Hymenolepis nana is the most common cestode reported in humans worldwide. It is prevalent among children in the tropics and subtropics, particularly in rural poor communities where sanitation is inadequate or lacking. This cross-sectional study aims to determine the prevalence and significant risk factors of H. nana infection among children in rural Yemen. Faecal samples were collected from 498 children and screened for intestinal parasites by using wet mount, formalin-ether concentration and Kato-Katz techniques. A pretested questionnaire was used to collect demographic, socioeconomic, housing condition, and personal hygiene information. Overall, 77.5 % (386/498) of the children were found to be infected by at least one intestinal parasite species. The overall prevalence of H. nana was 17.5 % (87/498). Multivariate analysis confirmed that an age of < 6 years (adjusted odds ratio [AOR] = 4.28; 95 % (confidence interval [CI] = 2.04, 8.98), presence of other family members infected with H. nana (AOR = 2.48; 95 % CI = 1.45, 4.24), living in the highlands (AOR = 2.87; 95 % CI = 1.56, 5.26), living in a house without improved toilet facilities (AOR = 2.19; 95 % CI = 1.23, 3.88), not washing vegetables before consumption (AOR = 2.11; 95 % CI = 1.06, 4.19), and not washing hands after defecation (AOR = 1.88; 95 % CI = 1.08, 3.27) were the key factors significantly associated with H. nana infection among the studied children. In conclusion, H. nana is prevalent among children in rural Yemen, particularly among preschool-aged children. Thus, an integrated and effective programme to control intestinal parasitic infections should include preschool-aged children. Such a programme should focus on providing health education on hygienic practices, providing adequate sanitation and improved sources of drinking water, and screening and treating other infected family members.
Polyelectrolyte-complex bilayer membrane (PCBM) was fabricated using biodegradable chitosan and alginate polymers for subsequent application in the treatment of bathroom greywater. In this study, the properties of PCBMs were studied and it was found that the formation of polyelectrolyte network reduced the molecular weight cut-off (MWCO) from 242kDa in chitosan membrane to 2.71kDa in PCBM. The decrease in MWCO of PCBM results in better greywater treatment efficiency, subsequently demonstrated in a greywater filtration study where treated greywater effluent met the household reclaimed water standard of <2 NTU turbidity and <30ppm total suspended solids (TSS). In addition, a further 20% improvement in chemical oxygen demand (COD) removal was achieved as compared to a single layer chitosan membrane. Results from this study show that the biodegradable PCBM is a potential membrane material in producing clean treated greywater for non-potable applications.
Mothers' recall data collected in Malaysia in 1976-1977 are analyzed to study correlates of mortality of 5471 infants. Respondent population is 1262 women living in 52 primary sampling units of Peninsular Malaysia. Lengths of unsupplemented and supplemented breastfeeding and presence of piped household water and toilet sanitation are related to infant mortality in regressions that also control other correlates. The analysis is disaggregated into three periods of infancy. Through six months of feeding, unsupplemented breastfeeding is more strongly associated with fewer infant deaths than is supplemented breastfeeding. Type of sanitation is generally more strongly associated with mortality than is type of water supply. The effects of breastfeeding and the environmental variables are shown to be strongly interactive and to change systematically during the course of infancy. Breastfeeding is more strongly associated with infant survival in homes without piped water or toilet sanitation. In homes with both modern facilities, supplemented breastfeeding has no significant effect, and unsupplemented breastfeeding is statistically significant only for mortality in days 8-28. Presence of modern water and sanitation systems appears unimportant for mortality of infants who are breastfed without supplementation for six months.
The effect of toilets, piped water, and maternal literacy on infant mortality was analyzed using data from the Malaysian Family Life Survey collected in 1976-1977. The effect of toilets and piped water on infant mortality was dependent on whether or not mothers were literate. The impact of having toilets was greater among the illiterate than among the literate, but the impact of piped water was greater among the literate than among the illiterate. The effect on the infant mortality rate for toilets decreased from 130.7 +/- 17.2 deaths in the absence of literate mothers to 76.2 +/- 25.9 deaths in the presence of literate mothers. The reduction in the mortality rate for maternal literacy dropped from 44.4 +/- 14.1 deaths without toilets to -10.1 +/- 23.9 deaths with toilets. Reductions in mortality rates for piped water increased from 16.7 +/- 12.7 deaths without literate mothers to 36.8 +/- 21.0 deaths with literate mothers. Similarly, reductions in the mortality rate for maternal literacy rose from 44.4 +/- 14.1 deaths in the absence of piped water to 64.5 +/- 19.5 deaths in the presence of piped water. The results from a logistic model provided inferences similar to those from ordinary least squares. The authors infer that literate mothers protect their infants especially in unsanitary environments lacking toilets, and that when piped water is introduced, they use it more effectively to practice better hygiene for their infants.