Endemic Areas Research Articles

Mammary Schistosomiasis: Malignancy Mimicker or More?

Abstract Introduction/Objective Schistosomiasis is a neglected tropical disease (NTD) which affects more than 200 million people worldwide, with approximately 85% of cases occurring in sub-Saharan Africa. It serves both as an important etiologic agent in the development of carcinomas of many organ systems, as well as a common incidental histological finding in various organs, including the prostate, lung, spine, and liver. Detection of Schistosoma ova in the breast is rare. Here, we present a case of schistosomiasis of the breast in a patient concurrently diagnosed with breast carcinoma of the contralateral breast. Methods/Case Report A 48-year-old Mozambican female presented with a right breast mass, with suspicious microcalcifications detected in the contralateral breast on mammography. Biopsy confirmed invasive ductal carcinoma of no special type (NST) in the right breast and identified Schistosoma ova in the left, notably lacking an associated inflammatory response. A Ziehl-Neelsen special histochemical stain was negative, favoring schistosoma Hematobium species. Results (if a Case Study enter NA) NA Conclusion Our case marks the first in English literature where schistosomiasis was identified in the context of contralateral breast carcinoma, posing the question as to whether there is an association between schistosomiasis and breast carcinoma in our patient. One possible theory suggests hyperestrogenism secondary to Schistosoma infection in the liver. Breast schistosomiasis presenting as microcalcifications poses a diagnostic challenge, as it may clinically and radiologically resemble malignant breast disease. Histopathological diagnosis is crucial to confirm the diagnosis and prevent unnecessary procedures. Contrary to other organ systems, our case highlighted that schistosomiasis in the breast may not be accompanied by any inflammatory response. Definitive conclusions regarding the exact species of schistosomiasis cannot be drawn histologically based solely on H&E findings due to the plane of sectioning; therefore, performing a Ziehl-Neelsen stain is beneficial. As screening mammography increases in endemic areas, a high index of suspicion and further research is warranted.

Urogenital schistosomiasis, a leading cause of bladder squamous cell carcinoma

Abstract Introduction/Objective Schistosoma, genus of trematodes, commonly known as blood flukes are parasitic flatworms responsible for a group of infections in humans termed schistosomiasis and hundreds of millions of people are infected worldwide. In areas where Shistosoma is not endemic to the region most cases of bladder malignancy are of urothelial origin. In areas where Shistosoma is endemic bladder malignancy is more commonly squamous cell carcinoma. However, with increased travel, migration and tourism it is important to potentially consider Shistosoma infection in areas that are not typically considered endemic regions. Methods/Case Report A 62-year-old male presented to our hospital and revealed through an interpreter he has had 1.5 years hematuria with “pieces of meat or brown dirt”. Cystoscopy was performed and showed a large necrotic mass. CT scan showed an 8.2 cm exophytic bladder dome mass. TURBT was performed and a diagnosis of invasive high-grade urothelial carcinoma with squamous differentiation and with multiple Schistosoma organisms identified.The patient received Schistosoma treatment and was scheduled for radical cystectomy and ileal conduct. A few days before the scheduled procedure the patient presented to our emergency department with acute abdominal pain. He was subsequently diagnosed with progressive bladder cancer with new left malignant ureteral obstruction, which lead to hydronephrosis, DVT, abdominopelvic ascites and intraperitoneal bladder perforation. Abdominal fluid cytology showed atypical keratinizing squamous cells suspicous for malignancy and marked acute inflammation. Patient underwent cystectomy with ileal conduit and the specimen was sent to pathology for examination. Results (if a Case Study enter NA) NA Conclusion Gross examination showed an irregular perforated bladder. Microscopic examination showed a high grade urothelial carcinoma with squamous and sarcomatoid differentiation with detrusor muscle invasion. Additionally, Schistosoma organisms with a terminal spine and calcified eggs were identified. Some of the calcified egg material was engulfed by giant cells. The organisms are surrounded by a prominent eosinophilic infiltrate. Lymphovascular invasion is also noted. Schistosomiasis is associated with the development of squamous cell carcinoma of the bladder. It is important to maintain high oncological alertness for squamous cell carcinoma, particularly for patients arriving from endemic areas. Such as in our case, a patient from Somalia living in Kansas City.

