• 한국식품위생안전성학회지
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• 제24권3호
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• pp.211-216
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• 2009

4,4'-diaminodiphenylmethane (4,4'-MDA)는 일차방향족아민 (primary aromatic amino, PAA)류의 일종으로, 최근 유럽에서는 RASFF를 통하여 나일론 재질의 주방용 국자, 주걱 등에서 4,4'-MDA 이행 사례를 보고하고 있어 국내 유통 합성수지제 조리기구 중 4,4'-MDA 이행량 실태를 조사하였다. 4,4'-MDA의 분석을 위하여 0.3 ppb의 정량한계 및 87.6% 이상의 우수한 회수율을 나타내는 LCMS/MS를 이용한 분석방법을 확립하였다. 식품유사용매 물, 4% 초산, 20% 에탄을 및 n-헵탄에 대하여 4,4'-MDA 이행여부를 조사한 결과, 4% 초산 및 20% 에탄올인 경우에는 분석대상 100 품목 중 나일론 재질 14 품목에서, 물인 경우에는 나일론 재질 11 품목에서 식품유사용매로 4,4'-MDA가 이행되는 것으로 나타났으나, n-헵탄을 사용한 경우에는 1개 품목에서만 미량의 4,4'-MDA가 이행되었다. 이중 유럽연합 기준인 0.01 ppm을 초과하는 제품은 2품목이었다.

• Parasites, Hosts and Diseases
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• 제58권2호
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• pp.109-119
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• 2020

Soil-transmitted helminths and Schistosoma haematobium affect more than 3 billion people globally and mainly occur in sub-Saharan Africa. The present study assessed the overall infection status of a 1716-student cohort of schoolchildren in Zanzibar and applied mass drug administration (MDA) to the cohort from 2007 to 2009. Schools in Pemba, Zanzibar, had a much higher prevalence of soil-transmitted helminth infections than those in Unguja, and the Chaani, Ghana, and Machui schools of Unguja exhibited high S. haematobium infection rates. The MDA program only partially controlled parasite infections, owing to high rates of re-infection. The infection rate of S. haematobium across all 10 schools, for example, was only reduced by 1.8%, and even this change not significant, even though the S. haematobium infection rates of the Chaani and Mzambarauni schools were significantly reduced from 64.4 and 23.4%, respectively, at the first screening, to 7.3 and 2.3% at the last screening. The overall infection rate of Ascaris lumbricoides was reduced from 36.0% at the first screening to 22.6% at the last screening. However, the infection rates for both Trichuris trichiura and hookworm were generally unaffected by MDA. In the future, parasite control programs should involve strategically designed MDA schedules and holistic intervention (e.g., sanitation improvement, hygiene behavior changes, and control of intermediated hosts).

• Parasites, Hosts and Diseases
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• 제58권2호
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• pp.195-200
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• 2020

Soil-transmitted helminths, including Ascaris lumbricoides and Trichuris trichiura, are important intestinal parasites mostly affecting younger people in developing countries. In 2014-2015, we performed mass fecal examinations targeting a total of 2,227 schoolchildren in 3 districts (South Dagon, North Dagon, and Hlaing-thar-yar) of Yangon Region, Myanmar, using the Kato-Katz thick smear technique. The egg positive children were subjected to a mass drug administration (MDA) using a single oral dose of 400 mg albendazole. The pre-treatment egg positive rate (EPG/person) of A. lumbricoides averaged 17.2% (15,532); it was 25.2% (21,796), 14.2% (11,816), and 12.8% (12,983) in 3 districts, respectively, and that of T. trichiura averaged 19.4% (1,074), and was 24.1% (1,040), 12.3% (852), and 21.2% (1,330) in 3 districts, respectively. Follow-up fecal examinations performed 4 months post-MDA revealed considerable decreases of A. lumbricoides prevalence (EPG/person) to av. 8.3% (12,429), and 13.7% (17,640), 8.0% (7,797), and 4.5% (11,849) in 3 districts, respectively. However, T. trichiura did not show any recognizable decrease in the prevalence (EPG/person) remaining at av. 18.2% (862), and 18.5% (888), 11.5% (812), and 23.3% (887) in 3 districts, respectively. The results demonstrated difficulty in short-term control of T. trichiura by MDA using albendazole and suggested necessity of either a long-term MDA (>10 years) or changing the albendazole regimen into 2~3-day course (total 800 or 1,200 mg), or using an alternative drug/drug combination.

