Evaluation of the Impact of the COVID-19 Pandemic on Cystic Echinococcosis Indirect Hemagglutination Test Dynamics: A Single-center Experience.

OBJECTIVE: Cystic echinococcosis (CE) is one of the neglected tropical diseases announced by the World Health Organization. In the period entered with the Coronavirus disease-2019 pandemic, the fight against such diseases has become even more difficult. In our study, we aimed to make inferences about the effects of the pandemic on the diagnosis of the disease by evaluating the number and results of CE indirect hemagglutination test (IHA) before and during the pandemic. METHODS: The number of IHA test requests and positivity rates in the 30-month periods before and after March 11, 2020, when the first case was seen in our country, were evaluated retrospectively. Statistical analysis was made with SPSS version 23 (SPSS, Chicago, IL, USA) program. RESULTS: The results of 1444 patients before the pandemic and 870 patients during the pandemic period were examined. The difference between IHA positivity rates, which was found to be 18.49% before the pandemic and 14.6% during the pandemic, was statistically significant (p=0.016). The positivity rates of women and men were found to be statistically similar in both periods (pbefore=0.621, pafter=0.238). The age group with the highest IHA positivity rate was 20-39 in both periods, and the difference between the positivity rates of the age groups was statistically significant (p<0.001). CONCLUSION: A significant decrease was observed in the rate of IHA positivity during the pandemic period. The status of no increase in positivity rates despite a significant decrease in IHA tests makes us think that the diagnosis may be missed in some patients or that there could be disruptions in their follow-up. For this reason, in order to continue the fight successfully against CE, which is an important public health problem for our country, early diagnosis and regular follow-ups should be emphasized with educations, and the laboratory-clinician communication should be strengthened in order to use tests more efficiently.

The Efficiency of Commercial Immunodiagnostic Assays for the Field Detection of Schistosoma japonicum Human Infections: A Meta-Analysis.

Although great strides have been achieved, schistosomiasis japonica remains a major public health concern in China. Immunodiagnostics have been widely accepted as the first choice in large-scale screening of Schistosoma japonicum human infections, and indirect hemagglutination test (IHA), enzyme-linked immunosorbent assay (ELISA), and dipstick dye immunoassay (DDIA) are currently the three most common immunological tests for the diagnosis of S. japonicum human infections in China. This meta-analysis aimed to comprehensively assess the performance of IHA, ELISA, and DDIA for the field diagnosis of S. japonicum human infections. A total of 37 eligible publications were enrolled in the final analysis, including 29 Chinese publications and 8 English publications. No significant heterogeneities were detected among the studies reporting ELISA (I2 = 88%, p < 0.05), IHA (I2 = 95%, p < 0.05), or DDIA (I2 = 84%, p < 0.05). DDIA showed the highest pooled sensitivity (90.8%, 95% CI: 84.6% to 94.7%) and IHA presented the highest pooled specificity for detection of S. japonicum human infections (71.6%, 95% CI: 65.9% to 76.7%). Summary receiver operating characteristic (SROC) curve analysis showed that IHA exhibited the highest area under the SROC curve (AUC) (0.88, 95% CI: 0.85 to 0.9), and ELISA presented the lowest AUC (0.85, 95% CI: 0.82 to 0.88). Deeks' funnel plots indicated no publication bias. IHA presented the highest sensitivity in medium-endemicity regions and the highest specificity for diagnosis of S. japonicum human infections in low-endemicity regions, and ELISA showed the highest diagnostic sensitivity in high-endemicity regions and the highest specificity in medium-endemicity regions, while DDIA exhibited the highest diagnostic sensitivity in high-endemicity regions and the highest specificity in low-endemicity regions. IHA and DDIA presented a higher efficiency for the diagnosis of S. japonicum human infections in marshland and lake regions than in hilly and mountainous regions, while ELISA showed a comparable diagnostic sensitivity between in marshland and lake regions and hilly and mountainous regions (88.3% vs. 88.6%), and a higher specificity in marshland and lake regions than in hilly and mountainous regions (60% vs. 48%). Our meta-analysis demonstrates a comparable diagnostic accuracy of IHA, ELISA, and DDIA for S. japonicum human infections, and the diagnostic sensitivity and specificity of IHA, ELISA, and DDIA vary in types and infection prevalence of endemic regions. DDIA combined with IHA is recommended as a tool for screening chemotherapy targets and seroepidemiological surveys during the stage moving towards schistosomiasis elimination in China. Further studies to examine the effectiveness of combinations of two or three immunological tests for diagnosis of S. japonicum human infections are warranted.

