Parasite Epidemiology and Control最新文献

Aim of study

This study assessed the effectiveness of community-based interventions, health awareness, and treatment in controlling schistosomiasis among schoolchildren to improve policies and strategies.

Methods

This pre- and post-intervention study was conducted in an Al-Alaqa male primary school, and systematic simple random sampling was used to investigate 237 participants, which resulted in 132 (55.7%) infected students. The infected and noninfected students (580 students) were treated by delivering the praziquantel doses immediately after the results; after 4 weeks, the infected students received the second dose. After 6 months, the rates were investigated again, and all procedures were performed after the height and weight of the students were recorded according to the protocol. Health education was provided for all participants using posters and leaflets. The data were collected via a questionnaire and urine test. The data were analyzed using SPSS (Statistical Package for the Social Sciences), and ANOVA and t-tests were used to determine the significant differences between the variables.

Results

A urine investigation was conducted on 237 students; 132 (55.7%) had positive results which showed marked improvement and the prevalence in the school decreased to 3.8% after the intervention. The researcher found strong evidence of a relationship between the prevalence of schistosomiasis before the intervention and availability of water in the home (chi-square = 18.331, df = 1, p value = 000). ANOVA showed strong statistical significance (0.002 and F = 6.564) between the mean score of student age and reasons behind going to the pond.

Conclusion

This study concluded that mass chemotherapy and treatment were highly effective when associated with a health program intervention. Mass chemotherapy alone may reduce the prevalence of disease for a short time.

Recommendation

Community-based interventions should be applied in schools with an emphasis on health education programs through the training of schoolteachers on investigations for schistosomiasis, treatment with praziquantel, and the provision of materials (microscopes, reagents, and drugs).

The prevalence of neglected tropical diseases, specifically those caused by soil-transmitted helminths (STHs) and other parasites that infest the intestine as part of their life cycle, remains a problem in Indonesia. We assessed the effects of deworming programs and socioeconomic and ecological factors on the incidence rate of infections with STHs and other parasites in an urban area of the Bandung Regency. We recruited 361 children with stunted growth who met the inclusion criteria, and 48 of those children were at high risk of STH infection. The study was conducted between September 2020 and September 2021. We collected possible socioeconomic factors influencing the incidence rate of infections. We found the incidence rate of STH infections among the children with stunted growth to be 3.6%. We confirmed infections with Cyclospora and Cryptosporidium after a Ziehl-Nieelsen stool smear examination in two of the 48 children at risk of infection. We found 43.75% of the children had short stature and weight below the normal limits, while stunting and severe stunting were associated with Ascaris lumbricoides infection (44.70%, p = 0.035). Parents of children with stunted and severely stunted growth were more likely to have a low education level, lack knowledge about deworming program, and to be earning a low income. The mother's occupation had a particularly strong influence on the severity of the stunting (89.58%, p = 0.012). Our results show that deworming programs can affect the growth and development of children and that socioeconomic and ecological factors also play a role.

Giardia duodenalis is one of the most common causes of waterborne disease worldwide, and is often associated with outbreaks of diarrhea in areas with poor sanitation and hygiene. This study aimed to assess the prevalence and genetic diversity of G. duodenalis assemblages in individuals attending major public hospitals in Shiraz, southwestern Iran. From August 2022 to May 2023, a total of 614 stool samples from individuals were collected and initially examined for G. duodenalis cysts using parasitological techniques, sucrose flotation, and microscopy. Microscopy-positive samples were validated by SSU-PCR amplification of the parasite DNA. A multilocus genotyping (MLG) scheme, which focused on the triose phosphate isomerase (tpi) and the glutamate dehydrogenase (gdh) genes, was employed for genotyping purposes. G. duodenalis cysts were found in 7.5% (46/614) and 8.5% (52/614) of samples through microscopy and SSU-PCR, respectively. Successful amplification and sequencing results were obtained for 77.3% (17/22) and 45.5% (10/22) of the infected samples at the tpi and gdh loci, respectively. MLG data for the two loci were available for only five samples. Out of the 22 samples genotyped at any loci, 54.5% (12/22) were identified as assemblage A, while 45.5% (10/22) were identified as assemblage B. AII was the most predominant sub-assemblage identified [54.5% (12/22)], followed by BIII [27% (6/22)], discordant BIII/BIV [13.6% (3/22)], and BIV [4.5% (1/22)]. In the present study, no assemblages suited for non-human animal hosts (e.g., CF) were detected. This suggests that the transmission of human giardiasis in Shiraz is primarily anthroponotic. Further molecular-based analyses are necessary to confirm and expand upon these findings. These analyses will also help determine the presence and public health importance of the parasite in environmental samples, such as drinking water.

