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Estimates of the incidence of pulmonary tuberculosis in developing countries are based on case reporting from local health laboratories or the annual risk of tuberculin skin test conversion. Because these methods are problematic, the authors used a multiple case ascertainment method to estimate the incidence of pulmonary tuberculosis from 1989 to 1993 in a Peruvian shantytown of 34,000 inhabitants. Two methods, face-to-face interview of all local inhabitants and examination of local laboratory smear records, were used for case gathering. The number of missed cases was estimated by capture-recapture analysis. Survey cases with positive smears were matched to age- and sex-matched controls and interviewed about socioeconomic conditions. The average annual incidence per 100,000 population was 364 (95% confidence interval 293-528) by capture-recapture methods. For the city encompassing the shantytown, the Peruvian Ministry of Heath reported an average annual incidence of 134 cases per 100,000 population. The authors conclude that, in Peru, alarming clusters of pulmonary tuberculosis are masked by government reports that pool zones of disparate incidence. Existing estimators of pulmonary tuberculosis incidence based on tuberculin conversion rates may be invalid in such areas. Within these hyperendemic areas, persons suitable for intensive prophylaxis efforts cannot be reliably identified by housing and socioeconomic risk factors.A multiple case ascertainment method was used to estimate the incidence of pulmonary tuberculosis in 1989-93 in a shantytown with 34,000 residents near Lima, Peru. Face-to-face interviews with all residents yielded 191 reports of smear-positive tuberculosis diagnoses at shantytown laboratories and 97 diagnoses from out-of-town laboratories during the study period. Local laboratory smear records identified 354 positive smears, confirming the oral reports of 139 residents (73%) who reported diagnoses at local laboratories. The number of missed cases was estimated by capture-recapture analysis. An average annual incidence of 364 pulmonary tuberculosis cases per 100,000 population was calculated. In contrast, an average annual incidence of 134 cases/100,000 was reported by the Peruvian Ministry of Health for the city (South Lima) encompassing the shantytown. For hyperendemic areas such as shantytowns, various household and socioeconomic factors have been proposed as screening tools to identify those at risk of tuberculosis and in need of chemoprophylaxis. Survey cases with positive smears were matched with controls by age and sex and interviewed about socioeconomic conditions. Logistic regression analysis identified three socioeconomic factors that were protective against pulmonary tuberculosis: a longer residence in the shantytown (odds ratio (OR), 0.91/year; 95% confidence interval (CI), 0.82-0.99), a larger number of doors in the home (OR, 0.80/door; 95% CI, 0.70-0.93), and recent consumption of alcohol (OR, 0.61; 95% CI, 0.29-1.01). The positive predictive value of a model comprised of these three factors was below 1%, however. These findings indicate that clusters of tuberculosis cases in areas such as shantytowns may be masked by their proximity to areas of lower incidence in the absence of special case finding efforts.

A miniaturized radionuclide cardiac probe incorporated in a semi-rigid plastic chest garment has made ambulatory left ventricular (LV) function evaluation possible, with gated nuclear data being stored on tape together with electrocardiographic data, for subsequent off-line processing. After red blood cell labelling with 555 MBq (15 mCi) 99mTc and standard gated blood pool imaging in 45 degrees LAO, we performed a continuous monitoring of LV function in 20 healthy male volunteers (age range: 22-25 years), in resting control conditions as well as during activities (standing, walking, climbing stairs) and after interventions (isosorbide dinitrate intake, Trendelenburg position, inflation of cuffs around the thighs). VEST-monitoring proved to be a reliable method that gave reproducible results: changes of ejection (EF) in basal conditions were lower than 5% in 95% of the patients. Changes in LV function caused by daily activities were easily demonstrated. While standing effected no significant EF changes, walking and climbing increased EF by 6.9% (p less than 0.05) and 21.2% (p less than 0.05) respectively. Changes in LV volumes caused by alterations in venous return were also demonstrated. Compared with baseline, Trendelenburg increased end-diastolic volume (EDV) by 2.9% while isosorbide dinitrate and inflation of cuffs decreased it by 5.7% and 2.2% respectively.

