Coinfection of slime feather duster worms (Annelida, Myxicola) by different gregarine apicomplexans (Selenidium) and astome ciliates reflects spatial niche partitioning and host specificity.

Individual organisms can host multiple species of parasites (or symbionts), and one species of parasite can infect different host species, creating complex interactions among multiple hosts and parasites. When multiple parasite species coexist in a host, they may compete or use strategies, such as spatial niche partitioning, to reduce competition. Here, we present a host­symbiont system with two species of Selenidium (Apicomplexa, Gregarinida) and one species of astome ciliate co-infecting two different species of slime feather duster worms (Annelida, Sabellidae, Myxicola) living in neighbouring habitats. We examined the morphology of the endosymbionts with light and scanning electron microscopy (SEM) and inferred their phylogenetic interrelationships using small subunit (SSU) rDNA sequences. In the host 'Myxicola sp. Quadra', we found two distinct species of Selenidium; S. cf. mesnili exclusively inhabited the foregut, and S. elongatum n. sp. inhabited the mid to hindgut, reflecting spatial niche partitioning. Selenidium elongatum n. sp. was also present in the host M. aesthetica, which harboured the astome ciliate Pennarella elegantia n. gen. et sp. Selenidium cf. mesnili and P. elegantia n. gen. et sp. were absent in the other host species, indicating host specificity. This system offers an intriguing opportunity to explore diverse aspects of host­endosymbiont interactions and competition among endosymbionts.

Beyond schistosomiasis: unraveling co-infections and altered immunity.

Schistosomiasis is a neglected tropical disease caused by the helminth Schistosoma spp. and has the second highest global impact of all parasites. Schistosoma are transmitted through contact with contaminated fresh water predominantly in Africa, Asia, the Middle East, and South America. Due to the widespread prevalence of Schistosoma, co-infection with other infectious agents is common but often poorly described. Herein, we review recent literature describing the impact of Schistosoma co-infection between species and Schistosoma co-infection with blood-borne protozoa, soil-transmitted helminths, various intestinal protozoa, Mycobacterium, Salmonella, various urinary tract infection-causing agents, and viral pathogens. In each case, disease severity and, of particular interest, the immune landscape, are altered as a consequence of co-infection. Understanding the impact of schistosomiasis co-infections will be important when considering treatment strategies and vaccine development moving forward.

Quantitative PCR as a marker for preemptive therapy and its role in therapeutic control in Trypanosoma cruzi/HIV coinfection.

BACKGROUND: Trypanosoma cruzi and HIV coinfection can evolve with depression of cellular immunity and increased parasitemia. We applied quantitative PCR (qPCR) as a marker for preemptive antiparasitic treatment to avoid fatal Chagas disease reactivation and analyzed the outcome of treated cases. METHODOLOGY: This mixed cross-sectional and longitudinal study included 171 Chagas disease patients, 60 coinfected with HIV. Of these 60 patients, ten showed Chagas disease reactivation, confirmed by parasites identified in the blood, cerebrospinal fluid, or tissues, 12 exhibited high parasitemia without reactivation, and 38 had low parasitemia and no reactivation. RESULTS: We showed, for the first time, the success of the timely introduction of benznidazole in the non-reactivated group with high levels of parasitemia detected by qPCR and the absence of parasites in reactivated cases with at least 58 days of benznidazole. All HIV+ patients with or without reactivation had a 4.0-5.1 higher chance of having parasitemia than HIV seronegative cases. A positive correlation was found between parasites and viral loads. Remarkably, treated T. cruzi/HIV-coinfected patients had 77.3% conversion from positive to negative parasitemia compared to 19.1% of untreated patients. Additionally, untreated patients showed ~13.6 times higher Odds Ratio of having positive parasitemia in the follow-up period compared with treated patients. Treated and untreated patients showed no differences regarding the evolution of Chagas disease. The main factors associated with all-cause mortality were higher parasitemia, lower CD4 counts/µL, higher viral load, and absence of antiretroviral therapy. CONCLUSION: We recommend qPCR prospective monitoring of T. cruzi parasitemia in HIV+ coinfected patients and point out the value of pre-emptive therapy for those with high parasitemia. In parallel, early antiretroviral therapy introduction is advisable, aiming at viral load control, immune response restoration, and increasing survival. We also suggest an early antiparasitic treatment for all coinfected patients, followed by effectiveness analysis alongside antiretroviral therapy.

