Presence Of Specific IgM Research Articles

Lymphocyte B Subtypes in Peripheral Blood: A Prognostic Biomarker for COVID-19 Patients.

In view of the scientific gap in knowledge of the involvement of the B-cell compartment and clinical prognostic in SARS-CoV-2 infection, this work aims to evaluate the B-cell subsets and the presence of specific IgM and IgG, as well as neutralizing antibodies against SARS-CoV-2, in unvaccinated patients diagnosed with COVID-19. This study included 133 patients with COVID-19. Cellular components were assessed by flow cytometry, and immunoglobulin levels and reactivity were measured by indirect enzyme-linked immunosorbent assay. Our results showed no changes in less differentiated B cells. However, non-switched memory B cells (NS-MBCs) and class-switched memory B cells (CS-MBCs) were reduced in the patients with moderate disease. Also, plasmablasts and double-negative (DN) or "atypical" memory B cells were increased in groups of patients with moderate to critical conditions. In addition, the production of IgM, IgG, and neutralizing antibodies against SARS-CoV-2 demonstrated a positive correlation between the positivity of antibodies against SARS-CoV-2 and disease severity. Besides being related to the development of a more severe course of the disease, the increase in DN B-cell count also contributed to a poorer disease outcome in patients with a higher percentage of these cells. On the other hand, we observed an increase in the absolute number of CS-MBCs in patients with greater chances of survival. This study demonstrates that the B-cell compartment may contribute to the development of clinical symptoms of COVID-19, with changes in B-cell subset counts linked to disease course and patient prognosis.

Seroprevalence of viral and bacterial pathogens among malaria patients in an endemic area of southern Venezuela

BackgroundMalaria remains a leading public health problem worldwide. Co-infections with other pathogens complicate its diagnosis and may modify the disease’s clinical course and management. Similarities in malaria clinical presentation with other infections and overlapping endemicity result in underdiagnosis of co-infections and increased mortality. Thus, the aim of this study was to determine the seroprevalence of viral and bacterial pathogens among diagnosed malaria patients in malaria-endemic areas in Venezuela.MethodsA cross-sectional study was conducted on malaria patients attending three reference medical centres in Ciudad Bolivar, Venezuela. Clinical evaluation and laboratory tests for dengue virus (DENV), chikungunya virus (CHIKV), viral hepatitis [hepatitis A virus (HAV), hepatitis B virus (HBV), and hepatitis C virus (HCV)], and leptospirosis (LEP) were performed by enzyme-linked immunosorbent assays. Previous exposure to these pathogens was defined by the presence of specific immunoglobulin (Ig) G, and co-infection or recent exposure (CoRE) was determined by the presence of specific IgM alone or IgM + IgG. Data analysis considered descriptive statistics. Parameter distribution was statistically evaluated using Kolmogorov–Smirnov test and the necessary comparison tests. Odds ratio (OR) for complications was determined according to CoRE presence with a 95% confidence interval (CI).ResultsA total of 161 malaria patients were studied, 66% infected with Plasmodium vivax, 27% with P. falciparum, and 7.5% harboured P. vivax/P. falciparum mixed infection. Previous exposure to DENV (60%) and CHIKV (25%) was frequent. CoRE was confirmed in 55 of the 161 malaria patients (34%) and were more frequent in P. falciparum (49%) than in P. vivax (29%) and mixed malaria patients (25%) (OR = 2.43, 95% CI: 1.39–4.25, P = 0.018). The most frequent CoRE was DENV (15%), followed by HAV (12%), HBV (6.2%), CHIKV (5.5%), and LEP (3.7%); HCV CoRE was absent. Complicated malaria was significantly more frequent in patients with CoRE (56%) than those without CoRE (36%; OR = 2.31, 95% CI: 1.18–4.92, P = 0.013).ConclusionsWe found high CoRE prevalence in malaria patients as determined by serology in the study region; cases were associated with a worse clinical outcome. Further prospective studies with samples from different infection sites and the use of molecular tools are needed to determine the clinical significance of these findings.Graphical abstract

