Indirect Hemagglutination Assay Research Articles

Validity of urine-CCA cassette test and indirect haem-agglutination assay (IHA) in the detection of schistosomiasis-mansoni infection relative to microscopic examination.

Several immunodiagnostic assays have been commercially presented over the last years as easy diagnostic methods for schistosomiasis using serum or urine samples. The performance of immunochromatographic test (ICT) and indirect hemagglutination assay (IHA) was validated in the identification of active schistosomiasis infection. Detection of circulating cathodic antigen (CCA) of the parasite in urine samples and anti-Schistosoma antibodies in serum using ICT (Urine-CCA Cassette test) and IHA respectively. Proved diagnosis of Schistosoma mansoni infection was defined by the sum of positive results from microscopic examination (Gold standard) and Kato-Katz method. Out of 173 (mean age, 45 ± 10years; 70 from Giza, 103 from different Egyptian governorates), 9 4 adult patients were infected. Urine-CCA cassette test despite showing high specificity (91.14%) it was of low sensitivity (23.40%). PPVs was 75.86% and NPV was 50.00% and diagnostic accuracy of 54.34%. The IHA showed a sensitivity of 57.45% and specificity of 48.10%. PPVs was 56.84% whereas NPVs was 48.72%. As for diagnostic accuracy, it was 53.18%. Urine-CCA Cassette test had lower sensitivity than expected for detection of circulating antigen and the IHA kit is generally more expensive than microscopic examination and Urine-CCA cassette test with low sensitivity and specificity. On the basis of this diagnostic performance none of the two tested immune-assays can be a sole tool in the principal diagnosis of active schistosomiasis infections.

Investigation of Melioidosis Using Blood Culture and Indirect Hemagglutination Assay Serology among Patients with Fever, Northern Tanzania.

.Prediction models indicate that melioidosis may be common in parts of East Africa, but there are few empiric data. We evaluated the prevalence of melioidosis among patients presenting with fever to hospitals in Tanzania. Patients with fever were enrolled at two referral hospitals in Moshi, Tanzania, during 2007–2008, 2012–2014, and 2016–2019. Blood was collected from participants for aerobic culture. Bloodstream isolates were identified by conventional biochemical methods. Non–glucose-fermenting Gram-negative bacilli were further tested using a Burkholderia pseudomallei latex agglutination assay. Also, we performed B. pseudomallei indirect hemagglutination assay (IHA) serology on serum samples from participants enrolled from 2012 to 2014 and considered at high epidemiologic risk of melioidosis on the basis of admission within 30 days of rainfall. We defined confirmed melioidosis as isolation of B. pseudomallei from blood culture, probable melioidosis as a ≥ 4-fold rise in antibody titers between acute and convalescent sera, and seropositivity as a single antibody titer ≥ 40. We enrolled 3,716 participants and isolated non-enteric Gram-negative bacilli in five (2.5%) of 200 with bacteremia. As none of these five isolates was B. pseudomallei, there were no confirmed melioidosis cases. Of 323 participants tested by IHA, 142 (44.0%) were male, and the median (range) age was 27 (0–70) years. We identified two (0.6%) cases of probable melioidosis, and 57 (17.7%) were seropositive. The absence of confirmed melioidosis from 9 years of fever surveillance indicates melioidosis was not a major cause of illness.

Serological evidence of Toxoplasma gondii and Chlamydia infection in alpacas (Vicugna pacos) in Shanxi Province, northern China

Toxoplasma gondii, Neospora caninum, Chlamydia and bluetongue virus (BTV) are four important pathogens which can cause reproductive loss. The present study was conducted to estimate the seroprevalence of T. gondii, N. caninum, Chlamydia and BTV in alpacas in Shanxi Province, northern China. A total of 251 serum samples were collected from alpacas, and antibodies against T. gondii and Chlamydia were examined by the modified agglutination test (MAT) and indirect hemagglutination assay (IHA), respectively. Antibodies to N. caninum and BTV were determined by using the commercially available competitive enzyme-linked immunosorbent assay (cELISA) kits, respectively. The overall seroprevalence of T. gondii was 9.16% (95% CI 5.59–12.73) in the three sampled counties, of which, no T. gondii-seropositive samples were detected in alpacas in Fanshi County. Gender differences in the T. gondii seroprevalence were observed. The overall Chlamydia seroprevalence was 13.94% (95% CI: 9.66–18.22), and there was a statistically significant difference in Chlamydia seroprevalence in alpacas between the two counties, Jiexiu and Fanshi. All serum samples tested negative for N. caninum and BTV antibodies, respectively. To our knowledge, this is the first report of T. gondii and Chlamydia seroprevalence in alpacas in China, which provides baseline information for controlling T. gondii and Chlamydia infection in alpacas in China.