Hemoparasite occurrence and hematological/serum chemistry variations in Podocnemis vogli turtles: A comparative analysis between wild-residing infected specimens and captive non-infected counterparts.

Reptiles show a high occurrence of hemoparasites in the wild; however, little is known about the impact of such infections on their hosts' physiology and health status. Podocnemis vogli is an ancient turtle distributed in South America, frequently infected by blood parasites. Specifically, we analyzed the hematological and serum chemistry parameters of 78 wild turtles. We compared these values with those obtained from non-infected turtles of the same species in ex-situ conditions, considering factors such as sex and coinfections. Two orders of hemoparasites were detected under microscopic analyses: Adelorina, represented by Haemogregarina sp. (98.72 ± 0.28%), and Haemosporida, represented by Haemocystidium sp. (30.77 ± 1.16%), the latter genus being always in coinfection with Haemogregarina. Significant differences were observed in 20 parameters between infected (free living) and uninfected (living in captivity) turtles. The ALP, PCV, Hb, and MCV were significantly different by sex; albumin, cholesterol, creatinine, percentage of heterophils, lymphocytes, and basophils differed in coinfection. This is the first report of reference intervals of P. vogli in the wild and the first study comparing hematological and blood biochemistry values between hemoparasite-infected and uninfected P. vogli turtles. However, the limited knowledge of these parameters in wild reptiles and the wide range of interval values makes it difficult to determine any significant impact on turtle health. Nevertheless, this study highlights the need for more in-depth research to explore the potential effects of blood parasite infections on turtles, including immune response and coevolution studies.

[A Marginal Case of Malaria: An Interesting Malaria Story of Cameroon Origin]. / Marjinal Bir Sitma Olgusu: Kamerun Orijinli Ilginç Bir Sitma Öyküsü.

Malaria is a serious, contagious infection caused by single-celled parasites. About 200 species of Plasmodium have been described that can cause infection in vertebrates. Five different species of Plasmodium are known to cause infection in humans to date. Infection with more than one type of pathogen is called coinfection. This type of infections can be caused by different species of the same genus, as well as by different species. Malaria coinfections are mostly caused by the combination of Plasmodium vivax and Plasmodium falciparum. In this study, a case of malaria admitted to the hospital and diagnosed was presented. Thin smear blood preparations were prepared from the peripheral blood of a 54 year-old Republic of Türkiye citizen male patient who applied to the emergency department with fever and chills. The preparations were stained with Giemsa and examined under a microscope with a x 100 objective, and trophozoite and gametocyte forms belonging to Plasmodium genus were determined. As a result of probe-based quantitative real-time polymerase chain reaction (qRt-PCR) study with primers specific to Plasmodium vivax, Plasmodium malariae, Plasmodium falciparum, Plasmodium ovale and Plasmodium knowlesi for definitive species identification, co-infection of P.vivax, P.falciparum, P.ovale and P.knowlesi was detected in the patient. In addition, it was proved that our patient was infected with four different species by conventional PCR study in which five species were studied and then by DNA sequence analysis. On the fourth day of artemether-lumefantrine treatment, the patient's fever response was observed and the trophozoite forms disappeared from the third day in the daily peripheral smear follow-up. Since P.vivax and P.ovale species were also detected after species determination by molecular methods, primaquine 1 x 30 mg tablet was added to the existing drugs for the treatment of hypnozoite forms of the parasite. In recent years, there has been an increase in malaria imported cases, especially after visits to African countries. Such rare cases of malaria coinfection may be encountered during visits to geographies located at the intersection of endemic regions. According to the data of the World Health Organization, maximum attention should be paid to the prevention and prophylaxis protocols from vectors, especially in travels to countries with the highest mortality and morbidity. In co-infection cases similar to our patient, for tertian malaria and tertiary ovale malaria, hypnozoid therapy should not be overlooked. When the insecticide-resistant vectors and drug-resistant Plasmodium strains encountered in recent years are evaluated as a whole, there is a need to develop more effective strategies in the fight against malaria. In addition to microscopic examination, which is accepted as the gold standard, we believe that evaluating molecular studies together in diagnosis is extremely important for the treatment process when hypnozoite periods are considered.

Molecular epidemiology of non-falciparum Plasmodium infections in three different areas of the Ivory Coast.

