Infection Rates Of Hookworm Research Articles

National surveillance of hookworm disease in China: A population study.

BackgroundHookworm disease is endemic in China and is widespread globally. The disease burden to humans is great.MethodsThe study described the national surveillance of hookworm implemented in 31 provinces/autonomous regions/municipalities (P/A/Ms) of China in 2019. Each P/A/M determined the number and location of surveillance spots (counties). A unified sampling method was employed, and at least 1000 subjects were investigated in each surveillance spot. The modified Kato-Katz thick smear method was employed for stool examination. Fifty samples positive with hookworm eggs were cultured in each surveillance spot to discriminate species between A. duodenale and N. americanus. Twenty-five soil samples were collected from each surveillance spot and examined for hookworm larva. The 2019 surveillance results were analyzed and compared with that of 2016–2018.ResultsA total of 424766 subjects were investigated in 31 P/A/Ms of China in 2019, and the overall hookworm infection rate was 0.85% (3580/424766). The weighted infection and standard infection rates were 0.66% (4288357/648063870) and 0.67% (4343844/648063870), respectively. Sichuan province had the highest standard infection rate (4.75%) in 2019, followed by Chongqing (2.54%) and Hainan (2.44%). The standard infection rates of other P/A/Ms were all below 1%, with no hookworm detected in 15 P/A/Ms. The standard hookworm infection rate in the males and the females were 0.61% (2021216/330728900) and 0.71% (2267141/317334970), respectively, with a significant difference between different genders ( = 17.23, P<0.0001). The highest standard hookworm infection rate (1.97%) was among age ≥ 60 years, followed by 45~59 years (0.77%), 15~44 years (0.37%), and 7~14 years (0.20%). The lowest standard infection rate was among the 0~6 years age group (0.12%). A significant difference was observed among different age groups ( = 2 305.17, P<0.0001). The constitute ratio for N. americanus, A. duodenale, and coinfection was 78.70% (1341/1704), 2.03% (346/1704), and 1.00% (17/1704), respectively. The detection rate of hookworm larva from soil was 3.45% (71/2056).ConclusionThe national surveillance showed that the hookworm infection rate has been decreasing annually from 2016 to 2019, and it is now below 1%. China has made significant progress in controlling hookworm. The national surveillance system is an important way to understand the endemic status and provide important information in this process and thus needs to be continually optimized.

The situation of parasitic infection in the Patients attending to the Hospital of Hue University of Medicine and Pharmacy from 2015 to 2019

Background: Parasitic and fungal disease is now a public health problem. Objective: To identify the rate of parasite infection at Hue University of Medicine and Pharmacy Hospital from 2015 to 2019. Materials and methods: Retrospective study, survey of laboratory data at the Department of Parasitology from 2015 to 2019. Results: The rates of serum positive for Fasciola sp., Taenia sp., Strongyloides sp., Toxocara sp. was 48.5%, 21.5%, 32.8%, 67.4%, respectively. Infection rates of hookworm, whipworm, strongyloidiasis, small liver fluke, Taenia sp. was 0.8%, 1.7 %, 1.0%, 2.0%, 1.7% respectively. The rate of vaginal yeast, fungal cutaneous infection was 24.2%, 41.1% respectively. Respiratory fungal infection: Candida albicans 31.7%, C. non albicans 21.6%. The rate of fungal infections of the outer ear canal: Aspergillus 54.6%, C. albicans 2.8%, C. non albicans 13%. Conclusion: These results show that the number of parasitic tests is increasing, which corresponds to the importance role of this kind of diseases to the public health. The Parasitology Department play an important role in order for hospital to improve quality to supplying the good service for public health care Key words: protozoa, Parasite, Fungi, Helminth, ELISA

Rural health in the Progressive Era: revisiting the hookworm intervention in the American South.