First Report of Chlamydia Seroprevalence and Risk Factors in Domestic Black-Boned Sheep and Goats in China

The Gram-negative bacteria of the genus Chlamydia cause a wide range of diseases in humans and animals. The seroprevalence of Chlamydia in domestic black-boned sheep and goats in China is unknown. In this survey, a total of 481 serum samples were collected randomly from domestic black-boned sheep and goats from three counties in Yunnan province, southwest China, from July to August 2017. The sera were examined by an indirect hemagglutination assay (IHA). Antibodies to Chlamydia were detected in 100/481 [20.79%, 95% confidence interval (CI), 17.16–24.42] serum samples (IHA titer ≥1:64). The Chlamydia seroprevalence ranged from 12.21% (95% CI, 7.81–16.61) to 30.89% (95% CI, 22.72–39.06) across different regions in Yunnan province, and the differences were statistically significant (P < 0.01). The seroprevalence in male domestic black-boned sheep and goats (28.64%; 95% CI, 22.36–34.92) was significantly higher than that in the females (15.25%; 95% CI, 11.05–19.45) (P < 0.01). However, there was no statistically significant difference in Chlamydia seroprevalence in domestic black-boned sheep and goats between ages and species (P > 0.05). To our knowledge, this is the first report of Chlamydia seroprevalence in domestic black-boned sheep and goats in Yunnan Province, southwest China. These data provide baseline information for future implementation of measures to control Chlamydia infection in these animals.

Epidemiological and clinical characteristics of Trypanosoma cruzi infection in dogs (Canis lupus familiaris) from a Chagas Disease-Endemic Urban Area in Colombia

In the last few years, an unusual increase in the number of acute Chagas disease outbreaks, presumably due to oral transmission, has been reported in urban areas in Santander, Colombia. Given the importance of dogs (Canis lupus familiaris) as reservoir hosts and sentinels of T. cruzi infection across different regions of America, we carried out a serological and molecular survey on T. cruzi infection in 215 dogs from the metropolitan area of Bucaramanga, Santander. Serological detection was carried out using enzyme-linked immunosorbent assay (ELISA), indirect immunofluorescence antibody test (IFAT), and indirect hemagglutination assay (IHA), while molecular detection was done using a nested PCR (nPCR), targeting the microsatellite region of T. cruzi nuclear DNA. Animals were defined as seropositive when at least two of the three serological tests were positive, and only these animals were evaluated with the nPCR. To discriminate DTU TcI from other DTUs, a multiplex PCR was performed in the T. cruzi-positive samples. Additionally, clinical and hematological traits were evaluated in these hosts. The dog sera showed a seropositivity rate of 27.9 % (60/215), of which 43.3 % (26/60) were positive for nPCR. Statistical analysis indicated that T. cruzi seropositive in dogs was associated with specific socioeconomic sectors and a lack of garbage collection in these municipalities. Hematological analyses showed that T. cruzi infection was associated with anemia and platelet alterations but not with alterations of aspartate aminotransferase (ASAT) and creatine kinase myocardial band (CK-MB). The high seroprevalence of infection and active circulation of T. cruzi I (TcI) in dogs reflect the risk of infection to humans in this area, which should be taken into consideration when Chagas disease control programs are implemented. In addition, T. cruzi infection may take a toll on dog health, which should be considered during dog care and management.