BACKGROUND: Malaria is a major public health problem, particularly in the tropical regions of America, Africa and Asia. Plasmodium falciparum is not only the most widespread but also the most deadly species. The share of Plasmodium infections caused by the other species (Plasmodium ovale and Plasmodium malariae) is clearly underestimated. The objective of the study was to determine the molecular epidemiology of plasmodial infection due to P. malariae and P. ovale in Côte d'Ivoire. METHODS: The study was cross-sectional. The study participants were recruited from Abengourou, San Pedro and Grand-Bassam. Sample collection took place from May 2015 to April 2016. Questionnaires were administered and filter paper blood samples were collected for parasite DNA extraction. The molecular analysis was carried out from February to March 2021. A nested PCR was used for species diagnosis. The data was presented in frequencies and proportions. RESULTS: A total of 360 patients were recruited, including 179 men (49,7%) for 181 women (50,3%). The overall Plasmodium positive rate was 72.5% (261/360). The specific index was 77.4% and 1.5% for P. falciparum and P. malariae in mono-infection, respectively. There was also 15% P. falciparum and P. malariae co-infection, 3.4% P. falciparum and P. ovale co-infection and 2.3% P. falciparum, P. malariae and P. ovale triple-infection. Typing of P. ovale subspecies showed a significant predominance of P. ovale curtisi (81.2% of cases). CONCLUSION: Plasmodium falciparum remains the most prevalent malaria species in Côte d'Ivoire, but P. malariae and P. ovale are also endemic mostly in co-infection. Malaria elimination requires a better understanding of the specific epidemiological characteristics of P. malariae and P. ovale with a particular emphasis on the identification of asymptomatic carriers.

Prevalence and risk distribution of schistosomiasis among adults in Madagascar: a cross-sectional study.

BACKGROUND: The goal to eliminate the parasitic disease of poverty schistosomiasis as a public health problem is aligned with the 2030 United Nations agenda for sustainable development goals, including universal health coverage (UHC). Current control strategies focus on school-aged children, systematically neglecting adults. We aimed at providing evidence for the need of shifting the paradigm of schistosomiasis control programs from targeted to generalized approaches as key element for both the elimination of schistosomiasis as a public health problem and the promotion of UHC. METHODS: In a cross-sectional study performed between March 2020 and January 2021 at three primary health care centers in Andina, Tsiroanomandidy and Ankazomborona in Madagascar, we determined prevalence and risk factors for schistosomiasis by a semi-quantitative PCR assay from specimens collected from 1482 adult participants. Univariable and multivariable logistic regression were performed to evaluate odd ratios. RESULTS: The highest prevalence of S. mansoni, S. haematobium and co-infection of both species was 59.5%, 61.3% and 3.3%, in Andina and Ankazomborona respectively. Higher prevalence was observed among males (52.4%) and main contributors to the family income (68.1%). Not working as a farmer and higher age were found to be protective factors for infection. CONCLUSIONS: Our findings provide evidence that adults are a high-risk group for schistosomiasis. Our data suggests that, for ensuring basic health as a human right, current public health strategies for schistosomiasis prevention and control need to be re-addressed towards more context specific, holistic and integrated approaches.

The Impact of Emerging Plasmodium knowlesi on Accurate Diagnosis by Light Microscopy: A Systematic Review and Modeling Analysis.

The five major Plasmodium spp. that cause human malaria appear similar under light microscopy, which raises the possibility that misdiagnosis could routinely occur in clinical settings. Assessing the extent of misdiagnosis is of particular importance for monitoring P. knowlesi, which cocirculates with the other Plasmodium spp. We performed a systematic review and meta-analysis of studies comparing the performance of microscopy and polymerase chain reaction (PCR) for diagnosing malaria in settings with co-circulation of the five Plasmodium spp. We assessed the extent to which co-circulation of Plasmodium parasites affects diagnostic outcomes. We fit a Bayesian hierarchical latent class model to estimate variation in microscopy sensitivity and specificity measured against PCR as the gold standard. Mean sensitivity of microscopy was low, yet highly variable across Plasmodium spp., ranging from 65.7% (95% confidence interval: 48.1-80.3%) for P. falciparum to 0.525% (95% confidence interval 0.0210-3.11%) for P. ovale. Observed PCR prevalence was positively correlated with estimated microscopic sensitivity and negatively correlated with estimated microscopic specificity, though the strength of the associations varied by species. Our analysis suggests that cocirculation of Plasmodium spp. undermines the accuracy of microscopy. Sensitivity was considerably lower for P. knowlesi, P. malariae, and P. ovale. The negative association between specificity and prevalence imply that less frequently encountered species may be misdiagnosed as more frequently encountered species. Together, these results suggest that the burden of P. knowlesi, P. malariae, and P. ovale may be underappreciated in a clinical setting.