• Parasites, Hosts and Diseases
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• 제58권4호
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• pp.421-430
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• 2020

This study aimed to investigate whether mass drug administration (MDA) intervention has an equivalent effect on reducing the prevalence and intensity of Schistosoma haematobium infection regardless of the baseline values. A repeated cross-sectional survey was performed targeting students of 12 primary schools in Al Jabalain and El Salam districts of White Nile State, Sudan, at both 1 week before and 8 months after the MDA. Prior to the baseline survey, schoolaged children in Al Jabalain had received MDA interventions twice in 4 years, while those in El Salam had not. The baseline prevalence was 9.1% in Al Jabalain and 35.2% in El Salam, which were reduced to 1.8% and 5.5% at 8 months after the MDA, respectively. The corresponding reduction rates were 80.3% and 84.4%, not significant difference between both districts. However, changes in the geometric mean intensity (GMI) of egg counts were significantly different between both districts. The baseline GMIs were 14.5 eggs per 10 ml of urine (EP10) in Al Jabalain and 18.5 EP10 in El Salam, which were reduced to 7.1 and 11.2 EP10 after treatment, respectively. The corresponding reduction rates were 51.0% and 39.5%. In conclusion, MDA interventions were found to bring about similar relative reduction in prevalence regardless of the baseline value; however, the relative reduction in infection intensity was more salient in the district with a low baseline value for both prevalence and intensity. This clearly points to the importance of repeated MDA interventions in endemic areas, which will eventually contribute to schistosomiasis elimination.

• Parasites, Hosts and Diseases
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• 제59권6호
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• pp.607-613
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• 2021

Soil-transmitted helminth (STH) infections are still a considerable challenge in Myanmar. We undertook a control program for STH infections (especially Trichuris trichiura) among schoolchildren in Myanmar using mass drug administration (MDA) and health education. Around 1,700 schoolchildren from 15 primary schools in 3 suburban districts (Shwe Pyi Thar, Twantay, and Kyauktan) of the Yangon Region were subjected in this study during 2017-2019. All of the schoolchildren in each school were orally administered albendazole (400 mg in a single dose) 2, 3, and 4 times a year in 2017, 2018, and 2019, respectively. The results revealed that the egg positive rate of any intestinal helminths (including STH) was reduced from 37.6% (649/1,724) in 2017 to 22.8% (352/1,542) in 2019. The egg positive rate of Ascaris lumbricoides was decreased remarkably from 23.3% (402/1,724) in 2017 to 3.6% (56/1,542) in 2019. However, that of T. trichiura was only slightly reduced from 26.9% (464/1,724) in 2017 to 20.2% (312/1,542) in 2019. The intensity of infection with A. lumbricoides and T. trichiura was both more or less reduced, and the proportion of light infection cases with A. lumbricoides and T. trichiura increased from 35.6% in 2017 to 64.3% in 2019 and from 70.3% in 2017 to 81.7% in 2019, respectively. The results indicated that repeated MDAs (2-4 times a year for 3 years) using albendazole on schoolchildren in Myanmar failed to control T. trichiura infection. For a successful control of trichuriasis in Myanmar, new MDA strategies, using a modified albendazole regimen (multiple daily doses for 2 or 3 days) or an alternative anthelmintic drug, such as oxantel pamoate, is strongly recommended.

