Survival of Ascaris eggs and hygienic quality of human excreta in Vietnamese composting latrines

<p>Abstract</p> <p>Background</p> <p>For centuries farmers in Vietnam have fertilized their fields with human excreta collected directly from their household latrines. Contrary to the official guideline of six-month storage, the households usually only store human excreta for three to four months before use, since this is the length of time that farmers have available to produce fertilizer between two cropping seasons. This study aimed to investigate whether hygienically safe fertilizer could be produced in the latrines within this period of time.</p> <p>Methods</p> <p>By inoculating eggs of the helminth parasite indicator <it>Ascaris suum </it>into heaps of human excreta, a die-off experiment was conducted under conditions similar to those commonly used in Vietnamese latrines. Half a ton of human excreta was divided into five heaps containing increasing concentrations of lime from 0% to 11%.</p> <p>Results</p> <p>Regardless of the starting pH, which varied from 9.4 to 11.6, a >99% die-off of eggs was obtained after 105 to 117 days of storage for all lime concentrations and 97% of eggs were non-viable after 88 days of storage. The most critical parameter found to determine the die-off process was the amount of ammonia (urine) in the excreta which indicates that longer storage periods are needed for parasite egg die-off if urine is separated from the excreta.</p> <p>Conclusion</p> <p>By inactivating >99% of all <it>A</it>. <it>suum </it>eggs in human excreta during a storage period of only three months the commonly used Double Vault Composting (DVC) latrine, in which urine is not separated, could therefore potentially provide a hygienic acceptable fertilizer.</p

A 6 year Geohelminth infection profile of children at high altitude in Western Nepal

<p>Abstract</p> <p>Background</p> <p>Geohelminth infections are a major problem of children from the developing countries. Children with these infections suffer from developmental impairments and other serious illnesses. This study aimed to measure the prevalence of geohelminth infection, infection intensity as well as the change in the intensity in children from Western Nepal over years.</p> <p>Methods</p> <p>This 6-year hospital based prospective study at the Manipal Teaching Hospital, Pokhara included children (< 15 years) visiting the hospital from Kaski and 7 surrounding districts. Samples were also collected from children in the community from different medical camps. Three stool samples from every child were processed using direct and concentration methods. The Kato-Katz technique was used for measuring the intensity of infection.</p> <p>Results</p> <p>The overall prevalence in hospital - attending children was 9.2% with 7.6% in preschool (0 – 5 y) and 11.0% in school-age (6 – 15 y) children, and in community 17.7% with 14.8% in pre-school and 20.5% in school-age children. <it>Ascaris lumbricoides</it>, <it>Trichuris trichiura</it>, <it>Ancylostoma deodenale </it>and <it>Strongyloides stercoralis </it>were the common geohelminths with a gradual decrease in worm load over the years. School-age children were found to be significantly more prone to geohelminth infection as compared to preschool children, but no statistical difference was detected by gender, district as well as season.</p> <p>Conclusion</p> <p>This heavy infection of geohelminths in children should be corrected by appropriate medication and maintaining strict personal hygiene. Health education, clean water, good sewage management and a congenial environment should be ensured to minimise infection.</p

Early diagnosis of hemoglobinopathies

Antibodies specific for human hemoglobins F, A, S, and C were isolated by affinity chromatography from antisera produced in rabbits and goats. These reagents were shown to possess adequate sensitivity for identifying and quantifying hemoglobins A, S, and C in cord blood by radial immunodiffusion (RID). Furthermore, single immunodiffusion plates combining up to three of the antibodies at differing concentrations produced up to three nonoverlapping immunoprecipitin rings, retaining the capability for identifying multiple hemoglobins by a single application of hemolyzed whole blood to the RID plate. Isolated antibodies were conjugated with fluorescein isothiocy- anate and incubated with red blood cells which were obtained from placental cord blood or from amniotic fluid obtained by amniocentesis and maternal venous blood at 16-20 weeks of gestation, and suspended in a thin layer of agar. Using antibodies against hemoglobins F, A, and S this method proved to possess sufficient sensitivity for detecting each of the respective hemoglobins in individual cells in all of the above classes of specimens. Since the red blood cells obtained by amniocentesis are potentially a mixture of fetal and maternal cells the proportion of F cells to A cells in amniotic fluid and in maternal venous blood were estimated. In 33 such sequential specimen pairs, 29 contained a higher F cell to A cell ratio in amniotic fluid than in maternal blood. Red blood cells from maternal blood and from amniotic fluid were incubated in vitro with L-[14C]serine. Incorporation of the serine into cells was identified by autoradiography. Since a substantial proportion of fetal red blood cells are synthetically active this provides a method for identifying hemoglobin phenotype in fetal-origin cells in a fetal-maternal mixture. Initial experience with a short series of specimens examined in this manner indicates that in amniotic fluid the proportion of cells which contain both hemoglobin and L-[14C]serine is typically higher than in maternal venous blood. Diagnostic accuracy for hemoglobin phenotypes of the fetus by the combination of autoradiography and fluorescent cytoimmunodiffusion is being tested currently in a substantial unselected sample of amniotic fluid specimens. Criteria for definitive diagnosis of SS phenotype in the fetus are fluorescent anti-S pattern in synthetically active cells, absence or rare occurrence of fluorescent anti-A pattern in such active cells, and a higher relative frequency of synthetically active F cells in amniotic fluid than in maternal blood. © 1978 International Pediatric Research Foundation, Inc