Clinical impact & pathogenic mechanisms of human parvovirus B19: A multiorgan disease inflictor incognito.

Human parvovirus B19 (B19V) causes myriads of clinical diseases; however, owing to lack of awareness and undetermined clinical impact, it has failed to become a virus pathogen of global concern. Cryptically, B19V causes significant morbidity and mortality. Half of the world population and 60 per cent of Indians are known to be serologically naive and are at risk of acquiring B19V infections. Cumulatively, our data showed 21.3 per cent B19V-infected patients with juvenile chronic arthropathy, recurrent abortions, multi-transfused thalassaemia and leukaemia. In addition, B19V-infected cases that ended fatally included patients with pure red cell aplasia, fulminant hepatitis and haemophagocytic syndrome. Novel clinical associations of B19V observed were amegakaryocytic thrombocytopaenia, myositis and non-occlusive ischaemic gangrene of bowel. B19V possesses multiple receptors which are distributed widely in human tissues. Vascular endothelial cell infection by B19V causes endothelialitis and vasculitic injuries besides antibody-dependent enhancement which empowered B19V to cause multiorgan diseases. Owing to lack of suitable animal model for B19V, true causal role remains to be determined, but numerous reports on B19V infections substantiate a causal role in multiorgan diseases. Hence, B19V infections need to be recognized, investigated and treated besides making efforts on vaccine developments.

A Young Child with Eosinophilia, Rash, and Multisystem Illness: Drug Rash, Eosinophilia, and Systemic Symptoms Syndrome After Receipt of Fluoxetine.

Drug rash, eosinophilia, and systemic symptoms (DRESS) syndrome is a severe systemic hypersensitivity reaction that usually occurs within 6 weeks of exposure to the offending drug. Diagnosis is usually straightforward in patients with pyrexia, skin rash, hepatitis, and eosinophilia with a preceding history of exposure to agents often associated with DRESS syndrome, such as aromatic anticonvulsants and sulfa drugs, but diagnosis of DRESS may still be a challenge. We report a 4-year-old child with probable DRESS syndrome complicated by multiple hematologic complications that developed 1 month after exposure to fluoxetine, a drug not known to be associated with such severe reactions.

Combined involvement of muscle, nerve, and myoneural junction following leptospira infection.

Leptospirosis is a zoonosis prevalent worldwide and is endemic in many parts of India. In early leptospiremic as well as late immune phase of the disease kidney, liver, heart, and lungs are commonly involved. Neurological manifestations are rare but may occur during immune phase in the form of aseptic meningitis, meningoencephalitis, seizures, myelitis, polyradiculoneuritis, and myalgia. In this report, we describe a rare case of leptospirosis with combined involvement of nerve, muscle, and myoneural junction in generalized fashion along with pulmonary, renal, and hepatic dysfunction.

Isolation, identification & characterization of Proteus penneri--a missed rare pathogen.

BACKGROUND & OBJECTIVES: Indole negative Proteus species are invariably incorrectly identified as P. mirabilis, missing isolates of Proteus penneri. P. penneri is an invasive pathogen capable of causing major infectious diseases still seldom reported in individual cases. We report here the isolation, differentiation, characterization and typing of P. penneri from patients with different clinical infections. METHODS: Urine, pus and body fluids collected from patients in intensive care units, wards and out patients departments of a tertiary health care institute from north India were cultured. A total of 61 indole negative Proteus isolates were subjected to extended biochemical tests to differentiate and identify P. penneri from P. mirabilis including failure to produce ornithine decarboxylase (by 0% strains of P. penneri and 100% strains of P. mirabilis) besides P. penneri being uniformly salicin negative, non-utilizer of citrate but ferments sucrose and maltose. Antibiograms and Dienes phenomenon were performed to characterize and type P. penneri isolates besides screening for ß-lactamase production. RESULTS: Eight isolates of P. penneri were identified; four from urine, three from abdominal drain-fluid and one from diabetic foot ulcer. P. penneri was isolated as the sole pathogen in all patients having underlying disease; post-operatively. Swarming was not seen in the first strain on primary isolation and was poor in strain-4. All eight isolates were biochemically homologous but multi-drug resistant (MDR) with resistance to 6-8 drugs (up to 12). ß-lactamase production was seen in three of five isolates while Dienes phenomenon found four distinct types and discriminated strains differing in resistance even with a single drug. INTERPRETATION & CONCLUSIONS: A few additional biochemical tests identified P. penneri isolates; it infected patients with underlying disease and strains were MDR and heterogenous.

