OBJECTIVE: To analyze the quality of blood smear examinations for malaria parasites in Chenzhou City, so as to provide insights into sustainable consolidation of malaria elimination achievements. METHODS: All positive blood smears from fever patients were irregularly sampled from each county (district) of Chenzhou City from 2018 to 2022 and reexamined, and no less than 3% negative blood smears were reexamined. The preparation, dyeing, cleanliness and microscopic examination results of blood smear were reexamined, and the quality of blood smear reexaminations was assessed using a descriptive statistical method. RESULTS: A total of 13 625 fever patients received blood smear examinations for malaria parasites in Chenzhou City from 2018 to 2022, of which 21 were positive and 13 604 were negative; 687 blood samples were reviewed, and the percentage of negative blood smear reexaminations was 4.90% (666/13 604), with a 63.51% rate of qualified negative blood smears preparation, a 67.87% rate of qualified dyeing and a 76.13% rate of qualified cleanliness, and no missing diagnosis found. There were 21 positive blood smears reexamined, and the proportions of qualified blood smears preparation, dyeing and cleanliness were all 85.71%, with 2 smears mistaking Plasmodium species (9.52%). The percentage of qualified negative blood smears preparation was 51.41% in 2022, which reduced by 31.61% in relative to that (75.17%) in 2019 (χ² = 9.033, P < 0.05), and the percentage of qualified negative blood smears dyeing was 60.19% in 2022, which reduced by 28.82% in relative to that (84.56%) in 2019 (χ² = 19.498, P < 0.05), while the percentage of qualified negative blood smears cleanliness was 62.96% in 2022, which reduced by 28.93% in relative to that (88.59%) in 2019 (χ² = 23.826, P < 0.001). In addition, there were no significant differences in the proportion of qualified negative blood smears preparation (χ² = 0.260, P > 0.05) or dyeing (χ² = 1.094, P > 0.05) among the three years, while a significant difference was detected in the percentage of qualified negative blood smears cleanliness (χ² = 12.175, P < 0.05). CONCLUSIONS No missing diagnosis was seen in blood smear examinations for malaria parasites among fever patients in Chenzhou City after malaria elimination; however, there were reductions in proportions of qualified blood smears preparation, dyeing and cleanliness. Quality control of blood smear examinations is recommended to be reinforced in key regions of Chenzhou City.
Animals ; Humans ; Parasites ; Malaria/prevention & control* ; Plasmodium ; Fever ; Microscopy

Parasite-derived non-coding RNAs (ncRNAs) not only contribute to life activities of parasites, and microRNA (miRNA), long non-coding RNA (lncRNA), and circular RNA (circRNA) may generate a competitive endogenous RNA (ceRNA) regulatory network with host miRNAs and mRNAs via extracellular vesicles, thereby participating in infection and pathogenic processes. This article presents an overview of characterizing ncRNAs derived from parasites and the cross-species regulatory role of parasite-derived ncRNAs in host gene expression and its underlying mechanisms.
Animals ; Parasites ; Gene Regulatory Networks ; MicroRNAs/metabolism* ; RNA, Messenger/genetics* ; RNA, Circular/genetics* ; RNA, Competitive Endogenous

Introduction: Dioctophyma renale, also known as the “giant kidney” worm is the largest nematode that infects mammals. Most commonly, it infects dogs and only a few cases of human infestation have been reported. Case Presentation: In this case, we present a 71-year-old male with a history of right flank pain, painless hematuria, obstructive urinary symptoms and occasional passage of a long red meat-like structure via urethra. Previous ultrasonography revealed a renal mass that was interpreted as renal malignancy. Patient was advised radical nephrectomy with biopsy; however, he was lost to follow up. After 8 years, he again presented with a 2-month history of right flank pain, gross hematuria, unintentional weight loss and obstructive urinary symptoms. He was admitted to our institution and laboratory findings revealed microcytic hypochromic anemia. Ultrasound showed a focal bulge in the superior wall of the urinary bladder and an enlarged right kidney with a large heterogeneous solid structure. Insertion of a foley catheter relieved the urinary obstruction and there was noted passage of a single roundworm measuring 55 cm by 0.32 cm. The specimen was sent for histopathology and microscopic examination revealed a necrotic body of a roundworm consistent with Dioctophyma renale. Case Discussion The clinical manifestations of D. renale infection are non-specific and the diagnosis can be a challenge as it commonly mimics renal malignancy and other intra-abdominal tumors. The diagnosis is often an incidental finding of the parasite on necropsy or by finding ova in the urine. The clinical findings of painless hematuria, unintentional weight loss and an ultrasound finding of renal mass usually point toward the diagnosis of renal cell carcinoma. As we present this case, it will be highlighted that such signs and symptoms, such as painless hematuria, unintentional weight loss and ultrasound finding of a renal mass, can also be found in patients with rare human parasitism from Dioctophyma renale.
Parasites ; Dioctophymatoidea ; Carcinoma ; Kidney

