Antibodies against serotonin have no diagnostic relevance in patients with fibromyalgia syndrome

OBJECTIVE: To determine the prevalence and potential diagnostic relevance of autoantibodies against serotonin, thromboplastin, and ganglioside Gm1 in patients with fibromyalgia syndrome (FM). METHODS: Sera from 203 patients with FM and 64 pain-free control subjects were analyzed with enzyme immunoassays. Clinical and psychometric data of the patients were analyzed for the presence or absence of autoantibodies. RESULTS: Compared with control subjects patients with FM had a significantly higher prevalence of autoantibodies against serotonin (20% vs 5%; p = 0.003) and thromboplastin (43% vs 9%; p < 0.001), but not against ganglioside Gm1 (15% vs 9%; p = 0.301). Differences in autoantibody prevalence between controls and FM patients were not related to age or sex. No association was found between autoantibody pattern and clinical or psychometric data, e.g., pain, depression, pain related anxiety, and activities of daily living. CONCLUSION: There is an elevated prevalence of antibodies against serotonin and thromboplastin in patients with FM. The pathophysiological significance of this finding is unknown. Calculation of positive predictive values of antiserotonin antibodies shows that measurement of these antibodies has no diagnostic relevance.     

Postpericardiotomy syndrome: no evidence for a viral etiology

BACKGROUND: Postpericardiotomy syndrome has been considered a disorder induced by viral infection. This conclusion is based on serologic criterions, but these may be unreliable following either cardiopulmonary bypass or transfusion therapy. Previous studies have not verified the proposed etiology either by isolation of viruses, or by detection of their genome. We sought, therefore, to clarify the role, if any, of viruses in this syndrome. METHODS AND RESULTS: We studied prospectively 149 children aged from 6 months to 16 years who were undergoing open heart surgery. Blood samples were collected from all prior to operation, and again 7 to 10 days post-operatively, and 47 were sampled at the time of development of symptoms of pericardial involvement. Serums were analyzed for the presence of IgM and IgG antibodies to cytomegalovirus, herpes simplex virus, and Epstein-Barr virus. The polymerase chain reaction was used for amplification when assessing the genome of the enteroviruses. Cultures for viruses were established on samples of stool, urine, and throat swabs collected 7 days post-operatively, and at the time of postpericardial symptoms. Pericardial fluid obtained from 5 patients with the syndrome was cultured for viruses, and tested for enterovirus genome. On the basis of clinical and echocardiographic findings, 34 children were determined to have definite evidence of the syndrome, 13 were considered to have possible evidence, and the results from these patients were compared to those from patients with no pericardial symptoms, the latter being matched for age and transfusion status. We isolated viruses from one or more sites in five patients with definite evidence (16%), from one (9%) of those with possible evidence, and from seven (19%) of the controls. All serums and pericardial samples were negative for enterovirus genome. IgM antibodies were found in only 5 patients, three with symptoms of pericardial involvement and two without. Rates of seroconversion to IgG for the viruses were lower in the patients with symptoms of pericardial involvement compared to controls, but were strongly influenced by transfusion status. CONCLUSION: Our study has provided no evidence to support a viral etiology for the postpericardiotomy syndrome.     

Consecutive evaluation of immunoglobulin M and G antibodies against hepatitis E virus