Surveillance-based evidence: elimination of schistosomiasis as a public health problem in the Peoples\u2019 Republic of China

BackgroundA steady progress on schistosomiasis control in the Peoples’ Republic of China (P.R. China) was achieved and broadened into the twelve-year medium and long term national plan (MLNP) which marled the implementation of an integrated control strategy across all endemic areas in P.R. China in 2004. To understand the endemic trends of schistosomiasis to assess the effectiveness of an integrated strategy, we conducted an analysis of schistosomiasis surveillance data spanned from 2005 to 2015.MethodsThe schistosomiasis sentinel surveillance data from sentinel sites were collected and analyzed from 2005 to 2015. In these sentinel sites, residents aged 6 years or above were screened annually by indirect hemagglutination assay (IHA), while only antibody positives were followed by stool examination either Kato-katz method (KK) and/or hatching technique (HT). Domestic animals raised in sentinel sites were examined by HT for confirming the infection of schistosomes. Snail investigation was conducted each year through systematic sampling method combined with environmental sampling method. The snails collected from field were tested by microscopic dissection method. The infection rates of schistosomes in residents, domestic animals and snails, as well as the indicators reflecting the snails’ distribution were calculated and analyzed. ANOVA analysis was used to examine the changes of the number of eggs per gram feces in population and Chi-square test was used to examine any change in proportions among groups.ResultsA total of 148 902 residents from sentinel sites attended this study and 631 676 blood samples were examined by IHA test during the 11 covered years. The annual average antibody positive rates presented a significant decrease trends, from 17.48% (95% CI: 17.20–17.75%) in 2005 to 5.93% (95% CI: 5.71–6.15%) (χ2 = 8890.47, P < 0.001) in 2015. During 2005–2015, the average infection rate of schistosomes in residents declined from 2.07% (95% CI: 1.96–2.17%) to 0.13% (95% CI: 0.09–0.16%), accompanied by significant decrease of infection intensity in population. In 2015, the stool positives were only found in farmers, fishermen and boatmen with infection rate of 0.16% (95% CI: 0.11–0.20%), 0.17% (95% CI: 0–0.50%) respectively. The infection rate of schistosomes in domestic animals dropped from 9.42% (538/5711, 95% CI: 8.66–10.18%) to 0.08% (2/2360, 95% CI: 0–0.20%) from 2005 to 2015. Infections were found in eight species of domestic animals at the beginning of surveillance while only two cattle were infected in 2015. Totally 98 ha of new snail habitats were found, while 94.90% (93/98) distributed in lake and marshland regions. The percentage of frames with snails decreased from 16.96% (56 884/33 5391, 95% CI: 16.83–17.09%) in 2005 to 4.28% (18 121/423 755, 95% CI: 4.22–4.34%) in 2014, with a slightly increase in 2015. Meanwhile, the infection rate of schistosomes in snails was decreased from 0.26% (663/256 531, 95% CI: 0.24–0.28%) to zero during 2005–2015.ConclusionsThe infection rate of schistosomes declined significantly, providing evidence that the goal of the MLNP was achieved. Elimination of schistosomiasis as a public health problem defined as WHO was also reached in P.R. China nationwide. Surveillance-response system should be improved and strengthened to realize the final goal of schistosomiasis elimination.

Toxoplasma gondii Seropositivity and Associated Risk Factors in Cats (Felis catus) in Three Provinces in Northeastern China from 2013 to 2019.

Toxoplasma gondii is an important protozoan parasite that can infect a range of animals. Cats are the most important definitive hosts for T. gondii. Therefore, an assessment of the level of T. gondii infection in cats is of public health importance. As limited information about seroprevalence of T. gondii infection in cats in northeastern China was available, 854 serum samples, including 235 cats in Jilin province, 267 cats in Liaoning province, and 352 cats in Heilongjiang province, were examined by an indirect hemagglutination assay (IHA) test, between September 2013 and July 2019. The overall seroprevalence of T. gondii was 19.09% (163/854) at the cutoff 1:64, with 19.60% (69/352), 18.29% (43/235), and 19.10% (51/267) in Heilongjiang, Jilin and Liaoning, respectively. Logistic regression analysis showed that mode of life was highly related to T. gondii infection in cats at the investigation areas. These results could provide foundation data for prevention and control of T. gondii prevalence in these regions. Moreover, the results also suggested that the effective control strategies should continue to be performed.