Hydatid disease is a zoonotic infection in humans. The disease is endemic in some parts of the world, including Africa, Australia, and Asia, where cattle grazing is common; the disease is spread by an enteric route following the consumption of food contaminated with the eggs of the parasite. Failure to identify this parasite results in delayed diagnosis and increased morbidity to the patient. Upon diagnosis, every possible step should be taken, both surgical and medical, to prevent anaphylactic reactions from the cystic fluid. Postsurgical long-term follow up along with periodical ultrasonography of the liver and computed tomography scan of the abdomen is essential to rule out possible recurrence.
Abdomen ; Africa ; Anaphylaxis ; Animals ; Asia ; Australia ; Cattle ; Delayed Diagnosis ; Diagnosis ; Echinococcosis ; Eggs ; Follow-Up Studies ; Humans ; Liver ; Ovum ; Parasites ; Recurrence ; Ultrasonography ; Zoonoses

Avian malaria is one of the most important general blood parasites of poultry in Southeast Asia. Plasmodium (P.) juxtanucleare causes avian malaria in wild and domestic fowl. This study aimed to identify and characterize the Plasmodium species infecting in Thai native fowl. Blood samples were collected for microscopic examination, followed by detection of the Plasmodium cox I gene by using PCR. Five of the 10 sampled fowl had the desired 588 base pair amplicons. Sequence analysis of the five amplicons indicated that the nucleotide and amino acid sequences were homologous to each other and were closely related (100% identity) to a P. juxtanucleare strain isolated in Japan (AB250415). Furthermore, the phylogenetic tree of the cox I gene showed that the P. juxtanucleare in this study were grouped together and clustered with the Japan strain. The presence of P. juxtanucleare described in this study is the first report of P. juxtanucleare in the Thai native fowl of Thailand.
Amino Acid Sequence ; Animals ; Asia, Southeastern ; Asian Continental Ancestry Group ; Base Pairing ; Cytochromes c ; Cytochromes ; Electron Transport Complex IV ; Humans ; Japan ; Malaria, Avian ; Parasites ; Plasmodium ; Polymerase Chain Reaction ; Poultry ; Sequence Analysis ; Thailand ; Trees

Rapid diagnostic tests (RDTs) for malaria using antibodies against pan-Plasmodium antigen lactate dehydrogenase (pLDH) are commonly used for malaria diagnosis. The level of malaria parasitemia determined by peripheral blood smears (PBS) correlates with the pLDH concentration in most cases. We report a case of malaria recurrence associated with false-negative RDT results. A 22-year-old male patient was admitted to the Armed Forces Capital Hospital with fever and chills, and was diagnosed with malaria infection. Four days after antimalarial treatment, these symptoms recurred. After admitting to our hospital, doxycycline was administered for 4 days. Even after administration of doxycycline, the malaria parasites in blood smears remained positive, but RDT showed negative results. Therefore, for patients receiving doxycycline, serial blood smear testing should be performed to exclude false-negative malaria RDT results.
Antibodies ; Arm ; Chills ; Diagnosis ; Diagnostic Tests, Routine ; Doxycycline ; Fever ; Humans ; L-Lactate Dehydrogenase ; Malaria ; Male ; Parasitemia ; Parasites ; Recurrence ; Young Adult

Toxoplasmosis is a cosmopolitan zoonotic infection, caused by a unicellular protozoan parasite known as Toxoplasma gondii that belongs to the phylum Apicomplexa. It is estimated that over one-third of the world's population has been exposed and are latently infected with the parasite. In humans, toxoplasmosis is predominantly asymptomatic in immunocompetent persons, while among immunocompromised individuals may be cause severe and progressive complications with poor prognosis. Moreover, seronegative pregnant mothers are other risk groups for acquiring the infection. The life cycle of T. gondii is very complex, indicating the presence of a plurality of antigenic epitopes. Despite of great advances, recognize and construct novel vaccines for prevent and control of toxoplasmosis in both humans and animals is still remains a great challenge for researchers to select potential protein sequences as the ideal antigens. Notably, in several past years, constant efforts of researchers have made considerable advances to elucidate the different aspects of the cell and molecular biology of T. gondii mainly on microneme antigens, dense granule antigens, surface antigens, and rhoptry proteins (ROP). These attempts thereby provided great impetus to the present focus on vaccine development, according to the defined subcellular components of the parasite. Although, currently there is no commercial vaccine for use in humans. Among the main identified T. gondii antigens, ROPs appear as a putative vaccine candidate that are vital for invasion procedure as well as survival within host cells. Overall, it is estimated that they occupy about 1%–30% of the total parasite cell volume. In this review, we have summarized the recent progress of ROP-based vaccine development through various strategies from DNA vaccines, epitope or multi epitope-based vaccines, recombinant protein vaccines to vaccines based on live-attenuated vectors and prime-boost strategies in different mouse models.
Animals ; Antigens, Surface ; Apicomplexa ; Cell Size ; Epitopes ; Humans ; Immunization ; Life Cycle Stages ; Mice ; Molecular Biology ; Mothers ; Parasites ; Prognosis ; Toxoplasma* ; Toxoplasmosis ; Vaccines ; Vaccines, DNA ; Vaccines, Synthetic ; Zoonoses