Adverse reproductive outcome induced by Parvovirus B19 and TORCH infections in women with high-risk pregnancy.

INTRODUCTION: The frequency of fetopathogenic viruses and Toxoplasma gondii infections in the TORCH group (Toxoplasma gondii, rubella virus, cytomegalovirus (CMV), herpes simplex virus) together with Parvovirus B19 (B19) in pregnant women with bad obstetric history (BOH) and/or concurrent pregnancy complications was investigated. METHODOLOGY: Sixty women (20-35 years) with BOH and/or antecedent pregnancy complications were studied. Twenty-nine healthy pregnant women matched for age, parity and gestational age served as controls. Sera were analyzed for IgM antibodies for B19 and TORCH agents by ELISA. Cord blood and 33 placental tissues from six malformed newborns were tested for B19 DNA by PCR. RESULTS: Out of 60 high-risk pregnant women, 47 (78%) had BOH while 23 (38.3%) had underlying complications including polyhydramnios (n=10), oligohydramnios (n=6) and intrauterine growth restriction (n=7). Adverse outcomes occurred in 36 (60%) high-risk cases.  All 16 cases with polyhydramnios/oligohydramnios resulted in preterm stillbirths while the remaining 20 cases resulted in seven abortions, six newborns with congenital malformations, four full-term stillbirths and three cases of non-immune hydrops fetalis (NIHF). IgM positivity to T. gondii, rubella, cytomegalovirus, herpes simplex virus and B19 virus was 8.3%, 15%, 30%, 3.3% and 13.6% respectively. B19 infection caused NIHF in three cases and cardiac anomaly in one. All placental tissues and cord blood were negative for B19 DNA. None of the controls had IgM antibodies to any pathogen. CONCLUSIONS: Women with BOH and/or pregnancy complications had a high frequency of TORCH and parvovirus B19 infections causing fetal wastage, IUGR, NIHF and congenital malformations.

Serological study on parvovirus B19 infection in multitransfused thalassemia major patients and its transmission through donor units.

BACKGROUND: Human parvovirus B19 (B19) virus is a newly recognized agent for transfusion transmitted diseases. Beta-thalassemia major patients receive a hypertransfusion regimen, hence, are prone to acquire B19 infection; moreover, B19 escapes viral inactivation methods and donor units are not tested for B19, but there are just a couple of studies globally and none from the Asian continent. Hence, a study was designed to find the frequency of B19 infection and its transmission in multitransfused thalassemia patients. MATERIALS AND METHODS: Ninety multitransfused beta-thalassemia major (thalassemia) patients, 32 controls (age, sex matched) without any history of transfusion were enrolled. Besides the donor units were tested in B19 un-infected patients. B19 specific IgG and IgM antibodies in the sera were analyzed by ELISA (in-house), using B19 VPI and VP2 recombinant and purified antigens; additionally HBsAg and anti-HIV and anti-HCV antibodies were tested for coexisting infections. RESULTS: Seventy-three (81%) thalassemia patients tested positive for anti-B19 IgG antibodies as compared to seven (21%) in the controls group (P < 0.01), while anti-B19 IgM antibodies were detected in 37 (41.1%) compared to two (6.2%) in the controls (P < 0.01). Mean age of the thalassemia patient was eight years (range 2 - 18 years) and B19 infection was highest in the six-to-ten year range. Seropositivity increased with the number of transfusions. Two of the four HBsAg positive and five of the seven anti-HCV IgM antibody-positive patients also had anti-B19 IgM. After a six-month follow-up, four (25%) of the 16 seronegative patients seroconverted and anti-B19 IgM antibodies were detected in their donor units. CONCLUSIONS: Most of multitransfused thalassemics were B19 seropositive or had anti-B19 IgM; in the remaining uninfected group, B19 got transmitted through infected / IgM-positive donor units.