Serological evidence of Toxoplasma gondii infection in Melanosuchus niger (Spix, 1825) and Caimam crocodilus (Linnaeus, 1758).

Toxoplasma gondii is a protozoan with worldwide prevalence, known to affect a large variety of warm-blooded hosts. However, its ability to induce long-lasting infections in cold-blooded animals remains unclear. The most likely source of infection is through consumption of meat containing tissue cysts or by ingestion of food or water contaminated with oocysts. The current global climate change trend and the progressive degradation of natural habitats are prone to alter the distribution of ectotherm populations over a short period of time, which may favor contact between these animals and the protozoan. In association, alligator meat is considered a delicacy in many regions and its consumption has been previously related to a diversity of foodborne diseases. In that sense, we proposed in this study to search for specific antibodies against T. gondii in serum samples of two common species of alligators from the Brazilian fauna (Melanosuchus niger and Caimam crocodilus). We obtained the serum samples from 84 alligators from the Araguaia region, which were tested by agglutination assays that do not require species-specific secondary antibodies (Modified Agglutination Test – MAT; Indirect Hemagglutination Assay – IHA). From the 84 samples tested, eight (9.5%) were positive by MAT. From those, seven (87.5% of MAT+, 8.3% of the total) were also positive by IHA, reassuring a probable exposure of these animals to the parasite. Direct parasite detection in muscle fragments of one serologically reactive alligator did not yield positive results. Our results provide serological evidence that Brazilian alligators may be exposed to T. gondii and further studies should be performed to elucidate whether alligators are natural hosts of this ubiquitous protozoan parasite.

Research progress of tetanus antibody detection technology in China

The situation of prevention of non-neonatal tetanus in China is severe. Strengthening the active immunization with tetanus toxoid vaccine (TTCV) is the key to prevent the non-neonatal tetanus. Through the detection of tetanus antibody (TAB), the immune status of individual can be determined, so as to implement the active immunization of TTCV correctly. The research on TAB detection technology is stagnant in aboard, but still in a development process in China since there is a realistic demand for TAB detection. This review collects relatively limited data of TAB detection technology in China, and summarizes the techniques such as mice toxin neutralization test (MTNT), indirect hemagglutination assay (IHA), double agar gel immune diffusion test (Rubin method), enzyme-linked immunosorbent assay (ELISA) and colloidal gold (CG), in order to provide a comprehensive basis for domestic TAB detection. The TAB detection technology in China has not yet achieved international recognition due to the lack of comparative study of domestic and international institutions and reference reagents. The special domestic situation of tetanus prevention makes the research of TAB detection technology have a certain practical significance, and rapid detection reagents such as ELISA and CG method have a certain application value in China.

Experimental Toxoplasmosis in Pigeons (Columba livia)

The purpose of the present study was to establish experimental model of toxoplasmosis in pigeons, to investigate pathogenesis and compare tissue lesions by clinical, histopathological, serological and bioassay techniques. Total of 60 unknown aged pigeons (Columba livia), 21 males and 39 females were used. They were divided into groups as oral (Group I and II) and parenteral (Group III, IV, V and VI) infection groups (Table 1). While some pigeons in Group IV showed acute infection signs such as anorexia, weight loss, pale cockscomb, bend of head and neck and partial paralyze; chronic infection signs such as anorexia, weakness, weight loss, diarrhea, difficulties in breathing, and conjunctivitis were seen in Group IV, V, and VI. In necropsy, the pigeons in Group IV had hyperemia and focal hemorrhages in the meninges and brain; the pigeons in Groups V and VI had yellowish color of the liver, the pigeons in Group V had the pale chest muscles, pericardial thickening and opaqueness. There were no macroscopic findings in pigeons in Group I and III. Histopathological examination revealed nonsuppurative meningoencephalitis and tachyzoites and bradyzoite cysts formation of T. gondii in brain tissue, lymphoid cell infiltration and necrotic focal hepatitis and nephritis in Group IV. While pigeons in Group V had nonsuppurative focal myositis, myocarditis, hepatitis, gastritis, enteritis, pneumonitis, and necrotic pancreatitis, one of them had toxoplasma bradyzoite cyst in the sinusoid in the liver. In group VI, nonsuppurative focal hepatitis, myocarditis, nephritis and necrotic pancreatitis were detected in pigeons. Bioassay tests were performed with tissue samples taken from seropositive pigeons and parasitic tachyzoites were isolated from the peritoneal fluid of the mice. Seropositivity in the oral and parenteral groups was determined by Sabin-Feldman Dye Test (SFDT) and Indirect Hemagglutination Assay (IHA). As a result; in similar studies that will be performed investigating pathogenesis of Toxoplasmosis and subclinical cases that may be overlooked, serologic tests and bioassay applications should be used together for the diagnosis of toxoplasmosis.