Features of laboratory parameters in children with multisystem inflammatory syndrome associated with SARS-CoV-2

Multisystem inflammatory syndrome (MIS-C) is a new childhood disease associated with coronavirus SARS-CoV-2 that manifests itself 3–4 weeks after infection. The development of MIS-C is possible, despite the asymptomatic course of coronavirus infection. The pathogenetic features of MIS-C remain unclear. The aim of the study was to investigate the state of peripheral blood parameters in children with multisystem inflammatory syndrome associated with SARS-CoV-2 upon admission to a hospital. Material and methods. We examined 52 children with MIS-C from 1 to 14 years old, hospitalized in Children`s Clinical Hospital No. 3 in Novosibirsk in October–December 2020. Testing for the isolation of SARS-CoV-2 RNA in scrapings from the nasopharynx and oropharynx was carried out using real time PCR (test systems of DNA-Technology, Russia). The presence of specific IgM and IgG antibodies to SARS-CoV-2 in blood serum was determined by ELISA using Vector-Best kits (Russia). Results and discussion. It was noted that SARS-CoV-2 virus RNA was found only in 12.8 % of cases, while specific IgG antibodies in blood serum were detected in 100 % of children. IgM to SARS-CoV-2 antigens were detected in the blood serum only in 53.85 % of children with MIS-C. It has been established that unexpressed leukocytosis was found both in children under the age of 7 and in children of 8–14 years old. However, the leukocytes content in children of the older age group was significantly lower than in children aged 1–7 years. At the same time, in both age groups, some children had extremely low values of the indicator. The causes of severe leukopenia against the background of excessive inflammation remain unclear. Age groups (1–7 and 8–14 years) do not differ statistically significantly in the relative content of lymphocytes and neutrophils. In the study of individual values of the relative content of lymphocytes within the age groups, it was noted that only some children had lymphopenia of varying severity. Conclusions. Against the background of minor leukocytosis in children with MIS-C, upon admission to the hospital, there is a tendency to develop both relative and absolute lymphopenia, regardless of age. The study noted an extremely pronounced variability of individual values of the evaluated peripheral blood parameters, regardless of age, which, with similar clinical symptoms, characterized as MIS-C, requires further study in dynamics, taking into account the initial values of the indicators.There is no pronounced relationship between the leukocytes content and specific IgM antibodies to SARS-CoV-2 antigens in the blood.

Measles outbreak in the sanitary area of Guadalajara (Spain): difficulty in microbiological diagnosis in the era of its elimination

IntroductionIn Spain, like in other countries where endemic measles has been eliminated, there is a need for available diagnostic tolos for confirming any cases in order to prevent and control its transmission. We describe the different microbiological tests used for the diagnosis of measles during an outbreak that occurred in 2019 in the province of Guadalajara (Spain). MethodsSerological and molecular tests were performed at the Microbiology laboratory of the Guadalajara University Hospital and at the National Center for Microbiology of the Carlos III Health Institute (Majadahonda, Spain). Patient data were obtained from the surveillance system. ResultsA total of 43 patients had a laboratory diagnosis of measles: 29 cases by PCR (pharyngeal exudate or urine) and positive specific IgM, 11 cases by PCR, and 3 cases only by a positive IgM. Genotype D8 was identified in 35 confirmed cases and genotype A in two that were discarded as post-vaccination cases. PCR was positive in the acute sera of 11 out of 14 patients with a negative IgM. Eleven confirmed cases had recieved one or two vaccine doses. Twelve adult patients were hospitalizated, all of them with a diagnostic of hepatitis. ConclusionsThe combination of molecular tests and the presence of specific IgM is necessary for a correct diagnosis of measles and also to classify patients with a breakthrough infection or vaccine failures (primary or secondary). Genotyping is essential for the correct classification of the patients in the context of a measles elimination program.