Hepatitis E virus (HEV) infection is sporadic in the Guangzhou city southern China. However, the evaluation of antibodies to HEV during consecutive time periods after infection has not been reported. We utilized enzyme immunosorbent assay (ELISA) to detect IgM and IgG anti-HEV in consecutive serum specimens from patients with acute hepatitis E and compared that data with detection rates of IgM and IgG anti-HAV in patients with acute hepatitis A. IgM anti-HEV can be detected as early as 4 days after onset of disease symptoms in some patients. The detection rate of IgM anti-HEV is significantly higher in specimens collected within 4 weeks (95%) of onset than in those specimens collected 4 to 18 weeks after onset (67.6%) (P<0.005). IgM anti-HEV had a similar pattern to IgM anti-HAV and can be used as a marker of acute HEV infection. In contrast with IgG anti-HAV, 56.8% of the specimens did not contain detectable levels of IgG anti-HEV (P<0.005). One should be cautioned against making a diagnosis of HEV infection solely by the currently available assays for IgG anti-HEV. In conclusion, IgM anti-HEV can be used as a reliable and sensitive marker for recent HEV infection, but serum specimens should be collected within 4 weeks after onset of symptoms to avoid false-negative results. In contrast, we should be aware of the failure to develop IgG anti-HEV in some patients. These patients carry the risk of reinfection.     

High titres of IgA antibodies to enterovirus in fulminant type-1 diabetes

Aims/hypothesis We have recently proposed that fulminant type-1 diabetes is a novel subtype of type-1 diabetes with abrupt onset of insulin-deficient hyperglycaemia without islet-related autoantibodies. The pathogenesis is still unknown, but flu-like symptoms are frequently observed before the onset of disease of this subtype. Enterovirus infection is a candidate environmental factor causing type-1 diabetes. The aim of this study was to determine whether enterovirus infection contributes to the development of fulminant type-1 diabetes.Methods We investigated 19 patients with recent-onset fulminant type-1 diabetes, 18 patients with recent-onset typical type-1A diabetes, and 19 healthy controls. IgM, IgG, and IgA subclasses of antibodies to enterovirus were determined by ELISA.Results IgA antibody titres to enterovirus were significantly higher in fulminant type-1 diabetes than in typical type-1A diabetes (p=0.033) and controls (p=0.0003). IgM antibodies to enterovirus were not detected in any subject. IgG titres were lower in autoimmune diabetes than fulminant type and controls (p=0.014 and 0.019, respectively).Conclusions/interpretation High titres of enterovirus IgA antibodies in serum suggest recurrent enterovirus infection in fulminant type-1 diabetic patients, indicating higher susceptibility to enteroviral infections among them. Such infections might have pathogenetic importance in the triggering of fulminant type-1 diabetes.     

严重急性呼吸综合征患者冠状病毒总抗体及N和S蛋白抗体的随访研究

目的了解SARS冠状病毒（SARS—CoV）感染者血清中特异性IgM、IgG抗体和两个结构蛋白抗体的持续时间及相互关系。方法对146例SARS临床确诊且血清抗-SARS—CoV阳性病例,随访采集发病当13至发病后660d期间的血液标本共362份。以ELISA法分别检测抗-SARS—CoVIgM和IgG抗体、SARS—CoVN蛋白和S蛋白IgG抗体。结果抗-SARS—CoV IgM阳性率在发病20d内为46．5％（20／43）,21—40d阳性率最高（80．6％,25／31）,尔后逐渐下降,至发病后500d左右仅为8．2％（6／73）。IgG总抗体在发病20d内阳性率（34．9％,15／43）低于IgM抗体,在发病21～40d迅速达到100％,至发病后600—660d,其阳性率仍高达98．6％（70／71）。N—IgG抗体在发病40d后阳性率（92．5％,37／40）高于S-IgG（67．5％,27／40）,在61～90d、450—510d和600—660d3个时间点检测阳性率均高于S-IgG抗体;但两种结构蛋白抗体阳性率随时间延长均逐渐下降,两者于不同时间点的阳性率均低于抗-SARS—CoV总IgG。结论临床与病原学确诊的SARS患者,SARS—CoV特异性抗体阳性率在21—40d达高峰,IgG抗体阳性率100％。IgM抗体91．8％在感染500d以内消失;感染后两年IgG总抗体阳性率仍高达98．6％,推测可持续阳性3—5年。N—IgG和S-IgG抗体持续时间可能较短。     

Detection of specific IgM antibodies for the diagnosis of Mycoplasma pneumoniae infections: a clinical evaluation