Serological Follow-up of Human Cystic Echinococcosis in the Thrace Region, Turkey.

Background: Parasites of the genus Echinococcus are common worldwide and are important cestodes that cause serious infections in humans and animals. This retrospective study evaluated the indirect hemagglutination (IHA) test results of serum samples obtained from patients with a pre-diagnosis of cystic echinococcosis (CE) within ten years. In addition, the role of the IHA test results of the patients in the follow-up of the treatment and determining possible recurrences was investigated. Methods: The IHA test results of 2426 serum samples of patients with a pre-diagnosed CE admitted to Trakya University Health Center for Medical Research and Practice in Edirne, Turkey, between January 2011 and December 2020 were evaluated retrospectively. The data of 53 patients with CE who had medical treatment and/or postoperative follow-up serological records were evaluated. Results: Of 2426 IHA tests, 376 (15.5%) were seropositive, and 2050 (84.5%) were seronegative. It was determined that 376 serum samples detected as positive belonged to 207 patients with CE. Of 207 CE patients, 109 (52.7%) were female and 98 (47.3%) were male. The most common organ involvement was the liver in 186 (89.9%) cases. Of 53 patients, 16 were considered relapse cases. The median follow-up period for 16 recurrent cases was 31.8 (1-77) months. Our results showed a statistically significant correlation between long-term serological follow-up and recurrence detection (P=0.034). Conclusion: Long-term serological follow-up after treatment is considered useful in determining possible recurrent cases. CE is an important public health problem for endemic regions, including our country, and we think our study results will contribute to the status and follow-up of the disease.

A Seroepidemiological Survey of Toxoplasma gondii and Chlamydia Infection in Chickens, Ducks, and Geese in Jilin Province, Northeastern China.

Toxoplasma gondii and Chlamydia are common protozoan pathogens, which can pose health risks to people around the world and cause considerable economic losses. Although information on the seroprevalence of T. gondii and Chlamydia in chickens can be found in China, knowledge on the infection of these two diseases in rural chickens, ducks, and geese is limited. Therefore, blood samples from 377 chickens, 268 ducks, and 379 geese were taken from rural areas in seven cities in northeastern China, and their seropositivity was analyzed by the indirect hemagglutination antibody (IHA) test with a cutoff titer of 1:64. The overall seroprevalence of T. gondii and Chlamydia was 10.6% and 21.0%, respectively. Moreover, the free-range poultry (20.75% and 30.55%) have significantly higher seroprevalences than caged poultry (5.47% and 15.66%) (p < 0.001). Moreover, the seroprevalence of T. gondii in older and younger poultry was found to be 5.48% and 12.89%, and those in Chlamydia were 23.53% and 15.16%, respectively. There were significant differences between different ages (p < 0.05). But regarding the prevalence of both, it is not clear in this way which one is the prevalence for younger and older for each specific pathogen. Logistic regression analysis suggested that geography were considered as a risk factor for T. gondii infection in this study. Our study is the first report on the seroprevalence of T. gondii and Chlamydia in poultry in rural areas of Jilin Province, China. These data reflect that T. gondii and Chlamydia are widespread in poultry in northeastern China, leading to a risk of infection in human health. Therefore, the prevention and control of Toxoplasma and Chlamydia infection in poultry, other animals, and humans should be strengthened.

Comparison of indirect and modified agglutination tests for detection of antibodies to Toxoplasma gondii in domestic cats.

Toxoplasma gondii is a protozoan parasite with worldwide distribution. The accurate detection of this zoonotic agent in cats and other hosts has public health importance. Blood samples from 89 domestic cats were tested for antibodies to T. gondii using 2 commercial agglutination test kits, an indirect (IHAT; Toxo-HAI FUMOUZE; Fumouze Diagnostics) and a modified (MAT; Toxoscreen DA; bioMérieux) agglutination test. Antibodies were found in 16 of 89 (18%) cats by the IHAT and in 23 of 89 (26%) cats by the MAT, with an overall agreement between the 2 serologic tests of 92% (κ = 0.77; i.e., substantial agreement beyond chance). Considering the MAT as the gold standard, the IHAT showed perfect relative specificity (100%) and lower relative sensitivity (70%). The suboptimal sensitivity of the IHAT limits its use in epidemiologic studies in cats.

Seroprevalence and risk factors of Toxoplasma gondii infection in domestic raccoon dogs in four provinces in northern China.

