Bacterial content in mosquito larvae and adults is altered by dynamic interactions during life and varies substantially in variety and composition depending on mosquito biology and ecology. This study aimed to identify the microbiota in Aedes aegypti and Aedes albopictus and in water from their breeding sites in northeastern Thailand, a dengue-endemic area. Bacterial diversity in field-collected aquatic larvae and subsequently emerged adults of both species from several locations were examined. The microbiota was characterized based on analysis of DNA sequences from the V3-V4 region of the 16S rRNA gene and exhibited changes during development, from the mosquito larval stage to the adult stage. Aedes aegypti contained a significantly higher number of bacterial genera than did Ae. albopictus, except for the genus Wolbachia, which was present at significantly higher frequencies in male Ae. albopictus (p < 0.05). Our findings also indicate likely transstadial transmission from larva to adult and give better understanding of the microbial diversity in these mosquitoes, informing future control programs against mosquito-borne diseases.

Human strongyloidiasis is an important soil-transmitted helminthiasis that affects millions worldwide and can develop into fatal systemic strongyloidiasis in immunosuppressed patients. We have developed two new rapid and simple-to-use immunochromatographic test (ICT) kits for rapid serodiagnosis that support stool examination for clinical diagnosis. Strongyloides stercoralis recombinant IgG immunoreactive antigen (GenBank: AAB97359.1; rSsIR-based ICT kit) was used for detection of IgG and IgG4 antibodies. The diagnostic efficacy of both kits was evaluated using human serum samples from strongyloidiasis patients, healthy individuals, and those with other parasitosis. At a prevalence of infection of 36.4%, the diagnostic sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the rSsIR-based IgG ICT kit were 91.7%, 83.8%, 76.4%, 94.6%, and 86.7%, respectively, and those of the rSsIR-based IgG4 ICT kit were 78.3%, 84.8%, 74.6%, 87.3%, and 82.4% respectively. The concordance between the two kits was 89.7%. The recombinant antigen can be produced to an unlimited extent and the kits can be used as point-of-care diagnostic tools and in large-scale surveys in endemic areas throughout tropical regions without necessitating additional facilities or ancillary supplies.

Chronic human liver fluke infections caused by Opisthorchis viverrini and Clonorchis sinensis can last for decades and cause liver and biliary diseases, including life-threatening pathology prior to cholangiocarcinoma (CCA). CCA generally has a poor prognosis. Serological diagnosis can support parasitological examination in diagnosing disease and screening for the risk of CCA. Here, we present an improved and innovative lateral flow immunochromatographic test (ICT) kit that uses whole-blood samples (WBS) rather than serum to diagnose human opisthorchiasis, which also successfully diagnosed human clonorchiasis. This ICT includes a soluble worm extract of O. viverrini adults and colloidal-gold-labeled conjugates of the IgG antibody to evaluate the diagnostic values with simulated WBS (n = 347). Simulated WBS were obtained by the spiking infection sera with red blood cells. The diagnostic sensitivity, specificity, positive and negative predictive values, and accuracy for detecting opisthorchiasis were 95.5%, 87.0%, 80.5%, 97.2%, and 90.1%, respectively. For clonorchiasis, these findings were 85.7%, 87.0%, 53.6%, 97.2%, and 86.8%, respectively. Combined for both diseases, they were 93.2%, 87.0%, 84.0%, 94.6%, and 89.6%, respectively. The ICT kit can possibly replace the ICT platforms for antibody detection in serum samples in field surveys in remote areas where sophisticated equipment is not available.

Human gnathostomiasis is a harmful food-borne zoonosis caused by roundworms of the genus Gnathostoma. The parasite can occasionally migrate to the central nervous system, causing life-threatening disease and death. Here, we report a new point-of-care (POC) test kit, the gnathostomiasis blood immunochromatographic test (GB-ICT) kit. The kit is based on recombinant Gnathostoma spinigerum antigen and detects specific IgG4 antibody in whole-blood samples (WBSs). The GB-ICT kit showed potentially high diagnostic values with simulated WBSs (n = 248), which were obtained by spiking patients’ sera with red blood cells. The accuracy, sensitivity, specificity, and positive and negative predictive values were 95.2%, 100%, 93.8%, 81.5%, and 100%, respectively. Ten WBSs from clinically suspected gnathostomiasis patients were all positive according to the GB-ICT kit, while 10 WBSs from healthy volunteers were negative. The GB-ICT kit is a simple and convenient POC testing tool using finger-prick blood samples: venous blood sampling and serum separation processes are not required. The GB-ICT kit can support clinical diagnosis in remote areas and field settings without sophisticated equipment facilities.

: Fascioliasis, which is caused by Fasciola hepatica and Fasciola gigantica (F. gigantica), is a public health problem worldwide. Stages infective to humans occur on aquatic plants and in water. The gold standard for diagnosing human infection depends on finding fluke eggs in stool samples. However, this method has low diagnostic sensitivity; eggs from other trematode species might be misidentified as those of Fasciola, and eggs are not voided in ectopic infections. Therefore, serological analysis can support the diagnosis of human fascioliasis. We evaluated whether a new fascioliasis immunochromatographic test kit, which detects specific IgG antibodies using F. gigantica excretory–secretory antigen, can be used for rapid diagnosis from whole blood. The kit (“the fascioliasis whole-blood test kit”) was evaluated under laboratory conditions using 250 whole-blood samples (WBSs), of which 41 were from fascioliasis cases. Results based on simulated WBSs and the corresponding serum samples were compared and showed almost perfect agreement (percent agreement = 97.2%; kappa value = 0.9145). The diagnostic sensitivity and specificity of the test using simulated WBSs were 97.6% and 96.2%, respectively. Comparable values when serum samples were tested were 100.0% and 93.3%, respectively. This kit represents a significant advance because it does not require extensive training of personnel, is easy to use, and can support diagnosis at the bedside or in local and remote hospitals with limited facilities. The kit may also contribute significantly to epidemiological surveys.

: Human strongyloidiasis is an important intestinal parasitic disease that affects public health globally and is transmitted through contact with infective larvae on contaminated soil. Immunocompromised hosts can experience hyperinfection, which can lead to fatal systemic strongyloidiasis. Here, an innovative point-of-care (POC) test kit, the strongyloidiasis immunochromatographic blood test (the NIE-SsIR whole-blood ICT) kit is described. The kit was used to detect anti-Strongyloides IgG antibody in whole-blood samples (WBSs) instead of serum to diagnose strongyloidiasis. The kit is based on a mixture of two recombinant Strongyloides stercoralis protein antigens (NIE and SsIR) and colloidal-gold-labeled conjugates of anti-human IgG antibody to evaluate diagnostic values with simulated and fresh anticoagulated WBSs. The NIE-SsIR whole-blood ICT kit showed potentially high diagnostic values with simulated WBSs, obtained by spiking patients’ sera with red blood cells. The sensitivity, specificity, and positive and negative predictive values were 93.0%, 93.7%, 88.6%, and 96.2%, respectively, at the prevalence of disease simulated under the laboratory conditions of 34.5%. In addition, 18 of 20 fresh anticoagulated WBSs from strongyloidiasis cases were positive, and all 15 WBSs from healthy volunteers were negative. The NIE-SsIR whole-blood ICT kit is a simple and convenient POC testing tool and can possibly be used with fingerstick blood samples, thereby not requiring the drawing of venous blood and separation of the serum. The NIE-SsIR whole-blood ICT kit can assist clinical diagnosis in remote areas and field settings without sophisticated equipment.