Humoral responses to Schistosoma japonicum soluble egg antigens in domestic animals in Lindu Subdistrict, Central Sulawesi Province, Indonesia

Background and Aim: Schistosomiasis japonica, a disease caused by Schistosoma japonicum, is a public health problem in the Philippines, the Republic of Indonesia, and the People's Republic of China. The disease is known as zoonotic, meaning other than humans, animals are involved as the reservoirs. In Indonesia, schistosomiasis surveillance in animals is not continuous. Thus, the study to determine the prevalence of the disease in animals is needed. The study was aimed to determine the seroprevalence of S. japonicum infection among four species of domestic animals in the Lindu Sub-district, Central Sulawesi Province of Indonesia. Materials and Methods: Blood samples of domestic animals were collected and analyzed for the presence of anti-S. japonicum immunoglobulin G antibodies against S. japonicum soluble egg antigens using the indirect hemagglutination assay. Animal stool samples were collected, and the miracidia-hatching assay was used for the detection of S. japonicum infection. Additional data concerning the animal identity and the management practices were obtained through a questionnaire used in surveys and interviews. Results: A total of 146 sera from 13 cattle, 24 buffaloes, 54 pigs, and 55 dogs were collected. The overall schistosomiasis seroprevalence was 64.4%. The serology prevalence in cattle, buffalo, pig, and dog was 100.0%, 41.7%, 74.1%, and 56.4%, respectively. Domestic animals in all of five villages have previous exposure with S. japonicum as seropositive animals detected in every village. A total of 104 animal stool samples from 146 animals sampled were obtained. The overall schistosomiasis prevalence determined by the miracidia hatching assay was 16.35%. The sensitivity and specificity of indirect hemagglutination assay (IHA) in the current study were 88.24% and 41.37%, respectively, with miracidia hatching assay as the gold-standard method. Conclusion: This study has shown a high seroprevalence of schistosomiasis japonica among domestic animals in the Lindu Subdistrict. IHA can be used as the screening method for the detection of S. japonicum infection in domestic animals. Chemotherapy and animal livestock grazing management programs to reduce the parasite burden and Schistosoma egg contamination in the environment must be implemented as part of one health approaches, in addition to other control measures.

Diagnostic performance of two specific schistosoma japonicum immunological tests for screening schistosoma haematobium in school children in Zambia

Dipstick Dye Immunoassay (DDIA) and Indirect Haemagglutination Assay (IHA), are two commercially available kits which have been widely used for screening Schistosoma japonicum in P.R. China. Whether they can be used for screening of Schistosoma haematobium are not clear. In order to evaluate the diagnostic efficiency of DDIA and IHA for screening Schistosoma haematobium, serum samples were collected from pupils in endemic areas in Zambia, Southern Africa, and tested by DDIA and IHA by single-blind manner. Meanwhile, the pupils were microscopically examined by infection with Schistosoma and soil-transmitted helminths, visually observed for parasite eggs. Of the enrolled 148 pupils, 61% tested positive for S. haematobium infection, while 31% and 36% of pupils were infected with hookworm and Ascaris respectively. Regarding the parasitological tests as reference standard, for the diagnosis of S. haematobium infection, IHA performed higher sensitivity (74%, 95% CI: 65%–83%) than that of DDIA (60%, 95%CI: 49%–70%). The sensitivities of IHA and DDIA are significant higher in 10–14 years old students than those of 7–9 years old group. The specificity of DDIA and IHA were 61% (95%CI: 49%–74%) and 72% (95%CI: 60%–84%), respectively. The co-infection with STHs decreased the specificity of DDIA but had no impact on that of IHA. Our study indicated that IHA has more potential as an alternative diagnostic tool for identifying schistosomiasis haematobium but need further improvement.

