Human Infestation Research Articles

Escalating Threat of Drug-Resistant Human Scabies: Current Insights and Future Directions.

Background: Scabies is a prevalent dermatological condition with significant public health implications. The recent rise in drug-resistant scabies presents new challenges for effective disease management and control. Methods: A comprehensive literature review was conducted using PubMed, Cochrane Library, and Web of Science. Studies published from 2000 to August 2024 were considered, focusing on those reporting drug-resistant scabies and advancements in treatment approaches. Results: Clinical studies, in vitro investigations, and case reports show significant resistance of human scabies to permethrin. Main resistance mechanisms involve genetic mutations in the mites' voltage-gated sodium channels (VGSCs) and enhanced activity or expression of the detoxifying enzyme glutathione S-transferase (GST). Resistance to ivermectin and benzyle benzoate, although suggested by some authors, seems less obvious. The clinical evidence of widespread ivermectin resistance in human scabies infestations is lacking, despite indications of increased tolerance in laboratory settings and anecdotal reports of resistance in patients with crusted scabies. Benzyl benzoate resistance in scabies mites remains unconfirmed. Conclusions: Permethrin-resistant scabies is an escalating threat requiring new management strategies and updated guidelines. Infection control measures, alternative treatments, and ongoing research into new therapeutics are crucial to mitigate the impact of drug-resistant scabies.

Using Parasite Analysis to Investigate the Pathoecology of the Inhabitants of the City of Berezov in Western Siberia (Sixteenth–Nineteenth Centuries)

ABSTRACT The first Russian settlers developed relatively large cities and a new phenomenon called ‘urban habitat’ to the north of Western Siberia. This article presents the results of a study on soil samples taken from the cultural layer of Berezov city during excavations of the city’s kremlin, or civic centre, posad, or town settlement area, and the farmstead within the posad. The samples are dated from the XVI to the end of the XVIII century. Examination of the samples revealed 12 types of parasite eggs from both humans and animals. The city's cultural layer was found to be relatively highly contaminated with parasite eggs. The species composition of parasite eggs in samples collected from the cultural layer varied according to land use, i.e. whether public, communal, or livestock, or sanitary condition in Berezov city. An analysis of historical and archaeological data enabled the reconstruction of certain nutritional aspects of the population in Berezov city at the time. Additionally, certain cultural and abiotic factors contributing to the high parasite infestation of humans and domestic animals were identified, and similarities can be found in the research of other Russian cities of Siberia in the XVI–XIX centuries.

One health approach to study human health risks associated with Dermanyssus gallinae mites

Despite the significant health risks associated with Dermanyssus gallinae infestations in humans, they are often overlooked. This study investigated a household case of D. gallinae infestation and explored the resulting clinical manifestations and risk of infection in family members. Microfluidic PCR was employed for high-throughput screening of pathogens in collected mites and blood samples from both chickens and family members. Morphological and molecular examinations confirmed the identity of the mites as D. gallinae sensu stricto (s.s.), with evidence indicating recent blood feeding. Results indicated that the mites exclusively harbored various pathogens, including Bartonella spp., Ehrlichia spp., Apicomplexa, and Theileria spp. Blood samples from family members and poultry tested negative for these pathogens, suggesting a potential reservoir role for D. gallinae. The study further identified haplotypes of D. gallinae, classifying them into D. gallinae s.s., cosmopolitan haplogroup A. Serological analysis revealed elevated IgE seroreactivity against mite proteins in the family member with bite lesions. Antibodies against Bartonella spp. were detected in this individual, indicating exposure to the pathogen. In summary, this study sheds light on the clinical manifestations, pathogen detection, and genetic characterization of D. gallinae infestations, underscoring the necessity of adopting comprehensive approaches to manage such infestations effectively.

