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Zhongguo Xue Xi Chong Bing Fang Zhi Za... Apr 2024Malaria is one of the most serious mosquito-borne infectious diseases in the world. The global malaria control progress has stalled in recent years, which is largely due... (Review)
Review
Malaria is one of the most serious mosquito-borne infectious diseases in the world. The global malaria control progress has stalled in recent years, which is largely due to the biological threats from the malaria pathogen and the vector mosquitoes. This article provides an overview of biological threats to global malaria elimination, including antimalarial drug resistance, deletions in the malaria rapid diagnostic test target histidine-rich protein 2/3 () genes, vector insecticide resistance and emergence of invasive vector species, so as to provide insights into malaria and vector research and the formulation and adjustment of the malaria control and elimination strategy.
Topics: Animals; Malaria; Humans; Mosquito Vectors; Anopheles; Drug Resistance
PubMed: 38952306
DOI: 10.16250/j.32.1374.2024095 -
Zhongguo Xue Xi Chong Bing Fang Zhi Za... Jun 2024To understand the progress of national schistosomiasis elimination program of China in 2023 and summarize the lessons and experiences, data on the endemic status of...
To understand the progress of national schistosomiasis elimination program of China in 2023 and summarize the lessons and experiences, data on the endemic status of schistosomiasis and national schistosomiasis surveillance results in the People's Republic of China were collected and analyzed at a national level. By the end of 2023, Shanghai Municipality, Zhejiang Province, Fujian Province, Guangdong Province and Guangxi Zhuang Autonomous Region continued to consolidate the achievements of schistosomiasis elimination, and Sichuan and Jiangsu provinces maintained the criteria of transmission interruption, while Yunnan and Hubei provinces were identified to achieve the criteria of transmission interruption in 2020, and Anhui, Jiangxi and Hunan provinces achieved the criteria of transmission interruption in 2023. A total of 451 counties (cites, districts) were found to be endemic for schistosomiasis in China in 2023, including 26 250 endemic villages covering 73 034 500 residents at risk of infections. Among the 451 endemic counties (cities, districts), 78.49% (354/451) achieved the criteria of schistosomiasis elimination and 21.51% (97/451) achieved the criteria of transmission interruption, respectively. In 2023, a total of 4 216 643 individuals received immunological tests, with 47 794 sero-positives identified, and a total of 184 216 individuals received parasitological examinations, with 4 egg-positives detected. A total of 27 768 cases with advanced schistosomiasis were documented in China by the end of 2023. In 2023, 539 548 bovines were raised in schistosomiasis-endemic areas of China, and 125 440 bovines received immunological tests, with 124 sero-positives detected, while no egg-positives were identified among the 133 508 bovines receiving parasitological examinations. In 2023, snail survey was performed at an area of 641 339.53 hm and 184 819.77 hm snail habitats were identified, including 51.53 hm emerging snail habitats and 642.25 hm reemerging snail habitats. In 2023, there were 20 198 schistosomiasis patients receiving praziquantel chemotherapy, and 598 183 person-time individuals and 283 954 herdtime bovines were given expanded chemotherapy. In 2023, snail control with chemical treatment was performed in 116 347.95 hm snail habitats, and the actual area of chemical treatment was 65 690.89 hm, while environmental improvements were performed in snail habitats covering an area of 1 334.62 hm. The national schistosomiasis surveillance results showed that the mean prevalence of infections were both zero among humans and bovines in 2023, and no infection was detected in snails. These data demonstrated that transmission interruption of schistosomiasis had been achieved across all endemic provinces in China in 2023, and the endemic status of schistosomiasis tended to be stable, while advanced cases were predominant among all schistosomiasis cases. However, the areas of snail habitats remained high and cattle re-raising was very common in some regions. Intensified schistosomiasis surveillance and forecast and snail control in high-risk areas are needed.
Topics: China; Humans; Schistosomiasis; Animals; Cattle; Cattle Diseases; Communicable Disease Control
PubMed: 38952305
DOI: 10.16250/j.32.1374.2024116 -
Veterinary Medicine and Science Jul 2024Sarcocystis is a food-borne zoonotic protozoan whose final hosts are humans, dogs, cats, and other carnivores and intermediate hosts are birds and mammals, especially...