A pilot study on parvovirus B19 infection in paediatric haematological malignancies.

BACKGROUND & OBJECTIVES: Leukaemia and lymphoma are common paediatric haematological malignancies acquiring human parvovirus B19 (B19) infection. In some studies anaemia has been found in children with acute lymphoblastic leukaemia (ALL) during maintenance therapy and rarely in lymphoma. We studied frequency of B19 infection and its implications in new onset acute leukaemia (mostly ALL) and lymphoma in children. METHODS: Seventy serum samples from 35 children (age <12 yr, 29 males) newly diagnosed with haematological malignancies (on induction therapy) were collected together with 34 controls (solid tumours). Children were examined clinically and for anti-B19 IgM antibodies by quantitative ELISA and B19 DNA by PCR (VP1-VP2) and nested-PCR (VP1 unique). Bone marrow aspirates were examined histopathologically, whenever possible. RESULTS: Of the 35 children, 22 had acute leukaemia while 13 had lymphoma. B19 infection was seen in six (17.1%) of 35 children (5 ALL, 1 NHL), two at diagnosis and four during follow up compared to none in the control. Among five B19 IgM positive ALL (n=18) children, two had B19 genome and two had giant pronormoblasts (lantern cells; but one lacked B19 DNA). Of the 70 serum samples tested, eight (11.4%) had anti-B19 IgM as two children had persistent B19 infection and one showed atypical maculopapular rashes (lower limbs) while 12 (34.3%) had anti-B19 IgG antibodies. B19 infected children had unexplained anaemia (80%), required more blood transfusions (6.6 ± 4.8 Units vs 3.0 ± 2.6 Units) besides induction chemotherapy was delayed (60%) and required longer duration of therapy (29.2 ± 20 vs 6.3 ± 7.8 days) (P<0.02). Five children (2 ALL, 2 AML, 1 NHL) died but none were infected with B19. INTERPRETATION & CONCLUSIONS: B19 infection should be considered in children with ALL as it frequently caused unexplained anaemia and delay in induction chemotherapy.

Standardization of B19 IgG ELISA to study the seroepidemiology of parvovirus B19 in North Indian voluntary blood donors.

BACKGROUND AND OBJECTIVES: Parvovirus B19 (B19) being a non-enveloped DNA virus is hence thermo-stable to the current methods of viral inactivation. Therefore transfusion of blood or its component from a viremic donor to non-immune recipients may result in transfusion-transmitted B19 infection with occasional sinister complications. The serologically naïve blood donor population in our country has not been studied. Hence a study was designed to find the sero-status of B19 virus in normal voluntary blood donor population (relatives of recipients) as an indirect measure of the susceptibility to B19 in north Indians together with seroepidemiology of B19. METHODS: An in-house anti-B19 IgG ELISA was standardized using cloned, baculovirus expressed, and purified VP1/VP2 capsid proteins as antigen. Anti-B19 IgG antibodies in sera (diluted 1:400) of 1000 healthy voluntary blood donors (18-60 years; mean 30.5 years) were analyzed and their epidemiologic data were documented. RESULTS: A total of 399 (39.9%) donors were seropositive for B19 virus. Seroprevalence was higher in males than females (44% vs 27%) and it increased with increasing age (P<0.01). Socioeconomically, B19 IgG antibody positivities were 61.8%, 61.1%, and 44.4% in low, medium, and high income groups respectively with unskilled laborers having higher seroprevalence in low (48.5%) and middle (58.7%) income group (P<0.05). Housing conditions revealed B19 seroprevalence as 42.6% in donors living in small houses compared to 20.4% in larger houses (P<0.01) but no difference with religion. CONCLUSIONS: Seroprevalence to B19 in normal voluntary blood donors was low leaving a large proportion of north Indians susceptible to B19 infection.