The role of zoophilic flies Hermetia illucens (Diptera: Stratiomyidae) in the spread of myiasis in mammals

The relevance of investigating the distribution, biology, and role of zoophilic flies Hermetia illucens of the family Stratiomyidae in the occurrence of myiasis in mammals lies in the ability of these flies to parasitise animals, which poses a threat to their health and life. The purpose of this review was to analyse scientific research on the possible spread of Hermetia illucens flies as a potential pathogen of parasitic diseases in Ukraine. The study employed the methods of analysis, comparison, and synthesis of scientific sources. It was found that the natural habitat of these flies is the countries of South and North America with tropical and subtropical climates. However, these flies are also found in European countries, namely: Portugal, Spain, Malta, France, Albania, Croatia, Slovenia, and Switzerland. To intensify biotechnology in the agricultural sector, the larvae of Hermetia illucens flies are used as an ecological utiliser of organic agricultural residues. It is believed that the main reason for the emergence of Hermetia illucens flies in Europe is their importation into seaports and subsequent introduction into coastal areas. Considering the above, it is possible that Hermetia illucens flies may also appear in Ukraine (in the southwestern regions). Cases of larval parasitism of these flies in mammals have been established. They were mostly detected as parasites in the gastrointestinal tract. Their ability to cause typical enteric myiasis has been confirmed. Larval parasitism is non-specific: diarrhoea (faeces with blood and mucus), flatulence, vomiting, loss of consciousness, etc. The larvae can also parasitise under the skin, forming boils. A frequent cause of human infestation is the consumption of unwashed, overripe fruit and vegetables on which these flies lay their eggs. The results of the review can be used to develop methods for controlling the spread and reproduction of Hermetia illucens flies, as a species whose larvae are capable of parasitising mammals

Living tape worms in the duodenal lumen: A rare case report

Fascioliasis is an infection caused by a trematode of the liver, Fasciola hepatica, which affects sheep, goats and cattle. Humans become accidental hosts through drinking contaminated water or ingesting raw green vegetables that has been contaminated with encysted metacercariae, which is the infective form. Fascioliasis has a hepatic phase and a biliary phase, each displaying different clinical signs and symptoms. Common signs and symptoms of the hepatic phase are abdominal pain, fever, eosinophilia, and abnormal liver function tests. The biliary phase of the disease usually presents with intermittent right upper quadrant pain with or without cholangitis or cholestasis. However, it is very rare to find a living flukes in the common bile duct (CBD) and duodenal lumen as it usually lives in gall-bladder and smaller biliary tracts. Here we report a case of human infestation of Fasciola hepatica, who presented with respiratory tract infection with abdominal pain & dyspeptic symptoms and eventually during evaluation, an upper gastro-intestinal endoscopy revealed several flat worms at the second part of the duodenum. The worms were sent to microbiology department for identification. The organisms were confirmed to be Fasciola hepatica. The patient was given tablet Nitazoxanide 500mg 12 hourly for 7 days. The symptoms reduced in intensity after two days of nitazoxanide. The patient was then discharged with an advice of a stool routine examination after one month of completion of nitazoxanide. As fasciolosis is non endemic in our country, a high degree of suspicion is required to ensure early detection and management of such cases. Patients with abdominal pain, altered liver function tests & eosinophilia should always be evaluated for a suspected Fasciola hepatica infection and should be kept as a differential in these cases. Bangladesh Crit Care J March 2024; 12 (1): 54-57

Socio-ecological risk factors associated with human flea infestations of rural household in plague-endemic areas of Madagascar.

Plague is a flea-borne fatal disease caused by the bacterium Yersinia pestis, which persists in rural Madagascar. Although fleas parasitizing rats are considered the primary vectors of Y. pestis, the human flea, Pulex irritans, is abundant in human habitations in Madagascar, and has been found naturally infected by the plague bacterium during outbreaks. While P. irritans may therefore play a role in plague transmission if present in plague endemic areas, the factors associated with infestation and human exposure within such regions are little explored. To determine the socio-ecological risk factors associated with P. irritans infestation in rural households in plague-endemic areas of Madagascar, we used a mixed-methods approach, integrating results from P. irritans sampling, a household survey instrument, and an observational checklist. Using previously published vectorial capacity data, the minimal P. irritans index required for interhuman bubonic plague transmission was modeled to determine whether household infestations were enough to pose a plague transmission risk. Socio-ecological risk factors associated with a high P. irritans index were then identified for enrolled households using generalized linear models. Household flea abundance was also modeled using the same set of predictors. A high P. irritans index occurred in approximately one third of households and was primarily associated with having a traditional dirt floor covered with a plant fiber mat. Interventions targeting home improvement and livestock housing management may alleviate flea abundance and plague risk in rural villages experiencing high P. irritans infestation. As plague-control resources are limited in developing countries such as Madagascar, identifying the household parameters and human behaviors favoring flea abundance, such as those identified in this study, are key to developing preventive measures that can be implemented at the community level.

