Methods to evaluate nutritional and economic implications of Ascaris infection

Prevalence of intestinal parasitic infections in certified food-handlers working in food establishments in the City of Nairobi, Kenya

Most intestinal parasites are cosmopolitan with the highest prevalence in the tropics and subtopics. Rural-to-urban migration rapidly increases the number of food eating places in towns and their environs. Some of these eating estabishments have poor sanitation and are overcrowded, facilitating disease transmission, especially through food-handling. Our investigations in Nairobi, therefore, were set to determine the presence of intestinal parasites in food-handlers with valid medical certificates. Direct and concentrated stool processing techniques were used. Chisquare test and ANOVA were used for data analysis. The parasites Ascaris lumbricoides, Entamoeba histolytica and Giardia lamblia were observed in certified food-handlers. Significant difference was found in parasite frequency by eating classes and gender (χ² = 9.49, P = 0.73), (F = 1.495, P = 0.297), but not in parasite occurrence between age brackets (χ² = 6.99, P = 0.039). The six-month medical certificate validity period may contribute significantly to the presence of intestinal parasites in certified food-handlers.

Neglected diseases of neglected populations: thinking to reshape the determinants of health in Latin America and the Caribbean

BACKGROUND

People living in poverty throughout the developing world are heavily burdened with neglected communicable diseases and often marginalized by the health sector. These diseases are currently referred to as Neglected Diseases of Neglected Populations. The neglected diseases create social and financial burdens to the individual, the family, the community, and the nation.

DISCUSSION

Numerous studies of successful individual interventions to manage communicable disease determinants in various types of communities have been published, but few have applied multiple interventions in an integrated, coordinated manner. We have identified a series of successful interventions and developed three hypothetical scenarios where such interventions could be applied in an integrated, multi-disease, inter-programmatic, and/or inter-sectoral approach for prevention and control of neglected diseases in three different populations: a slum, an indigenous community, and a city with a mix of populations.

SUMMARY

The objective of this paper is to identify new opportunities to address neglected diseases, improve community health and promote sustainable development in neglected populations by highlighting examples of key risk and protective factors for neglected diseases which can be managed and implemented through multi-disease-based, integrated, inter-programmatic, and/or inter-sectoral approaches. Based on a literature review, analysis and development of scenarios we visualize how multiple interventions could manage multiple disease problems and propose these as possible strategies to be tested. We seek to stimulate intra- and inter-sectoral dialogue which will help in the construction of new strategies for neglected diseases (particularly for the parasitic diseases) which could benefit the poor and marginalized based on the principle of sustainability and understanding of key determinants of health, and lead to the establishment of pilot projects and activities which can contribute to the achievement of the Millennium Development Goals.

The problem and control of gastrointestinal helminthiases in Zimbabwe

An overview of the problem of gastrointestinal (GI) helminthiases in Zimbabwe is given in terms of prevalence, distribution, clinical significance of individual parasites and their transmission patterns. Although data on these aspects are incomplete, the available information and the results of studies conducted elsewhere should assist in the planning and implementation of effective helminthiasis intervention strategies. Community-based integrated helminthiasis control measures that include mass chemotherapy, improved sanitation and health education are considered to be the most practical interventions and are being evaluated in Zimbabwe. This community-based approach is cost-effective, as most of the control measures are carried out on a self-help basis. Besides, local voluntary health committees provide consistent community-level surveillance to promote and motivate the population to join in the intervention measures that include improved sanitation and health education, aspects which have broader implications for improved health.

Contributions of ascariasis to poor nutritional status in children from Chiriqui Province, Republic of Panama

Relationships between ascariasis and lactose digestion and between ascariasis and food transit time from mouth to caecum were investigated in young children from Chiriqui Province, Republic of Panama. The breath hydrogen method was used in both studies. Ascaris-infected children showed a significantly poorer degree of lactose digestion following a test oral load than uninfected children. Recovery of the capacity of the children to digest lactose was still not fully complete for at least 3 weeks following anthelmintic treatment. On average, the mouth-to-caecum transit time was similar in infected and uninfected children, but among the Ascaris-infected children the transit time tended to be shorter in relation to the intensity of infection. Evidence from a cross-sectional survey indicated that ascariasis was significantly associated with reduced plasma vitamin A and carotenoid concentrations. This relationship remained after controlling for a range of socio-economic variables. Ascaris-infected children were frequently found to have lower haematocrits and blood haemoglobin concentrations than uninfected children, but these relationships could not be attributed to ascariasis alone.

Nutritional aspects of infection

Current knowledge is examined about the means whereby ascariasis, hookworm disease, strongyloidiasis and trichuriasis may contribute to the aetiology of human malnutrition. Results from experiments with related parasites in the laboratory have demonstrated the role of gastrointestinal helminthiases in animal malnutrition. Some evidence shows that in children, infection with the intestinal stages of Ascaris lumbricoides is associated with reduced growth rate, disturbed nitrogen balance, malabsorption of vitamin A, abnormal fat digestion, lactose maldigestion and an increased intestinal transit time. The main impact of hookworm infection is its relationship with iron-deficiency anaemia which may have effects at the community level as regards work and productivity in adults and learning and school performance in children. More research is needed to extend knowledge of the nutritional impact of ascariasis and hookworm disease in order to establish their public health significance. Research is needed also to identify the range of nutritional effects on man that occur as a result of trichuriasis and strongyloidiasis. The significance of less prevalent and more localized gastrointestinal helminthiases should not be ignored.

Chronic ascariasis and malnutrition

Malnutrition is the most widespread ill of mankind. Its global distribution coincides indistinguishably with that of the common roundworm. Ascaris lumbricoides is common - infecting about one-quarter of the world's population. Acute clinical ascariasis sometimes requires hospital treatment, but chronic infections contribute to long-term malnutrition. This alone should justify greater expenditure on the treatment and control of Ascaris.