Contribution of Wastewater Irrigation to Soil Transmitted Helminths Infection among Vegetable Farmers in Kumasi, Ghana.

Wastewater irrigation is associated with several benefits but can also lead to significant health risks. The health risk for contracting infections from Soil Transmitted Helminths (STHs) among farmers has mainly been assessed indirectly through measured quantities in the wastewater or on the crops alone and only on a limited scale through epidemiological assessments. In this study we broadened the concept of infection risks in the exposure assessments by measurements of the concentration of STHs both in wastewater used for irrigation and the soil, as well as the actual load of STHs ova in the stool of farmers and their family members (165 and 127 in the wet and dry seasons respectively) and a control group of non-farmers (100 and 52 in the wet and dry seasons, respectively). Odds ratios were calculated for exposure and non-exposure to wastewater irrigation. The results obtained indicate positive correlation between STH concentrations in irrigation water/soil and STHs ova as measured in the stool of the exposed farmer population. The correlations are based on reinfection during a 3 months period after prior confirmed deworming. Farmers and family members exposed to irrigation water were three times more likely as compared to the control group of non-farmers to be infected with Ascaris (OR = 3.9, 95% CI, 1.15-13.86) and hookworm (OR = 3.07, 95% CI, 0.87-10.82). This study therefore contributes to the evidence-based conclusion that wastewater irrigation contributes to a higher incidence of STHs infection for farmers exposed annually, with higher odds of infection in the wet season.

[Investigation on prevalence and risk factors of HIV/AIDS and Schistosoma japonicum, Ascaris lumbricoides and Trichuris trichiura infections in a rural community of southwestern China].

OBJECTIVE: To investigate the prevalence and risk factors of helminthic infections including Schistosoma japonicum, Ascaris lumbricoides and Trichuris trichiura and human immunodeficiency virus (HIV), and find out the association among them in a rural community of southwestern China. METHODS: A community-based cross sectional study was conducted. One town was selected randomly; the infections of S.japonicum, A.lumbricoides and T.trichiura were detected with the modified Kato-Katz thick smear method and HIV infection with the diagnostic Test Kit among all residents. A questionnaire survey was conducted to investigate the related risk factors. RESULTS: Among the participants, the infection rates of HIV, S.japonicum, A.lumbricoides and T.trichiura were 2.33%, 2.05%, 13.47% and 30.59% respectively; 7.08% (31/438) were infected with both A.lumbricoides and T.trichiura; 0.23% (1/438) were co-infected with HIV and A.lumbricoides, and the same with HIV and T.trichiura. The multivariate logistic regression analysis showed that sex (male, OR=3.26, 95% CI：0.97, 10.95) and drug abuse (OR=72.86, 95% CI：18.51, 286.76) were significantly associated with HIV infection. Home toilet was negatively related to A.lumbricoides infection (OR=0.52, 95% CI：0.27, 0.98) and T.trichiura infection (OR=0.48, 95% CI：0.28, 0.80). Compared with the people in Villages Four, the people living in Village One were at a higher risk for A.lumbricoides infection (OR=3.14, 95% CI：1.35, 7.27), and compared with the people living in Village Four, the people living in Village Two and Village Three were more likely to be infected with T.trichiura (OR=3.73, 95% CI：1.92, 7.26; OR=4.53, 95% CI：2.12, 9.68). The people aged between 11 and 20 years had a higher T.trichiura infection risk than the people aged more than 50 years (OR = 3.72, 95% CI：1.59, 8.67). There was a significant association between A.lumbricoides and T.trichiura infections (OR = 3.11, 95% CI：1.63, 5.93). There was no association between S.japonicum infection and related factors above mentioned. CONCLUSIONS: The infection rates of HIV, S.japonicum, A.lumbricoides and especially T.trichiura were rather high in this area, and therefore, the prevention and treatment of these diseases should be strengthened. Further studies on the relationship between HIV and the infections of helminths, especially S.japonicum are needed.