Novel detection of parvovirus B19 DNA & IgM antibodies in patients with non-occlusive gangrene of stomach & bowel.

BACKGROUND: Gangrene of stomach or intestines owing to non-occlusive bowel infarction (NOBI) is a rare event with unknown etiology. Since B19 may cause vasculitis, arteritis, angiopathy and more importantly, localized microvascular thrombi formation hence patients with bowel gangrene were investigated for B19 infection. METHODS: Twelve patients (8 male and 4 females; median age 40 yr) of ischemic unexplained gangrene of bowel underwent emergency laparotomy. Eight cases had NOBI while four had occlusive bowel infarction (OBI). Anti-B19 antibodies in sera by ELISA and Western-blot and B19 DNA by PCR in sera and resected tissues were analysed. RESULTS: All patients underwent resection of gangrenous bowel; with exteriorization followed by restoration wherever appropriate. Histopathology showed loss of bowel mucosa and crypts with inflammatory cell infiltration besides fibrin thrombus in gastric vessels. Sera of all 8 patents of NOBI had B19 genome by nested-PCR (VP1 unique) and in 6 by PCR (VP1-VP2). In three patients resected bowel tissues also had B19 DNA besides anti-B19 IgM and IgG antibodies. NOBI patients were reticulocytopenic and anaemic while one had necrotizing vasculitis of skin a year ago. No IgM antibodies to agents causing vasculitis (HTLV-I, HIV-1+2, CMV, HSV1+2, mumps virus and Mycobacterium tuberculosis) nor any abnormality in coagulation profiles were detected. In four OBI cases's sera and resected bowel tissues and in control bowel tissues (n=36) no anti-B19 IgM antibodies or B19 DNA were detected. CONCLUSIONS: Novel finding of active B19 infection in non-occlusive gangrene of the bowel may be causal rather than casual.

Parvovirus B19-induced thrombocytopenia and anemia in a child with fatal fulminant hepatic failure coinfected with hepatitis A and E viruses.

A 5-year-old male, drowsy, jaundiced child presented with fulminant hepatitis and had HAV and HEV infection. He had hepatic encephalopathy grade 1, fever, pallor, hypotension, crepitations in his right lung base and hepatosplenomegaly with dyspnoea. He had highly raised liver enzymes and hypoalbuminemia (2.8 g/dl) but anemia (hemoglobin of 7.7 g/dl and 5.7 g/dl 2 days later), reticulocytopenia and severe thrombocytopenia (44 x 10(9)/l) were unexplained. Parvovirus B19-specific IgM antibodies and B19 DNA were found in the serum of the child. Chest X-ray showed pleural effusion and bronchopneumonia, while blood culture isolated coagulase-negative staphylococci (BACTEC 9120) and he had low oxygen saturation. Hence, he was treated with IV amoxicillin+ clavulinic acid and oxygen inhalation. He had seizures and cardiac arrest but was revived. On the third day his condition worsened and the child died despite intensive care. Hence it is concluded that his anemia and thrombocytopenia were B19 induced and this might have aggravated or caused fulminant hepatitis.

Prevalence of infections in renal transplant recipients of north India.