BACKGROUND
Sarcocystis is a food-borne zoonotic protozoan whose final hosts are humans, dogs, cats, and other carnivores and intermediate hosts are birds and mammals, especially humans and herbivores. Humans become infected by eating raw and undercooked meat contaminated with bradyzoites or by consuming water or food contaminated with the sporocyst stage of the parasite.
OBJECTIVES
The aim of this study was to investigate the effects of gamma radiation and electron beam on the survival rate of Sarcocystis bradyzoites in infected beef and to determine the effective dose.
METHODS
Three replicates of 100 g of infected meat were treated with different doses (0.5, 1, 1.5 and 2 kGy). As a control, 20 g of contaminated meat was stored separately at 4°C. The viability of the bradyzoites after digestion in pepsin solution was assessed, stained (trypan blue) and unstained, under a stereomicroscope. To assess survival of the bradyzoites, the irradiated meat samples were fed to 30 dogs. After 10 days, faecal samples were examined for sporocysts.
RESULTS
The results showed that the highest and lowest mortality rate of Sarcocystis bradyzoites in infected organs using electron beam at a dose of 2 kGy were 92.5% and 100%, respectively, and the lowest mortality rate at a dose of 0.5 kGy were 2.5% and 7.89%, respectively.
CONCLUSION
The results of statistical analysis showed that the mortality rate of Sarcocystis bradyzoites was significant between different doses of gamma ray and electron beam, so that gamma rays were better compared to electron beam in destroying Sarcocystis bradyzoites.
Topics: Sarcocystis; Animals; Cattle; Sarcocystosis; Red Meat; Gamma Rays; Dogs; Food Irradiation; Dose-Response Relationship, Radiation; Cattle Diseases; Electrons
PubMed: 38952247
DOI: 10.1002/vms3.1519 -
Parasites & Vectors Jul 2024Application of numerous malaria control interventions has led to reduction in clinical malaria cases and deaths but also the realisation that asymptomatic parasite...
BACKGROUND
Application of numerous malaria control interventions has led to reduction in clinical malaria cases and deaths but also the realisation that asymptomatic parasite carriers play a key role in sustaining transmission. This study assessed the effectiveness of using the Ultra-sensitive NxTek eliminate RDT (uRDT) and conventional SD Bioline HRP2 RDT (cRDT) in diagnosing asymptomatic parasitaemia while measuring the impact of mass testing, treatment and tracking (MTTT) on the prevalence of asymptomatic malaria over a 1-year period in Ghana.
METHODS
A total of 4000 targeted participants from two towns, Obom and Kofi Kwei, with their surrounding villages, were tested for asymptomatic malaria four times over the study period using uRDT (intervention) and the cRDT (control) respectively. Participants carrying malaria parasites were followed by home visit and phone calls for compliance to treatment, and filter paper blood blots collected from participants were used to determine true parasite carriage by PET-PCR. A mathematical model of the study site was developed and used to test the impact of test sensitivity and mass migration on the effect of MTTT.
RESULTS
The start and end point sensitivities of the cRDT were 48.8% and 41.7% and those for the uRDT were 52.9% and 59.9% respectively. After a year of MTTTs, asymptomatic parasite prevalence, as determined by PCR, did not differ statistically in the control site (40.6% to 40.1%, P = 0.730) but decreased at the intervention site (55.9% to 46.4%, P < 0.0001). Parasite prevalence by RDT, however, indicated statistical reduction in the control site (25.3% to 22.3%, P = 0.017) and no change in the intervention site (35.1% to 36.0%, P = 0.614). The model predicted a mild effect of both diagnostic sensitivity and human movement in diminishing the impact of MTTT in the study sites.
CONCLUSIONS
Asymptomatic parasite prevalence at the molecular level reduced significantly in the site where the uRDT was used but not where the cRDT was used. Overall, the uRDT exhibited higher sensitivity relative to the cRDT. Highly sensitive molecular techniques such as PET-PCR should be included in parasite prevalence estimation during MTTT exercises.
Topics: Ghana; Humans; Female; Male; Sensitivity and Specificity; Adult; Adolescent; Child, Preschool; Young Adult; Child; Diagnostic Tests, Routine; Parasitemia; Malaria, Falciparum; Middle Aged; Malaria; Plasmodium falciparum; Prevalence; Mass Screening; Infant
PubMed: 38951912
DOI: 10.1186/s13071-024-06354-x -
Parasites & Vectors Jul 2024Abiotic factors play a significant role in the evolution of Leishmania infantum infection due to its vectorial nature. This study aims to assess the evolution in the...