Objective: In this study, we investigated Progressive Era public health interventions and connected two subsequent efforts to improve outcomes in the American South: the Rockefeller Sanitary Commission's hookworm eradication efforts in the early 1910s and investments in local health infrastructure between the 1910s and the 1930s. We tested whether hookworm eradication had the largest effects in areas that invested in public health and whether county health organizations-cooperative public-private institutional arrangements-impacted the Rockefeller Sanitary Commission program's success. Materials and Methods: The methods used to measure the effects involved estimation of difference-in-difference and triple-difference models across the geographic samples of the Rockefeller Sanitary Commission's surveyed area, the American South, and the United States. Material on hookworm infection rates and activities by the Rockefeller Sanitary Commission is obtained from the Rockefeller Foundation Annual Reports. Material on the activities, spending, and duration of the different county health organizations is obtained from the Public Health Service Bulletin 222 titled, "A history of county health organizations in the United States: 1908-1933". Results: By comparing similar cooperative and independent county health organizations in the American South with the rest of the United States, we find that cooperative efforts are generally important and strengthen the Rockefeller Sanitary Commission's impact on human capital outcomes in the American South. Simultaneously, independent county health organizations produced negative or non-significant effects. Conclusion: The Rockefeller Sanitary Commission is important in guiding local health efforts. Our results are robust in both the short and long runs. This study sheds light on the effectiveness of public-private partnerships in rural public health during the Progressive Era.

Effect of Lymphatic Filariasis and Hookworm Infection on Pregnancy Course and Outcome in Women Living in the Democratic Republic of the Congo.

.Little is known about the effect of helminth infections on the natural gynecological and pregnancy course. Our goal was to assess the relationship between Wuchereria bancrofti and hookworm (HW) infections with pregnancy course and outcome in a group of 82 women living in a rural area of the Democratic Republic of the Congo. Demographics and information on gynecological and obstetrical histories were collected retrospectively with standardized questionnaires. Wuchereria bancrofti and HW infections were diagnosed using a filarial antigen-detection test and the Kato–Katz method, respectively. Analyses consisted of multivariable logistic regressions adjusting for age, number of deliveries, and history of anthelmintic treatment (HAHT). The median age of study participants was 35 (interquartile range [IQR]: 30–44) years, and the median number of deliveries was five (IQR: 3–7). Wuchereria bancrofti and HW infection rates were 44.5% and 43.3%, respectively. Filarial antigenemia and HW infection were not significantly associated with the number of deliveries. The proportions of women with a history of pregnancy resulting in neonatal death, miscarriage, premature birth, and postpartum hemorrhage were 56%, 44%, 23%, and 36%, respectively. History of pregnancy associated with neonatal death was less frequent in women with HAHT, tended to be more frequent in women with filarial antigenemia, and was not associated with HW infection. None of the three other pregnancy events studied (miscarriage, premature birth, and postpartum hemorrhage) were associated with filarial antigenemia or HW infection. The positive association found between HAHT and lower risk of neonatal death warrants investigation in larger groups of women.

Prevalence and potential zoonotic risk of hookworms from stray dogs and cats in Guangdong, China

Hookworm infection is globally prevalent among dogs and cats representing a major public health risk. Although previous studies have surveyed canine and feline hookworms in Guangzhou city, the status of these infection needs to be further explored in other regions of South China. To investigate the prevalence and zoonotic risk of canine and feline hookworms in eight cities (Guangzhou, Foshan, Shenzhen, Huizhou, Zhongshan, Shaoguan, Shantou and Chaozhou) of Guangdong province, China, we developed specific PCR methods based on ITS sequence for identifying three common hookworm species. The results showed that the prevalence of hookworms from stray dogs and cats was 20.23% (142/702) and 15.26% (47/308), respectively. The established PCR methods could identify Ancylostoma ceylanicum, A. caninum and A. tubaeforme. The mixed infections of A. caninum and A. ceylanicum were detected in stray dogs of Guangzhou and Shaoguan, with the rate of 8.3% and 21.2%, respectively. Among the stray dogs in Foshan, the infection rate of A. ceylanicum was higher than that of A. caninum. The stray cats in four of five investigated cities were infected with A. ceylanicum. The different region, age and rearing environments had an impact on the hookworm infection rates of stray dogs and cats. In conclusion, the reported higher infection rate of A. ceylanicum than other hookworm species in stray dogs and cats poses a potential risk to public health.