The diagnostic value of detection of specific IgM antibodies was analysed in Mycoplasma pneumoniae infections. In a retrospective clinical and serological study, M. pneumoniae IgM antibodies were determined by a mu-capture ELISA using enzyme-labelled antigen. The study group consisted of 91 patients with significantly raised titers in paired sera or a single high titer of complement fixation antibodies. About 40% of the patients had been treated with antibiotics ineffective against M. pneumoniae infections prior to admission to hospital. Treatment with erythromycin or tetracycline was shown to give a shorter period of fever compared to if no or ineffective therapy was given. Specific IgM antibodies were detected in about 80% of sera sampled 9 days or more after onset of symptoms. In sera sampled at 7-8 days after onset IgM antibodies were found in about 40% of the sera but only occasionally in sera sampled earlier. In the age group 0-20 years 88% of the patients developed an IgM response. In the higher ages (greater than 60 years) a significantly lower rate of IgM responders was observed.     

Evaluation of serological response to Bartonella henselae by enzyme immunoassay in cat scratch disease

The IgG and IgM titers to Bartonella henselae were determined by an enzyme immunoassay (EIA). The EIA test for detection of IgG and IgM antibodies to B. henselae concerning CSD showed that 8 (40%) of 20 patients with CSD had a serum IgG antibody titer of 12 EIA unit or more and that 5 (25%) patients had a serum IgM titer of 12 EIA unit or more. Totally 12 (60%) of the 20 patients with CSD were seropositive for B. henselae. The mean age of IgG positive patients were higher than IgM positive patients. The IgM antibodies to B. henselae disappeared within 4 to 12 weeks after onset of disease. The IgG antibodies to B. henselae disappeared within 3 to 8 weeks after onset of the symptoms in 2 cases of CSD. Another 2 cases CSD produced high levels of IgG antibodies in the acute phase of the disease. Different course of IgG and IgM antibody titers were found in sera from patients.     

ADAMTS13 autoantibodies in patients with thrombotic microangiopathies and other immunomediated diseases

Autoantibodies neutralizing human ADAMTS13 (a disintegrin-like and metalloproteinase with thrombospondin type 1 motif), the metalloprotease that physiologically cleaves von Willebrand factor, are a major cause of severe deficiency of the protease and of acquired thrombotic thrombocytopenic purpura (TTP). We evaluated prevalence of anti-ADAMTS13 antibodies in 59 patients with thrombotic microangiopathies (TMAs) and in 160 patients with immunologic or thrombocytopenic diseases different from TTP, using an enzyme-linked immunosorbent assay (ELISA). Immunoglobulin G (IgG) antibodies directed against ADAMTS13 were found in 97% of untreated patients with acute acquired TMA who had plasma levels of ADAMTS13 activity below 10%. The corresponding prevalence of IgM antibodies was 11%. In contrast, anti-ADAMTS13 antibodies of G or M isotypes were detected in 20% of patients with TMA with ADAMTS13 activity above 10%. The ELISA was more sensitive than the standard functional inhibitor assay for detecting antibodies against ADAMTS13. Patients with thrombocytopenia from various causes (n = 50), systemic lupus erythematosus (SLE; n = 40), and the antiphospholipid antibody syndrome (APS; n = 55) had prevalences of IgG antibodies of 8%, 13%, and 5% respectively, only slightly higher than the prevalence in 111 healthy donors (4%). A rather high prevalence of anti-ADAMTS13 IgM antibodies was found in patients with SLE and APS (18% each). The clinical significance of IgM antibodies in these groups is unclear. In conclusion, the ELISA method detected anti-ADAMTS13 IgG antibodies in a very large proportion of patients with acquired TMA associated with severe ADAMTS13 deficiency, and was more sensitive than the inhibitor assay.     