Does a therapeutical dose of ivermectin impairs testicular homeostasis of rats via excessive apoptosis?

Ivermectin is a medication used to treat parasite infestations in humans and in veterinary medicine. Previously we showed that therapeutical doses of ivermectin impaired spermatogenesis and spermiogenesis in adult rats. The present study was proposed to understand the pathophysiological mechanism that triggered these impairments induced by ivermectin. It was a particular objective to study if ivermectin induced excessive apoptosis. Adult rats were treated with a therapeutical dose of ivermectin (subcutaneously). Their testis was evaluated for the expression of caspase-3 (a marker of apoptosis), using immunohistochemistry techniques. Results revealed that ivermectin treatment increased the expression of caspase-3 (labeled seminiferous tubules and strongly labeled tubules), as well as increased the number of tubules that presented labeled cells in the tubular lumen, compared to the data of the control group. In conclusion, a therapeutical dose of ivermectin induced expressive apoptosis in cells of the seminiferous tubules of rats, affecting the testicular natural homeostasis process, which resulted in the spermatogenesis and spermiogenesis impairments previously reported.

Cerebral Hydatid Disease Patients Admitted to Duhok City Hospitals: Management and Outcome

Background and objectives: The human systemic infestation with Echinococcus granulosus affects the brain in 2% of cases, cerebral hydatid cyst, which presents clinically as slowly growing intracranial mass lesion leading to variable symptomatology of raised intracranial pressure, neurological deficit, and epilepsy. The condition, when occurs, needs prompt surgical removal in order to avoid fatal consequences. The aim of this article is to report clinical data and our experience concerning cerebral hydatid cyst presentation, surgical management, complications, and outcome. Methods: A retrospective case-series study encompassing 8 patients, four females and four males, whose ages ranged between 3.5-35 years, harboring cerebral hydatid cysts, including one cerebral hydatid abscess. The current study was conducted at Duhok Teaching Hospitals, during January 2005-May 2021. The diagnosis was established on clinical and radiological, computed tomography and magnetic resonance imaging backgrounds, and confirmed by operative findings, and histopathology (abscess cyst). Via appropriate craniotomies, all cerebral hydatid cysts, and abscess, were successfully removed, except, the recurrent hydatid cysts which needed an additional posterior fossa craniectomy to achieve total removal. There was no need for the use of advanced statistical system. Results: Compared to their original neurological deficit at presentation, seven cases could achieve complete recovery, except, the patient with recurrence, whose recovery was delayed and suboptimal due to repeated surgeries; there was no mortality. Conclusion: The operating surgeon should practice meticulous care avoiding the possible risk of an accidental rupture during cyst delivery. Various opinions address the pre-operative, intra-operative and post-operative use of Albendazloe, however, we are not sure whether the use of this medication could have prevented the recurrence of CHC which followed the accidental rupture.

Healthcare users' knowledge and experiences regarding the management of scabies in the Deder district, Ethiopia.

Scabies is an ectoparasitic, highly contagious skin disease caused by a human itch mite infestation of the skin, and it is the leading cause of morbidity and disease burden in developing countries. The purpose of this study was to investigate healthcare users' current knowledge and experiences with scabies management provided at primary healthcare facilities. A qualitative research design was used to address the research objectives. Focus group interviews with 58 health care users were used to collect data. Thematic analysis was performed on the verbatim transcriptions using Tesch's approach. The findings showed that the knowledge of healthcare users who participated in the study on scabies, its management, prevention, and control was limited. Health care users experience different challenges regarding scabies and the management thereof. Five themes emerged after data analysis. These were knowledge regarding scabies, knowledge regarding the management of scabies, knowledge regarding the prevention of scabies, perceptions regarding receiving treatment for scabies, and recommendations regarding the availability of materials and medication. Healthcare users in the area had limited knowledge and experienced different challenges regarding scabies and their management. These challenges contribute to low-quality health services with undesirable health outcomes. To narrow this gap, consistent and programed health education was provided to the community through different modalities by using the existing health system to increase awareness regarding scabies. Following the implementation of community awareness, each community member was positioned to prevent and control scabies.