Human cystic echinococcosis: Serological diagnosis by indirect hemagglutination test, enzyme-linked immunosorbent assay, immunoelectrophoresis, and immunoblotting in surgically confirmed patients versus cases diagnosed by imaging techniques

IntroductionHuman cystic echinococcosis (CE) diagnosis is based on imaging findings and serology. Serology is the first-line test followed by imaging tests. Materials and methodsA total of 268 serum samples from CE patients were included in this study. The serodiagnosis was made simultaneously by indirect hemagglutination assay (IHA), enzyme-linked immunosorbent assay (ELISA), immunoblotting test (IB), and immunoelectrophoresis (IEP). ResultsIn serum samples belonging to surgically confirmed CE patients, we observed a percentage of positivity of 83.7% [77.2%–89.0%] and 80.7% [73.9%–86.4%] for IHA and IgG-ELISA, respectively. IgG-IB was associated with a higher positivity rate than IEP with 81.3% [74.6%–86.9%] and 62.0% [54.2%–69.5%], respectively. IHA and ELISA results were analyzed using cut-off generated by receiver operating curves. The best diagnostic performances were achieved by IHA (cut-off ≥1/128) and ELISA (>1.16 index). Sensitivities reported in patients with suggestive imaging findings and positive Echinococcus IB were 86.2% [78.0%–92.2%], 72.5% [62.8%–80.9%], 49.0% [39.0%–59.1%] for IHA, IgG-ELISA, and IEP, respectively. All tests gave false negative results in the confirmed CE group. Overall, 18.6% of negative results were obtained by IgG-IB test. Cross-reactivities with non-hydatid serum samples were observed in all tests. Only one patient carrying Taenia saginata serum cross-reacted with 8/12 kDa band by IB. We observed specificity at 73% [63.2%–81.4%], 87% [78.8%–92.9%], 99% [94.6%–100.0%], and 99% [94.6%–100.0%] with IHA, IgG-ELISA, IEP, and IgG-IB, respectively. Serology was less sensitive (74%) in lung cysts. Sensitivity was better in liver cysts, especially by IgG-IB (96%).

Establishment and operation of schistosomiasis diagnostic reference laboratory in Jiangsu Province

To construct the schistosomiasis diagnostic reference laboratory in Jiangsu Province, and to examine the role and diagnostic efficiency of the reference laboratory. A schistosomiasis diagnostic reference laboratory was built in Jiangsu Province according to the requirements of the construction of the national schistosomiasis diagnostic reference laboratory in China. Inter-laboratory comparisons were conducted and the diagnostic capability of grassroots laboratories was evaluated in Jiangsu Province. The organization structure, environmental conditions, administration and quality systems of the schistosomiasis diagnostic reference laboratory in Jiangsu Province all met the requirements for construction of the national schistosomiasis diagnostic reference laboratory in China, and the schistosomiasis diagnostic reference laboratory in Jiangsu Province was issued a certificate of a province-level schistosomiasis diagnostic reference laboratory. During the 6 inter-laboratory comparisons performed by national schistosomiasis diagnostic reference centers of China, the qualitative and quantitative results of each detection item were all in agreement with the reference samples (Kappa = 1), and the diagnostic capability was identified excellent. The results of indirect hemagglutination assay of 426 serum samples from 4 grassroots laboratories were re-examined, and the mean coincidence rate was 94.13% (range, 92.08% to 96.25%) with the grassroots laboratories, with a mean Kappa value of 0.85 (range, 0.83 to 0.86) and a mean missing rate of 10.19% (range, 0 to 17.65%). The schistosomiasis diagnostic reference laboratory has been successfully established and effectively operated in Jiangsu Province, which plays an active role in improving the capability of schistosomiasis diagnostic equality in the province.

