Parasite Epidemiology and Control最新文献

Skin biopsies (Skin snips) have historically been the gold standard for the diagnosis of onchocerciasis. However, in low prevalence areas and in areas with successful ivermectin mass drug administration (MDA) programs, skin snips are not sensitive enough to decide when to stop MDA; thus, serological diagnostic tools have been recommended for this purpose. This study assessed the sensitivity and specificity of the Ov16 Rapid Diagnostic Test (SD BIOLINE Onchocerciasis RDT) compared to skin snip in endemic areas undergoing ivermectin mass distribution using Community Directed Treatment with Ivermectin (CDTI) strategy. A cross-sectional study was conducted between September and November 2016 in five endemic villages in the Cascades region in Burkina Faso. Children aged 2 to 9-years were examined during the impact epidemiological survey using both the skin snip and Ov16 Rapid Diagnostic Test. The Ov16 Rapid Diagnostic Test sensitivity and specificity were determined with reference to the skin biopsy. Skin snip positivity was 1.25% in this population, while seroprevalence was 6.5%. When compared to the skin snip as the gold standard, the sensitivity of the Ov16 Rapid Diagnostic Test was 60% and the specificity 94%. When the Ov16 Rapid Diagnostic Test was considered as the gold standard, the skin snip exhibited a sensitivity of 11.5% and a specificity of 99.5%. These results are similar to other studies comparing the performance of the Ov16 ELISA to skin snips, suggesting that the Ov16 RDT may be a useful tool for ivermectin STOP MDA and post transmission surveys, assuming that the prevalence of infection is low or close to zero, and the Ov16 RDT detected also pre patent infections.

Cystic echinococcosis (CE) is a significant health problem in both human and veterinary medicine. It is caused by the tapeworm Echinococcus granulosus (E. granulosus). The objective of this study was to investigate molecular diversity of E. granulosus from the paraffin-embedded human (FFPE) tissue samples using sequencing of mitochondrial genes. Thirty-five FFPE tissue samples were collected from different regions of Guilan province, north of Iran. Demographic data were recorded using a questionnaire. Five sections (1 mm) of the tissue were prepared and deparaffined using xylene and ethanol methods. Molecular analysis was performed using the Nad1 and Cox1 genes using PCR and DNA sequencing. Totally, 25 cases (71.43%) were women and 10 cases (28.57%) were men. The most affected age group was 21–30 yr old. The most of cysts were isolated from the liver (n = 19; 54.29%) and others in the lung (n = 16; 45.71%). The Cox1 and Nad1 genes were successfully amplified in 16 (45.71%) and 12 (34.28%) DNA samples from FFPE tissue. Sequencing analysis revealed that all samples were E. granulosus sensu stricto complex (G1 and G3). In this study, E. granulosus sensu stricto complex G1 and G3 were identified in human hydatid cysts and showed the presence of sheep/dog cycle in human infection. This finding confirmed and completed previous studies on the geospatial distribution of E. granulosus sensu stricto complex G1 and G3 in the southern and coastal areas of the Caspian Sea region.

Human toxocariasis (HT) is a widespread zoonotic infection globally, notably prevalent in tropical areas. Enhancing our understanding of toxocariasis can lead to increased attention towards the socioeconomic impact and control of this neglected zoonosis. We conducted a comprehensive review of all available articles and official documents on toxocariasis in Iran to identify research gaps and critical needs for its control. This review highlights that despite numerous studies exploring various aspects of toxocariasis in definitive and paratenic hosts, as well as humans and environmental contamination, significant data deficiencies and gaps persist across different regions in the country. These gaps involve investigating the worm burden and reinfection rates in definitive hosts, developing more sensitive methods to detect and differentiate of Toxocara species, and understanding the behavior of definitive host animals. Additionally, identifying potential paratenic hosts for HT and exploring the organ-specific affinity and survival duration of Toxocara larvae within these hosts are essential areas for exploration. It's also imperative to comprehend the sylvatic and domestic cycles of the parasite in paratenic hosts. Furthermore, assessing egg density in the environment, exploring potential new sources such as water, and identifying regions with optimal climatic conditions for the survival and development of Toxocara eggs are crucial for the formulation of effective prevention and control strategies. Identifying at-risk groups, developing early diagnosis techniques, employing imaging methods, and identifying long-term complications in humans are also crucial. Community health organizations should prioritize health education for the public and professionals. Furthermore, accurately estimating definitive host populations, monitoring and preventing their movements in public places, implementing regular deworming practices for pets and stray hosts, and recognizing the infection's significance as a health priority are critical. This comprehensive understanding advocates for a holistic “one health” approach to control of HT.

Background

Visceral leishmaniasis (VL) is a public health issue in endemic countries with poor sanitation facilities. In this study, the seroprevalence rate and associated risk factors of VL were investigated during September 2020 to February 2021 in pregnant women referred to Ostad Mottahari and Peymanieh hospitals in Jahrom county, Fars province, southern Iran.