Detection of antibodies against wheat germ agglutinin bound glycoproteins on the islet-cell membrane

An attempt was made to detect islet cell surface antibodies (ICSAb) using solubilized islet-cell glycoproteins as antigens. Isolated rat islets were labelled with 125I-wheat germ agglutinin (WGA) and solubilized by Nonidet P-40 with sonication. 125I-WGA-bound islet-cell proteins were incubated with test sera, and bound antibodies were precipitated with anti-human IgG or IgM immunobeads. Serum which had a bound percent beyond the mean plus 2SD of control sera was defined as antibody-positive. Results obtained by this method correlated well with those by the immunofluorescence method of detecting ICSAb. Prevalences of antibodies were 21/114 (18%) for IgG antibodies and 9/114 (8%) for IgM antibodies in patients with insulin-dependent diabetes mellitus (IDDM). The prevalence was highest for both IgG and IgM antibodies in patients within a year of the onset of disease (38 and 25%, respectively), and decreased thereafter. The prevalence of IgM antibodies was lower than that of IgG antibodies at all stages. In NIDDM patients, the prevalence of antibodies was 5/72 (7%) for both IgG and IgM antibodies. If these preliminary results are confirmed, this radioassay may be developed to detect antibodies against islet cell membrane proteins on a large scale.     

An outbreak of West Nile fever among migrants in Kisangani, Democratic Republic of Congo

In February 1998, an outbreak of acute febrile illness was reported from the Kapalata military camp in Kisangani, the Democratic Republic of Congo. The illness was characterized by an acute onset of fever associated with severe headache, arthralgia, backache, neurologic signs, abdominal pain, and coughing. In 1 individual, hemorrhagic manifestations were observed. The neurologic signs included an altered level of consciousness, convulsions, and coma. Malaria was initially suspected, but the patients showed negative blood films and failed to respond to antimicrobial drugs. A total of 35 sera collected from the military patients in the acute phase were tested for the presence of IgM against vector-borne agents. Serum IgM antibodies against West Nile fever virus were found in 23 patients (66%), against Chikungunya virus in 12 patients (34%), against dengue virus in 1 patient (3%), and against Rickettsia typhi in 1 patient (3%). All sera were negative for IgM antibody against Rift Valley fever virus, Crimean Congo hemorrhagic fever virus, and Sindbis virus. These data suggest that infections with West Nile fever virus have been the main cause of the outbreak.     

Early diagnosis of enteroviral meningitis by a solid-phase reverse immunosorbent test and virus isolation

45 cases of aseptic meningitis/meningoencephalitis were studied with regard to enteroviral etiology by virus isolation and solid-phase reverse immunosorbent test (SPRIST), a cross-reacting test for enterovirus IgM. An etiological diagnosis was reached in 37/45 (82%) patients. Etiological diagnoses other than enteroviruses were found in 8 patients: Borrelia burgdorferi in 4, varicella-zoster virus in 2, herpes simplex virus in 1 and mumps virus in 1 patient. Enteroviruses (echovirus 6, 21 and 30) were isolated from cerebrospinal fluid (CSF) in 26/37 (70%) and from stool samples of 20/21 (95%) of patients with no other etiology. Altogether enteroviruses were isolated from CSF and/or faecal samples in 29 patients. Echovirus 30 dominated as etiologic agent. In 34/40 (85%) of the samples with an enterovirus, a cytopathogenic effect was observed in cell culture within 4 days. In patients with an enterovirus isolate a SPRIST IgM response to echovirus 3, 5, 7 and/or coxsackievirus B3 was detected in 6/13 (46%) sera sampled 3-4 days after the onset of meningeal symptoms and in altogether 17/25 patients (68%). In 4 out of these virus isolation positive and SPRIST negative patients a single serum for SPRIST was available less than 4 days after onset of meningeal symptoms. Antigen from echovirus 5 gave the highest diagnostic yield. The SPRIST IgM test was positive in 2 cases where virus isolation, complement fixation and neutralization tests were negative. Epidemiological data however supported an enteroviral diagnosis in both of them. In conclusion, both SPRIST and virus isolation seem to be valuable for the early diagnosis of enteroviral meningitis.     