Survey of Schistosoma japonicum infections in wild animals in hilly transmission-controlled areas of Jiangxi Province

To understand the situation of Schistosoma japonicum infections in wild animals in transmission-controlled schistosomiasis-endemic areas in Jiangxi Province, so as to provide scientific evidence for implementing precision control interventions and achieving the goal of transmission interruption and elimination of schistosomiasis. Five endemic villages from Ruichang City and Pengze County that were heavily endemic for schistosomiasis in Jiangxi Province, were selected as the study villages. Wild animals like wild mice were captured, and the livers of wild animals were purchased from the snail habitats in the study villages for detection of S. japonicum infections. In the study villages, S. japonicum human infections were screened using indirect hemagglutination assay (IHA) followed by parasitological examinations with miracidial hatching test and Kato-Katz method, and the S. japonicum infection in livestock was tested using a miracidial hatching test with a plastic tube. In addition, snail survey was conducted in the study villages by means of systematic sampling combined with environmental sampling, and the S. japonicum infection in snails was detected using a loop-mediated isothermal amplification (LAMP) assay. A total of 240 liver specimens were sampled or purchased from 5 species of wild animals in the study villages, including wild mice, weasels, pigs, deer and rabbits. A total of 172 wild mice were captured, with a 2.91% rate of S. japonicum infection, and there was no S. japonicum infection detected in other wild animals. The prevalence of Capillaria hepatica infection was 12.21%, 1.96% and 12.50% in wild mice, deer and pigs, respectively. In addition, there was no S. japonicum infection found in either humans or livestock in the study villages, and the mean snail density varied from 0.13 to 0.80 snails/0.1 m2 in the study villages. LAMP assay detected S. japonicum infection in 2 tubes in a study village. The role of wild animals in schistosomiasis transmission and their potential risks can not be neglected in hilly schistosomiasis-endemic areas of Jiangsu Province after transmission control. Intensified surveillance and targeted control measures should be implemented to consolidate schistosomiasis control achievements.

First Report of Chlamydia Seroprevalence in Slaughter Pigs in Shandong Province, Eastern China.

Chlamydia, a kind of obligate intracellular Gram-negative bacteria, can infect humans and animals worldwide, including pigs. However, the information on Chlamydia infection is unavailable in pigs in Shandong province, eastern China. To assess the seroprevalence and risk factors of Chlamydia infection in pigs in Shandong province, eastern China, a total of 2108 serum samples of slaughter pigs were collected between January 2017 and December 2018, and specific antibodies against Chlamydia were detected by the indirect hemagglutination assay. The overall Chlamydia seroprevalence was 24.15% (509/2108, 95% confidence interval: 22.32-25.97). Species, sampling regions, and rearing systems of pigs were considered as risk factors for Chlamydia infection through statistical analysis by SAS analysis (p < 0.05). These results indicated that Chlamydia is highly prevalent in slaughter pigs in Shandong province, eastern China, and may pose a potential risk for human health. To our knowledge, this is the first investigation of Chlamydia seroprevalence in slaughter pigs in Shandong province, eastern China. Moreover, this is the first report to compare the Chlamydia seroprevalence between domestic pigs and farmed wild boars in a same study, which may provide important data for preventing and controlling Chlamydia infection in pigs in China.

Chagas disease in the Bolivian Chaco: Persistent transmission indicated by childhood seroscreening study

BackgroundScreening for Trypanosoma cruzi infection was performed amongst children in a rural community in the Bolivian Chaco, an area known for high prevalence. The force of infection (FOI) was estimated. MethodsA total of 423 children attending the local school were screened using the Chagas Detect Plus (CDP) rapid test (InBios International, Inc.). CDP-positive specimens were further tested by indirect haemagglutination assay (IHA) and Wiener Recombinante v3.0 ELISA. A catalytic model was used to estimate FOI. ResultsConfirmed seroprevalence was 0.22, rising steeply with age. The mean age of seropositive individuals was 13 years. The calculated specificity of the rapid test was 91.9%. The annual incidence estimated from the FOI was 0.021. ConclusionsThis study demonstrates persistent transmission and continuing high levels of T. cruzi infection in the Bolivian Chaco, and highlights the practicality of school-based screening.

