Association between Sociodemographic Factors and Diarrhea in Children Under 5 Years in Rwanda

Diarrheal disease is the second leading cause of mortality and morbidity in children under 5 years old worldwide, and is the most common cause of malnutrition in sub-Saharan Africa. In Rwanda, diarrhea is the third leading cause of death in children under 5 years old. This study examined the association between sociodemographic factors and diarrhea in children under 5 years using the data of 7,474 households in the 2014-2015 Rwanda Demographic and Health Survey. Overall prevalence of diarrhea in this study was 12.7% in children. An increased risk for diarrhea was found for children aged 12-23 months (odds ratio (OR)=4.514), those with a low economic status (OR=1.64), those from the Western province (OR=1.439), those with poorly-educated mothers (OR=5.163), and those with families engaged in agricultural activities (OR=1.624). In conclusion, sociodemographic factors significantly affect the risk of developing diarrhea in children under 5 years in Rwanda. Designing and implementing health education promoting awareness of early interventions and rotavirus vaccination are essential to reduce diarrheal diseases for the Rwandan community.

Significance of Serology by Multi-Antigen ELISA for Tissue Helminthiases in Korea

It is clinically important to differentiate tissue-invading helminthiasis. The purpose of this study was to assess the specific immunoglobulin G (IgG) antibody positive rates for clonorchiasis, paragonimiasis, cysticercosis, and sparganosis 4 helminthiases from 1996 to 2006 using multi-antigen enzyme-linked immunosorbent assay (ELISA) in Korea. Results of 6,017 samples, which were referred to our institute for serodiagnosis, were analyzed. The subjects with positive serum IgG antibodies were 1,502 (25.0%) for any of the 4 helminthiases. The overall positive numbers for clonorchiasis, paragonimiasis, cysticercosis, and sparganosis were 728 (12.1%), 166 (2.8%), 729 (12.1%), and 263 (4.4%), respectively. The positive serologic reaction to multi-antigens was determined in 309 (20.6%) of the 1,502 total seropositive subjects. Those with multi-antigen positivity were regarded as positive for the antigen of strongest reaction but cross-reaction to others with weak positive reaction. Annual seropositive rates for those 4 tissue helminthiases ranged from 12.1% to 35.7%. The highest rate was observed in age from 60 to 69 years old and prevalence of men (27.4%; 1,030/3,763) was significantly higher than of women (19.1%; 332/1,741). Hospital records of 165 ELISA positive patients were reviewed to confirm correlation with their clinical diagnosis. Paragonimiasis was highly correlated as 81.8% (9/11), cysticercosis 29.9% (20/67), clonorchiasis 29.0% (20/69), and sparganosis 11.1% (2/18). In conclusion, the multi-antigen ELISA using 4 helminth antigens is useful to differentiate suspected tissue-invading helminthiases, especially ELISA diagnosis of paragonimiasis is reliable. The seropositivity is still high among suspected patients in Korea.

A Case of Severe Anemia by Necator americanus Infection in Korea

This report describes clinical and parasitological findings of an 82-yr-old female patient who lived in a local rural village and suffered from severe chronic anemia for several years. She was transferred to the National Police Hospital in Seoul for management of severe dyspnea and dizziness. At admission, she showed symptoms or signs of severe anemia. Gastroduodenoscopy observed hyperemic mucosa of the duodenum and discovered numerous moving roundworms on the mucosa. Endoscopy isolated seven of them, which were identified as Necator americanus by characteristic morphology of cutting plates in the buccal cavity. The patient was treated with albendazole and supportive measures for anemia, and her physical condition much improved. This case suggests the possibility that hookworm N. americanus is still transmitted in a remote local mountainous area in Korea.

Infection Status of Freshwater Crabs and Crayfish with Metacercariae of Paragonimus westermani in Korea

The present study investigated the infection status of Paragonimus westermani metacercariae in freshwater crabs (n = 363) and crayfish (n = 31) from October 2007 to October 2008 using the crush method. All of the freshwater crabs, Eriocheir japonicus, were negative for P. westermani metacercariae while 10 (32.3%) of the 31 examined crayfish were positive. The 10 positive crayfish were caught in Haenam, Jeollanam-do, and there were 8-59 (mean 28.4) metacrcariae per infected crayfish. These results suggest that P. westermani metacerariae are still transmitted by crayfish enzootically in southern Korea, and that freshwater crabs may transmit metacercariae only on rare occasions.

Effects of Excretory/Secretory Products from Clonorchis sinensis and the Carcinogen Dimethylnitrosamine on the Proliferation and Cell Cycle Modulation of Human Epithelial HEK293T Cells

Clonorchis sinensis is one of the most prevalent parasitic helminths in Korea. Although cholangiocarcinoma can be induced by C. sinensis infection, the underlying mechanism is not clearly understood. To assess the role of C. sinensis infection in carcinogenesis, an in vitro system was established using the human epithelial cell line HEK293T. In cells exposed to the excretory/secretory products (ESP) of C. sinensis and the carcinogen dimethylnitrosamine (DMN), cellular proliferation and the proportion of cells in the G2/M phase increased. Moreover, the expression of the cell cycle proteins E2F1, p-pRb, and cyclin B was dramatically increased when ESP and DMN were added together. Similarly, the transcription factor E2F1 showed its highest level of activity when ESP and DMN were added simultaneously. These findings indicate that DMN and ESP synergistically affect the regulation of cell cycle-related proteins. Our results suggest that exposure to C. sinensis and a small amount of a carcinogen such as DMN can promote carcinogenesis in the bile duct epithelium via uncontrolled cellular proliferation and the upregulation of cell cycle-related proteins.

Infection Status of Freshwater Fish with Metacercariae of Clonorchis sinensis in Korea

This study investigated freshwater fish for their current infection status with metacercariae of Clonorchis sinensis in Korea. Twenty-one species of freshwater fish (n = 677) were collected from 34 regions nationwidely from February 2007 to June 2008. They were individually examined by digestion technique. Eight species of freshwater fish from 17 different regions were recognized positive for the metacercariae of C. sinensis. The positive rates (range of metacercariae number per fish) of fish by the species were as follows: 48% (1-1,142) in Pseudorasbora parva, 60% (1-412) in Pungtungia herzi, 15.7% (1-23) in Pseudogobio esocinus, 29% (1-7) in Acheilognathus intermedia, 21% (1-4) in Odontobutis interrupta, 33% (1-6) in Zacco temmincki, 3.6% (1-4) in Zacco platypus, and 26.3% (1) in Hemibarbus labeo. The two species, P. parva and P. herzi, are able to be the index fish for estimation of C. sinensis transmission in a certain locality. Still several species of freshwater fish are briskly transmitting C. sinensis infection in many riverside areas of southern Korea.