• 한국식품위생안전성학회지
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• 제30권1호
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• pp.81-86
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• 2015

국내 유통 중인 총 321건의 폴리아미드, 폴리우레탄, ABS, 아크릴 수지 재질 식품용 기구 중 이행우려가 있는 모노머인 4,4'-메틸렌디아닐린, 2,4-톨루엔디아민, 아닐린, 아크릴로니트릴 및 메틸메타크릴레이트에 대하여 이행량을 조사하고 안전성 평가를 실시하였다. 83건의 폴리아미드, ABS 및 아크릴 수지 재질 식품용 기구 검체에서 현행 식품용 기구 및 용기 포장 공전상의 용출규격 이하인 4,4'-메틸렌디아닐린, 2,4-톨루엔디아민, 아크릴로니트릴 및 메틸메타크릴레이트가 이행되었다. 이행량 결과를 토대로 안전성 평가 시나리오에 적용하여 4,4'-메틸렌디아닐린, 2,4-톨루엔디아민, 아크릴로니트릴 및 메틸메타크릴레이트의 EDI를 산출한 후 TDI와 비교하여 위해도를 평가하였다. EDI는 폴리아미드 재질 기구의 4,4'-메틸렌디아닐린과 2,4-톨루엔디아민의 경우 각각 $2.39{\times}10^{-9}$, 및 $1.20{\times}10^{-9}mg/kg\;bw/day$, ABS 재질 기구의 아크릴로니트릴의 경우 $4.32{\times}10^{-9}mg/kg\;bw/day$, 아크릴 수지 재질 기구 메틸메타크릴레이트의 경우 $2.27{\times}10^{-7}mg/kg\;bw/day$이었다. ABS 재질 기구 이행 아크릴로니트릴의 위해도는 RfD 대비 $4.32{\times}10^{-4}%$ 수준이었고, 아크릴 수지 재질 기구 이행 메틸메타크릴레이트의 위해도는 TDI 대비 $1.89{\times}10^{-5}%$ 수준이었다. 결론적으로 검토된 평가 항목들의 위해도는 TDI 대비 $4.32{\times}10^{-4}%$와 $1.89{\times}10^{-5}%$에 불과한 것으로 조사되어 안전한 수준인 것으로 사료되었다. 이러한 결과들은 앞으로 기구 및 용기 포장의 안전관리를 위한 과학적인 근거자료로 이용될 수 있을 것으로 판단된다.

• Parasites, Hosts and Diseases
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• 제53권5호
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• pp.535-543
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• 2015

Integrated control strategies are important for sustainable control of schistosomiasis and soil-transmitted helminthiasis, despite their challenges for their effective implementation. With the support of Good Neighbors International in collaboration with National Institute of Medical Research, Mwanza, Tanzania, integrated control applying mass drug administration (MDA), health education using PHAST, and improved safe water supply has been implemented on Kome Island over 5 years for controlling schistosomiasis and soil-transmitted helminths (STHs). Baseline surveys for schistosomiasis and STHs was conducted before implementation of any integrated control strategies, followed by 4 cross-sectional follow-up surveys on randomly selected samples of schoolchildren and adults in 10 primary schools and 8 villages, respectively, on Kome islands. Those follow-up surveys were conducted for impact evaluation after introduction of control strategies interventions in the study area. Five rounds of MDA have been implemented from 2009 along with PHAST and improved water supply with pumped wells as other control strategies for complementing MDA. A remarkable steady decline of schistosomiasis and STHs was observed from 2009 to 2012 with significant trends in their prevalence decline, and thereafter infection rate has remained at a low sustainable control. By the third follow-up survey in 2012, Schistosoma mansoni infection prevalence was reduced by 90.5% and hookworm by 93.3% among schoolchildren while in adults the corresponding reduction was 83.2% and 56.9%, respectively. Integrated control strategies have successfully reduced S. mansoni and STH infection status to a lower level. This study further suggests that monitoring and evaluation is a crucial component of any large-scale STH and schistosomiasis intervention.