The risk of enteric infections associated with wastewater reuse: the effect of season and degree of storage of wastewater.

The effect of season and wastewater storage on the risk of Ascaris lumbricoides infection and diarrhoeal disease associated with wastewater reuse was studied in Mexico in 1991. Data were collected from 10,489 individuals during a dry-season survey. Exposure was to untreated wastewater, or effluent from 1 reservoir (< or = 1 nematode egg/L), or no wastewater irrigation (control group). The results were compared with a previous rainy-season survey which included effluent from 2 reservoirs in series. Direct exposure to untreated wastewater was associated with an excess risk of A. lumbricoides infection in children aged < 5 years (OR = 18.0) and persons aged > 5 years (OR = 13.5) and an increased risk of diarrhoea, particularly to children aged < 5 years (OR = 1.75); effects were stronger in the dry than in the rainy season. There was also an excess risk associated with the 1-reservoir group for A. lumbricoides infection (OR = 21.2 and 9.4) and for diarrhoeal disease (OR = 1.1 and 1.5) but little excess associated with the 2-reservoirs group. Therefore, wastewater retention in 1 reservoir (quality 10(5) faecal coliforms/100 mL, < or = 1 egg/L) does not significantly reduce risks of Ascaris infection and diarrhoeal disease whereas retention in 2 reservoirs in series (quality 10(3) faecal coliforms/100 mL, no detectable eggs/L) does.

Epidemiology of human geohelminth infections (ascariasis, trichuriasis and necatoriasis) in Lushui and Puer Counties, Yunnan Province, China.

Between April and June of 1998, the prevalence and intensity of geohelminth infections caused by hookworm, Ascaris and Trichuris were investigated in two rural Yunnan villages. In Liuku, a village of Lisu indigenous people in Lushui County, there was an overall geohelminth prevalence of 72% (48%, 43% and 16% for hookworm infection, ascariasis, and trichuriasis, respectively). The prevalence of ascariasis was greatest among preschool and school aged children, whereas the prevalence of trichuriasis was greatest among teenagers and the prevalence of hookworm increased until the age of 10-15 and then remained high throughout adulthood. In Linger, a village of Han Chinese, located in Puer County, there was an overall geohelminth prevalence of 77% (30%, 60% and 36% for hookworm infection, ascariasis, and trichuriasis, respectively). The differences in prevalence for hookworm and ascariasis were statistically significant. The prevalence of hookworm in Linger increased steadily with age and did not plateau, but there were no discernible patterns of prevalence versus age for either ascariasis or trichuriasis. Heavy trichuriasis infections were noted to occur in Linger. In both villages, more than 98% of the hookworm infections were of light and moderate intensity. Both by morphologic identification of third-stage infective larvae (L3) from eggs as well as identification of adult hookworms recovered from adult residents after treatment with quantrel, Necator americanus was identified as the exclusive hookworm in each village. Geohelminth infections caused by Ascaris, Trichuris and hookworm remain highly endemic to the rural areas of Yunnan Province in southwestern China.

Concurrent infections and neutrophil phagocytic function in Nigerians with urinary schistosomiasis.

Bacteria infections, parasitic infections and neutrophil phagocytic function were assessed in 60 urinary schistosomiasis (USS) subjects and 36 healthy controls. Only Salmonella was isolated from the blood samples of few USS subjects (3%) and controls (1%). The species of bacteria detected in the urine of USS and control subjects are Escherichia coli, Salmonella, Staphylococcus aureus, Streptococcus faecalis and Klebsiella. There was no significant difference in the proportion of the USS subjects with bacteriuria compared with the controls (X2 = 0.20, P > 0.20). Higher proportions of USS subjects compared with the controls were concurrently infected with Ascaris lumbricoides, hookworms, Giardia lambila and Taenia solium. In contrast, significantly higher proportion of the control subjects were concurrently infected with Plasmodium falciparum and Schistosoma mansoni. There was no significant reduction in neutrophil phagocytic function of USS subjects compared with the controls (P > 0.49). This study suggests that S. haematobium protects its host from certain blood dwelling parasites and that Nigeria USS subjects expressed adequate neutrophil phagocytic function. These may explain the absence of clinical manifestations of bacterial and viral infections in these subjects.