Current status of human hookworm infection in Jiangxi Province in 2014

To understand the status of human hookworm (Ancylostoma duodenale or Necator americanus) infection in Jiangxi Province. A stratified cluster random sampling was conducted based on the geographical location and economic condition in 2014. Kato-Katz's thick smear method was used for stool examinations, and filter paper cultivation was conducted for distinguishing the species of hookworms. A total of 21 615 persons were involved in the investigation, and there were 1 095 persons infected with hookworm with the prevalence of 5.07% (standardized rate of 4.05%). The infection rate of hookworm in Nanfeng County was the highest (13.96%). Most of the infected people had low worm burden (95.43%). The infection rate of hookworm of the female was higher than that of the male (χ2 = 28.03, P < 0.05). The prevalence increased with the age, while the infection rate of hookworm in people at ages of 75 years and higher was the highest (14.79%). Housewife was the highest risk occupation with the infection rate of 7.55%. The differences of infection rates among different educational level groups were significant (χ2 = 135.88, P < 0.05). The prevalence rates of hookworm in different landforms were significantly different (χ2 = 34.37, P < 0.05). The priority species was N. americanus (80.41%) in Jiangxi Province. The infection rate of hookworm decreases obviously in Jiangxi Province. The high risk groups of hookworm infection are the people with low educational level, female and elder age-group.

Trends of soil-transmitted nematode infections in Jiangxi Province

To analyze the status and trends of soil-transmitted nematode infections in Jiangxi Province from 1989 to 2014, so as to provide the evidence for generating the strategy of soil-transmitted nematode prevention and control. The data of three epidemiological surveys on human parasitic diseases (in 1989, 2002 and 2014) were classified and analyzed. The stool examination by Kato-Katz's thick smear method was adopted for the investigation of soil-transmitted nematode infections. The total infection rate of soil-transmitted nematodes decreased by 91.89% from 77.67% in 1989 to 6.30% in 2014, in which the infection rate of Ascaris lumbricoides decreased by 98.78% from 71.11% to 0.87%, the infection rate of Trichuris trichiura decreased by 96.80% from 29.67% to 0.95%, and the infection rate of hookworm declined by 73.57% from 17.63% to 4.66%. The infection rates of soil-transmitted nematodes in the female were higher than those in the male in three surveys. In different ecological districts, the infection rates of soil-transmitted nematodes in the female were also higher than those in the male, except in Zhe-Min Ecological District in 2002 and 2014. A declined trend of the infection was showed in all age-groups in the three surveys, but it slowed down by the growth of age, i.e., the reduction rate was 97.03% in the age group of < 10 years while 80.62% in the age group of >70 years. In 2014, the number of persons infected with soil-transmitted nematodes occupied 65.4% of the whole number of persons infected with intestinal parasites. The mean infection rates of soil-transmitted nematodes decrease obviously in human population in different ecological districts, but the soil-transmitted nematodes are still the main species in intestinal parasite infections. The sequence of dominant species changes from A. lumbricoides, hookworm and T. trichiura in 1989 to hookworm, T. trichiura and A. lumbricoides in 2014. The rural female and elder people are the key population, while hookworm is the key species for the prevention and control of soil-transmitted nematodes.