Among the potential animal reservoirs of the zoonotic parasite T. gondii, birds have received relatively little attention. This systematic review and meta-analysis aimed to assess the global status and to provide an overview of the epidemiology of T. gondii infection in birds. The standard protocol of preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were followed. Scopus, PubMed, Web of Science, Science Direct, ProQuest, and Google Scholar were searched for relevant publications from January 1990, to March 2024. All peer-reviewed original research articles describing the prevalence of T. gondii in birds were included. Inclusion and exclusion criteria were applied, and both direct and indirect detection were considered. The point estimates and 95% confidence intervals were calculated using the meta-package in R (version 3.6.1). The variance between studies (heterogeneity) was quantified by the I² index. Finally, 258 articles (including 380 datasets) were eligible for inclusion in the systematic review and meta-analysis. The global pooled prevalence was 24% (21 - 26%). The highest prevalence of T. gondii was observed in buzzards (52%, 34 - 70%), turkeys (31%, 17 - 46%), and chickens (30%, 26 - 34%). The present study provides a comprehensive view of the global prevalence of T. gondii in birds.

Immunisation of livestock with high-quality vaccines and the use of acaricides are highly ranked tick control strategies worldwide. However, the effects of coupling livestock immunisation and acaricide control on mitigating the spread of East Coast Fever (ECF) is not well understood. Effective strategies to curb the disease require an understanding of the influence of control strategies on ECF dynamics. This paper presents a new mathematical model for ECF in ticks and livestock to analyze the effect of livestock immunisation and acaricide control on preventing ECF spread. Our research is focused on examining how vaccine efficacy, inoculation rate, and acaricide efficacy affect disease progression. Our finding is that acaricide control alone may not be sufficient to stop the spread of ECF, even if it has an 80% effectiveness all the time. However, by pairing acaricide control with livestock vaccination, disease transmission is significantly reduced and elimination is possible under certain circumstances. Overall, results show that it is crucial to understand the influence of combining control strategies to mitigate the spread of this devastating livestock disease and enhance decision making among policymakers and livestock keepers.

Ticks and tick-borne pathogens are the main challenge to livestock production and productivity in sub-Saharan Africa, particularly in Ethiopia, where favorable conditions exist for the activity of various parasites due to its geographical location, climate, and biological and cultural characteristics. This study was to provide pooled estimates for individually available data on ixodid ticks, their trend comparisons, and ixodid tick grouping among cattle in Ethiopia. Cochrane's Q, I², sensitivity analysis, funnel plot, Begg, and Egger regression tests were used to check heterogeneity and publication bias. A random effect model was used to calculate the pooled magnitude of ixodid ticks among cattle. A total of 17,161 cattle from 41 studies were included. The pooled prevalence of ixodid ticks among cattle was 64.42% (95% CI = 57.13–71.71). A total of 82,804 adult ticks belonging to three different genera of ixodid ticks, namely Rhipicephalus (Boophilus) (47.53%), Amblyomma (46.10%), and Hyalomma (6.37%), were recorded from the included studies. The general trend for the prevalence of ixodid tick infestation among cattle has decreased, from 68.65% in 2010–2015 to 60.13% in 2021–2023. In the present scenario, ixodid tick infestation range from 59.21 to 89.58% and are higher in Gambella region.

Cystic echinococcosis (CE) is a major medical and veterinary concern in the world. It is one of the significant diseases in livestock farming communities managed under extensive grazing system like Ethiopia. Domestic intermediate hosts are an important reservoir for the disease spread. A cross-sectional study was conducted to determine the occurrence and economic losses associated with CE in cattle slaughtered at Mekaneyesuse Municipality abattoir, South Gondor zone of Amhara Region, North West Ethiopia. Ante-mortem inspection, postmortem examinations of organs, hydatid cyst characterization and financial loss estimations were conducted. The study was conducted on 384 cattle. The involvement of different organs was as follows: lungs (46.09%), liver (45.22%), heart (6.09%), and kidneys (2.6%). Out of the total of 115 cysts observed, small cysts constituted 57.39%, medium-sized were 34.78%, and large cysts accounted for 7.83%. Of these 115 cysts, 53.9% were fertile which included both viable (29%) and non-viable (71%) cysts. Furthermore, 46.1% cysts were non fertile, 62.3% were sterile and 37.7% were calcified. Based on the origin of animal, the prevalence of hydatid cysts was recorded to be 31.25%, 24%, 22.05% and 14.25% in Tachgayent, Semada, Andabet and Estie district, respectively. Higher cyst occurrence was observed in animals with poor body condition (51.56%) followed by medium (13.7%) and good body condition scores (8.25%). The total annual economic loss due to the direct condemnation of organs and indirect losses were estimated to be 851,252.68 ETB ($16,061.06). This study revealed that CE is economically important disease at Mekaneyesuse, South Gondar Zone, Amhara Region, Northwest Ethiopia. A more comprehensive investigation is required on prevalence and genotyping of Echinococcus granulosus s.l. cysts is important also to identify and estimate the relative contribution of each species or genotype to the disease in this area. Moreover, efforts to enhance public awareness in the area should also be pursued.

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.