• Parasites, Hosts and Diseases
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• 제58권6호
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• pp.627-634
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• 2020

Belitung district in Bangka-Belitung Province, Indonesia with a population of 0.27 million is endemic for Brugia malayi and 5 rounds of mass drug administration (MDA) were completed by 2010. Based on the results of 3 transmission assessment surveys (TAS), the district is declared as achieving elimination of lymphatic filariasis (LF) in 2017. The findings of an independent survey conducted by the National Institute of Health Research and Development (NIHRD) in the same year showed microfilaria (Mf) prevalence of 1.3% in this district. In 2019, NIHRD conducted microfilaria survey in 2 villages in Belitung district. Screening of 311 and 360 individuals in Lasar and Suak Gual villages showed Mf prevalence of 5.1% and 2.2% with mean Mf density of 120 and 354 mf/ml in the respective villages. Mf prevalence was significantly higher among farmers and fishermen compared to others and the gender specific difference was not significant. The results of a questionnaire based interview showed that 62.4% of the respondents reported to have participated in MDA in Lasar while it was 57.7% in Suak Gual village. About 42% of the Mf positive cases did not participate in MDA. Environmental surveys identified many swampy areas supporting the breeding of Mansonia vector species. Persistence of infection is evident and in the event of successful TAS3 it is necessary to monitor the situation and plan for focal MDA. Appropriate surveillance strategies including xenomonitoring in post-MDA situations need to be developed to prevent resurgence of infection. Possible role of animal reservoirs is discussed.

• Parasites, Hosts and Diseases
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• 제61권2호
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• pp.216-224
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• 2023

In several schistosomiasis-endemic countries, the prevalence has remained high in some areas owing to reinfection despite repeated mass drug administration (MDA) interventions; these areas are referred to as persistent hot spots. Identifying hotspots is critical for interrupting transmission. This study aimed to determine an effective means of identifying persistent hot spots. First, we investigated the differences between Schistosoma haematobium and Schistosoma mansoni prevalence among school-aged children (SAC) estimated by a community-based survey, for which local key informants purposively selected communities, and a randomly sampled school-based survey. A total of 6,225 individuals residing in 60 villages in 8 districts of North Kordofan, Blue Nile, or Sennar States, Sudan participated in a community-based survey in March 2018. Additionally, the data of 3,959 students attending 71 schools in the same 8 districts were extracted from a nationwide school-based survey conducted in January 2017. The community-based survey identified 3 districts wherein the prevalence of S. haematobium or S. mansoni infection among SAC was significantly higher than that determined by the randomly sampled school survey (e.g., S. haematobium in the Sennar district: 10.8% vs. 1.1%, P<0.001). At the state level, the prevalence of schistosomiasis among SAC, as determined by the community-based survey, was consistently significantly higher than that determined by the school-based survey. Purposeful selection of villages or schools based on a history of MDA, latrine coverage, open defecation, and the prevalence of bloody urine improved the ability for identifying persistent hot spots.

• Parasites, Hosts and Diseases
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• 제55권5호
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• pp.533-540
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• 2017

Schistosoma mansoni is highly endemic in Tanzania and affects all age groups at different degrees. However, its control approach does not include adult individuals who are equally at risk and infected. To justify the inclusion of adult individuals in MDA programs in Tanzania, the present study focused on determining the prevalence of S. mansoni infection and its related morbidities among adult individuals. This was a cross sectional study conducted among 412 adult individuals aged 18-89 years living in selected villages of Rorya and Butiama districts located along the shoreline of the Lake Victoria. A pretested questionnaire was used to collect socio-demographic and socio-economic information of participants. Ultrasonographic examinations were conducted for all study participants using the Niamey protocol. A single stool sample was obtained from all study participants and examined for S. mansoni using the Kato-Katz technique. The study revealed a high prevalence of S. mansoni (56.3%), and the majority of infected individuals had a light intensity of infection. Ultrasonographic findings revealed that 22.4% of adult individuals had periportal fibrosis (PPF) (grade C-F), with 18.4% having grade C and D and 4% having grade E and F. Males had the highest prevalence of PPF (31.7% vs 10.8%, P<0.001). Organomegaly was common with 28.5% and 29.6% having splenomegaly and hepatomegaly, respectively. S. mansoni infection and its related morbidities included PPF, hepatomegaly, and splenomegaly were common among adult individuals. To reduce the level of transmission of S. mansoni infection, planned mass drug administration campaigns should include adult individuals living in these villages.