ELISA test for antimeningococcal IgG and IgM antibodies: application to epidemiology and diagnosis.

We have developed an enzyme-linked immunosorbent assay (ELISA) in order to quantitate antimeningococcal IgM and IgG serum antibodies. The B:15 meningococcal strain was used as coating antigen, and class specific antibodies were detected by using alkaline phosphatase labelled rabbit anti-human IgM or IgG as conjugate. The specific IgG activity was higher in sera from healthy meningococcal carriers than non-carriers, but the difference was not statistically significant. Antimeningococcal IgM serum antibodies were more frequent in carriers that in non-carriers. Acute sera from 34 patients with fulminant meningococcal disease contained less specific IgG and had a higher prevalence of IgM than healthy carriers and non-carriers. By combining measurement of antimeningococcal IgG and IgM antibodies in both acute and convalescent sera 15/18 meningococcal patients demonstrated an increase in either IgG and IgM antibodies during the hospital stay, giving a sensitivity of 83%. 8/118 individuals without meningococcal disease had detectable specific IgM antibodies in their serum, giving a clinical specificity of the test of 93%. We conclude that quantitation of specific IgG antimeningococcal antibodies by a whole bacteria ELISA test may be a useful test for the study of immunity against meningococcal disease in single individuals as well as in epidemiological studies. The combined use of the IgG and IgM tests is helpful in the diagnosis of meningococcal disease when blood or cerebrospinal fluid cultures are negative.     

Clinical interpretation of antineutrophil cytoplasmic antibodies: parvovirus B19 infection as a pitfall

BACKGROUND: While antibodies directed against proteinase 3 (PR3-ANCA) and myeloperoxidase (MPO-ANCA) have a high specificity for the diagnosis of systemic vasculitis, they may also be found as an epiphenomenon of acute viral infection. OBJECTIVE: To investigate whether positive ANCA test results may be a common feature of acute parvovirus B19 infection. METHODS: Sera were analysed from 1242 patients from a rheumatology outpatient clinic for reactivity with parvovirus B19 and EBV antibodies. They were tested for the presence of PR3-ANCA and MPO-ANCA, along with sera known to contain IgM antibodies to these viruses obtained from among 41,366 samples submitted for virological screening. RESULTS: ANCA were found in 10% (5/50) of the sera positive for IgM antibodies to parvovirus and in 3/51 sera containing IgM antibodies to EBV. Three of six patients with arthritis and concomitant parvovirus infection were found positive for PR3-ANCA and two were found positive for MPO-ANCA. All six patients tested negative for ANCA after six months of follow up. CONCLUSIONS: PR3-ANCA and MPO-ANCA may occur transiently in patients with acute B19 infection or infectious mononucleosis, highlighting the importance of repeated antibody tests in oligosymptomatic clinical conditions in which systemic autoimmune disease is suspected.     

The possible role of Coxsackie A and echo viruses in the pathogenesis of type I diabetes mellitus studied by IgM analysis.

IgM antibodies to Coxsackie B virus (CBV) have recently been observed in the serum of a relatively high proportion of children with newly diagnosed insulin-dependent diabetes mellitus (IDDM). In the present study, 108 IDDM patients below the age of 15 years, diagnosed during the period 1976 to 1985, were investigated at the onset of their disease by mu-antibody-capture radioimmunoassay (RIA) of IgM against seven different enterovirus antigens, namely virions of CBV serotypes 1-5 (CBV 1-5) and procapsids of CBV 3 and CBV 5. As has been shown the RIAs with virions give type-specific or narrow type-specific reactions, whereas procapsids react with IgM against both homotypic and heterotypic enteroviruses. The annual frequency of IgM against virions varied between 15 and 76% (mean 38%). IgM against CBV3 and CBV2 predominated, but IgM against the other serotypes was also observed. When procapsids were used as antigen, the frequency of IgM varied between 11 and 86% (mean 63%). With virions and procapsids, the corresponding variation was 44-100% (mean 70%). The total number of patients exhibiting virion-IgM was 41, whereas procapsid-IgM alone [indicating an infection with Coxsackie A virus (CAV) and/or echo virus (EV)] was detected in 36 patients. For 2 of the years, samples of serum from control groups were included. These showed a significantly lower frequency of IgM in both the virion and the procapsid RIAs. It is concluded that not only infection with CBV but also that with other enteroviruses, such as CAV and/or EV, may be involved in the pathogenesis of IDDM in children.     