Material and methods

A total of 220 serum samples of pregnant women were assessed for the presence of Anti-Leishmania infantum antibodies by direct agglutination antigen (DAT). The associated risk factors were obtained using questionnaires.

Results

The overall seroprevalence of VL in pregnant women was 12.72% (28/220). Considering the antibody titer, titer 1:1600 was detected in 23 samples, titer 1:3200 in 4 samples, and titer 1:6400 in one sample. All 5 women with titer >3200 had mild fever. As such, there was a statistically significant difference regarding the age (≥39 years old with p-value: 0.01).

Conclusions

We recommend an appropriate health education program for pregnant women and serological screening of VL before pregnancy in endemic cities. Moreover, we believed a need for more epidemiological studies for better understand the status of VL in pregnant women.

Cyprinid fishes are commonly acted as second intermediate hosts of Opisthorchis viverrini and Haplorchis spp. This research investigated the prevalence and intensity of both parasites in cyprinid species. This process is regularly used as a guideline for disease surveillance and as a preventive measure in the Upper Northeastern region of Thailand. Fish samples were collected from both lentic and lotic water sources between November 2020 and October 2021, and classified them by their species. Acid pepsin-HCL solution was used to digest the individual samples and create a build-up of precipitate in order to view metacercariae using a stereomicroscope. A total of 3583 fish were caught and classified into 23 species. Out of these fish, 5.49% of them were found O. viverrini, 26.54% Haplorchis taichui, 10.04% Haplorchis pumilio, and 9.29% Haplorchoides sp. Ten species of fish were observed to have been infected with O. viverrini. Amongst the collected fish, M. obtusirostris had the highest prevalence of infection at 52.94%, while B. gonionotus had only 1.71%. The prevalence of O. viverrini infection was highest at 27.41% in Udon Thani Province. No prevalence of O. viverrini infection was observed in Bueng Kan Province. High prevalence of O. viverrini infection in cyprinid fishes was found in both lentic and lotic water sources in almost all provinces in the region. The prevalence of infection and intensity depended on the fish species and fish habitats.

In the present research, ginger extracted compounds, namely; Gingerol {(1-[4′-hydroxy-3′-methoxyphenyl]-5-hydroxy-3-decanone} (1), Zingerone {(4-(4-Hydroxy-3-methoxyphenyl)-2-butanone)} (2), and Shogoals {(E)-1-(4-Hydroxy-3- methoxyphenyl) dec-4-en-3-one)} (3) have been investigated as SARS-Cov-2 inhibitors. The interaction of extracted compounds with the virus's spikes may restrict the virus's reproduction or give time to the body's immune system to detect viruses, consequently producing appropriate antibodies. Gaussian 09 with a 6-311G (d, p) basis set, UCA FUKUI, MGL implement, DSV, and LigPlus software were utilized. The active sites for adsorption were identified using the total electron density (TED), FUKUI function, and Millikan charges. Furthermore, docking analysis clearly showed that the inhibition of viral replication depends on binding energy (Eb) and ligand efficiency (LE). A docking study revealed that the inhibition ability of the studied compounds on SARS-CoV-2 was in the order of 2 > 3 > 1.

Objectives

This study intends to evaluate the prevalence of active Schistosomiasis in school children, as well as their awareness, attitude, and behavior towards the illness in El-Rahad province.

Methods

This facility-based analytical cross-sectional study among 495 primary school children aged seven to 13 in five villages; Structured and pre-tested questionnaires were used to collect the data in face-to-face interviews, in addition, urine samples were collected from each pupil and then assessed microscopically for S. Haematobium eggs Presence. Data was analyzed using SPSS version 25.0.

Results

A total of 424 primary school students participated in the study. Almost all the students (96%) had poor knowledge about urinary schistosomiasis. In general, 100% of the students had poor practices. Attitude revealed that females have lower chance of having the infection than their male counterparts. About 27% (n = 115) of them had active urinary schistosomiasis infection at the time of the study.

Conclusion

The study revealed poor level of awareness and knowledge, positive attitude, and poor practices among primary school students. There was also high level of active infection among participants.

Background

Worldwide, >654 million children live in regions where soil-transmitted helminth (STH) infections are endemic. These parasites cause a variety of symptoms, including anemia.

Methods

In May 2023, fecal and blood samples were collected from children aged 6 to 11 years attending government run (public) elementary schools in the Simanindo and Ronggur Nihuta sub-districts of Samosir Island, Indonesia where a twice a year mass drug administration (MDA) program is currently in place. A questionnaire was administered to students' parents or adult family members on possible risk factors for STH infections. Qualitative data were collected through in-depth interviews and focus group discussions.