The Food and Nutrition Research Institute (FNRI) of the Department of Science and Technology (DOST), as in the past, led the review and revision of the 1989 Recommended Dietary Allowances (RDAs) for Filipinos, a vital and essential tool recognized in the nutrition and health community as the source of information on recommended energy and nutrient intakes for the maintenance of good health. This set of dietary standards is periodically evaluated and updated to keep pace with new knowledge on energy and nutrient requirements and metabolism. The set of updated standards is now called Recommended Energy and Nutrient Intakes (RENIs), defined as levels of intakes of energy and nutrients which, on the basis of current scientific knowledge, are considered adequate for the maintenance of good health and well-being of nearly all healthy Filipinos. As in the 1989 edition, intakes of energy, protein, calcium, phosphorus, iron, iodine, zinc, vitamins A, C, D and E, thiamin, riboflavin, niacin, folate, pyridoxine, water and electrolytes (sodium, potassium, chloride) are recommended in this new edition. The desirable proportions of protein, fats, carbohydrates as well as fiber are also provided, in addition to information on recommended intake levels for selenium, magnesium, manganese, fluoride, cobalamin, and vitamin K. These recommendations were derived from a review of current evidences, principally the UN-FAO/WHO's 2002 human vitamin and mineral requirements and the US-Institute of Medicine-Food and Nutrition Board (IOM-FNB)'s series of Dietary Reference Intakes, taking into consideration applicability in and achievability among specific population groups.

Issues and opportunities for RDA harmonization within the SEA region were first raised during the First Regional Forum and Workshop "RDAs: Scientific Basis and Future Directions", held in Singapore in March 1997. A regional review on RDAs in SEA showed general similarities for the different RDAs, although in some cases a country listed an exceptionally high or low RDA for a particular nutrient for a specific group. It also revealed differences in physiologic groupings and reference body weights, nutrients included and units of expression. Realizing these differences in RDA components between countries which makes technical composition different, a consensus on the need for regional collaboration and harmonization of RDAs was reached by participants from Indonesia, Malaysia, Philippines, Singapore, Thailand and Vietnam. A follow-up workshop was organized to work towards agreement throughout the region on common approaches, concepts and terminologies; application and uses, format and a research agenda. Round table discussions were held to arrive at specific recommendations for achieving harmonization. While divergence in opinions were expected, some clear-cut agreements were settled. Globalization envisions to achieve economic growth and development, with the effects expected to ripple through health, nutrition and welfare improvements. The harmonization of RDAs in SEA seeks to reach this vision by strengthening R and D capabilities (both logistic and manpower) within the region and within the countries in the region, as well as harmonizing the efforts of governments and industry within the region to reduce potential trade barriers such as those relating to food and nutrition quality assurance standards.

The protein quality of typical rice-based menu of Filipino preschool child and adult and cooked milled rice was assessed for true digestibility (TD), biological value (BV) and net protein utilization (NPU) in growing rats. Lysine and energy digestibilities were also determined. For the preschool child diet, TD was 88.8%, BV 90.0%, and NPU 79.9%. For the adult diet, TD was 87.3%, BV 86.6%, and NPU 75.5%, whereas cooked rice had 90.0% TD, 82.5% BV and 74.3% NPU. Lysine digestibility was 95.4% for preschool child diet, 95.7% for adult diet, and 100.0% for rice. Digestible energy was 91.3% for preschool child diet, 93.0% for adult diet, and 95.3% in rice. Amino acid scores were 100.0% for preschooler diet, 92.1% for adult diet, and 62.2% for rice. Protein quality based on amino acid score corrected for TD was 88.8% for preschool child diet. 80.4% for adult diet, and 56.0% for rice. If based on lysine digestibility instead of TD, protein quality would be 7.1% higher.

Adult Onchocerca gibsoni worms were fractionated into a surface-enriched fraction, a saline extract, a saline insoluble-detergent soluble fraction and a total glycoproteins extract. The antigens in each fractions were separated by electrophoresis in polyacrylamide gels and examined with an immuno-blot technique for reactive antibodies in sera from individuals infected with a variety of filarial and non-filarial nematode worms. Radiolabelled monoclonal antibodies were used to determine the Ig heavy chain isotypes. A number of antigens were demonstrated in all of the extracts, with many antigens of each extract being unique. Although some Onchocerca antigens stimulated antibodies of all human immunoglobulin classes, the panel of antigens recognized by each Ig isotype was different. The IgE response was restricted and directed at antigens not recognized by antibodies to other nematode parasites. IgM and IgA responses tended to recognize many antigens, whilst IgG responses were directed at intermediate numbers of antigens. The control of isotype balance to individual parasite antigens is thus independently regulated. This survey provides a rational basis for the exploration of Onchocerca antigen-human antibody class systems with relevance for diagnosis, protection and pathology.