BACKGROUND
Abiotic factors play a significant role in the evolution of Leishmania infantum infection due to its vectorial nature. This study aims to assess the evolution in the detection of new L. infantum infection cases in Valdeorras (Ourense, Northwestern Spain) over a 20-year period and how different climatic variables and preventive measures may have affected it.
METHODS
Indirect immunofluorescence antibody tests (IFAT) were performed on serum samples collected from dogs attending the 'Servicios Veterinarios de Sil' veterinary clinic (Valdeorras, Northwestern Spain) between May 2003 and April 2023 to detect L. infantum exposure. The percentage of new cases of L. infantum infection was calculated from May of one year to April of the following year. Climatic conditions in the region, global sales of ectoparasiticides and the number of vaccines against L. infantum delivered in the veterinary clinic from 2003 to 2022 were recorded. Statistical analyses were conducted to determine the associations between these factors and the percentage of new cases of L. infantum infection.
RESULTS
A total of 2909 dogs were assessed, and 3785 IFAT tests were performed between May 2003 and April 2023. The mean percentage of new seropositive cases over the 20-year period studied was 21.65 ± 10.8%, with a decline from the beginning to the end of the period studied. The percentage was significantly higher between May 2003 and April 2008 compared with the other periods (May 2008 to April 2013, May 2013 to April 2018 and May 2018 to April 2023). There was a positive correlation between the percentage of new cases of L. infantum infection and the maximum relative humidity in winter. Conversely, there was a negative correlation between the percentage of new cases and sales of ectoparasiticides and vaccination against L. infantum.
CONCLUSIONS
This study is one of the longest evaluations of the evolution of L. infantum infection in a fixed location and its association with external factors including climatic conditions and preventive measures. The results confirm that Valdeorras is a high-risk area for L. infantum infection. The use of ectoparasiticides and vaccines against L. infantum has been shown to play a significant role in preventing L. infantum infection, highlighting the crucial role of veterinarians in the fight against this disease.
Topics: Dogs; Animals; Spain; Dog Diseases; Leishmania infantum; Leishmaniasis, Visceral; Climate; Antibodies, Protozoan; Male; Fluorescent Antibody Technique, Indirect; Female
PubMed: 38951858
DOI: 10.1186/s13071-024-06357-8 -
BMJ Open Jul 2024Toxoplasmosis is a zoonotic parasitic disease caused by . It has a wide host range and is capable of vertical transmission in pregnant women, which may lead to...
BACKGROUND
Toxoplasmosis is a zoonotic parasitic disease caused by . It has a wide host range and is capable of vertical transmission in pregnant women, which may lead to undesirable pregnancy outcomes such as congenital malformations, miscarriage, premature birth and stillbirth. This study investigated the seroprevalence of infection among pregnant women attending the antenatal clinic at Namwala District Hospital in Southern Zambia.
METHODS
This was a cross-sectional study where blood was collected, and the serum was tested for IgG and IgM. A questionnaire was administered to participants on demographic characteristics and risk factors. Data were entered in Microsoft Excel and exported to STATA version 14 for analysis.
RESULTS
A total of 401 women were enrolled in the study from 3 March to 5 August 2021. The seroprevalence of IgG was 4.2% (n=17), while the seroprevalence of IgM was 0.7% (n=3). The median age was 27 (IQR: 24-30) years, and a larger proportion had primary-level education (n=223, 55.6%). The majority (81.6%) of the women were married. None of the risk factors investigated in this study were significant for infection.
CONCLUSION
There was a low seroprevalence of infection among pregnant women in the Namwala district of Southern Province, Zambia, and regular screening may not be warranted in this population. Continued research on toxoplasmosis is recommended to understand its epidemiology across Zambia.
Topics: Humans; Female; Zambia; Cross-Sectional Studies; Seroepidemiologic Studies; Adult; Pregnancy; Toxoplasmosis; Risk Factors; Toxoplasma; Young Adult; Immunoglobulin M; Antibodies, Protozoan; Pregnancy Complications, Parasitic; Immunoglobulin G; Prenatal Care
PubMed: 38950992
DOI: 10.1136/bmjopen-2024-084582 -
PLoS Pathogens Jul 2024The regulation of inflammatory responses and pulmonary disease during SARS-CoV-2 infection is incompletely understood. Here we examine the roles of the prototypic pro-...