Toxoplasma gondii is an obligate intracellular apicomplexan parasite that can infect almost all homoiothermal animals, including domestic raccoon dogs (Nyctereutes procyonoides). However, related reports on T. gondii infection in domestic raccoon dogs were limited in China. Therefore, a serological investigation was undertaken to investigate the seroprevalence and risk factors for T. gondii infection in domestic raccoon dogs. A total of 962 serum samples were collected from Jilin, Liaoning, Heilongjiang and Hebei provinces, northern China between April 2016 and November 2017, and were detected by the indirect hemagglutination test (IHA). The seroprevalence of T. gondii infection was 7.28% in the overall surveyed raccoon dogs by IHA, which was different among the four provinces ranging from 6.54% to 7.57%. The seroprevalence of T. gondii infection in male and female raccoon dogs was 6.62% and 7.79%, respectively. Based on statistical analysis, age was regarded as an important risk factor for T. gondii infection in raccoon dogs in this study (P < 0.05). This study reported the seroprevalence and risk factors of T. gondii infection in domestic raccoon dogs in northern China, which provided essential data for prevention and control of T. gondii infection in raccoon dogs in Jilin province, Liaoning province, Heilongjiang province and Hebei province.

Assessment of antibody assay methods in determination of prevalence of infectious bursal disease among local chickens and guinea fowls in Kwara state, North Central Nigeria.

AIM: This study aimed to assess available assay methods for infectious bursal disease (IBD) diagnosis and seromonitoring in local birds. It also sought to know the prevalence of IBD antibodies among local chickens and guinea fowls in Kwara state, North Central Nigeria. MATERIALS AND METHODS: Sera were obtained from local chickens and guinea fowls and IBD virus (IBDV) antibodies were assayed using enzyme-linked immunosorbent assay (ELISA), indirect hemagglutination (IHA) test, and agar gel immunodiffusion (AGID) test. RESULTS: A total of 265 sera were obtained from local birds during dry and wet seasons. ELISA recorded the highest prevalence of 81.1% (215/265) while IHA and AGID detected IBDV antibodies in 183 (69.1%) and 122 (46%) birds, respectively. Significant differences were established for IBD-positive sera based on the assay method used, bird species, and seasons. CONCLUSION: This study indicated that ELISA is the most sensitive and reliable assay method while AGID is the least. It also showed that there is a high prevalence of IBDV antibodies among local birds which were not vaccinated, and this implies a high IBDV activity among these bird species in the study area. This may have significant epidemiological implications on the spread of the virus to exotic bird reared in the rural areas on a commercial scale. Thus, this study suggests continuous surveillance, awareness campaign, and advocacy for vaccination of indigenous birds against IBD.

Application and evaluation of indirect hemagglutination test in the Meriones unguiculatus natural focus of Inner Mongolia / 中华地方病学杂志

Objective To analyze and evaluate the application of indirect hemagglutination test (IHA) method in the epidemic area of Meriones unguiculatus in Inner Mongolia.Methods The plague monitoring summary and epidemic analysis reports of each year in Inner Mongolia from 1996 to 2016 were collected.The serum results of the IHA method were analyzed,including the time,region and the distribution of host animals.Results From 1996 to 2016,a total of 38 096 serum samples were detected from various host animals,and 172 positive samples were detected,with a positive rate of 0.45％.In the 21 years,except 2001 and 2015,the occurrence and prevalence of plague were judged by the IHA method for the remaining 19 years.There were 10 counties detected positive sera by IHA method;the positive results were detected by IHA method in 6 kinds of host animals,including 5 rodents and 1 carnivorous,and the positive rate of Rhombomys opimus was up to 6.17％ (91/1 475),the highest titer of the seropositive host animals was as high as 1:10 240.Conclusions The IHA method is easy to operate and economical.It plays a huge role in the timely detection of the epidemic in systematic monitoring of the Meriones unguiculatus in Inner Mongolia.