Rectal Schistosomiasis and Adenocarcinoma

Abstract Introduction/Objective Schistosoma infestation has been implicated by the International Agency for Research on Cancer as an etiology for several cancers such as colon, liver, and bladder. S. japonicum is classified as a probable carcinogen in humans (class 2B). These trematodes may cause chronic infection in the affected organ leading to the trend of “inflammation-adenoma-carcinoma”. There is rising evidence that infection with Schistosoma japonicum is correlated with the liver and colorectal carcinoma in endemic Asian countries. We herein present a case of rectal adenocarcinoma associated with Schistosoma as a possible causal factor. Methods/Case Report An 88-year-old-woman from China, currently living in United States for past six years, presented with rectal bleeding. Colonoscopy showed evidence of a rectosigmoid mass 2.2 x 1.0 x 0.3 cm. She underwent trans-anal excision of the tumor. Microscopic examination showed moderately differentiated adenocarcinoma with tumor invading the muscularis propria (pT2). There were numerous oval / round calcified eggs (30 - 46 microns) with minute subterminal or no spine morphologically consistent with Schistosoma japonicum associated with granulomatous and foreign body giant cell reaction, fibrosis, and tissue eosinophilia. She was treated with Praziquantel and is currently undergoing endoscopic surveillance for recurrence. Results (if a Case Study enter NA) N/A Conclusion Patients with chronic Schistosoma japonicum infection have 3 times increased risk of developing colorectal cancer than those with no previous exposure to schistosomal infection. We believe that chronic S. japonicum infection is the likely etiology of rectal cancer in our patient. Physicians should be aware of such associations, especially for immigrants from endemic areas, to facilitate accurate diagnosis and management.

New Strides in Prevention of Malaria during Pregnancy Present Multitudinous Opportunities.

Pregnant women are at a higher risk of developing complications from malaria, a mosquito-borne disease caused by Plasmodium parasites, resulting in considerable maternal and infant morbidity and mortality. Malaria in pregnancy causes unfavorable and life-threatening outcomes for both the mother and fetus not limited to maternal anemia, hypoglycaemia, cerebral malaria, pulmonary edema, and puerperal sepsis. WHO recommends wide-ranging strategies for this detrimental but preventable disease; however, numerous challenges persist in ensuring high uptake of preventive therapies, effective usage of insecticide-treated bed nets, and early initiation and optimal antenatal care coverage for pregnant women. This work distils recent global advances in preventive strategies for malaria in pregnancy. We discuss three mainstay interventions by WHO, viz. intermittent preventive treatment of malaria in pregnancy (IPTp), utilization and outcomes of insecticide-treated bed nets (ITNs), and headways in malaria case management using therapeutic drugs. We cover multitudinous facets of antenatal care, WHO-advised community-based delivery of IPTp (c-IPTp), intermittent screening and treatment for malaria in pregnancy (ISTp), a malaria vaccine for pregnant women, and auxiliary factors that are crucial for improving prevention outcomes. Despite the reduction in malaria globally, malaria in pregnancy remains a prevalent issue in endemic areas, which warrants strengthening of preventative strategies. This work attempts to consolidate pivotal observations of the prevention of malaria during pregnancy by highlighting key advances, priority areas, new opportunities, research gaps, and challenges that need to be addressed to ensure improved outcomes in pregnant women infected with malaria.

Long lasting insecticidal nets (LLINs) intervention impact on use, misuse and challenges in malaria and lymphatic filariasis transmission