The regulation of inflammatory responses and pulmonary disease during SARS-CoV-2 infection is incompletely understood. Here we examine the roles of the prototypic pro- and anti-inflammatory cytokines IFNγ and IL-10 using the rhesus macaque model of mild COVID-19. We find that IFNγ drives the development of 18fluorodeoxyglucose (FDG)-avid lesions in the lungs as measured by PET/CT imaging but is not required for suppression of viral replication. In contrast, IL-10 limits the duration of acute pulmonary lesions, serum markers of inflammation and the magnitude of virus-specific T cell expansion but does not impair viral clearance. We also show that IL-10 induces the subsequent differentiation of virus-specific effector T cells into CD69+CD103+ tissue resident memory cells (Trm) in the airways and maintains Trm cells in nasal mucosal surfaces, highlighting an unexpected role for IL-10 in promoting airway memory T cells during SARS-CoV-2 infection of macaques.
PubMed: 38950078
DOI: 10.1371/journal.ppat.1012339 -
PloS One 2024Toxoplasma gondii can cause symptomatic toxoplasmosis in immunodeficient hosts, including in people living with human immunodeficiency virus (PLWH), mainly because of...
INTRODUCTION
Toxoplasma gondii can cause symptomatic toxoplasmosis in immunodeficient hosts, including in people living with human immunodeficiency virus (PLWH), mainly because of the reactivation of latent infection. We assessed the prevalence of toxoplasmosis and its associated risk factors in PLWH in the Asia-Pacific region using data from the TREAT Asia Human Immunodeficiency Virus (HIV) Observational Database (TAHOD) of the International Epidemiology Databases to Evaluate AIDS (IeDEA) Asia-Pacific.
METHODS
This study included both retrospective and prospective cases of toxoplasmosis reported between 1997 and 2020. A matched case-control method was employed, where PLWH diagnosed with toxoplasmosis (cases) were each matched to two PLWH without a toxoplasmosis diagnosis (controls) from the same site. Sites without toxoplasmosis were excluded. Risk factors for toxoplasmosis were analyzed using conditional logistic regression.
RESULTS
A total of 269/9576 (2.8%) PLWH were diagnosed with toxoplasmosis in 19 TAHOD sites. Of these, 227 (84%) were reported retrospectively and 42 (16%) were prospective diagnoses after cohort enrollment. At the time of toxoplasmosis diagnosis, the median age was 33 years (interquartile range 28-38), and 80% participants were male, 75% were not on antiretroviral therapy (ART). Excluding 63 out of 269 people without CD4 values, 192 (93.2%) had CD4 ≤200 cells/μL and 162 (78.6%) had CD4 ≤100 cells/μL. By employing 538 matched controls, we found that factors associated with toxoplasmosis included abstaining from ART (odds ratio [OR] 3.62, 95% CI 1.81-7.24), in comparison to receiving nucleoside reverse transcriptase inhibitors plus non-nucleoside reverse transcriptase inhibitors, HIV exposure through injection drug use (OR 2.27, 95% CI 1.15-4.47) as opposed to engaging in heterosexual intercourse and testing positive for hepatitis B virus surface antigen (OR 3.19, 95% CI 1.41-7.21). Toxoplasmosis was less likely with increasing CD4 counts (51-100 cells/μL: OR 0.41, 95% CI 0.18-0.96; 101-200 cells/μL: OR 0.14, 95% CI 0.06-0.34; >200 cells/μL: OR 0.02, 95% CI 0.01-0.06), when compared to CD4 ≤50 cells/μL. Moreover, the use of prophylactic cotrimoxazole was not associated with toxoplasmosis.
CONCLUSIONS
Symptomatic toxoplasmosis is rare but still occurs in PLWH in the Asia-Pacific region, especially in the context of delayed diagnosis, causing advanced HIV disease. Immune reconstitution through early diagnosis and ART administration remains a priority in Asian PLWH.
Topics: Humans; Male; Risk Factors; Adult; Female; Toxoplasmosis; HIV Infections; Asia; Retrospective Studies; Case-Control Studies; Middle Aged; Prevalence; Prospective Studies; Toxoplasma
PubMed: 38950027
DOI: 10.1371/journal.pone.0306245 -
PloS One 2024Co-infections are a common reality but understanding how the immune system responds in this context is complex and can be unpredictable. Heligmosomoides bakeri...