Investigation of soil - transmitted nematode infections in Xiding Township, Menghai County, Yunnan Province

To understand the status of soil-transmitted nematode infections in Xiding Township, Menghai County, Yunnan Province, so as to provide the reference for formulating the strategy of soil-transmitted nematodosis control. Soil-transmitted nematode eggs in feces were detected by the Kato-Katz method, and the eggs of Enterobius vermicularis were detected by the cellophane tape method in children. The soil samples were collected from vegetable, fruit and other crop fields of 15 residents randomly to detect hookworm. The stool samples from 1 002 residents were examined and the soil -transmitted nematode infection rate was 20.06% (201/1 002). The infection rates of hookworm, Ascaris lumbricoides and Trichuris trichura were 18.96% (190 cases), 1.70% (17 cases) and 0.90% (9 cases) respectively. The percentages of people with light infection of hookworm, A. lumbricoides and T. trichura were 97.37% (185/190), 88.24% (15/17) and 100% (9/9) respectively. No infection of E. vermicularis was found. Fifteen soil samples were tested, and no hookworm was found in the soil. The infection rate of soil-transmitted nematode in Xiding Township, Menghai County is high, but the infectiosity is light. The control and monitoring of soil-transmitted nematodosis should be strengthened in this area.

Effect of control program of human intestinal parasitic diseases in Nanping City

To understand the epidemic status of human intestinal parasitic diseases and evaluate the effect of the control program in Nanping City, so as to provide an evidence for improving the disease control. The villages were selected by the stratified cluster sampling method and the residents in these villages were surveyed for human intestinal parasitic diseases, and kindergartens were also selected and the children in these kindergartens were surveyed for Enterobius vermicularis infection. In 2007, before the control program, 9 851 residents of Nanping City were surveyed, with the parasitic infection rate of 9.10% (896 infection cases), and the infection rate of E. vermicularis of children was 18.56% (328/1 767). From 2011 to 2014, when the control program was performed, 4 679 residents were surveyed, with the infection rate of 4.06% (190 infection cases), and the infection rate of E. vermicularis of children was 3.87% (33/853). After the control program was launched, the infection rates of human intestinal parasites were decreased. The overall parasitic infection rate and hookworm infection rate showed increasing trends by age (χ2 = 49.03 and 53.58 respectively, both P < 0.01). The infection situation of human intestinal parasites is decreased after the implementation of the control program but the infection rate is still at a high level, and the control work should be strengthened.

Xác định thành phần loài giun móc ở chó nhà tại tỉnh Đồng Tháp và Sóc Trăng bằng phân tích hình thái học và sinh học phân tử

Canine hookworm is one of the most popular parasitic diseases in domestic dogs in Vietnam, which has the potential of animal to human transmission. Therefore, the disease influences not only on animal health but also public health. The study was conducted to identify hookworm species in domestic dogs in Dong Thap and Soc Trang provinces. Hookworms were collected by post-mortem examination in Dong Thap and Soc Trang provinces. The hookworm samples were identified based on morphological characteristics, documented by Phan The Viet và cs., (1977), Levine N. D. (1968), Soulsby (1977) and molecular biology method. PCR-Restriction Fragment Length Polymorphism (PCR-RFLP) assay with the target internal transcribed spacer 1 (ITS-1) using Restriction enzyme RSaI was applied to differentiate hookworm species at molecular level. The results showed that the accumulative hookworm infection rate was 64.00%, with A. caninum, A. ceylanicum and A. braziliense (59.65%, 25.00% and 16.35%, respectively). The hookworm infection of 12-24 month-age dogs was up to 71.03%, which was higher than those over 24 months of age (60.55%). Infection rates had the tendency to decrease along with the increase of age. Unbridled dogs had infection rate of (71.6%), which was higher than that of dogs kept in cage (38.20%). Basing on morphological characteristics and molecular biology techniques, PCR - RELP showed the 3 phenotypes A1, A2 and A3 with 3 species of hookworm A. caninum, A. braziliense and A. ceylanicum, respectively. After sequencing and analyzing the ITS1 sequence, the results were completely in accordance with the patterns from PCR – RELP of three above mentioned species.

