Prevalence and Intensity of Soil-Transmitted Helminths and Associated Factors among Adolescents and Adults in Bibugn Woreda, Northwest Ethiopia: A Community-Based Cross-Sectional Study

Background. Soil-transmitted helminths are a common public health problem in Ethiopia, affecting all age groups. However, epidemiological studies and interventions primarily target school-age children, despite the fact that 44.6 million adults live in endemic areas. Hence, data on the prevalence and intensity of soil-transmitted helminths infections and associated factors among adolescents and adults helps to expand interventions. Objective. The aim of the study was to assess the prevalence and intensity of soil-transmitted helminths and associated factors among adolescents and adults in Bibugn Woreda, East Gojjam, Northwest Ethiopia. Methods. A community-based cross-sectional study was conducted in Bibugn Woreda from February to September 2021. Using multistage proportionate sampling technique, 641 adolescents and adults were enrolled in this study. Data on sociodemographic characteristics and factors associated with helminthic infections was collected using structured questionnaire prepared in Amharic and administered through face-to-face interview. Parasite detection in stool samples was performed using modified formol-ether concentration and Kato-Katz techniques following standard protocols. Data was entered and analyzed using Statistical Package for the Social Sciences software version 25. Multivariable logistic regression was used to assess factors associated with soil-transmitted helminths infections. P value <0.05 was considered as statistically significant. Results. The overall prevalence of soil-transmitted helminths infection was 20.9% (134/641). The most detected parasite was Ascaris lumbricoides (12.5%), followed by hookworm species (7.5%) and Trichuris trichiura (1.1%). Fecal egg counts revealed that 96.5% (112/116) of the infections were with light parasite intensity, while 3.5% (4/116) were with moderate parasite intensity. Family size >5 (AOR = 1.866; 95% CI: 1.221–2.853; P = 0.004 ), absence of latrine (AOR = 3.675; 95% CI: 1.599–8.449; P = 0.002 ), and no habit of hand washing before meal (AOR = 2.622; 95% CI: 1.073–6.405; P = 0.034 ) were significantly associated with soil-transmitted helminths infections. Conclusion. There was moderate prevalence of soil-transmitted helminths among adolescents and adults with predominance of A. lumbricoides. Family size greater than five, absence of latrine, and no hand washing habit before meal predisposed adolescents and adults for soil-transmitted helminths. The existing school-based interventions should expand to address adolescents and adults.

Prevalence and Intensity of Ectoparasites on Cultivated Catfish (Clarias sp.) in Aquaculture Ponds and Bioflocs System in Aceh Besar, Indonesia.

The purpose of this research is to determine the intensity and the prevalence of ectoparasites found in catfish biofloc aquaculture ponds and traditional catfish in Aceh Besar. The research was conducted at the Fish Quarantine Agency for Quality Control and Safety of Fishery Products (BPKIPM) Blang Bintang. This research used a descriptive method while the catfish samples were taken using a random sampling method. The sample of catfish is 100 samples which are devided into 50 catfish with biofloc system and 50 catfish using the traditional system. The organs observed in catfish are fins (back, chest, tail, anal, stomach), gills, and mucus. The results of this study indicate that there were 3 types of ectoparasites have been identified, Vorticella sp., Trichodina sp., and Dactylogyrus sp. The highest prevalence rate is infection parasite by Dactylogyrus sp. in Leubok village, Aceh Besar which use a traditional system, and it is categorized as “always” or “very severe infection” (100%) while for the biofloc system in the village of Reukih Dayah, Indrapuri, Aceh Besar it is categorized as “moderate or “moderate infection”(88%). For the lowest prevalence rate in ectoparasites is Vorticella sp. It is found in biofloc ponds and categorized as “rare” infections about (2%). The highest level of parasite intensity is infection with Dactylogyrus sp. Both media are categorized as “medium”. The differences in the intensity value of the two media are biofloc media has an intensity of 22.7 meanwhile the traditional has 11.3.

The correlation between ectoparasite infestation and total Vibrio parahaemolyticus bacteria in Pacific white shrimp (Litopenaeus vannamei) in Super Intensive Ponds

This study aimed to determine the type, intensity, degree of ectoparasite infestation and its correlation to the total V. parahaemolyticus bacteria in super-intensive pacific white shrimp culture. In this study, sampling was carried out in 3 super-intensive pacific white shrimp pond areas spread out in East Java, namely Bangil, Tuban, and Lamongan with 50 shrimps (PL30-PL 40). The obtained data underwent regression and correlation analysis. Based on the results, there were three types of ectoparasites, namely Zoothamnium sp., Epistylis sp. and Vorticella sp. High ectoparasite intensity was found in pacific white shrimp from Lamongan and Tuban ponds, namely 76 and 55 individuals/shrimp, respectively, showing the heavy infestation. High total V. parahaemolyticus bacteria was found in Tuban (1.16 × 105 CFU/gr) and Lamongan (1.16 × 105 CFU / gr) ponds. Based on the results, the coefficient value was R = 0.807 showing positive correlation of V. parahaemolyticus with the increasing parasite intensity and low oxygen levels.