Серопревалентность к вирусу SARS-CoV-2 среди медицинских работников г. Москвы в апреле–декабре 2020 года

We evaluated humoral immunity (presence of specific IgM and IgG) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among healthcare professionals providing inpatient care for individuals with COVID-19. Objective. To detected and measure the level of anti-SARS-CoV-2 antibodies in healthcare professionals and to identify how many of them contacted with COVID-19 patients, including those who had asymptomatic or subclinical disease. Materials and methods. Anti-SARS-CoV-2 antibodies were detected using enzyme-linked immunosorbent assay (ELISA) with the ‘SARS-CoV-2-ELISA- Vector’ kit for IgG (State research Center of Virology and Biotechnology ‘Vector’) and ‘SARS-CoV-2-IgGELISA-BEST’ and ‘SARS-CoV-2-IgМ-ELISA-BEST’ kits for IgM and IgG (Vector-Best LLC). Samples were collected in several healthcare institutions of Moscow and in G.N.Gabrichevskiy Moscow Research Institute of Epidemiology and Microbiology. A total of 24,373 serum specimens from 74 healthcare institutions were tested. All study participants filled in special questionnaires. Results. Among 24,373 healthcare professionals tested in this study, 5,382 people were IgG-positive to SARS-CoV-2 (seroprevalence index 22.1%). The seropositivity rate was 21.5% in senior medical staff, 22.2% in nursing professionals, and 22.8% in medical assistants/technicians. We found that the proportion of SARS-CoV-2 seropositive individuals had changed over time, gradually increasing from 17.9% in April 2020 to 37.6% in December 2020. The proportion of SARS-CoV-2 seropositive people doubled among senior medical staff and nursing professionals during the year. The proportion of individuals with asymptomatic or subclinical COVID-19 was 13.8%. Conclusion. The methodological approaches used in this study allowed us to assess the humoral immunity to SARS-CoV-2 among healthcare professionals in Moscow. Our findings can be used for further improvement of anti-epidemic measures in healthcare institutions. Key words: seroprevalence, SARS-CoV-2, healthcare professionals, enzyme-linked immunosorbent assay, IgG, IgM

Local Transmission of SARS-CoV-2 Virus in Rome, Italy: A Single Center Experience

In the present study, we analysed the results from the use of serological tests for the evaluation of the antibody response to SARS-CoV-2 virus, with the aim of verifying the seroprevalence for SARS-CoV-2 virus infection in Rome. Evaluations related to the seroprevalence are important for defining the epidemiological parameters of this disease. We therefore analysed the data deriving from 1586 subjects, residing in the geographical area of Rome, subjected to a rapid test, capable of detecting the presence of specific IgM and IgG class antibodies directed against the SARS-CoV-2 virus. Among the 1586 cases, 83 had positive conversion of IgM antibody and/or IgG antibody and 1503 tested negative. Out of 83 positive cases, 48% (40/83) samples resulted positively for both IgM and IgG, while 45% (37/83) were positive for IgG only, and 7% (6/83) for IgM only. The prevalence of anti-SARS-CoV-2 antibodies in the considered geographical area was 5% (83/1586), and 54% (45/83) of our population was an asymptomatic carrier. The study was performed to better evaluate the population prevalence in the studied geographic area. To our knowledge, this is the first study carried out in the Lazio region reporting data related to the asymptomatic carriers.

Modified Widal test using 2-mercaptoethanol for detecting anti-salmonella IgM in febrile patients

Introduction: Despite limitations, the Widal test is widely used in resource-constrained settings because it is fast, inexpensive and user-friendly. Therefore, efforts continue to improve its diagnostic utility. Aims: Using 2-mercaptoethanol (2-ME) to detect the IgM fraction of total agglutinins detected by the Widal test in the serum of febrile patients. Materials and Methods: Single serum specimens were collected from 333 patients presenting to our hospital with fever. One aliquot of serum was tested by standard Widal test; a positive result was defined as simultaneous elevation of ‘O’ and 'H' titres to 1:80 or above. A second aliquot was simultaneously tested by a modified Widal test in which serum was diluted in isotonic saline with added 2-ME (0.12M) instead of in plain isotonic saline. Differences in titre between the two versions of Widal test were noted. A four-fold or greater reduction in titre upon testing with 2-ME, was considered evidence of specific IgM. Results: Standard Widal test was positive in 55 (16.5%) out of 333 patients. A ?4-fold reduction of ‘O’ titre in modified Widal test was found in 38 (69.1%) out of 55 cases, indicating the presence of specific IgM. A similar reduction of 'H' titre was seen in only 6 (11%) out of 55 cases. Conclusion: Simultaneous use of standard Widal test and modified Widal test with 2-ME allows the detection of specific IgM at a low cost. This can increase the diagnostic utility of the Widal test. Keywords: Acute febrile illness, Typhoid fever, Serology, IgM, Laboratory diagnosis.