Humoral antimalaria immune response in Nigerian children exposed to helminth and malaria parasites.

Background: Malaria and helminthic parasites are endemic in tropical countries, and co-infections might influence host-parasite interactions. In this community-based cross-sectional study, the effect that the presence of soil-transmitted helminths (STH) (Hookworm, Hymenolepis nana) and Schistosoma haematobium infections could have on the immunoglobulin (Ig) candidate protein of the malaria vaccine GMZ2 levels was evaluated. Methods: Blood, stool, and urine samples were collected from 5-15-year-old children to diagnose P. falciparum (Pf), STH, and Schistosoma haematobium, respectively. Identification and quantification of the parasite load of STH and S. haematobium were achieved by light microscopy. A polymerase chain reaction was carried out to detect submicroscopic infections of P. falciparum. Plasma levels of GMZ2 specific IgG and its subclasses were quantified by ELISA. Results: The median level of total IgG in individuals with co-infection with Pf/H. nana was significantly lower in the mono-infected group with Pf (p = 0.0121) or study participants without infection (p=0.0217). Similarly, the median level of IgG1 was statistically lower in Pf/H. nana group compared to Pf-group (p=0.0137). Equally, the Pf/H. nana infected individuals posted a lower level of IgG1 compared to Pf-group (p=0.0137) and IgG4 compared to the Pf-group (p=0.0144). Spearman rank correlation analyses indicated positive relationships between the densities of H. nana (ρ=0.25, p=0.015) and S. haematobium (ρ=0.36, p<0.0001). Conclusions: Hookworm and H. nana infections are associated with reduced GMZ2 specific IgG levels. This study shows the possible manipulation of immune responses by helminths for their survival and transmission, which may have serious implications for vaccine development and deployment in helminth-endemic regions.

Vector-borne pathogens in dogs from areas where leishmaniosis is endemic.

Many vector-borne pathogens (VBPs), including Ehrlichia canis and Dirofilaria immitis, may infect simultaneously dogs in areas where Leishmania infantum is endemic, especially in the tropics, where highly abundant arthropod vectors thrive. The aim of this study was to compare the frequency of simultaneous VBPs infection in Leishmania-positive and Leishmania-negative dogs. Animals enrolled in this study were divided in two groups (G1 and G2), G1 being comprised of L. infantum-infected dogs (n = 58) and the G2 of L. infantum-negative dogs (n = 58). Blood samples were screened using a qualitative ELISA test (SNAP® 4Dx® Plus, IDEXX Laboratory, Westbrook, Maine, USA) for detection of antibodies against Anaplasma spp., Borrelia burgdorferi sensu lato, Ehrlichia spp. and antigens of Dirofilaria immitis. Overall, 89.7% (52/58) of dogs from G1 were positive for at least one VBP, whereas 50.0% (29/58) of dogs from G2 dogs were positive as well. The highest positivity was to E. canis (67.2%; 78/116), followed by D. immitis (12.9%; 15/116), and A. platys (6.0%; 7/116). None of the animals scored positive for B. burgdorferi s.l.. There was a statistically significant difference for the simultaneous positivity to E. canis plus D. immitis between groups. Furthermore, 43.1% (25/58) of dogs from G1 were infested by ectoparasites (ticks, fleas, or both), compared to 20.6% (12/58) of dogs from G2. In conclusion, Leishmania-infected dogs were more co-infected with other VBPs than Leishmania-negative animals. Therefore, it is pivotal to increase the awareness of veterinarian and dog owners about the importance of testing Leishmania-infected dogs for other VBPs, as this may directly affect treatment decisions and management.

Circulating IL-6, IL-10, and TNF-alpha and IL-10/IL-6 and IL-10/TNF-alpha ratio profiles of polyparasitized individuals in rural and urban areas of gabon.