The impact of two semiannual treatments with albendazole alone on lymphatic filariasis and soil-transmitted helminth infections: a community-based study in the Republic of Congo.

Implementation of mass drug administration (MDA) with ivermectin plus albendazole (ALB) for lymphatic filariasis (LF) has been delayed in central Africa because of the risk of serious adverse events in subjects with high Loa loa microfilaremia. We conducted a community trial to assess the impact of semiannual MDA with ALB (400 mg) alone on LF and soil-transmitted helminth (STH) infections in the Republic of Congo. Evaluation at 12 months showed that ALB MDA had not significantly reduced Wuchereria bancrofti antigenemia or microfilaria (mf) rates in the community (from 17.3% to 16.6% and from 5.3% to 4.2%, respectively). However, the geometric mean mf count in mf-positive subjects was reduced from 202.2 to 80.9 mf/mL (60% reduction, P = 0.01). The effect of ALB was impressive in 38 subjects who were mf-positive at baseline and retested at 12 months: 37% had total mf clearance, and individual mf densities were reduced by 73.0%. MDA also dramatically reduced the hookworm infection rate in the community from 6.5% to 0.6% (91% reduction), with less impressive effects on Ascaris and Trichuris. These preliminary results suggest that semiannual community MDA with ALB is a promising strategy for controlling LF and STH in areas with coendemic loiasis.

Prevalence and epidemiology of intestinal parasitism, as revealed by three distinct techniques in an endemic area in the Brazilian Amazon.

This survey aims to estimate the prevalence of intestinal parasitic infections in Santa Isabel do Rio Negro, Amazonian Brazil, through three distinct techniques, correlating the prevalence rates with family income and age groups as well as assessing the household clustering of infections. Prevalence rates were assessed through Graham (n=113), Baermann-Moraes (n=232) and Ritchie (n=463) methods. The Graham method was adopted only for children under 5 years old, 15% of whom were positive for Enterobius vermicularis. By the Baermann-Moraes technique, 5·6% of the samples were positive for Strongyloides stercoralis larvae. The Ritchie technique disclosed the following results: Ascaris lumbricoides (26%), Trichuris trichiura (22·5%), hookworms (9·5%), Entamoeba histolytica/Entamoeba dispar (25·3%), Giardia lamblia (12·5%) and E. vermicularis (0·6%). Children aged 5-14 years presented the highest prevalence for pathogenic parasites. Giardiasis and hookworm infection rates were inversely related to family income. The presence of positive contacts in the same household substantially increased the risk of infection by enteric parasites: odds ratio (OR)=2·70, 95% confidence interval (CI)=1·69-4·29 for ascariasis; OR=2·17, 95% CI=1·34-3·51 for trichuriasis; OR=2·13, 95% CI=1·08-4·17 for hookworm disease; OR=3·42, 95% CI=1·86-6·30 for giardiasis; and OR=2·16, 95% CI=1·35-3·47 for amoebiasis, supporting infection clustering in the home. Intestinal parasitoses are extremely frequent in the studied area, and routine methods for diagnosis may underestimate the prevalence of enterobiasis and strongyloidiasis.

Hookworm infection, anaemia and genetic variability of the New Zealand sea lion

Hookworms are intestinal blood-feeding nematodes that parasitize and cause high levels of mortality in a wide range of mammals, including otariid pinnipeds. Recently, an empirical study showed that inbreeding (assessed by individual measures of multi-locus heterozygosity) is associated with hookworm-related mortality of California sea lions. If inbreeding increases susceptibility to hookworms, effects would expectedly be stronger in small, fragmented populations. We tested this assumption in the New Zealand sea lion, a threatened otariid that has low levels of genetic variability and high hookworm infection rates. Using a panel of 22 microsatellites, we found that average allelic diversity (5.9) and mean heterozygosity (0.72) were higher than expected for a small population with restricted breeding, and we found no evidence of an association between genetic variability and hookworm resistance. However, similar to what was observed for the California sea lion, homozygosity at a single locus explained the occurrence of anaemia and thrombocytopenia in hookworm-infected pups (generalized linear model, F = 11.81, p < 0.001) and the effect was apparently driven by a particular allele (odds ratio = 34.95%; CI: 7.12–162.41; p < 0.00001). Our study offers further evidence that these haematophagus parasites exert selective pressure on otariid blood-clotting processes.