The validity of indirect haemagglutination assay (IHA) in the detection of Schistosoma haematobium infection relative to microscopic examination

Background : Several schistosome serodiagnostic assays have been developed over the last years, most of them are designed for the detection of anti-schistosomal antibodies which might remain for long periods of time after treatment, this study aimed to evaluate commercially available kit, indirect hemagglutination assay (IHA) as alternative to microscopic examination to diagnose S.haematobium infection Subjects and methods: This study is a cross-sectional study designed to evaluate an indirect hemagglutination assay (IHA), a commercially available kit was used for determine urinary schistosomiasis in the study population, this performed on 50 positive S.haematobium samples and 50 negative samples for individuals matching in age and gender, in addition, urine microscopic examination was done for detection of S.haematobium eggs by sedimentation centrifugation and nuclepore filtration techniques. Results: The results showed that an indirect hemagglutination assay (IHA) had a sensitivity of 42% and specificity of 80%. PPVs were 67.7% whereas NPVs were 57.97 %. As for diagnostic efficiency, it was 61%, where the area under the curve (AUC) was bad 0.58. Conclusion and Recommendations: Years ago this commercial kit which used in this study and also used in all medical laboratories in Egypt for detection of schistosome antibody in serum is called Fumouzebilharzial IHA Kit, this study showed low sensitivity (42%) and specificity (80%), that lower than expected results for detection of antibody and the kit is generally more expensive than microscopic examination for S.haematobium infection.

Canine trypanosomiasis in an endemic Costa Rican community: Demonstration of the active infection cycle.

A cross-sectional study was conducted to determine the prevalence of canine trypanosomiasis in an endemic community of Costa Rica. The indirect hemagglutination and indirect immunofluorescence assay yielded positive results in 6.4% (20/314) of canine samples analyzed; polymerase chain reaction (PCR) and light microscopy yielded positive results in one dog. Subsequently, a longitudinal study was carried out with 55 negative T. cruzi canines in the cross-sectional study. These dogs were divided into two groups: Group 1, which consisted of 25 individuals that lived in dwellings where triatomines were found in their homes; and Group 2, which consisted of 30 dogs that lived in dwellings where triatomines were not found during the previous study in their homes. Seroconversion occurred in six dogs (10.9%) in Group 1 in the first months of the year (dry season); these dogs remained seropositive until the end of the study. Only one of the six seropositive canines was also found positive once in T. cruzi PCR. The analysis of the amplified T. cruzi sequences of dogs and triatomines showed that all of them belonged to the TcI lineage. It is recommended that residents be made aware of the need to eliminate vectors in their homes and their surroundings.

Humoral Immune Effect of Methanolic Extract of Spondiamombin, Mucunapruriens and Acanthus montanus in Cockerel

This study was conducted to assess the effect of methanolic plant extract of some selected plants (Acanthus montanus, Spondia mombins and Mucuna pruriens) on immune response in cockerel. One hundred and forty birds were allotted to 7 groups (n=10) in this experimental unit and replicated twice. Birds were administered Spondias mombin orally at 250mg/kg bw, Spondias mombin at 500mg/kg bw, Mucuna pruriens at 250mg/kg bw, Mucuna pruriens at 500mg/kg bw, Acanthus montanus at 250mg/kg bw, Acanthus montanus administered orally to birds at 500mg/kg bw and distilled water and designated as Groups 1-7 respectively. Birds were vaccinated against Gumboro twice at days 10 and 21 while Lasota vaccine was administered twice at days 14 and 28. Blood samples were collected brachial vein (wing vein) of the animal on days 9, 23 and 37 to obtain sera samples which were used for indirect haemagglutination assay (IHA) (Gumboro) and days 13, 27 and 42 for sera samples used for Haemaglutination inhibition test (HI) (Newcastle). There were no significant differences (p>0.05) in the initial antibody titre among the birds for both IHA and HI. The highest antibody titre, 28.0 was found in birds administered with Acanthus montanus (500mg/kg) at day 42 for HI. The highest antibody titre for the IHA was found in birds administered with Acanthus montanus (500mg/kg) at day 37. The control birds had 23.5 and 23.7 at days 37 and 42 for IHA and HI respectively.From this study, A. montanus at 500mg/kg is recommended as adjuvant to gumboro and Newcastle vaccines in poultry.