Synthesis and systematic review of reported neonatal SARS-CoV-2 infections

A number of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infections have been reported in neonates. Here, we aim to clarify the transmission route, clinical features and outcomes of these infections. We present a meta-analysis of 176 published cases of neonatal SARS-CoV-2 infections that were defined by at least one positive nasopharyngeal swab and/or the presence of specific IgM. We report that 70% and 30% of infections are due to environmental and vertical transmission, respectively. Our analysis shows that 55% of infected neonates developed COVID-19; the most common symptoms were fever (44%), gastrointestinal (36%), respiratory (52%) and neurological manifestations (18%), and lung imaging was abnormal in 64% of cases. A lack of mother–neonate separation from birth is associated with late SARS-CoV-2 infection (OR 4.94 (95% CI: 1.98–13.08), p = 0.0002; adjusted OR 6.6 (95% CI: 2.6–16), p < 0.0001), while breastfeeding is not (OR 0.35 (95% CI: 0.09–1.18), p = 0.10; adjusted OR 2.2 (95% CI: 0.7–6.5), p = 0.148). Our findings add to the literature on neonatal SARS-CoV-2 infections.

Avidity of IgG to Rickettsia prowazekii and the presence of specific IgM in blood sera for retrospective analysis of the 1998 epidemic typhus outbreak in Russia

The authors applied a new methodological approach based not only on the study of IgM/IgG to Rickettsia prowazekii in sera, but also on the estimation of the avidity index of specific IgG. The data allowed the authors to draw new conclusions about the 1998 epidemic typhus outbreak in Russia.

Immunoserology of European seabass (Dicentrarchus labrax) and white grouper (Epinephelus aeneus) as a non-lethal diagnostic tool for viral nervous necrosis

Viral nervous necrosis (VNN) is a lethal fish disease that has spread worldwide over the last two decades, causing severe losses in aquaculture. Diagnosis of the infection is generally made by sampling brain tissue, which involves sacrificing often valuable fish. Aiming at developing a non-lethal diagnostic method, the immune responses to an experimental nervous necrosis virus (NNV) infection in sea bass Dicentrarchus labrax and white grouper Epinephelus aeneus, two species most susceptible to the disease, were studied. RT-qPCR revealed presence of NNV in the fish brain within 24 h post-infection, the virus titer remaining high up to 30–35 days post-infection. In D. labrax blood, the virus was detectable within the first 5 days, after which its presence declined rapidly. Mx gene expression correlated to the virus presence in the blood and brain. An indirect ELISA was developed that quantified anti-NNV IgM in the fish blood. In D. labrax, anti-NNV IgM titer increased significantly within 5 days post-infection, and presence of specific IgM was detectable for 180 days. A sandwich ELISA was developed for E. aeneus. In this latter species, anti-NNV IgM titer increased significantly within the first 12 days and was detectable for 208 further days. The sandwich ELISA can be used as a diagnostic tool for detecting NNV exposure in all fish species for which specific antibodies against their IgMs are not yet commercially available. Our immunoserological method can reliably be used for diagnosis of VNN infection and does not require sacrificing the fish.