Malaria, blood-borne filarial worms and intestinal parasites are all endemic in Gabon. This geographical co-distribution leads to polyparasitism and, consequently, the possibility of immune-mediated interactions among different parasite species. Intestinal protozoa and helminths could modulate antimalarial immunity, for example, thereby potentially increasing or reducing susceptibility to malaria. The aim of the study was to compare the cytokine levels and cytokine ratios according to parasitic profiles of the population to determine the potential role of co-endemic parasites in the malaria susceptibility of populations. Blood and stool samples were collected during cross-sectional surveys in five provinces of Gabon. Parasitological diagnosis was performed to detect plasmodial parasites, Loa loa, Mansonella perstans, intestinal helminths (STHs) and protozoan parasites. Nested PCR was used to detect submicroscopic plasmodial infection in individuals with negative blood smears. A cytometric bead array was used to quantify interleukin (IL)-6, IL-10 and tumour necrosis factor (TNF)-α in the plasma of subjects with different parasitological profiles. Median IL-6 and IL-10 levels and the median IL-10/TNF-α ratio were all significantly higher among individuals with Plasmodium (P.) falciparum infection than among other participants (p<0.0001). The median TNF-α level and IL-10/IL-6 ratio were higher in subjects with STHs (p = 0.09) and P. falciparum-intestinal protozoa co-infection (p = 0.04), respectively. IL-6 (r = -0.37; P<0.01) and IL-10 (r = -0.37; P<0.01) levels and the IL-10/TNF-α ratio (r = -0.36; P<0.01) correlated negatively with age. Among children under five years old, the IL-10/TNF-α and IL-10/IL-6 ratios were higher in those with intestinal protozoan infections than in uninfected children. The IL-10/TNF-α ratio was also higher in children aged 5-15 years and in adults harbouring blood-borne filariae than in their control counterparts, whereas the IL-10/IL-6 ratio was lower in those aged 5-15 years with filariae and intestinal parasites but higher in adults with intestinal parasitic infections. Asymptomatic malaria is associated with a strong polarization towards a regulatory immune response, presenting high circulating levels of IL-10. P. falciparum/intestinal protozoa co-infections were associated with an enhanced IL-10 response. Immunity against malaria could differ according to age and carriage of other parasites. Helminths and intestinal protozoa can play a role in the high susceptibility to malaria currently observed in some areas of Gabon, but further investigations are necessary.

Can cloning and sequencing help to genotype positive Toxoplasma gondii clinical samples? Results and validation using SAG3 as a model.

Genotyping of T. gondii in human cases is relevant to understand the transmission patterns and epidemiology of this parasitosis. However, this genetic characterization can be hampered by the difficulty of isolating the parasite from mild or asymptomatic cases and by the detection efficiency of molecular assays such as the multilocus nested-polymerase chain reaction-restriction fragment length polymorphism (Mn-PCR-RLFP). To propose an alternative for the genotyping of positive clinical samples of T. gondii with a low amount of the parasite DNA mixed within the host DNA or mixed infections, we carried out this study to validate the sequences of the SAG3 gene of T. gondii obtained after two rounds of amplification cloned into a bacterial model, thereby achieving the separation and identification of more than one genotype of T. gondii. Also, the detection limit of the parasite DNA and the fidelity of the reagents used in the nested PCR-RFLP in artificial clinical samples by sequencing were determined. T. gondii DNA was detected from 6.25 ng of DNA and 200 parasites/mL of blood. The fidelity of the AmpliTaq Gold™ polymerase after 65 cycles of amplification was 100%. Denaturation of the products obtained after two rounds of nested PCR amplification showed no evidence of chimera or artifact production. The cloning efficiency was 97.5% (39/40 clones), and none of the experiments produced recombinant sequences. Thus, the generation of chimeras with this methodology could be ruled out. Genotyping of clinical samples is important because there is no strain selection bias, as can occur in the bioassay (where more virulent strains can be selected over nonvirulent strains), and therefore, mixed infections can be detected through cloning and sequencing. Furthermore, these two techniques could be useful tools to genotype weak amplicons of any T. gondii gene obtained during nested PCR.

Parasite load evaluation by qPCR and blood culture in Chagas disease and HIV co-infected patients under antiretroviral therapy.