Occurrence of Neoechinorhynchus curemai (Acanthocephala: Neoechinorhynchidae) in Prochilodus nigricans (Characiformes: Prochilodontidae), in southwestern Amazon

Prochilodus nigricans is extensively exploited in fishing and aquaculture activities in the Brazilian Amazon, it is the definitive host for Neoechinorhynchus curemai Noronha, 1973. Thus, the present study aimed to evaluate the occurrence of N. curemai in P. nigricans and the parasite-host relationship in three rivers (Juruá, Crôa and Môa) in the municipality of Cruzeiro do Sul, state of Acre, Brazil. Fish were caught, weighed, measured, and subjected to necropsy, and the gastrointestinal tract and viscera were analyzed. A total of 178 specimens of N. curemai were found in 61 infected fish, with the (p= 58.62%). The prevalence, mean intensity, and mean abundance were higher in hosts from the Môa River, and lower from the Juruá River. Regarding the length-weight relationship, the b-value did not differ statistically from three (b=3) for fish species in the three locations, nor in parasitized and non-parasitized species. In addition, growth was considered isometric, and in the case of the relative condition factor, there was no difference in fish hosts between the three rivers. The correlation between parasite intensity, condition factor, length, and weight of P. nigricans was not significant. Thus, this parasite infestation varied between the habitats. However, this did not influence the growth and development of the hosts.

Canalization and developmental stability of the yellow-necked mouse (Apodemus flavicollis) mandible and cranium related to age and nematode parasitism

Background Mammalian mandible and cranium are well-established model systems for studying canalization and developmental stability (DS) as two elements of developmental homeostasis. Nematode infections are usually acquired in early life and increase in intensity with age, while canalization and DS of rodent skulls could vary through late postnatal ontogeny. We aimed to estimate magnitudes and describe patterns of mandibular and cranial canalization and DS related to age and parasite intensity (diversity) in adult yellow-necked mice (Apodemus flavicollis). Results We found the absence of age-related changes in the levels of canalization for mandibular and cranial size and DS for mandibular size. However, individual measures of mandibular and cranial shape variance increased, while individual measures of mandibular shape fluctuating asymmetry (FA) decreased with age. We detected mandibular and cranial shape changes during postnatal ontogeny, but revealed no age-related dynamics of their covariance structure among and within individuals. Categories regarding parasitism differed in the level of canalization for cranial size and the level of DS for cranial shape. We observed differences in age-related dynamics of the level of canalization between non-parasitized and parasitized animals, as well as between yellow-necked mice parasitized by different number of nematode species. Likewise, individual measures of mandibular and cranial shape FA decreased with age for the mandible in the less parasitized category and increased for the cranium in the most parasitized category. Conclusions Our age-related results partly agree with previous findings. However, no rodent study so far has explored age-related changes in the magnitude of FA for mandibular size or mandibular and cranial FA covariance structure. This is the first study dealing with the nematode parasitism-related canalization and DS in rodents. We showed that nematode parasitism does not affect mandibular and cranial shape variation and covariance structure among and within individuals. However, parasite intensity (diversity) is related to ontogenetic dynamics of the levels of canalization and DS. Overall, additional studies on animals from natural populations are required before drawing some general conclusions.

Malaria-Resistant Mosquitoes (Diptera: Culicidae); The Principle is Proven, But Will the Effectors Be Effective?

Over the last few decades, a substantial number of anti-malarial effector genes have been evaluated for their ability to block parasite infection in the mosquito vector. While many of these approaches have yielded significant effects on either parasite intensity or prevalence of infection, just a few have been able to completely block transmission. Additionally, many approaches, while effective against the parasite, also disrupt or alter important aspects of mosquito physiology, leading to corresponding changes in lifespan, reproduction, and immunity. As the most promising approaches move towards field-based evaluation, questions of effector gene robustness and durability move to the forefront. In this forum piece, we critically evaluate past effector gene approaches with an eye towards developing a deeper pipeline to augment the current best candidates.