HUMAN LICE INFESTATION, DIAGNOSIS AND TREATMENT: A MINI-REVIEW

HUMAN LICE INFESTATION, DIAGNOSIS AND TREATMENT: A MINI-REVIEW

Prevalence of Fasciola Infection in Cattle- Ready- for -Slaughtering at some Abattoirs in Oyo, Oyo State, Nigeria

Fascioliasis is one of the most prevalent and economically significant parasitic illnesses of domestic animals, particularly cattle, sheep, goats, and man. It is particularly widespread in countries with heavy cattle production especially places with low interest in vector-related diseases. Therefore, the study was designed to investigate the prevalence of this parasitic disease among the cattle slaughtered in the selected abattoirs in Oyo, Oyo State, Nigeria. Two hundred and fifty (250) faecal samples were collected from the rectum of the slaughtered cattle. The samples were analyzed using the Formol-ether Concentration technique. Also, post mortem examination of the liver and other organs of the slaughtered cattle (250) at the abbattior were also examined for Fasciola infestation. The data were were analyzed with Chi-square at 5% level of significance using SPSS. It was observed that 77 (30.8%) were positive to fascioliasis out of the 250 slaughtered cattle examined. The prevalence of the infection based on the sex of the cattle was found to be statistically significant (p = 0.001).The percentage of fascioliasis depending on the breed of the cattle was observed to be lowest (25%) in Sokoto Gudali and highest (33.33%) in White Fulani. The analysis implied that there was a strong association between infection and cattle breeds. Prevalence of fascioliasis based on the estimated age of animals was not statistically significant however; animals aged 3 years and 6 months had the highest percentage (54.1%) while those within 2 years and 6 months had no cases of fascioliasis. Fascioliasis is an endemic illness in the study area among cattle slaughtered for consumption. This suggests the possibility of human infestation through consumption especially when it is under-processed. The need for health policy to ensure slaughtering of healthy cattle become important to ensure safe public health especially through consumption of meat. Also, public health intervention through mass vaccination of cattle, education of cattle farmers and introduction of veterinary inspectors at the point of slaughter is important in controlling Fascioliasis.

Temporal variation of Triatoma dimidiata abundance and infection with Trypanosoma cruzi in domestic and sylvatic habitats of rural Yucatan, Mexico

In the Yucatan Peninsula, Mexico, Triatoma dimidiata is the main vector of Chagas disease. This is a native species in the region that principally inhabits sylvatic habitats. Nevertheless, it shows a tolerant behavior to anthropogenic disturbance, with adult bugs frequently infesting human dwellings, principally during the warm and dry season. Yet, whether the temporal variation of abundance is independent of the habitat and how this is related to the infection rate with Trypanosoma cruzi in Yucatan is still poorly understood. The objective of this study was to simultaneously analyze the temporal variations of T. dimidiata abundance and infection with T. cruzi in domestic and sylvatic habitats from two localities of rural Yucatan (Sudzal, 20°52ʹ19″N, 88°59ʹ20″W and Teya, 21°02ʹ55″N, 89°04ʹ25″W) to help for the further improvement of locally adapted strategies aimed at controlling T. cruzi vector transmission. Using community participation and a combination of different trapping techniques, we collected T. dimidiata bugs during 29 consecutive months within domestic and sylvatic habitats. We then assessed by PCR the infection of the bugs with T. cruzi. Generalized linear models were used to evaluate the effect of climatic variables on the abundance of T. dimidiata and the effect of bug sex, season and habitat on the prevalence of infection with T. cruzi. Overall, 3640 specimens of T. dimidiata were collected. We clearly observed peaks of maximum abundance in both habitats during the warm and dry season and found a negative association of bug abundance with relative humidity. The overall prevalence of infection of the bugs with T. cruzi was 15.2 %. Additionally, bugs collected in domestic habitats displayed a significantly higher prevalence of infection than sylvatic bugs (19.6% vs. 6.1 %, respectively), suggesting an increased risk of T. cruzi transmission related with anthropogenic disturbance. Our study is the first to describe the annual pattern of abundance of T. dimidiata in sylvatic habitats of rural Yucatan and constitutes a contribution to the knowledge of T. dimidiata ecology and of T. cruzi transmission cycle dynamics in the region. In Yucatan, where the use of mosquito nets has shown to be effective to limit human dwelling infestation by T. dimidiata, reinforcing the awareness of local residents about the increased risk of T. cruzi transmission during the warm and dry season when realizing activities in the sylvatic ambient should be, among others, also considered to improve control strategies and limit the risk of vector transmission.