Chagas disease also known as American trypanosomiasis, is caused by Trypanosoma cruzi and transmitted by triatominae-contaminated feces. It is considered a neglected tropical disease that affects 6 to 7 million people worldwide. The reactivation of Chagas disease occurs when the chronically infected hosts are not able to control T. cruzi infection, generating recurrence of the acute phase. HIV is the main immunosuppressive infection that can lead to the reactivation of chronic Chagas disease in AIDS conditions. In co-infected patients, the reactivation of Chagas disease is related to their high parasite load, high HIV viral load, and CD4 T-cell counting less than 200/mm3, which may evolve to meningoencephalitis and myocarditis. Eight T. cruzi/HIV co-infected patients under antiretroviral therapy (ART) and ten Chagas disease patients without HIV infection that attended at Study Group of Chagas Disease, Hospital de Clínicas, University of Campinas (GEdoCh/HC/UNICAMP-SP) and Pontifical Catholic University of Campinas SP (PUCC/SP) were evaluated. Tests for Chagas disease were performed, such as qPCR and T. cruzi blood culture. The patient's medical records were analyzed to verify clinical and epidemiological data, viral load, and CD4 T-cell counting since the outset of ART. For both groups, we found no statically significant differences between parasite load via blood culture and qPCR. In T. cruzi/HIV co-infected subjects, we observed a significant increase of CD4 T-cells counting and viral load decrease, which became undetectable over the years after ART. Parasites isolated from the patient's blood culture were genotyped, being the majority of them infected with TcII and one case of mixed infection (TcII and TcV/TcVI). These results were expected according to the region of origin of the patients. We suggest that the parasite load be monitored through qPCR in T.cruzi/HIV co-infected patients. We conclude that ART in people living with HIV improves infection and immunosuppression control, enabling the natural evolution of the American trypanosomiasis.

Strongyloides stercoralis and Trypanosoma cruzi coinfections in a highly endemic area in Argentina.

BACKGROUND: Strongyloidiasis and Chagas disease are endemic in northern Argentina. In this study we evaluate the association between S. stercoralis and T. cruzi infections in villages with diverse prevalence levels for these parasites. Further understanding in the relationship between these Neglected Tropical Diseases of South America is relevant for the design of integrated control measures as well as exploring potential biologic interactions. METHODOLOGY: Community based cross-sectional studies were carried in different villages of the Chaco and Yungas regions in Argentina. Individuals were diagnosed by serology for S. stercoralis and T. cruzi. The association between S. stercoralis and T. cruzi, and between anemia and the two parasites was evaluated using two approaches: marginal (Ma) and multilevel regression (Mu). RESULTS: A total of 706 individuals from six villages of northern Argentina were included. A total of 37% were positive for S. stercoralis, 14% were positive for T. cruzi and 5% were positive for both. No association was found between infection with S. stercoralis and T. cruzi in any of the models, but we found a negative correlation between the prevalence of these species in the different villages (r = -0.91). Adults (> 15 years) presented association with S. stercoralis (Ma OR = 2.72; Mu OR = 2.84) and T. cruzi (Ma OR = 5.12; Mu OR = 5.48). Also, 12% and 2% of the variance of infection with S. stercoralis and T. cruzi, respectively, could be explained by differences among villages. On the other hand, anemia was associated with infection with S. stercoralis (Ma OR = 1.73; Mu OR = 1.78) and was more prevalent in adults (Ma OR = 2.59; Mu OR = 2.69). CONCLUSION: We found that coinfection between S. stercoralis and T. cruzi is not more frequent than chance in endemic areas. However, the high prevalence for both parasites, raises the need for an integrated strategy for the control of STH and Chagas disease.

Geostatistical modelling enables efficient safety assessment for mass drug administration with ivermectin in Loa loa endemic areas through a combined antibody and LoaScope testing strategy for elimination of onchocerciasis.

The elimination of onchocerciasis through community-based Mass Drug Administration (MDA) of ivermectin (Mectizan) is hampered by co-endemicity of Loa loa, as individuals who are highly co-infected with Loa loa parasites can suffer serious and occasionally fatal neurological reactions from the drug. The test-and-not-treat strategy of testing all individuals participating in MDA has some operational constraints including the cost and limited availability of LoaScope diagnostic tools. As a result, a Loa loa Antibody (Ab) Rapid Test was developed to offer a complementary way of determining the prevalence of loiasis. We develop a joint geostatistical modelling framework for the analysis of Ab and Loascope data to delineate whether an area is safe for MDA. Our results support the use of a two-stage strategy, in which Ab testing is used to identify areas that, with acceptably high probability, are safe or unsafe for MDA, followed by Loascope testing in areas whose safety status is uncertain. This work therefore contributes to the global effort towards the elimination of onchocerciasis as a public health problem by potentially reducing the time and cost required to establish whether an area is safe for MDA.

Infections and Coinfections by Trypanosomatid Parasites in a Rural Community of Venezuela.