Serological diagnosis methods of schistosomiasis japonica at different preva-lence:a meta-analysis / 中国血吸虫病防治杂志

Objective To comprehensively evaluate the effects of indirect hemagglutination test(IHA),enzyme?linked im?munosorbent assay(ELISA),and dipstick dye method(DDIA)in the diagnosis of schistosomiasis japonica at different preva?lence by using Meta?analysis. Methods Through the literature review according to the inclusion and exclusion criteria,a data?base was established,and by using Meta?disc and R software,the Meta?analysis was performed including the threshold test,het?erogeneity test,weighted by the quantitative effect of merger,SROC curve fitting,etc. Results A total of 60 papers were in?cluded in the final analysis. The sensitivities of IHA were 0.84,0.76 and 0.94 in heavy,medium and low endemic areas,and specificities were 0.73,0.64 and 0.73 respectively;the sensitivities of ELISA were 0.88,0.80 and 0.93 in heavy,medium and low endemic areas,and the specificities were 0.59,0.59 and 0.62 respectively;the sensitivities of DDIA were 0.93,0.81 and 0.93 in the heavy,medium and low endemic areas,and specificities were 0.66,0.69 and 0.59 respectively. The weighted sensi?tivities of IHA,ELISA and DDIA were 0.83,0.87 and 0.90 respectively;the weighted specificities were 0.69,0.60 and 0.62 re?spectively. The areas under the curve of SROC were 0.89,0.96 and 0.92 in IHA,ELISA and DDIA respectively. Conclusions In different prevalence,the effectiveness of different methods for serological diagnosis of schistosomiasis is different. The sensi?tivity and specificity of all diagnostic methods of schistosomiasis need to further improve.

Development of a recombinant OppA-based indirect hemagglutination test for the detection of antibodies against Haemophilus parasuis.

An indirect hemagglutination (IHA) test that could detect antibodies against Haemophilus parasuis was developed. The full-length cDNA sequence of the oligopeptide permease ABC transporter membrane protein (OppA) gene was cloned, and inserted into the prokaryotic expression vector pET-30a(+) to construct recombinant plasmid pET-30a-OppA. The recombinant OppA protein was expressed partly in soluble form in Escherichia coli BL21 (DE3) and then purified by Ni(2+) column. Furthermore, the recombinant OppA protein was used as an antigen to develop an IHA assay for detecting antibodies against H. parasuis. Results showed that this IHA test could detect species-specific antibodies against H. parasuis. Compared with currently available ELISA, the IHA test had a sensitivity of 85.0% and a specificity of 95.0%. The overall agreement between these two methods was 90.0%. The developed IHA test was used to evaluate the seroprevalence of H. parasuis in Hubei Province, China. The H. parasuis seroprevalence rate ranged from 5.5% to 26.2% in 325 tested clinical serum samples that were collected from three different pig farms in Hubei Province, China. The IHA test developed in this study will greatly contribute to the epidemiological surveys and immunization surveillance of H. parasuis.

Primary case of human pneumonic plague occurring in a Himalayan marmot natural focus area Gansu Province, China.

A case of primary pneumonic plague (PPP) caused by Yersinia pestis is reported. This case occurred in the largest plague area in China. The patient died after contact with a dog that had captured an infected marmot. Three of 151 contacts were shown to be positive for antibody against F1 antigen by indirect hemagglutination assay, but none had clinical symptoms. There was no secondary case.

Seroprevalence of Toxoplasma gondii infection in yaks (Bos grunniens) on the Qinghai-Tibetan Plateau of China.

Toxoplasma gondii (T. gondii), a zoonotic parasite infects almost all warm-blooded animals and causes significant economic losses. To date, however, it is still unclear whether yaks from the Qinghai-Tibetan plateau of China are exposed to T. gondii. On the present study, a survey was conducted for the first time, to investigate the seroprevalence of T. gondii infection in yaks (Bos grunniens) on the Qinghai-Tibetan Plateau (Qinghai, Tibet, Hongyuan area of Sichuan province). A total of 905 and 736 serum samples were collected from yaks in these areas in 2012 and 2013, respectively and assayed for T. gondii antibodies by an indirect hemagglutination test (IHA). The results showed that seroprevalence on plateau was 21.7% and 29.1% in 2012 and 2013, respectively with the prevalence of 22.4%, 19.4% and 25.5% in 2012 for Qinghai, Tibet and Hongyuan of Sichuan, respectively and of 26.4%, 27.0% and 33.7% for these three regions in 2013, respectively. The present survey indicated that the infection with T. gondii in yaks was widely spread in recent years on the plateau causing a high risk factor for animals and humans.