To assess the effectiveness and misuse status of Long Lasting Insecticidal Nets (LLINs), intervention, a study was conducted in areas of malaria and lymphatic filariasis endemicity from November 2021 to August 2022. A preliminary survey preceded a cross-sectional survey of the misuse of LLINs. Considering the outcome of the former, 57 households misusing LLINs were reported. Thirty (30) cohorts each from LLIN misusing and LLIN non misusing households served as permanent cohorts for mosquito collections (60 rooms in 60 households in 3 sentinel villages). The study also investigated the status of LLIN usage and non usage. Mosquitoes caught with Aspirators and Pyrethrum Knockdown (PKD) techniques were identified using standard morphological keys. Among those who used LLIN, 68.42% used it for other purposes than vector control while 31.58% didn’t utilize it for mosquito control. About 59.65% didn’t know the effect of using it for purposes other than malaria/LF control while 40.35% were familiar. Of 8,180 endophilic mosquitoes caught and assessed for parity, infection/infectivity status, 60.07% (4,914/8,180) and 39.93% (3,266/8,180) represented LLIN misusing and LLIN non-misusing catches respectively. Overall, insignificantly higher catches were made in LLIN misusing cohorts than LLIN non misusing cohorts (63.54% versus 36.45%, 58.89% versus 41.11%, 58.86% versus 41.18%) for 2015, 2016 and 2017 respectively. Specifically, malaria/LF vector densities showed that Anopheles gambiae s.l. (82.53% versus 74.04%) was the highest followed by An. funestus s.l. (10.15% versus 12.19%) and Culex quinquefasciatus (6.82% versus 3.83%) while other species were rarely present. The physiological, infection (0.28% versus 0.49%) and infectivity (0.00% versus 0.00%) statuses with Wuchereria bancrofti were insignificant between the cohorts (p>0.05). None of the Anopheles assessed for Plasmodium sporozoite were positive for both cohorts. The percentage level of LLIN household use was 43.33% while 41.03% slept under LLIN daily, 58.97% slept sometimes. Obstacles to LLIN use included hot/heat (56.86%), dislike (21.57%), lack of protection (11.86%) and ineffectiveness (9.80%). The role of significant misuse of LLIN was highlighted by the study. The results indicated the intensity of filariasis transmission by transmitting vectors was higher than that of malaria and re-emphasis the need to promote positive attitude towards the use of LLIN for control of the two diseases.

Abundance and taxonomic characterization of chigger mites (Acari: Trombiculidae and Walchiidae) associated with rodents in selected scrub typhus-prone areas in Southern and Western provinces of Sri Lanka

Larval trombiculid mites (chiggers) are the vectors and reservoirs of the potentially lethal infectious disease, scrub typhus (ST) caused by Orientia tsutsugamushi. Small rodents are natural hosts of parasitic larval stage of the chigger mites. This study focused on determining the abundance of chigger mites associated with rodents in Sri Lanka and the taxonomic characterization of field-caught chiggers. Field sampling was conducted in the districts of Galle, and Hambantota of the Southern Province, and Gampaha of the Western Province, in 2019 and 2020. Sampling sites were selected according to the patient distribution. A total of 58 small mammals (rodent species: Rattus rattus (Black rat), Rattus norvegicus (Brown rat), Tatera indica (Indian gerbil), Gollunda ellioti (Indian bush rat) and Suncus murinus (Asian house shrew)) were captured using baited traps. Chiggers from the captured rodents were speciated morphologically by visual inspection and morphometry using a camera-mounted light microscope (x100). A total of 394 chigger mites were collected. Three different genera were identified, including Leptotrombidium, Schoengastiella, and Microtrombicula. Leptotrombidium imphalum (72.59%; n=286) was the predominant species, followed by Schoengastiella punctata (8.12%; n=32). Some specimens were identifiable only up to genus level, Leptotrombidium sp. (3.55%; n=14) and Microtrombicula sp. (4.82%; n= 19). Some (7.11%; n=28) were not trombiculid mites, while 3.81%; n=15 was damaged beyond identification. Leptotrombidium imphalum was detected for the first time parasitizing the murids - Rattus novergicus and Tatera indica in the district of Galle, a new locality. In addition, S. punctata was recorded in a new locality in the Gampaha district, Western province with a new host association, Golunda ellioti. This study emphasizes the need for further entomological surveys in ST disease-endemic areas. Developing a morphological identification key for chigger mites in Sri Lanka is a top priority to facilitate field surveys.

Seronegative brucella meningitis diagnosed by CSF PCR: report on seven cases

IntroductionNeurobrucellosis (NB) can be associated with meningitis and present as a headache with or without meningeal signs. Pseudotumor presentation of NB has been reported to be accompanied by lymphocytic predominant cerebrospinal fluid(CSF) pleocytosis. NB is diagnosed by means of isolation of Brucella from blood or CSF and/or the presence of anti-Brucella antibodies in the CSF. Molecular techniques have been used in chronic or challenging cases of NB.Clinical findingsWe report on seven cases of NB presenting with different types of headache and signs of meningeal involvement. In five cases, signs of intracranial hypertension were evident in the form of papilledema, sixth nerve palsy and blurred vision.DiagnosisMRIs of the brain revealed signs of intracranial hypertension in three patients, basal meningeal enhancement in one patient and white matter lesions in one patient. Brucella serology in the blood and CSF was negative in all patients. It was interesting that four patients had normocellular CSF analysis with normal glucose and protein results. The diagnosis was made by Brucella PCR in all patients.ConclusionNB should be considered in the differential diagnoses of pseudotumor cerebri syndrome in endemic areas. It is important to employ molecular techniques using sterile CSF samples in the investigation of Brucella.