INTRODUCTION: Trypanosoma cruzi, Trypanosoma rangeli and Leishmania spp. are parasites that coexist in several endemic areas. The identification of these parasites in hosts is important for the control programs. METHODS: 216 samples from human blood (101), blood of other mammals (45) and triatomine intestinal content and hemolymph (70), from an endemic area of Venezuela, were analysed. The samples were evaluated by; serology (only humans) and PCR for T. cruzi in human, other mammals and triatomines, PCR for T. rangeli in mammals-including human and triatomines and PCR for Leishmania in mammals-including human. RESULTS: The 9.9% of the human samples were positive for T. cruzi by serology, 11.9% by PCR, 4% for T. rangeli PCR and none for Leishmania spp. PCR. 60% of the samples of other mammals showed DNA amplification for T. cruzi, 42.2% for T. rangeli and 4.4% for Leishmania spp. 61.4% of the triatomine samples showed DNA amplification for T. cruzi and 10% for T. rangeli. CONCLUSIONS: High T. cruzi infection was detected in mammals and triatomines compared with T. rangeli. Low leishmanial infection was detected in other mammals. It is the first time that T. cruzi/T. rangeli coinfection, in humans, Canis familiaris (dog), and Bos Taurus (cow), were reported world-wide, and that this coinfection was described in Tamandua tetradactyla (anteater) from Venezuela. The coinfection T. cruzi/T. rangeli in mammals-including humans and triatomines, and coinfection T. cruzi/Leishmania spp. in non-human mammals, show the risk for trypanosomic zoonoses in this endemic area.

Characterising co-infections with Plasmodium spp., Mansonella perstans or Loa loa in asymptomatic children, adults and elderly people living on Bioko Island using nucleic acids extracted from malaria rapid diagnostic tests.

BACKGROUND: Regular and comprehensive epidemiological surveys of the filarial nematodes Mansonella perstans and Loa loa in children, adolescents and adults living across Bioko Island, Equatorial Guinea are lacking. We aimed to demonstrate that blood retained on malaria rapid diagnostic tests, commonly deployed for malaria surveys, could be used as a source of nucleic acids for molecular based detection of M. perstans and L. loa. We wanted to determine the positivity rate and distribution of filarial nematodes across different age groups and geographical areas as well as to understand level of co-infections with malaria in an asymptomatic population. METHODOLOGY: M. perstans, L. loa and Plasmodium spp. parasites were monitored by qPCR in a cross-sectional study using DNA extracted from a subset malaria rapid diagnostic tests (mRDTs) collected during the annual malaria indicator survey conducted on Bioko Island in 2018. PRINCIPAL FINDINGS: We identified DNA specific for the two filarial nematodes investigated among 8.2% (263) of the 3214 RDTs screened. Positivity rates of M. perstans and L. loa were 6.6% and 1.5%, respectively. M. perstans infection were more prominent in male (10.5%) compared to female (3.9%) survey participants. M. perstans parasite density and positivity rate was higher among older people and the population living in rural areas. The socio-economic status of participants strongly influenced the infection rate with people belonging to the lowest socio-economic quintile more than 3 and 5 times more likely to be L. loa and M. perstans infected, respectively. No increased risk of being co-infected with Plasmodium spp. parasites was observed among the different age groups. CONCLUSIONS/SIGNIFICANCE: We found otherwise asymptomatic individuals were infected with M. perstans and L. loa. Our study demonstrates that employing mRDTs probed with blood for malaria testing represents a promising, future tool to preserve and ship NAs at room temperature to laboratories for molecular, high-throughput diagnosis and genotyping of blood-dwelling nematode filarial infections. Using this approach, asymptomatic populations can be reached and surveyed for infectious diseases beyond malaria.

Unreported mixed Plasmodium species infection may increase vivax malaria in India: a challenge for malaria elimination.

BACKGROUND: In India, there are several malaria-endemic regions where non-falciparum species coexist with Plasmodium falciparum. Traditionally, microscopy and rapid diagnostic tests are used for the diagnosis of malaria. Nevertheless, microscopy often misses the secondary malaria parasite in mixed-infection cases due to various constraints. Misdiagnosis/misinterpretation of Plasmodium species leads to improper treatment, as the treatment for P. falciparum and Plasmodium vivax species is different, as per the national vector-borne disease control program in India. METHODS: Blood samples were collected from malaria-endemic regions (Jharkhand, Madhya Pradesh, Chhattisgarh, Maharashtra, Odisha, Assam, Meghalaya, Mizoram and Telangana) of India covering almost the entire country. Molecular diagnosis of Plasmodium species was carried out among microscopically confirmed P. falciparum samples collected during a therapeutic efficacy study in different years. RESULTS: The polymerase chain reaction analysis revealed a high prevalence (18%) of mixed malaria parasite infections among microscopically confirmed P. falciparum samples from malaria patients that are either missed or left out by microscopy. CONCLUSIONS: Deployment of molecular tools in areas of mixed species infection may prove vital for accurate diagnosis and treatment of malaria. Further, it will help in achieving the goal of malaria elimination in India.