Results

In total, 187 and 221 children in Simanindo and Ronggur Nihuta provided samples, respectively. The STH infection prevalence in Simanindo was 4.8% (9/187) and the infection prevalence in Ronggur Nihuta was 5.9% (13/221). In Simanindo, all infections were caused by Trichuris trichiura (n = 9), and in Ronggur Nihuta infections were caused by Ascaris lumbricoides (n = 6), Trichuris trichiura (n = 5), and A. lumbricoides + T. trichiura (n = 2). Three children had anemia but were negative for STH infections. While the results of the parent/adult questionnaires indicated access to a generally safe water supply and septic system, information from the in-depth interviews and focus groups revealed that the local water supply becomes greatly diminished during the dry season.

Conclusions

While MDA has been shown to effectively control roundworms and hookworms, additional measures to control trichuriasis are needed. There is also a need for the government to invest in improving the public water supply infrastructure.

Globally, Corona Virus Disease (COVID-19) has significantly affected communities in various aspects. The World Health Organization proposed different measures to prevent the pandemic. However, these measures in some instances have not effectively minimized the impacts of COVID-19, due to innumerable factors, inter alia, considerable “infodemic” related to myths, misinformation, and misconceptions. Knowledge of the “infodemic” on COVID -19 can lead to effective interventions to rid societies of COVID-19, hence reduction of COVID-19-related risks and outcomes. This article explores the “COVID-19 infodemic” that affected community responses to COVID-19 in Africa. The study employed a scoping review approach involving peer-reviewed articles from numerous search engines and databases. The keywords involved in the search query were: “COVID-19 infodemic, COVID-19 false news, COVID-19 in Africa, ‘knowledge of COVID-19, ‘myths, misinformation, and misconceptions on COVID-19, ‘history of COVID-19’, ‘community responses to COVID-19 in Africa”. Findings show that 5G technology transferred coronavirus, high temperature and alcohol can kill coronavirus, blacks are immune to COVID-19, COVID-19 vaccine development has been rushed hence not very effective and safe and also causes infertility. Diverse community responses have been registered which in some ways frustrated efforts in combating the pandemic. Therefore, the “infodemic” consisting of myths, misconceptions, and misinformation have been resulting from the history of COVID-19 which first affected white people more than blacks. Also, low knowledge of how the virus is transmitted and affect human being; and the notion that COVID-19 affects richer than poor people, hence since white people are richer than black people then they were the first to be affected by the pandemic. Obviously in presence of such myths, misconceptions, and misinformation; community responses in combating COVID-19 have not been very effective in Africa. For these interventions to be effective, collective efforts involving various stakeholders to raise awareness of COVID-19 are needed.

Background

Loiasis is an endemic filarial infection in the rainforest zone of West and Central Africa. Repeated annual community-directed treatment with ivermectin (CDTI) delivered for several years to control onchocerciasis has been shown to reduce the prevalence and intensity of Loiasis in some Loa loa-Onchocerca volvulus co-endemic areas. However, the impact of these multiple rounds of CDTI on entomological indicators of loiasis transmission is not known, and was therefore assessed in this study in areas with contrasting histories of CDTI.

Methods

The study was conducted in the East, North-west and South-west 1 CDTI project sites of Cameroon. Two communities per CDTI project were selected for fly collection and dissection. Ivermectin treatment coverage was documented in these areas, and this was correlated to Chrysops infection and infective rates. A total of 7029 female Chrysops were collected from 6 communities of the 3 CDTI projects (East, North-west, and South-west 1) and from 2 communities in a non-CDTI district (East).

Results

Chrysops biting densities and parous rates were significantly reduced in the North-west and South-west sites post-CDTI, while in the East, biting densities were similar in non-CDTI and CDTI sites, with higher parous rates observed in the non-CDTI site. Infection and infective rates in the East non-CDTI site were 4.4% and 1.8% respectively, as compared to 3.3% and 1.3% in the CDTI site after 10 ivermectin rounds (there were no baseline data for the latter). In the North-west site, significant reductions in Chrysops infection and infective rates from 10.2% and 4.2% respectively, to 3.5% and 1.2 (after 9 rounds of ivermectin treatment), were recorded following CDTI. In the South-west, infection rate significantly increased from 1.74% to 2.8% and infective rate remained statistically unchanged after 14 rounds of CDTI (0.45% - 0.40%). Similar trends in Mean Head L3 were observed except in the East site where this indicator was similar in both CDTI and control sites. Only in the North-west site did monthly transmission potentials decrease significantly.

Conclusion

This study demonstrated that the impact of repeated annual treatment with ivermectin for the control of onchocerciasis using community directed delivery approach on the entomological indicators of loiasis varies with bioecological zones. Community directed treatment with ivermectin induced a significant reduction in the entomological indicators of loiasis in the North-West project site which lies in forest savanna area. A non-significant decrease was observed in the East project site and in contrast, a significant increase was observed in the South-West 1 project site which both lies in the rainforest zones.