Preliminary field evaluation of indirect ELISA test using the recombinant antigen rLicNTPDase-2 for serodiagnosis of canine leishmaniasis in Colombia

Leishmaniasis is a significant public health concern, with dogs as the primary reservoir in urban scenarios and facilitating transmission. Diagnosing infected dogs is a crucial step for public health interventions, and the development of new diagnostic platforms can significantly enhance efforts in various regions worldwide. Given the limited availability of diagnostic methods in Colombia, this study evaluates the effectiveness of an Indirect Enzyme-Linked Immunosorbent Assay (ELISA) based on the recombinant protein rLicNTPDase-2 to detect Leishmania in infected dogs. Serum samples were collected from dogs in both endemic and non-endemic areas and classified as natural standards based on prior parasitological diagnoses. The results revealed 24 true positives (TP) and 9 true negatives (TN). Subsequently, the test was then validated with samples from symptomatic and asymptomatic animals, alongside the standards, yielding a specificity of 96 %, a sensitivity of 81 %, efficiency of 90.6 %, a positive predictive value of 92.8 %, and a negative predictive value of 89.6 %. The positive likelihood ratio (RV+) was 20, while the negative likelihood ratio (RV-) was 0.19, indicating high relevance and a robust clinical utility. The area under the curve (AUC) was 1.00, suggesting that the test has excellent discriminatory ability, significantly deviating from the reference diagonal. This is further supported by the significant difference(p < 0.0001) between TN and TP results determined by Fisher's exact test. Involving 163 animals showed 47 % positive and 46 % negative results with a significant difference (p < 0.05) in the mean optical density (OD) values between positive and negative samples. These findings indicate that the ELISA test effectively differentiates between positive and negative samples based on OD values. This study suggests that ELISA based on the recombinant antigen rLicNTPDase-2 could serve as a viable alternative for the serodiagnosis of leishmaniasis in canines in Colombia.

Artemisinin combination therapy at delivery to prevent postpartum malaria: A randomised open-label controlled trial

ObjectivesAlthough the incidence of malaria is increased in women in endemic areas after delivery compared to non-pregnant women, no studies have assessed the benefit of presumptive antimalarial treatment given postpartum. MethodsA randomised controlled trial investigating the efficacy of antimalarial treatment in preventing postpartum malaria was performed in healthy Papua New Guinea mothers immediately following delivery. Participants were randomised 1:1 to no treatment (n = 90) or artemisinin combination therapy (ACT), with further 1:1 ACT randomisation to artemether-lumefantrine (AL; n = 45) or dihydroartemisinin-piperaquine (DP; n = 45). Standardised reviews were conducted monthly for 6 months, including clinical assessment, malaria screening and haemoglobin measurement. The primary endpoint was incidence of slide-positive malaria within 6 months of delivery. ResultsOf 183 recruited participants, 151 completed study procedures and were included in per-protocol analyses (no treatment n = 71, AL n = 40, DP, n = 40). Those allocated to ACT were significantly less likely to develop slide-positive malaria during the 6-month follow-up period compared to those who were untreated (n = 17 (21%) vs n = 27 (38%); P = 0.016; hazard ratio 0.49 (95% confidence intervals 0.27-0.90). There was no significant difference in malaria incidence between the two ACT groups. ConclusionA treatment course of ACT at time of delivery halved the incidence of malaria infection during the first 6-month postpartum.

Lung Damage Induced by Plasmodium berghei ANKA in Murine Model of Malarial Infection is Mitigated by Dietary Supplementation with DHA-Rich Omega-3.

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are severe complications that can occur in infections caused by any Plasmodium species. Due to the high lethality rate and the lack of specific treatment for ALI/ARDS, studies aimed at understanding and searching for treatment strategies for such complications have been fundamental. Here, we investigated the protective role of dietary supplementation with DHA-rich fish oil against lung damage induced by Plasmodium berghei ANKA in a murine model. Our results demonstrated that alveolar vascular damage, lung edema, and histopathological alterations were significantly reduced in mice that received dietary supplementation compared to those that did not receive the supplementation. Furthermore, a significant reduction in the number of CD8+ T lymphocytes, in addition to reduced infiltration of inflammatory cells in the bronchoalveolar lavage fluid was also observed. High levels of IL-10, but not of TNF-α and IFN-γ, were also observed in infected mice that received the supplementation, along with a reduction in local oxidative stress. Together, the data suggest that dietary supplementation with DHA-rich fish oil in malarial endemic areas may help reduce lung damage resulting from the infection, thus preventing worsening of the condition.