Prognostic significance of circulating antibodies against carcinoembryonic antigen (anti-CEA) in patients with colon cancer

OBJECTIVE: The discovery of antibodies against carcinoembryonic antigen (CEA) in patients with digestive cancers, in the late 1970s, initiated a number of studies on the role of these antibodies in patients with cancers of the GI tract. Our aim was to determine the prevalence and prognostic significance of the IgG and IgM anti-CEA antibodies in the serum of patients with colon cancer. METHODS: Using an enzyme-linked immunoassay, the sera of 58 colon cancer patients were examined for the presence of carcinoembryonic antigen (CEA) and for circulating antibodies against the CEA (anti-CEA). An inhibition assay was carried out for the determination of the specificity of the IgG and IgM anti-CEA antibodies. RESULTS: The CEA was elevated (> or =10 ng/ml) in only 12 patients (20.6%). Anti-CEA IgM and/or IgG antibodies were detected in 46 patients with colon cancer (79.1%). In the control group (n = 28), 10% of the individuals had detectable amounts of IgG and/or IgM anti-CEA antibodies. Patients with detectable amounts of circulating IgM anti-CEA antibodies (n = 14, 30.5%) had a statistically significantly better 2-yr survival compared to the rest of the patients (p = 0.017). The IgM anti-CEA antibodies can also be used as an independent prognostic factor in these patients (p = 0.0323). CONCLUSIONS: In this study, a high number of colon cancer patients have circulating anti-CEA antibodies in their sera. These may be used as diagnostic markers and as independent prognostic factors. In addition, the presence of these antibodies in the patients studied is associated with better prognosis and significantly increased 2-yr survival. It was also found that the anti-CEA antibodies (IgG and IgM) are more sensitive markers than CEA. These findings underline the biological importance of the anti-CEA antibodies and provide additional information on their potential use as markers of the immune status in patients with colon cancer.     

High prevalence of antibodies to calreticulin of the IgA class in primary biliary cirrhosis: a possible role of gut-derived bacterial antigens in its aetiology?

BACKGROUND: In a preliminary study we showed that antibodies to the endoplasmic reticulum protein calreticulin (CR) occur in primary biliary cirrhosis (PBC) and autoimmune hepatitis type 1 (AIH). Since anti-CR antibodies have also been found in patients with infectious diseases, we investigated their prevalence and immunoglobulin classes in patients with various hepatic and intestinal diseases, hoping to get some information on a possible relationship between an infectious trigger and the induction of a certain class of anti-CR antibodies. METHODS: Sera were tested for anti-CR antibodies of the IgA, IgG, and IgM class by Western blotting, using CR isolated from human liver: in autoimmune liver diseases (primary biliary cirrhosis (PBC) (n = 86) and autoimmune hepatitis (AIH) type 1 (n = 57)), alcoholic liver cirrhosis (ALC) (n = 32), viral liver infections (acute hepatitis A (n = 8), acute hepatitis B (n = 20), and chronic hepatitis C (n = 28)), and intestinal diseases (Crohn disease (CD) (n = 30), acute yersiniosis (n = 26)). Sera from 100 healthy individuals served as negative controls. RESULTS: The most prominent finding was the high prevalence of anti-CR antibodies of the IgA class and the similarity in the anti-CR antibody class pattern in PBC (IgA, 62%; IgG, 43%; IgM, 55%) and yersiniosis (IgA, 62%; IgG, 39%; IgM, 42%). Class IgA anti-CR antibodies also occurred frequently in ALC (IgA, 44%; IgG, 41%; IgM, 19%). In contrast, in AIH anti-CR antibodies were predominantly of class IgG (IgA, 28%; IgG, 60%; IgM, 33%). In hepatitis A anti-CR antibodies were absent. In the other diseases they had a low prevalence and were mostly of class IgG (acute hepatitis B: IgA, 0%; IgG, 15%; IgM, 0%; chronic hepatitis C: IgA, 7%; IgG, 21%; IgM, 0%; CD: IgA, 13%; IgG, 20%; IgM, 13%). Of the healthy individuals 7% had anti-CR antibodies exclusively of class IgG. CONCLUSIONS: The high prevalence of anti-CR antibodies of class IgA in patients with PBC and yersiniosis as well as in alcoholic liver disease reflects a reactivity of the gut-associated immune system and could imply that a still undefined gut-derived bacterial (?) agent may trigger PBC.     