[Trypsin and alpha-amylase activities in the pancreas of guinea pigs. II. Effect of per os and intra-intestinal infection with invasive ova of Ascaris suum]. / Aktywnosc trypsyny i alfa-amylazy w trzustce swinek morskich. II. Wplyw zarazenia per os i dojelitowo inwazyjnymi jajami ascaris suum.

The guinea pigs were infected orally or intraintestinally (after laparotomy) with 5000 invasive eggs of Ascaris suum. On the 7th day after infection the invasion was controlled by lung's weight, degree of congestion, and number of larvae in the lungs. The activity of amylase was determined according to Fennel method, trypsin to Anson method. The activities of both enzymes in pancreas of orally infected animals (after laparotomy or not) were lower, and relative weight of lungs of these animals was higher than in control animals. In pancreas of guinea pig with invasive material introduced into its, the activities of amylase and trypsin were higher than in control animals, but only the activity of trypsin differed significantly.

[Trypsin and alpha-amylase activity in the pancreas of guinea pigs. IV. Comparison of the effects of administration of the mixtures of volatile organic acids, invasive ova of Ascaris suum and their homogenates]. / Aktywnosc trypsyny i alfa-amylazy w trzustce swinek morskich. IV. Porównanie wplywu podawania mieszaniny lotnych kwasów organicznych, inwazyjnych jaj Ascaris suum i ich homogenatów.

The activity of alpha-amylase in the experimental groups of guinea pigs was lower than in control animals. The decreased level of activity of trypsin was noted (p less than 0.05) also in infected animals, and in treatment with organic acids. In the group of guinea pigs, which was administrated homogenized eggs of parasite, the activity of enzyme was a little higher than in control animals. The infection of animals was associated with increase of relative weight of lungs. The guinea pigs treatment with organic acids had also a higher weight of spleen.

Ascaris lumbricoides infection and parasite load are associated with asthma in children.

INTRODUCTION: Association between Ascaris lumbricoides infection and asthma is a controversial subject that has been studied by several authors based on the hygiene theory. This work contributes to better understanding this issue. METHODOLOGY: This was a cross-sectional study involving 1,004 children from a neighborhood of low socioeconomic status in Campina Grande, Paraíba, northeastern Brazil. Asthma was diagnosed using the International Study of Asthma and Allergy in Childhood (ISAAC) questionnaire. Intestinal parasitosis was diagnosed by parasitological examination (the Ritchie technique), and parasite load determined by the Kato-Katz technique. The statistical analysis was descriptive, and hypotheses were tested according to odds ratios. RESULTS: A total of 260 children were infected with A. lumbricoides, and 233 had asthma. Light parasite loads were significantly associated with asthma (wheezing more than three times per year); p = 0.003, OR = 0.41(IC 0.22 - 0.75), while the heavy parasite loads were not; p = 0.002, OR = 2.37(IC 1.35 - 4.18). Similar results were observed in almost all the symptoms of asthma. No association was found with maternal educational level. CONCLUSION: In children living in urban areas of low socioeconomic status, a light parasite load of A. lumbricoides is a protective factor against asthma and its symptoms. Meanwhile, heavy parasite load is a risk factor and contributes to the high prevalence of asthma and its symptoms among these children.

Prevalence and risk factors of soil-transmitted helminth infection in Nepal.