Unnoticed freshwater leech as a hidden cause for recurring epistaxis: a case series and review of literature conducted at Tertiary Care Hospital Sikkim, North East India

BackgroundWhile leeches as intranasal foreign bodies are not frequently encountered, they can be one of the causes of epistaxis. The aim of the study is to raise awareness among healthcare professionals about the possibility of patients from leech endemic regions presenting with epistaxis.Case presentationWe present a series of epistaxis cases due to intranasal leech infestation. In our series of 10 cases, there were 7 male and 3 female patients, aged between 2 and 53 years old. The duration of the complaint ranged from 1 to 5 weeks. All patients experienced with blood-stain nasal discharge or frank nasal bleeding at some point and most of them have a history of leech infestation from spring water as a local source. This article presents our approach to managing nasal leech infestation as epistaxis and outlines the precautionary measures taken for the retrieval of this living foreign body.ConclusionDetails of the history must be taken before concluding the diagnosis. Maintain a high index of suspicion of leech infestation as a hidden cause of epistaxis especially in patients coming from endemic areas.

Environmental suitability throughout the late quaternary explains population genetic diversity

Genetic variation among populations is reflected in biogeographic patterns for many species, but general rules of spatial genetic variation have not been established. In this paper, we establish a theoretical framework based on projecting environmental Grinellian niches back through time to relate the present geographic distribution of population genetic structure to a given species' historical evolutionary context. Thanks to advances in next‐generation sequencing technologies, as well as more accurate climate models and the amassing of information stored in biological collections, it is possible to implement this theoretical framework directly. We develop a case study of the tassel‐eared squirrel Sciurus aberti to jointly analyze spatial, environmental, and genetic data to predict the historical endemic area of this species. Our results reveal that in cases of genetic isolation by geographic distance, the prevalence of environmental suitability over time corresponds to the genetic fixation index (Fst) of populations with respect to a source population. Populations closer to the historical endemic area show higher genetic diversity and a lower Fst value. This empirical example relates back to the theoretical framework, allowing two further advances: 1) a layer of biogeographic explanation for the results obtained from population genomic methods; and 2) predictive maps of this genetic structure to support biodiversity conservation efforts. Overall, this work advances a perspective that integrates population genetics with historical patterns of species distribution. The limitations posed in the theoretical framework should be considered before implementing the suitability prevalence area (SPA) in a general way over different taxa. Otherwise, the predictability of the genetic diversity of populations as a product of environmental stability over time may not be adequate.

Force of Infection (FOI) and Multiplicity of Infection (MOI) in Plasmodium falciparum Infected Children Aged 1.5-12 Years Living in the Malaria Endemic Area of Banfora, Burkina Faso.

The aim of this study was to explore molecular measures of P. falciparum malaria burden (FOI and MOI) in the context of seasonal malaria chemoprevention. We analyzed malaria cases collected as part of a longitudinal cohort study. The cohort included P. falciparum-negative children aged 1.5 to 12, as confirmed by PCR 21 days after a radical cure using DHA-PQ or AS. Children were followed up for six months using active and passive case detection methods. At each visit, dried blood spots and blood smears were collected by finger prick, along with clinical data. Parasite DNA was extracted and analyzed by nested PCR for detection and genotyping of P. falciparum parasites. A total of 458 P. falciparum isolates collected during follow-up from October 2020 to March 2021 were genotyped. During the follow-up, children contracted 1.05 (95% IC [0.81-1.30]) new P. falciparum infections/child/time of exposure, and the MOI value was 3.00 (SD 1.60). Age is a protective factor (IRR: 0.74; 95% CI: 0.61, 0.90) against the occurrence of an episode of malaria, unlike an increase in MOI (IRR: 1.63; 95% CI: 1.04, 1.99), which is a favorable factor (p < 0.05). This study confirms the reduction in malaria transmission in our study area, probably due to the massive deployment of control tools.