Risk factors and immune response to hepatitis E viral infection among acute hepatitis patients in Assiut, Egypt

Hepatitis E virus (HEV) infection is a common cause of acute viral hepatitis (AVH) in Egypt. We aimed to identify risk factors of HEV among acute hepatitis cases, measure HEV specific immune response to differentiate between symptomatic and asymptomatic infections. The study included symptomatic acute hepatitis (AH) patients (n = 235) and asymptomatic contacts (n = 200) to HEV cases. They completed a lifestyle questionnaire, screened for common hepatotropic viruses. Blood and serum samples were collected from patients and contacts after onset of disease and follow-up samples collected until convalescence. PBMC were separated and tested for specific HEV T-cell response by INF-gamma ELISPOT assay. Serum samples were tested for IgM and IgG anti-hepatitis E virus by ELISA. IgM antibodies to HAV were detected in 19 patients (8.1%), 37 (15.7%) with HBV, 10 (4.3%) with HCV. HEV infection was identified in 42 (16%) patients with AVH. Of the 200 contacts, 14 (7%) had serological evidence of recent HEV asymptomatic infection, showed stronger CMI responses than HEV infected subjects (2540 +/- 28 and 182 +/- 389 ISCs/106 cells, respectively; P < 0.05). In conclusion, HEV is a major cause of AVH in Egypt. Asymptomatic HEV patients are likely to have stronger immune responses including CMI responses, than symptomatic cases.     

Investigation of a Chikungunya-like illness in Tirunelveli district, Tamil Nadu, India 2009-2010

Objective To identify the aetiological agent/s of an outbreak of chikungunya‐like illness with high morbidity and several fatalities in Tamil Nadu, India, 2009–2010. Methods Two hundred and seventeen serum samples were collected from the affected areas and screened for chikungunya virus (CHIKV), dengue virus (DENV) and Japanese encephalitis virus (JEV) IgM antibodies using MAC‐ELISA kits. A few selected samples were also tested for Ross River, Sindbis, and Murrey Valley viruses by RT‐PCR and Hantan virus by serology. Twelve acute serum and mosquito samples were processed for virus isolation in C6/36 cells. CHIKV isolate was characterised by RT‐PCR and sequencing. Results Diagnostic levels of IgM antibodies were detected in 107 (49.3%) CHIKV samples and 22 (10.1%) DENV samples. IgM antibodies against JEV were not detected (n = 46). Characterisation of the CHIKV isolate at genetic level demonstrated it as ECSA (E1: 226A). Thirty‐six selected samples were also negative for Ross River, Sindbis, Murrey Valley and Hantan viruses. Conclusion High prevalence of CHIKV IgM antibody positivity, clinical symptoms, virus isolation and the presence of vector mosquitoes clearly suggest CHIKV as the aetiological agent responsible for the outbreak.