Six-year trend analysis of malaria prevalence at University of Gondar Specialized Referral Hospital, Northwest Ethiopia, from 2014 to 2019.

Globally, malaria is the major public health disease caused by plasmodium species and transmitted by the bite of the female anopheles mosquito. Assessment of the trend of malaria prevalence is important in the control and prevention of the disease. Therefore, the objective of this study was to assess the six year trend of malaria prevalence at the University of Gondar Comprehensive Specialized Hospital, northwest Ethiopia, from 2014 to 2019. A retrospective laboratory registration logbook review study was conducted on the malaria blood film examination results at the University of Gondar Comprehensive Specialized Hospital. The data was collected by using a data extraction tool and entered into SPSS version 20 for analysis. Descriptive statistics were used to summarize the socio-demographic characteristics of study participants and presented by graphs, tables and texts. The binary logistic regression was also used to test the association the trend of malaria prevalence and different factors like sex, age, year, and season. From a total of 17,500 malaria blood film examinations, 1341 (7.7%) were confirmed for malaria parasites. Of the confirmed malaria cases, 47.2%, 45.6% and 7.2% were P. vivax, P. falciparum and mixed infection, respectively. The proportion of P. vivax was the predominant species in the first three study years (2014-2016) and P. falciparum became the predominant species in the last three study years (2017-2019). The odds of malaria prevalence was lower by 68%, 60% and 69% in the year 2017, 2018 and 2019 compared to 2014, respectively. It was also 1.41 times higher in males than in females. Moreover, the odds of malaria prevalence were 1.60, 1.64, 2.45 and 1.82 times higher in the age group of < 5, 5-14, 15-24 and 25-54 years old compared to the older age groups (> 54 years old), respectively. Even there was a significant declining in prevalence trend; malaria is still a major public health problem. The study showed that there was high seasonal fluctuation from year to year. Moreover, males and the younger age groups were more affected than females and old age groups, respectively. Therefore, malaria prevention and control activities should be strengthened and require extra efforts by considering these variability.

Magnitude and associated factors of Intestinal Parasitosis and Tuberculosis among Tuberculosis suspected patients attending Kuyu General Hospital, North Shewa, Oromia, Ethiopia.

BACKGROUND: Intestinal parasites and Tuberculosis (TB) co-infection is a major public health problem. The parasitic infection suppresses the cell mediated immunity that protects tuberculosis. Helminthes-induced immune modulation promotes progression to active tuberculosis. However, there is paucity of evidences on the intestinal parasites-tuberculosis co-infection in Ethiopia. This study explores the magnitude and associated factors of intestinal parasitic infection and TB among suspected pulmonary Tuberculosis (PTB) patients. METHODOLOGY: A cross-sectional study design was conducted in Kuyu General Hospital from December 2019-March 2020. The socio-demographic data and associated factors were collected by structured questionnaire and then spot-spot sputum and fresh stool samples were collected following standard guidelines and were processed. Descriptive analysis was conducted and reported in frequency and percentage. Bivariate analysis was computed and a multivariable analysis was conducted to provide an adjusted odds ratio (AOR). P-value <0.05 at 95% confidence interval was considered as statistically significant. RESULTS: The burden of intestinal parasites was 20.2% (49/ 242) and 6.1% (20/ 242) of them were helminths infections and 14.1% (29/ 242) were protozoa infections. Of 242 patients, 14.9% (36/242) were sputum smear-positive for acid fast-bacilli. Of 36 smear positive patients, 9(25%) had TB-intestinal parasites co-infection. Dwelling in rural areas and having untrimmed fingernails were statistically significantly associated with intestinal parasites. Having a contact history of Tb patients was significantly associated with pulmonary tuberculosis. CONCLUSIONS: The magnitude of intestinal parasites and TB among PTB suspected patients were high. Hookworm infection was the predominant helmenthic infection. It is important to consider screening TB patients for intestinal parasites and treat co-infection properly.