Infection investigation of Toxoplasma gondii in tree shrews from various sources / 中国比较医学杂志

Objective To investigate the infection status of Toxoplasma gondii in different colonies of tree shrews and then provide the basis for parasitological monitoring .Methods Each of the forty blood samples were randomly collected from three tree shrews colonies : wild origin, domesticated and first generation, respectively.Both indirect hemagglutination test (IHA) and PCR assay were used to detect the Toxoplasma gondii.Results No positive sample of Toxoplasma gondii was detected from either IHA or PCR results .The results from IHA and PCR assays were in coincidence with each other.Conclusions According to the survey none of the tree shrews from the three groups is infected with Toxoplasma gondii.More samples or infection experiments are needed to determine whether tree shrews can be infected with Toxoplasma gondii.

Efficiency of three methods for detecting Toxoplasma IgG antibody / 中国血吸虫病防治杂志

Objective To discuss the test efficiency of three methods for detecting Toxoplasma IgG antibody. Methods To-tally 304 specimens were detected parallelly for Toxoplasma IgG antibody by using the gold marked method,indirect hemagglutina-tion test(IHA),and enzyme-linked immunosorbent assay(ELISA),and the sensitivity,specificity and Youden index of these methods were compared. Results The detection sensitivities of gold marked method,IHA,and ELISA for Toxoplasma IgG anti-body were 85.5%,89.8%and 91.9%respectively(χ2=4.12,P>0.05);the specificities were 92.4%,96.6%and 97.5%respec-tively(χ2=4.06,P>0.05). The detection efficiency and Youden index of ELISA were 94.1%and 0.89 respectively,being high-er than those of IHA and gold marked method. Conclusion The sensitivity and specificity of the ELISA method for Toxoplasma IgG antibody are higher,and in addition,it can be automated. Therefore,it is suitable for large-scale Toxoplasma IgG antibody screening.

Infection by Toxoplasma gondii in Neotropical non-human primates / Infecção por Toxoplasma gondii em primatas neotropicais não-humanos

Toxoplasma gondii (Nicolle et Manceaux, 1909) is an obligatory intracellular protozoan parasite of warm animals, including human and non-human primates. Domestic and wild felids are considered definitive hosts. Several authors have already identified lesions in New World primates caused by T. gondii. Nevertheless, little is known about serological studies on those animals. With this reason, New World non-human primates of the genera Cebus and Callithrix that were apprehended by governmental authorities and sent to the Wildlife Screening Center (Cetas)/IBAMA, at the municipality of Seropédica, state of Rio Janeiro, were bled and sera were submitted to the indirect hemagglutination test for detection of anti-T. gondii antibodies. From 21 sera of Cebus primates, 76.19% (16/21) had anti-T. gondii antibodies. Titles varied from 16 to 2048. In samples from 21 Callithrix, only 4.5% (1/22) had anti-T. gondii antibodies. Only one animal had a title of 32. During all the time those animals were clinical evaluated until sample was collected; none of them had any clinical sign or sequel related to infection by T. gondii. The fact that the origin of these primates is unknown and that there is no information about their feeding habits before captivity makes it difficult to determine the source of T. gondii infection.

Toxoplasma gondii (Nicolle et Manceaux, 1909) é um protozoário parasita intracelular obrigatório de animais homeotérmicos, incluindo primatas humanos e não humanos, e que tem felídeos domésticos e silvestres como hospedeiros definitivos. Inúmeros trabalhos já identificaram lesões causadas por T. gondii em primatas neotropicais, entretanto, poucos estudos abordando a resposta sorológica destes animais ao parasito foram feitos. Com este intuito, primatas neotropicais do gênero Cebus e Callithrix apreendidos por órgãos governamentais e enviados ao Centro de Triagem de Animais Silvestres (Cetas)/IBAMA, no município de Seropédica/RJ, tiveram amostras de sangue coletadas e as alíquotas séricas submetidas ao teste de hemaglutinação indireta para detecção de anticorpos anti-T. gondii. Dos 21 animais do gênero Cebus avaliados, em 76,19% (16/21) das amostras foram identificados anticorpos hemaglutinantes anti-T. gondii. Os títulos hemaglutinantes variaram desde 16 até 2048. Por outro lado, dos 22 primatas do gênero Callithrix cujas amostras séricas foram testadas, apenas 4,5% (1/22) apresentaram anticorpos anti-T. gondii. Apenas o título de 32 foi identificado em um único animal. Durante a avaliação clínica e o tempo em que os animais permaneceram no CETAS, desde a chegada, em nenhum animal foram observados sinais clínicos ou sequelas condizentes com a infecção por T. gondii. O desconhecimento sobre a verdadeira procedência desses símios, bem como os aspectos sanitários relativos à alimentação deles dificulta a determinação da fonte de infecção por T. gondii.