Rapid antigen detection test for diagnosis of post kala-azar dermal leishmaniasis: application of CL Detect™ rapid test for active case detection in the endemic area.

Post-kala-azar dermal leishmaniasis (PKDL) is a skin condition that occurs in a small percentage of people who have been cured of visceral leishmaniasis (VL), and contributes to transmission of VL. The rK39 rapid test cannot decisively diagnose PKDL due to presence of antileishmanial antibodies from past VL episodes. CL Detect™ Rapid Test, an in-vitro diagnostic test that detects Leishmania antigen peroxidoxin, was assessed for diagnosing PKDL. The CL Detect RDT had 73.3% sensitivity and 100% specificity in the study. The test can be used as a primary screening tool to monitor PKDL in endemic regions and identify active Leishmania infection.

The Development and Application of Lyophilized LAMP Detection Reagent for Listeria monocytogenes.

Listeria monocytogenes, a zoonotic foodborne pathogen, presents a significant threat to global public health. Therefore, rapid and sensitive detection methods are crucial in mitigating the spread of L. monocytogenes induced diseases. This study introduced a loop-mediated isothermal amplification (LAMP) lyophilized powder detection reagent specifically designed for identifying Listeria monocytogenes. The reagent is user-friendly, quick, and can be easily transported and stored at room temperature. It exhibits no cross-reactivity with eight other types of bacteria and boasts a sensitivity of 101CFU/mL. In a comparative study of 30 samples, the LAMP lyophilized powder detection reagent demonstrated higher sensitivity than the commercial Listeria monocytogenes qPCR detection kit. Additionally, the experimental time was reduced by approximately 30min, making it highly suitable for rapid diagnosis. Preparation of lyophilized LAMP reagents may facilitate large-scale deployment, particularly in endemic areas or regions facing rapid outbreaks. This could greatly aid in controlling the transmission of pathogens, especially those transmitted through food.

Intestinal parasites in children from native communities of Salta, Argentina.

Intestinal parasites particularly affect vulnerable populations, making their management crucial in endemic areas. To evaluate the relationship between intestinal parasites, socioeconomic characteristics, and anthropometric nutritional status. This is an observational, cross-sectional study conducted on children aged 1 to 15 years in Tartagal, Argentina, for a year. Intestinal parasitic infections were determined through fecal analysis using sedimentation techniques (Teleman), Kato-Katz, and the Baerman method. Demographic and socioeconomic data were collected using a standardized survey. Height, weight, and mid-upper arm and head circumference were measured in the participants. Of the 588 participants who provided fecal samples, 55.4% had intestinal parasites, with G. lamblia and H. nana being the most prevalent species. Additionally, 31.9% of participants were found to have malnutrition due to excess weight. Risk factors for intestinal parasite presence included age, overcrowding, and walking barefoot, while owning a refrigerator, having an animal corral, adequate water storage, and belonging to the Guaraní ethnic group were protective factors. High vulnerability areas were observed regarding housing conditions and access to public services. An association between socioeconomic conditions and the risk of intestinal parasite presence was observed. However, no association was found between anthropometric nutritional status and the presence of intestinal parasites.

Saurian-associated Leishmania tarentolae in dogs: Infectivity and immunogenicity evaluation in the canine model.

In canine leishmaniosis endemic areas, Leishmania infantum may occur in sympatry with the non-pathogenic Leishmania tarentolae, which is associated to reptiles. The potential infectivity of L. tarentolae for mammals raises questions about the interactions between the two Leishmania species, and the potential cross-immune protection in dogs. This study aimed to assess the outcome of experimental L. tarentolae infection in dogs, determining: i) the anti-L. tarentolae antibody production, ii) the duration of the immunity and cytokine expression, and iii) the possible pathogenic effect in the canine host. Twelve purpose-bred beagle dogs were randomly allocated to three groups (intravenous inoculation, G1; intradermal inoculation, G2; negative control, G3). G1 and G2 dogs were inoculated twice (day 0, day 28) with 108 promastigotes of L. tarentolae strain (RTAR/IT/21/RI-325) isolated from a Tarentola mauritanica gecko. The animals were followed until day 206. Blood, serum, conjunctival swabs and lymph node aspirate samples were collected monthly and bone marrow, liver and spleen biopsies on day 91. Hematological and biochemical parameters were assessed monthly, as well as serology (IFAT and ELISA) and molecular identification of L. tarentolae. Mononuclear cells (PBMC) were obtained to assess the cytokine expression through in vitro stimulation or (re-) infection. Data from this study demonstrated that DNA from L. tarentolae is detectable up to 3 months post-infection, with seroconversion after day 28. Moreover, the non-pathogenic nature of L. tarentolae was confirmed, with a neutral Th1/Th2 polarization, and a possible shift to Th1 phenotype after derived macrophages (re-) infection, as demonstrated by the expression of IFN-gamma. Therefore, L. tarentolae demonstrated a great potential as a surrogate pathogen and/or immune-prophylaxis/immune-therapy against Leishmania infections in dogs and humans.