Efficacy of different chemotherapeutic schemes for hookworm-infected villagers in China

A comparative analysis has been made of the efficacy of different chemotherapeutic schemes against hookworm infections in China. Hookworm eggs were detected by the improved Kato's thick smear method. Benzimidazole was offered to residents in the tested villages, while NaHCO3 was used as placebo in control villages. Data were analysed by negative binomial distribution with statistic software R2.2.1. In the tested village as a result of the application of selective chemotherapy, hookworm infection rate decreased from 58.79% to 1.08%, while the average of eggs per gram (EPG) reduced from 526.29 to 56.91. The infection rates in the target chemotherapy village and in the mass chemotherapy village declined from 6.90% to 1.92% and 10.10% to 0.65% respectively. It was concluded that the consecutive selective chemotherapy could rapidly decrease the infection rate and EPG of hookworm and maintain the infection rate at low level. The curative effect of the target chemotherapy was similar to that of the mass chemotherapy in the low hookworm endemic area.

Effect of intestinal helminthiasis on intestinal permeability of early primary schoolchildren

Intestinal permeability of 246 early primary schoolchildren at 2 schools (106 of whom were infected with intestinal helminths) was assessed by using the lactulose/mannitol differential absorption test. The ratio of the urinary recoveries of lactulose and mannitol was determined after oral administration of a standard solution of the 2 sugars. Assessment of intestinal permeability was repeated on 100 infected children after treatment and on a cohort of 68 uninfected children. Infected and uninfected groups were compared with respect to baseline lactulose/mannitol ratio ( L M1 ) and change in lactulose/mannitol ratio between assessments ( ΔL M ). The correlations between baseline intensity of infection and L M1 , and between fall in intensity and ΔL M , were evaluated. Based on a crude index of socioeconomic status, each child was assigned to one of 3 socioeconomic groups; all but 3 children belonged to either groups 2 or 3. Trichuris trichiura and Ascaris lumbricoides were the 2 predominant infections; the hookworm infection rate was relatively low. The results suggested that helminthiasis exerted only a marginal effect on intestinal permeability, the impact of which in children from lower socioeconomic backgrounds was negligible in comparison with the cumulative effects of other factors.

Imported Opisthorchis viverrini and parasite infections from Thai labourers in Taiwan

In order to determine the prevalence of intestinal parasites among labourers from Thailand in Taiwan, the stool samples from 1364 Thai labourers were examined by the formalin-ether concentration method and 18.0% were found to be infected with one or more parasites. The infection rates of hookworm, Opisthorchis viverrini, Strongyloides stercoralis, Enterobius vermicularis, Ascaris lumbricoides, Hymenolepis nana, Capillaria philippinensis, Schistosoma japonicum, Echinostoma sp., Entamoeba coli, Giardia lamblia, and Entamoeba histolytica, were 7.6%, 7.0%, 3.2%, 0.5%, 0.3%, 0.1%, 0.1%, 0.1%, 0.1%, 0.4%, 0.2%, and 0.1% respectively. The prevalence was highest among the 21-25 age group (24.8%). Among the 245 infected persons, 91% were infected with one parasite, 8% with two parasites and 1% with three parasites. The finding that parasitic infections are prevalent among Thai labourers demonstrates the need for control measures in foreign labourers in Taiwan and further studies to determine the susceptibility of O. viverrini to the snail hosts of Clonorchis sinensis.