Neuroborreliosis mimicking demyelinating disease of the central nervous system: case reports

We present two patients with neuroborreliosis initially considered as demyelinating disease of the central nervous system. The first patient developed facial numbness on the right side, diplopia and dizziness that lasted about half a year. Magnetic resonance imaging of the brain showed confluent hyperintense lesions and visual evoked potentials revealed prolonged latencies of the P wave. The second patient developed weakness, numbness and pain in the left hand that lasted several weeks. Magnetic resonance imaging of the cervical spine demonstrated hyperintense lesions commonly found in multiple sclerosis. In both cases, positive serology for Borrelia burgdorferi was an indicator of past infection. However, the cerebrospinal fluid analysis showed proteinorrhachia and lymphocytic pleocytosis and the presence of specific IgM and IgG antibodies in the cerebrospinal fluid confirmed the diagnosis of neuroborreliosis. The clinical symptoms, abnormal cytological, biochemical and immunological cerebrospinal fluid findings in combination with good response to antibiotic therapy confirmed the diagnosis of neuroborreliosis in our patients.

The complement receptor CRIg dominates clearance of intravascular parasites during African trypanosome infection

Abstract Kupffer cells (KCs), the liver resident macrophages, play a prominent role in clearance of blood-borne pathogens. The mechanisms by which KCs engulf circulating parasites such as African trypanosomes have yet to be determined. Here we show that depletion of KCs resulted in uncontrolled parasitemia in mice infected with Trypanosoma congolense, indicating the essential role of KCs in clearance of intravascular parasites. By using intravital microscopy, we further investigated the dynamics of interactions of KCs with circulating T. congolense in real-time. The results demonstrate that KCs catch circulating parasites in the presence of specific IgM and IgG antibodies, but fail to do so in the absence of specific antibodies. Complement C3 is critically involved in the capture of the parasites mediated by both IgM and IgG. We further demonstrate that complement receptor CRIg, but not CR3, is crucial for KCs to catch the parasites. In support of the findings gained by in vivo imaging, mice deficient of C3 or CRIg, but not CR3, could not control the first wave of parasitemia, and had a dramatic reduced survival time compared to wild-type mice following infection with T. congolense (10 days vs over 100 days). Collectively, our data demonstrate that CRIg play a dominant role in the clearance of circulating parasites by KCs in an antibody dependent manner.

A Serological Survey About Zoonoses in the Verkhoyansk Area, Northeastern Siberia (Sakha Republic, Russian Federation).

In 2012, a seroprevalence survey concerning 10 zoonoses, which were bacterial (Lyme borreliosis and Q fever), parasitic (alveolar echinococcosis [AE] and cystic echinococcosis [CE], cysticercosis, toxoplasmosis, toxocariasis, and trichinellosis), or arboviral (tick-borne encephalitis and West Nile virus infection), was conducted among 77 adult volunteers inhabiting Suordakh and Tomtor Arctic villages in the Verkhoyansk area (Yakutia). Following serological testing by enzyme-linked immunosorbent assay and/or western blot, no positive result was found for cysticercosis, CE, toxocariasis, trichinellosis, and both arboviral zoonoses. Four subjects (5.2%) had anti-Toxoplasma IgG, without the presence of specific IgM. More importantly, eight subjects (10.4%) tested positive for Lyme borreliosis, two (2.6%) for recently acquired Q fever, and one (1.3%) for AE. Lyme infection and Q fever, whose presence had not been reported so far in Arctic Yakutia, appeared therefore to be a major health threat for people dwelling, sporting, or working in the Arctic area of the Sakha Republic.

Prescription et interprétation des bilans sérologiques dans le cadre d’infections maternelles à risque de transmission fœtale