Phenotypic variation in the lipopolysaccharide O-antigen of Salmonella Paratyphi A and implications for vaccine development

Enteric fever remains a major public health problem in South and Southeast Asia. The recent roll-out of the typhoid conjugate vaccine protecting against S. Typhi exhibits great promise for disease reduction in high burden areas. However, some endemic regions remain vulnerable to S. Paratyphi A due to a lack of licensed vaccines and inadequate WASH. Several developmental S. Paratyphi A vaccines exploit O-antigen as the target antigen. It has been hypothesised that O-antigen is under selective and environmental pressure, with mutations in O-antigen biosynthesis genes being reported, but their phenotypic effects are unknown. Here, we aimed to evaluate O-antigen variation in S. Paratyphi A originating from Nepal, and the potential effect of this variation on antibody binding. O-antigen variation was determined by measuring LPS laddering shift following electrophoresis; this analysis was complemented with genomic characterisation of the O-antigen region. We found structural O-antigen variation in <10 % of S. Paratyphi A organisms, but a direct underlying genetic cause could not be identified. High-content imaging was performed to determine antibody binding by commercial O2 monoclonal (mAb) and polyclonal antibodies, as well as polyclonal sera from convalescent patients naturally infected with S. Paratyphi A. Commercial mAbs detected only a fraction of an apparently “clonal” bacterial population, suggesting phase variation and nonuniform O-antigen composition. Notably, and despite visible subpopulation clusters, O-antigen structural changes did not appear to affect the binding ability of polyclonal human antibody considerably, which led to no obvious differences in the functionality of antibodies targeting organisms with different O-antigen conformations. Although these results need to be confirmed in organisms from alternative endemic areas, they are encouraging the use of O-antigen as the target antigen in S. Paratyphi A vaccines.

Current Opinion in Clinical Management of Human Cystic Echinococcosis in the Liver

Cystic echinococcosis remains a serious and threatening disease in countries on all continents where it is endemic. It is a zoonosis that continues to be neglected, despite all the efforts of the teams working on it and the WHO. Therefore, it is never too much to remember the clinical management of this disease in humans. This is what we intend in this manuscript. The disease is caused by the larval stages of cestodes (tapeworms) of the genus Echinococcus found in the small intestine of carnivores, which infects humans due to accidental ingestion of eggs of these parasites. The most frequent and most widespread across all continents is cystic echinococcosis, caused by Echinococcus granulosus (sensu lato). The annual incidence of CE can range from less than 1 to 200 per 100,000 inhabitants in various endemic areas. In China and Central Asia, the population risk is more than 40 million people, with a mortality rate of about 2% - 4%. Objectives: One of the objectives of this manuscript is to recall the parasite cycle and the form of contamination, a very important public health aspect, and draw attention to this neglected zoonosis that affects millions of people, particularly in the countries of Central Asia, the Mediterranean basin and South America. Last but not least, we intend to draw attention to the correct nomenclature in relation to the terms that define the disease, the different stages, and the proper designations, particularly with regard to therapeutic modalities. Method: The manuscript also aims to describe the form of contamination of the disease, the diagnostic methods, in particular the use of ultrasound, and the therapeutic modalities, some of which, particularly the invasive ones, must be carried out in Centres dedicated to the study and treatment of this zoonosis. Conclusion: Despite these important data and the socioeconomic impact Echinococcosis remains a neglected disease. Given this situation, all forms of echinococcosis remain serious public health threats, particularly in South America, the Mediterranean basin, and Central Asia, which must deserve the attention of the states of these continents and the WHO.

Detection of Insecticide Resistance in Aedes aegypti from Dengue Endemic Areas of Northern India

Detection of Insecticide Resistance in Aedes aegypti from Dengue Endemic Areas of Northern India