What's Eating You? Tropical Rat Mite (Ornithonyssus bacoti).

The tropical rat mite (Ornithonyssus bacoti) commonly infests wild and pet rodents, but they are not host specific. Bodily contact with wild or domesticated rodents is the most common source of infestation. Mites can live off many mammal hosts for a long period of time; therefore, living in quarters infested by mice can lead to mite exposure. Human infestation presents as urticarial, pruritic, cutaneous lesions that may be misdiagnosed as an arthropod bite, an infection, or contact dermatitis. Symptomatic relief of pruritus can be provided with a topical corticosteroid or antihistamine. The most effective treatment is an antiparasitic, such as permethrin cream, as well as extermination of rodents, mites, and any other pests in the patient's living space.

The East Indies reptile tick Amblyomma helvolum Koch, 1844 (Acari: Ixodidae), taxonomy, biology and new host records, including the first record of human infestation

Amblyomma helvolum is a widespread, generalist ectoparasite of reptiles in the oriental region, and has the potential to become highly invasive should it be inadvertently introduced outside its native range through the exotic pet trade. All life stages of A. helvolum are re-characterised morphologically and the first examples of nanism (dwarfism) and gynandromorphy (male and female tissue in one animal) for the species are described. Eighteen new hosts records are presented for A. helvolum, including the first case of human infestation. The taxonomy, distribution, ecology, phenology, disease associations, and invasion biology of the species are also discussed.

Efficacy of nitenpyram on the treatment of tungiasis in dogs from brazilian southern amazonic region

Tungiasis is a zoonotic skin disease caused by the penetration of the female flea of Tunga penetrans into the skin of many mammal hosts. Among the hosts, domestic, synanthropic and sylvatic animals serve as reservoirs. However, the dogs are considered the main source of human infestation in rural and endemic communities. The aim of this study was to evaluate the tungicidal efficacy of nitenpyram for the treatment of tungiasis caused by Tunga penetrans in naturally infested dogs from brazilian amazonic region. Twelve dogs presenting from three to fifty-three viable lesions received one dose of nitempyram. The animals received dosages according to the manufacture’s recommendation. The criteria used to determine the drug efficacy were the number of viable lesions after treatment. These were quantified at 3, 7- and 14-days post-treatment. According to the results, the efficacy of Nitempyram was 92,20%, 88,07% and 66,06% in the 3, 7 and 14-days post-treatment.

Evaluation of resistance of human head lice to pyrethroid insecticides: A meta-analysis study

IntroductionPediculosis is one of the most common annoying infections caused by parasitic lice in humans. Pyrethroids are one of the main insecticides used to treat this infection. But recently, due to the Resistance of lice to this group of insecticides, its insecticidal effects have been affected. The present study was conducted through a meta-analysis to investigate the prevalence of pyrethroid resistance against these insecticides worldwide. MethodsThis study was conducted as a meta-analysis of the prevalence of treatment resistance in human head lice against pyrethroid insecticides worldwide. Based on this, all articles published without a time limit until the end of June 2022 in PubMed/MEDLINE, Web of Science (ISI), Scopus, and Google Scholar databases were extracted and using random-effects meta-analysis model statistical methods in the meta-analysis, Cochrane, Index I2, and funnel plot were analyzed by STATA software. ResultsTwenty studies were included in the meta-analysis process. According to this, the prevalence of pyrethroid resistance insecticides in human head lice was estimated at 59% (CI95%: 50%–68%). Among pyrethroid insecticides, the highest prevalence of pyrethroid resistance against permethrin insecticide was 65%. Regarding the prevalence of Resistance by year, the prevalence before 2004 was estimated at 33%, but after 2015, this rate reached 82%. Also, the majority of pyrethroid resistance was estimated at 68% using genetic diagnosis methods and 43% using clinical diagnosis methods. ConclusionMore than half of human head lice pyrethroid resistance insecticides. Based on this, it is recommended that before using this treatment method to treat human head lice Infestation, it should investigate the prevalence of pyrethroid resistance in that area, and if the majority of Resistance is high, alternative or combined treatment methods should be used.