Prevention is an essential aspect of management of infections that can be transmitted from mother to fetus during pregnancy: The prescription and interpretation of serologic markers differ according to clinical context: screening, counts, clinical signs, or ultrasound signs. Testing for rubella IgG antibodies is recommended at the beginning of pregnancy, in the absence of written results proving either immunity or previous vaccination with two doses. Monthly serologic monitoring (IgG and IgM) is recommended for woman lacking immunity to toxoplasmosis. Diagnosis of a primary infection requires the concomitant detection of IgG and IgM. Nonetheless, the presence of specific IgM is not necessarily a marker of recent infection. IgG avidity must be measured to confirm or rule out a recent primary infection when IgM is positive. The observation of stable antibody titers is often inaccurately considered to be reassuring. In fact, depending on the individuals tested and especially the technique used, antibodies may reach a plateau several days or several weeks after the onset of the infection. Clinical diagnosis of rubella is not reliable, and its rarity today means that physicians are unlikely to recognize it or consider it as a possible differential diagnosis. Nonetheless, residual circulation of the rubella virus continues in France. A chickenpox rash is diagnosed clinically. For atypical eruptions, the virus can be sought directly in the vesicular fluid. Serology is not helpful in this case.

ABSTRACT 299

Background and aims: Encephalitis is a complication of rubella (1/5 000 case). It affects unvaccinated children aged 5 to 14 years. Aims: The Objective of the present work is to report clinical biological and radiologic features of rubella encephalitis in childhood and assess its prognostic impact. Methods: from January to June 2013, 11 children have been hospitalized for rubella encephalitis in the PICU of the university hospital center in Oran, Algeria. Results: 11 unvaccinated children have been hospitalized for rubella encephalitis: 06 boys and 05 girls. The average age was 12.8 years. The average time between the generalized maculopapular eruption and neurological manifestations was 4 days. The seizures were the inaugural symptom in all cases. Study of Cerebrospinal fluid reveals a clear liquid in all cases with 8 elements in average (0–34 elements) and a lymphocytic predominance in 100% of cases, protein average was 0, 87 g/l, normal cerebrospinal glucose. Rubella blood serology was positive with the presence of specific IgM in all cases. The bacteriological examination was negative. Slowdowns in the background rythm to EEG have been objective in 5 cases with paroxysmal waves in 2 cases. Magnetic resonance imaging (MRI) of the brain was performed for all patients and was abnormal for one case: cerebral venous thrombosis. Intubation and artificial ventilation was required in one case for refractory status epilepticus to antiepileptic treatment. The evolution was favorable with total recovery in 100% of cases. Conclusions: These observations of rubella encephalitis illustrate the potential seriousness of this disease. The vaccination program has to be revised in Algeria.

A review of diagnostic tests for congenital syphilis in newborns

Congenital syphilis (CS) can occur when a mother is inadequately treated or not treated at all for an active Treponema pallidum infection. Symptoms of CS are often subtle and non-specific, and it is estimated that up to 60% of affected infants are asymptomatic at birth, making the diagnosis dependent on laboratory findings. Despite decades of experience with CS, problems still arise in its diagnosis because laboratory test results for children at risk for CS can be inconclusive and no single diagnostic test can be used to diagnose CS. The development of diagnostic tests such as enzyme immunoassays, immunoblotting and polymerase chain reaction (PCR) has increased the sensitivity and specificity of diagnoses, but the detection of specific IgM is currently the most sensitive serological method, and the presence of specific IgM should be considered as evidence of a congenital T. pallidum infection. Suspected cases can also be confirmed or excluded by serial post-partum tests of antibody kinetics. The authors note strongly that it is considered unethical not to treat a baby at risk of contracting CS, even without a definitive diagnosis. In this review, we describe the various microbiological methods-and their shortcomings-used in the laboratory diagnosis of CS.

Prospective and descriptive study of adult dengue cases in an emergency department, in Martinique

Objective Knowing about the clinical aspects of dengue in endemic zones is essential to implementation of appropriate case management protocols and public health interventions. Patients and methods The authors made a 4-year prospective, observational study of dengue-infected patients admitted to the emergency department of the Fort-de-France University Hospital. Results Two hundred and sixty-three male and 297 female patients were included. The median age was 37 years (range: 14–91). The diagnosis was based on a positive RT-PCR (463 patients) or on the presence of specific IgM (97 patients). Two hundred and seventy-seven patients (49.5%) presented with dengue fever without complications. According to WHO criteria, 95 patients (17%) developed plasma leakage, including 39 patients (7%) diagnosed with DHF, and 10 (1.8%) diagnosed with DSS. Among the other patients without plasma leakage, 84 (15%) had isolated thrombocytopenia, 14 (2.5%) had internal bleeding, and 90 (16%) had unusual manifestations. Seven patients died (1.3%): fulminant hepatitis (two), myocarditis (one), encephalitis (one), acute respiratory failure (one), gangrenous cholecystitis (one), and post-traumatic intracranial hemorrhage (one). The other patients recovered. Seven patients were pregnant (1.3%) from 6 to 27 weeks of amenorrhea and carried their pregnancy to term without complications. Conclusion With this experience, we were able to develop appropriate case management protocols for patients during dengue epidemics.