We analyzed Clonorchis sinensis ancient DNA (aDNA) acquired from the specimens of the Joseon mummies. The target regions were cytochrome C oxidase subunit 1 (CO1), internal transcribed spacer 1 (ITS1), nicotinamide adenine dinucleotide hydrogen (NADH) dehydrogenase subunits 2 (NAD2) and 5 (NAD5). The sequences of C. sinensis aDNA was completely or almost identical to modern C. sinensis sequences in GenBank. We also found that ITS1, NAD2 and NAD5 could be good markers for molecular diagnosis between C. sinensis and the other trematode parasite species. The current result could improve our knowledge about genetic history of C. sinensis.
Clonorchis sinensis ; Cytochromes c ; Cytochromes ; Databases, Nucleic Acid ; Diagnosis ; DNA ; Electron Transport Complex IV ; Hydrogen ; Mummies ; NAD ; Niacinamide ; Oxidoreductases ; Parasites ; Republic of Korea

The gastrointestinal tract is a vast reservoir for internal microbiota; it is exposed directly to various externally introduced microbes, including bacteria, viruses, parasites and others. In immune-compromised conditions, the gastrointestinal tract is frequently affected by infectious diseases that seldom manifest clinically in immune-competent hosts. Immune-compromised conditions result from a variety of reasons, including human immunodeficiency virus infection, anti-cancer chemo-radiotherapy, immune suppressive therapy for autoimmune diseases, and organ transplantations. The stomach is a relatively rare site for opportunistic infections in immune-compromised patients compared to the esophagus and colon, where esophagitis and colitis develop frequently and cause significant clinical consequences. Helicobacter pylori infection is majorly involved in gastric malfunctioning in immune-compromised patients, followed by cytomegalovirus infection. Infections by Cryptosporidium, Mycobacterium avium complex, histoplasmosis, leishmaniasis, aspergillosis, or treponema, have been reported; however, gastric involvement of these agents is extremely rare. This review discusses the general aspects and recent reports on gastric infection in immune-compromised patients.
Aspergillosis ; Autoimmune Diseases ; Bacteria ; Colitis ; Colon ; Communicable Diseases ; Cryptosporidium ; Cytomegalovirus Infections ; Esophagitis ; Esophagus ; Gastrointestinal Tract ; Helicobacter pylori ; Histoplasmosis ; HIV ; Humans ; Leishmaniasis ; Microbiota ; Mycobacterium avium Complex ; Opportunistic Infections ; Organ Transplantation ; Parasites ; Stomach ; Transplants ; Treponema

Anisakidosis is a term that collectively refers to a human infection caused by larvae of the family Anisakidae. Because Anisakis simplex was the main cause, it was originally called anisakiasis or anisakiosis, but since other parasites such as Pseudoterranova decipiens also cause similar diseases, the family name is now used as the diagnostic name. Anisakidosis cases have been increasing steadily owing to the propagation of the Japanese raw-fish-eating culture, such as sushi and sashimi, around the world; the traditional raw-fish-eating habits of individual countries; the establishment of marine mammal protection laws; and the development of endoscopic diagnostic techniques. The disease continues to occur in Korea, where most human parasites are believed to have been eradicated and is probably the most common parasitic disease encountered in clinical practice. Anisakidosis is a disease associated with acute abdominal pain. Anisakid larvae can invade the entire digestive tract and abdominal cavity and cause abdominal pain and a variety of digestive system symptoms. Thus, the history of eating raw fish is very important for its differential diagnosis. The lack of a precise understanding of the pathogenesis and clinical course of this disease may lead to unnecessary surgery. Anisakidosis may also manifest as allergic symptoms. Therefore, it is necessary to understand anisakidosis from the perspective of public health, food hygiene, and preventive medicine.
Abdominal Cavity ; Abdominal Pain ; Anisakiasis ; Anisakis ; Asian Continental Ancestry Group ; Diagnosis, Differential ; Digestive System ; Eating ; Food Hypersensitivity ; Gastrointestinal Tract ; Host-Parasite Interactions ; Humans ; Hygiene ; Jurisprudence ; Korea ; Larva ; Mammals ; Parasites ; Parasitic Diseases ; Preventive Medicine ; Public Health ; Raw Foods ; Unnecessary Procedures