Summary A surface enriched fraction was prepared from adults of Onchocerca volvulus by brief extraction of entire worms with detergent. This was then gel filtered to yield a low molecular weight fraction which functioned specifically in ELISA analysis. An identical result was also obtained when the related cattle parasite, O. gibsoni, was similarly fractionated and tested. The low molecular weight fraction contained at least four antigenic components when examined by coprecipitation and immunoblotting studies. One ml of packed worms yielded sufficient low molecular weight antigen to examine about 2000 human sera by the ELISA procedure, and the test was sensitive at human serum dilutions down to 1/400. A preliminary study with individual sera from Onchocerciasis endemic and non-endemic areas of Southern Mexico yielded 0/24 false positives, 3/24 false negatives and a significant ELISA value in 21/24 sera from proven cases of Onchocerciasis.

Specific diagnosis of antibodies to Onchocerca was achieved through (1) the construction of direct and indirect ELISA systems, and (2) restricting ELISA assays to the IgG4 class. The direct ELISA was based on the isolation of a surface derived, low molecular weight surface antigen preparation containing two main antigens (M. wt. 16.2 and 12.8 kDA) as defined by Western blot analysis. The direct ELISA system detected antibodies in children of six years old, and may therefore be applicable to detecting reinvasion in OCP areas of Onchocerca volvulus control. The indirect ELISA system was a competitive binding ELISA-based assay using a monoclonal antibody recognising two Onchocerca components (M. wts. 15.6 and 25.9) on a Western blot. The direct and indirect ELISA systems were similarly specific and sensitive when evaluated in a preliminary survey. The direct ELISA system yielded a specificity and sensitivity of: 100% and 100% respectively, using Mexican endemic and Mexican intestinal nematode infection sera as positive and negative controls respectively: 91% and 96% respectively, using Venezuelan endemic and Venezuelan Mansonella ozzardi infection sera as positive and negative controls, respectively: 87% and 93% respectively, using African endemic and Papuan (New Guinea) Wuchereria bancrofti infection sera as positive and negative controls respectively: 93% and 93% respectively, using African endemic and Indian W. bancrofti infection sera as positive and negative controls respectively. Similar specificity and sensitivity levels were obtained when the same comparisons were made using the indirect (inhibition) ELISA assay. These values may be contrasted with the currently used PBS extract of O. volvulus which yielded specificities of less than 10% in all the above comparisons.(ABSTRACT TRUNCATED AT 250 WORDS)

A thorough study of parasite antigens is a prerequisite for control programmes based on protection by vaccination, accurate serodiagnosis and perhaps immune modulation to diminish pathological sequelae. Stage specific surface secreted and somatic antigens may be of particular value in proceeding towards these goals. The design of vaccines is most appropriately focused on surface antigens. With respect to pathology, certain antigens must stimulate humoral and, or cellular immune responses which are responsible for the undesirable immunopathologic consequences of the disease. The ultimate objective, therefore, is identification of those particular antigens followed by appropriate down regulation of the immune system in order to delete such potentially harmful immunological reactions. The relevant illustration presented in this context is an interesting correlation between one particular clinical condition of onchocerciasis (“sowda”) and the serological response, defined both in terms of the parasite antigen and an immunoglobulin class restricted antibody response. Current parasitological methods of diagnosis consistently underestimate parasite prevalence. Failure to detect low level patent infections incurs the risk of having a reservoir capable of perpetuating infections. There is, then, an urgent requirement for accurate serodiagnosis, to be used in association with, and for the evaluation of, drug treatment and vector elimination in parasite control programmes. Given the high sensitivity of current immunoassay technology, the only bar to establishing the necessary immunological tests is the choice of suitably specific antibody-antigen systems. Once these are identified, a combination of recombinant nucleic acid biochemistry and hybridoma technology should provide the necessary reagents for inexpensive, robust and specific diagnostic tests. In addition, it may not be many years beore the ubiquitous RIA and ELISA technology gives way to the newly developing biosensor systems. Finally, given the sensitivity and specificity of today's nucleic acid hybridization techniques, we may soon expect to see specific identification of infective larvae in their vectors of this, a cloned DNA probe specific for Onchocerca volvulus , and with potential for the detection of infective larvae in blackflies is described.