BACKGROUND: The purpose of this study is to evaluate the prevalence and intensity and examine the risk factors of soil transmitted helminth (STH; i.e., roundworm [Ascaris lumbricoides], hookworms [Ancylostoma duodenale and Necator americanus], and whipworm [Trichuris trichiura]) infections in Nepal. METHODS: Five hundred and ninety-four adults (256 men and 338 women) were selected via convenience sampling from five communities in Nepal. The Kato-Katz method was used to assess the prevalence and intensity of STH infection in this population. RESULTS: Prevalence of STH infection ranged from 3.3% in Birendranagar in Chitwan, 3.5% in Kuleshor in Kathmandu, 11.7% in Kanyam in Ilam, 17.0% in Dhikurpokhari in Kaski and 51.4% in Khokana in Lalitpur District [corrected]. Multivariable regression analysis revealed that not using soap for hand-washing was significantly associated with the prevalence and infection intensity of roundworm, hookworms and whipworm. Similarly, not wearing sandals or shoes outside was significantly associated with the prevalence and infection intensity of roundworm and hookworms, but not with infection intensity of whipworm. Literacy, being underweight or overweight, anemia and occupation were not associated with prevalence and intensity of roundworm and hookworms infection, but there was an association between occupation and the prevalence of whipworm infection. CONCLUSION: STH infection was associated with individual hygiene behavior, but not with nutritional status or socio-demographic characteristics. Health policy focusing on changing individual hygiene behaviors might be useful in addressing STH infection in Nepal.

Hepatolithiasis after Hepaticojejunostomy: Ascaris lumbricoides in the biliary tract.

BACKGROUND: Biliary ascariasis is a common problem in Third World countries and other underdeveloped areas of the world. Ascaris lumbricoides migrates into the biliary tree, where it is apparent commonly on diagnostic imaging. We present a unique case of a patient with chronic right upper quadrant abdominal pain, massive hepatolithiasis, and stricture of a previous hepaticojejunostomy in whom ascariasis was found. METHODS: A 28-year-old female presented to the emergency department with right upper quadrant abdominal pain, syncope, and seizure-like activity. She was found by magnetic resonance cholangiopancreatography to have cholangitis, choledocholithiasis, and bile duct stricture. After multiple radiographic studies, she was taken to the operating room for revision of a hepaticojejunostomy performed 10 years previously. RESULTS: Ascaris lumbricoides was found in the right intrahepatic bile duct, that had not been identified by multiple radiologic modalities. The worm was sent to the pathology department for identification. A Fogarty catheter was passed into the hepatic ducts for successful stone extraction. The hepaticojejunostomy was revised, with catheter placement in the Roux limb to accommodate radiologic stone extraction as necessary. Post-operatively, she was given a single dose of albendazole and discharged on hospital day 19. CONCLUSION: The worm was likely the nidus for the stricture and stone formation. Surgical exploration of the biliary tree was required to diagnose and treat her condition accurately. This case is unique in that typical means of diagnosis failed to identify the causative agent of hepatolithiasis because of the prior Roux-en-Y hepaticojejunostomy.

Geophagy and potential health implications: geohelminths, microbes and heavy metals.

The practice of geophagy (soil-eating) is widespread among pregnant and breast-feeding women in sub-Saharan Africa. To assess some of the potential risks accompanying the consumption of geophagic material, we analysed contamination with bacteria, fungi, and geohelminths as well as heavy metals (lead, mercury and cadmium) in 88 African geophagic soil samples, which were purchased in Central, West and East Africa, Europe and the United States. Median microbial viable counts of positive samples were 440 cfu/g (maximum 120,000 cfu/g). The median metal concentrations were 40 mg/kg lead (up to 148 mg/kg), 0.05 mg/kg mercury (up to 0.64 mg/kg), and 0.055 mg/kg cadmium (maximum 0.57 mg/kg). No geohelminth eggs were found in these samples. Our results suggest that geophagic soil samples can be highly contaminated with microbes and may contain high levels of lead. Geophagy, however, is not a cause of adult helminth infection. The periodic consumption of geophagic materials at high dosages might be problematic particularly during pregnancy.