Isolated hepatomegaly revealing visceral toxocariasis: A unique case report

Toxocariasis is a zoonotic helminth infection secondary to the infestation of humans by larvae of Toxocara sp. These are nematodes

PRIMARY HYDATID CYST OF THE THIGH - ABOUT A CASE AND REVIEW OF THE LITERATURE

Hydatid disease is a parasitic infestation of humans and herbivorous animals, caused by Echinococcus granulosus. Dogs and some wild carnivores, such as foxes, are definitive hosts, harboring worms in their intestines. Musculoskeletal cysts represent 0.7 to 3% of the total number of cases of hydatidosis. Primary muscular hydatidosis without involvement of the thoracic or abdominal organs is extremely rare. Intramuscular infestation can mimic a soft tissue tumor resulting in inappropriate rupture of the cyst with the associated risks of anaphylaxis and dissemination to other organs. Preoperative evaluation is therefore essential to avoid life-threatening complications. We report the case of a 64-year-old patient presenting with a cystic swelling of the thigh admitted to the emergency department for a ruptured hydatid cyst. Surgical excision with complementary pharmacological treatment is necessary to obtain complete cure.

Detection of Arthropod-Borne Bacteria and Assessment of MALDI-TOF MS for the Identification of Field-Collected Immature Bed Bugs from Mauritania.

Human infestations by bed bugs have upsurged globally in recent decades, including in African countries, where recent reports pointed out an increase in infestation. Sympatric dwelling has been described for two species of bed bug parasitizing humans: Cimex hemipterus (the tropical bed bug) and C. lectularius. Identification of these two species is based on morphological characteristics, and gene sequencing, and may also rely on Matrix-Assisted Laser Desorption Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF MS). The present work aimed to assess whether MALDI-TOF MS was applicable for species level identification of immature stages of Cimex. Arthropods were collected in domestic settings in Nouakchott, Mauritania. Identification used morphological keys and MALDI-TOF MS identification was assessed for immature stages. Quantitative PCR and sequencing assays were used to detect arthropod-associated bacteria in each specimen. A total of 92 arthropods were collected, all morphologically identified as C. hemipterus (32 males, 14 females and 45 immature stages). A total of 35/45 specimens produced good quality MALDI-TOF MS spectra. Analysis allowed species level identification of all immature C. hemipterus after their spectra were entered into our in-house MALDI-TOF MS arthropod spectra database. Molecular screening allowed detection of Wolbachia DNA in each specimen. These results suggested that MALDI-TOF MS is a reliable tool for species level identification of Cimex specimens, including immature specimens. Future studies should assess this approach on larger panels of immature specimens for different Cimex species and focus on the precise staging of their different immature developmental stages.

Molecular diagnosis and subtyping of Blastocystis sp.: Association with clinical, colonoscopic, and histopathological findings.

Blastocystis sp. is the most common parasitic infestation in humans. However, its pathogenicity remains controversial. Our aim was to study the prevalence of Blastocystis sp. parasite subtypes in patients with gastrointestinal manifestations referred for colonoscopy and assess possible correlation with clinical, colonoscopic, and histopathological findings. One hundred patients with gastrointestinal manifestations referred for colonoscopy were enrolled. Stool samples were collected and examined both microscopically and by real-time quantitative polymerase chain reaction (qPCR) for detection of Blastocystis sp. Subtyping was done for positive samples by qPCR and confirmed by sequencing. qPCR sensitivity far exceeded microscopy in detection of Blastocystis sp. (58% vs. 31%, agreement 38.5%). The most commonly detected subtype was 3 (50%), followed by 2 (32.8%) and 4 (13.8%). Abdominal pain was the most common clinical symptom; inflammation and colitis were the most common abnormal colonoscopic and histopathological findings. The most frequent subtype encountered in those findings was Subtype 3. This study confirmed the importance of using qPCR in diagnosis of Blastocystis sp. An association between abnormal clinical, colonoscopic, and histopathological findings on the one hand, and Blastocystis sp. infestation, especially Subtype 3, on the other hand, is also posed. This necessitates further studies to assess the mechanism of association with pathogenicity.