Heligmosomoides bakeri and Toxoplasma gondii co-infection leads to increased mortality associated with changes in immune resistance in the lymphoid compartment and disease pathology.
Co-infections are a common reality but understanding how the immune system responds in this context is complex and can be unpredictable. Heligmosomoides bakeri (parasitic roundworm, previously Heligmosomoides polygyrus) and Toxoplasma gondii (protozoan parasite) are well studied organisms that stimulate a characteristic Th2 and Th1 response, respectively. Several studies have demonstrated reduced inflammatory cytokine responses in animals co-infected with such organisms. However, while general cytokine signatures have been examined, the impact of the different cytokine producing lymphocytes on parasite control/clearance is not fully understood. We investigated five different lymphocyte populations (NK, NKT, γδ T, CD4+ T and CD8+ T cells), five organs (small intestine, Peyer's patches, mesenteric lymph nodes, spleen and liver), and 4 cytokines (IFN©, IL-4, IL-10 and IL-13) at two different time points (days 5 and 10 post T. gondii infection). We found that co-infected animals had significantly higher mortality than either single infection. This was accompanied by transient and local changes in parasite loads and cytokine profiles. Despite the early changes in lymphocyte and cytokine profiles, severe intestinal pathology in co-infected mice likely contributed to early mortality due to significant damage by both parasites in the small intestine. Our work demonstrates the importance of taking a broad view during infection research, studying multiple cell types, organs/tissues and time points to link and/or uncouple immunological from pathological findings. Our results provide insights into how co-infection with parasites stimulating different arms of the immune system can lead to drastic changes in infection dynamics.
Topics: Animals; Coinfection; Toxoplasma; Mice; Cytokines; Nematospiroides dubius; Strongylida Infections; Toxoplasmosis; Female; Toxoplasmosis, Animal; Spleen; Parasite Load; Lymphoid Tissue
PubMed: 38950025
DOI: 10.1371/journal.pone.0292408 -
PloS One 2024Although the overall burden of malaria is decreasing in Ethiopia, a recent report of an unpredictable increased incidence may be related to the presence of...
Although the overall burden of malaria is decreasing in Ethiopia, a recent report of an unpredictable increased incidence may be related to the presence of community-wide gametocyte-carrier individuals and a high proportion of infected vectors. This study aimed to reveal the current prevalence of gametocyte-carriage and the sporozoite infectivity rate of Anopheles vectors for Plasmodium parasites. A community-based cross-sectional study was conducted from May 01 to June 30/2019. A total of 53 households were selected using systematic random sampling and a 242 study participants were recruited. Additionally,515 adult female Anopheles mosquitoes were collected using Center for Diseases Control and Prevention (CDC) light traps and mouth aspirators. Parasite gametocytemia was determined using giemsa stain microscopy, while sporozoite infection was determined by giemsa staining microscopy and enzyme linked immunosorbent assay (ELISA). Among the total 242 study participants, 5.4% (95%, CI = 2.9-8.3) of them were positive for any of the Plasmodium species gametocyte. Furthermore, being female [AOR = 15.5(95%, CI = 1.71-140.39)], age group between 15-29 years old [AOR = 16.914 (95%, CI = 1.781-160.63)], no ITNs utilization [AOR = 16.7(95%, CI = 1.902 -146.727)], and high asexual parasite density [(95%, CI = 0.057-0.176, P = 0.001, F = 18.402)] were identified as statistically significant factors for gametocyte carriage. Whereas sporozoite infection rate was 11.6% (95%, CI = 8.2-15.5) and 12.7% (95%, CI = 9.6-16.3) by microscopy and ELISA, respectively. Overall, this study indicated that malaria remains to be an important public health problem in Gondar Zuria district where high gametocyte carriage rate and sporozoite infection rate could sustain its transmission and burden. Therefore, in Ethiopia, where malaria elimination program is underway, frequent, and active community-based surveillance of gametocytemia and sporozoite infection rate is important.
Topics: Animals; Ethiopia; Humans; Anopheles; Female; Adult; Sporozoites; Adolescent; Young Adult; Male; Cross-Sectional Studies; Mosquito Vectors; Child; Child, Preschool; Malaria; Middle Aged; Plasmodium; Infant; Plasmodium falciparum; Prevalence
PubMed: 38950022
DOI: 10.1371/journal.pone.0306289