tested. Besides treatment, the ultimate goal is an effective cure, and histopathological analyses of the lesion cicatrices constitute an important measure of treatment success, or otherwise, in this respect. In this paper, we describe histopathological patterns in cases of American cutaneous leishmaniasis in 32 patients from the municipality of Caratinga, Minas Gerais, Brazil, before and after treatment with the following therapeutic methodos: l) leishvacin + glucantime; 2) leishvacin + BCG associated with glucantime; 3) glucantime; 4) leishvacin + BCG. Lesion fragments were collected from all patients by biopsy prior to, and approximately 30 days after, each treatment which resulted in a clinical diagnosis of cure. Following the analysis of slides, the preparations were described from a histopathological point of view and grouped taking into account the prevalence or significance of the characteristic elements. This process resulted in the following classification: 1. exsudative reaction (ER); 2. exsudative giant cell reaction (EGCR); 3. exsudative productive reaction (EPR); 4. exsudative productive giant cell reaction (EPGCR); 5. exsudative productive necrotic reaction (EPNR); 6. necrotic exsudative reaction (NER); 7. productive exsudative reaction (PER), 8. productive giant cell reaction (PGCR); 9. productive exsudative giant cell reaction (PEGCR); 10. productive exsudative giant cell granulomatous reaction (PEGCGR); 11. productive reaction (PR) and 12. productive cicatricial (cure) reaction (PCR). After this analysis, it was noted that clinical cure did not always coincide with histopathological cure.

Education in primary school as a strategy to control dengue

The proliferation of Aedes aegypti, a species of mosquito that is the vector of the dengue pathogen, is being augmented by the population's lack of care in allowing the formation of larval habitats. One form of controlling dengue is the distribution of information on the mosquito to improve awareness and to provide the means necessary for the elimination of its reproductive habitats. To evaluate a teaching method concerning the vector and dengue, students from the 5th and 6th years of primary education were compared before and after didactic intervention with a group of control students. The students who received intervention were more successful in identifying the stages of the cycle, biological and morphological characteristics of the adult insect and the importance of the mosquito in health issues. The didactic intervention was successful in developing knowledge leading to increased awareness of the importance of preventative measures that should be taken against the vector and the disease.

Retrospective study of the occurrence of Cyclospora cayetanensis at Clinical Hospital of the University of São Paulo Medical School, SP

Cyclospora cayetanensis causes watery diarrhea in tropical countries, among travelers and after ingestion of contaminated water and food. Very little is known about its epidemiology, pathogenic aspects and reservoirs. In Brazil, its prevalence is unknown and to date there have been reports of three outbreaks. We report here a retrospective study of 5,015 stool samples from 4,869 patients attended at Clinical Hospital of the University of São Paulo Medical School, SP, Brazil between April 1996 and January 2002, with 14 cases of Cyclospora cayetanensis being detected there was a prevalence of 0.3%. Of the 14 infected patients, the mean age was 38 years and 71.4% were female. Ten patients presented symptoms; six presented levels of immunological markers and five patients were immunodeficient.

Resistance Training After Myocardial Infarction in Rats: Its Role on Cardiac and Autonomic Function

Background: Although resistance exercise training is part of cardiovascular rehabilitation programs, little is known about its role on the cardiac and autonomic function after myocardial infarction. Objective: To evaluate the effects of resistance exercise training, started early after myocardial infarction, on cardiac function, hemodynamic profile, and autonomic modulation in rats. Methods: Male Wistar rats were divided into four groups: sedentary control, trained control, sedentary infarcted and trained infarcted rats. Each group with n = 9 rats. The animals underwent maximum load test and echocardiography at the beginning and at the end of the resistance exercise training (in an adapted ladder, 40% to 60% of the maximum load test, 3 months, 5 days/week). At the end, hemodynamic, baroreflex sensitivity and autonomic modulation assessments were made. Results: The maximum load test increased in groups trained control (+32%) and trained infarcted (+46%) in relation to groups sedentary control and sedentary infarcted. Although no change occurred regarding the myocardial infarction size and systolic function, the E/A ratio (-23%), myocardial performance index (-39%) and systolic blood pressure (+6%) improved with resistance exercise training in group trained infarcted. Concomitantly, the training provided additional benefits in the high frequency bands of the pulse interval (+45%), as well as in the low frequency band of systolic blood pressure (-46%) in rats from group trained infarcted in relation to group sedentary infarcted. Conclusion: Resistance exercise training alone may be an important and safe tool in the management of patients after myocardial infarction, considering that it does not lead to significant changes in the ventricular function, reduces the global cardiac stress, and significantly improves the vascular and cardiac autonomic modulation in infarcted rats.