Human Oesophagostomum infection in northern Togo and Ghana: epidemiological aspects.

Recently, it has been established that human infection with Oesophagostomum bifurcum is common in northern Togo and northeastern Ghana. Two surveys were conducted in this area. In a regional survey, O. bifurcum infection appeared to occur in 38 of 43 villages. The highest prevalences (up to 59%) occurred mostly in small isolated villages and were usually associated with high hookworm infection rates. The infection was relatively rare in children under five years of age (7% infected). In older individuals, females showed higher prevalences than males (30% vs. 24%). In a second survey, the entire population of two high-prevalence villages was examined. Infection rates were low in children under three years of age, but rose quickly thereafter, suggesting intense transmission. A stable level of infection was reached by 10 years of age. Oesophagostomum larvae were found more frequently in hookworm-positive than in hookworm-negative coprocultures, and possible explanations for the association between infection with Oesophagostomum and hookworm are discussed.

A compound catalytic model with both reversible and two-stage types and its applications in epidemiological study.

A compound catalytic model with both reversible and two-stage types was studied. Using this model, the age-specific infection rate of hookworm in Changshou region was analysed. The fit of this model was checked by using the chi 2 test. It revealed that the data were fitted reasonably with the present model. The result indicated that this new model could be useful in epidemiological investigation.

Study on the status of helminthic infections in Koreans

Study on the status of helminthic infections in Koreans

EPIDEMIOLOGICAL STUDIES ON ASCARIS AND HOOKWORM INFECTION

During the period from July, 1957, to September, 1958, epidemiological studies were carried out, with the specific object of investigating familial prevalence, on Ascaris and hookworm infection among the inhabitants of 10 agricultural communities and 1 residential area (the control) in and around Chiba City. The rural areas where the investigation was carried out had been so selected that they included lands with different geographical features-the reclaimed land, the land where paddy-fields predominte, and the land where fields prodominate. With over 90 per cent of the inhabitants participating in the program, tests for infection with Ascarides and hookworms were conducted by means of smear method, suspension method and culture method.1. The smear method proved superior to the suspension method in detecting unfertilized Ascaris eggs, whereas the culture method was better than the suspension method in detecting hookworm eggs.2. Farmers and part-time farmers had a higher incidence of positive reactions to tests for Ascaris and hookworm infection than did non-farmers. The farmers cultivating fields ranging in area from 0.1 to 2.0 tan (1 tan corresponds to 0.245 acre) had the highest rate of Ascaris infection.Hookworm infection had no relation to the area of land cultivated. Both Ascaris and hookworm infection rates were low among the farmers using night soils fertilizer by mixing it with manure, than among the farmers employing other methods of night soil disposal.3. Among adults, those who were engaged in agriculture had the highest incidence of both Ascaris and hookworm infection. Among those engaged in agriculture, males had a higher incidence of infection with Ancylostoma duodenale, and females with Ascarides and Necator americanus.4. A. duodenale' showed the highest familial prevalence, followed by Ascarides and N. americanus in the indicated order. The prevalence of A. duodenale and N.americanus among those members of the family who were engaged in agriculture was as high as the familial prevalence, but the prevalence of Ascarides among those members of the family who were engaged in agriculture was lower than familial prevalence. Familial infection of these parasite worms in terms of the relations between husband and wife and parent and child gave the following picture: husband had a close relation with wife in infection with Ascarides; parent and husband had a close relation with child and wife, respectively, in infection with A. duodenale; and husband had a close relation with wife in infection with N.americanus.5. The following picture of mixed infection was obtained: Ascarides were closely related to A. duodenale in infecting children; Ascarides and A. duodenale were closely related to A. duodenale and N. americanus, respectively, in infecting adults. No close relation was found between Ascarides and N. americanus.6. In the light of the result of present investigation, it would seem that A. duodenale has larger possibilities of invading the human body by mouth than N. americanus.