Congenital toxoplasmosis: evaluation of serological methods for the detection of anti-Toxoplasma gondii IgM and IgA antibodies

A study was carried out to evaluate the presence of serological markers for the immunodiagnosis of the vertical transmission of toxoplasmosis. We tested the sensitivity, specificity and predictive values (positive and negative) of different serological methods for the early diagnosis of congenital toxoplasmosis. In a prospective longitudinal study, 50 infants with suspected congenital toxoplasmosis were followed up in the ambulatory care centre of Congenital Infections at University Hospital in Goiânia, Goiás, Brazil, from 1 January 2004-30 September 2005. Microparticle Enzyme Immunoassay (MEIA), Enzyme-Linked Fluorescent Assay (ELFA) and Immune-Fluorescent Antibody Technique (IFAT) were used to detect specific IgM anti-Toxoplasma gondii antibodies and a capture ELISA was used to detect specific IgA antibodies. The results showed that 28/50 infants were infected. During the neonatal period, IgM was detected in 39.3% (11/28) of those infected infants and IgA was detected in 21.4% (6/28). The sensitivity, specificity and predictive values (positive and negative) of each assay were, respectively: MEIA and ELFA: 60.9%, 100%, 100%, 55.0%; IFAT: 59.6%, 91.7%, 93.3%, 53.7%; IgA capture ELISA: 57.1%, 100%, 100%, 51.2%. The presence of specific IgM and IgA antibodies during the neonatal period was not frequent, although it was correlated with the most severe cases of congenital transmission. The results indicate that the absence of congenital disease markers (IgM and IgA) in newborns, even after confirming the absence with several techniques, does not constitute an exclusion criterion for toxoplasmosis.

Toxoplasmosis

Toxoplasma gondii is a worldwide zoonotic infection. The sexual cycle occurs only in the cat family; only the cat's faeces are infectious, but cysts in animals and birds can cause infection when these are consumed. Acquired acute Toxoplasma infection can be asymptomatic or have nonspecific, flu-like symptoms. Lymphadenopathy is the most recognized presentation and may last more than 6 months. Retinochoroiditis is usually a result of reactivated congenital infection. Increasingly recognized is chronic infection producing chronic fatigue syndrome. Reactivated infections, particularly in the immunocompromised, are a major problem and prophylaxis may be required. Toxoplasma status should also be determined before transplantation. Laboratory diagnosis depends on the presence of specific IgM or IgA, and by increases in specific IgG. Diagnosis may require Western blotting or polymerase chain reaction analysis. First-line treatment is pyrimethamine, sulfadiazine and folinic acid. Other drugs (clindamycin, clarithromycin, azithromycin or atovaquone) can be helpful.

Myélite aiguë transverse a Mycoplasma pneumoniae chez un enfant de huit ans

Many Mycoplasma pneumoniae extra respiratory infections have already been reported. The authors report the case of an eight year old child, presenting with acute transverse myelitis, with a PCR proven involvement of M. pneumoniae in CSF as well as the presence of specific IgM in blood. Acute transverse myelitis may have many causes, most of the time viral. The mechanisms of neurological involvement in M. pneumoniae infections are still unclear, but several points indicate an immune reaction. Corticotherapy first i.v. then per os has proved to be an efficient treatment for acute myelitis. Antibiotherapy is discussed because of the undocumented mechanisms of neurological involvement related to the mycoplasma.