Renal transplant is usually performed at the end stage of renal disease. Most of the transplant recipients become susceptible to infections due to chronic uremia, protein depletion, anemia and administration of immunosuppressive drugs. It is a retrospective study of 510 post renal transplant recipients. 378 (74%) renal transplant recipients suffered from the infections. Most common site of infection was urinary tract infection (53%). Out of 26% of wound infections, the deep wound infection (23%) was six times higher than superficial wound infection (3.5%). Chest infection and bacteraemia were noticed to be 18% and 8%, respectively. The common isolate was Escherichia coli (160) followed by Staphylococcus aureus (140), Enterococcus (86) and Pseudomonas (69).

Serological study of parvovirus B19 infection in women with recurrent spontaneous abortions.

The feto-pathogenic association of parvovirus B19 (B19) has been sparingly studied in women with abortion, but not in women with recurrent spontaneous abortions (RSA). Serum samples from 116 women with RSA who were pre-screened for S-TORCH, Chlamydia trachomatis infections, anatomical, chromosomal, endocrinal abnormality and Rh incompatibility and those who had no such known causes of abortion were included in the study. Sera were also collected from 136 normal pregnant women and 120 normal non-pregnant women as disease and normal control respectively. All sera were tested at 1:400 dilutions for B19 IgM by in-house ELISA using cloned and baculovirus expressed VP1 and VP2 antigens of B19. The frequency of anti-B19 IgM antibodies in women with RSA was 19.8%, in pregnant females it was 11% and in normal non-pregnant female was 5%. Sera of 23 women with RSA which were positive for B19 IgM tested negative for B19 DNA by PCR. Patients with RSA should be screened for B19 infection and guidelines for treatment should emerge.

Detection of parvovirus B19 in a case of erythema infectiosum with myositis.

A well documented case of erythema infectiosum is being reported here for the first time from India which was associated with myositis that has not been reported globally. A 9-year-old child presented with moderate to high grade fever, mild anemia, and erythematous rash involving face, trunks and limbs associated with arthralgia, myalgia and myositis. Parvovirus B19 infection was confirmed by detection of IgM antibodies (inhouse ELISA) and DNA (nested PCR) in patient's serum.

Standardization of parvovirus B19 DNA extraction from serum and quantitative PCR.

Human parvovirus B19 (B19) is a newly emerging virus causing a wide spectrum of clinical conditions. The corner stone of diagnosis of acute B19 infection is demonstration of anti-B19 IgM antibodies and its DNA by PCR. Sera of patients infected with B19 acutely or persistently shows intense viraemia (up to 10(12) virus particles/ ml) but extraction of B19 DNA from serum is a problematic task. There is no single standardized, cost-effective in-house method, which can successfully extract DNA of B19 from serum samples and which has been subsequently tested repeatedly by many investigators over time. We describe here an efficient in-house method of extraction of B19 DNA from serum and quantitate extracted DNA by PCR. Firstly, a quantitative PCR was done using 3 microl of a cloned B19 DNA (33.3 pg/ml) mixed in 47 microl of sterile distilled water which were further diluted from 10(-1) up to 10(-7) to find the lower limit of DNA detection. To mimic human serum samples with known quantity of B19, 3 ml of cloned B19 DNA (33.3 pg/ml) were mixed with 47ml of fetal calf serum (FCS; free of B19) and were similarly log diluted from 10(-1) to 10(-7) in 50 ml volume. In-house method of DNA extraction from serum (FCS+B19 DNA) were then performed followed by quantitative PCR. In both the cases, we were able to detect B19 DNA up to 10(-4) dilution which contained 0.6 fg of B19 DNA corresponding to 12 B19 genome equivalents/PCR reaction or 2.4 x 10(2) genome quivalents/ml of serum. Further, the entire procedure was repeated two more times and identical results were obtained confirming its reproducibility. Using this in-house method we extracted and amplified B19 DNA successfully from sera of clinically suspected cases of B19 infection (data not shown). Compared to other studies, the sensitivity of our in-house method was found to be superior hence recommended for developing countries as commercial kits are too costly.

Infection with cytomegalovirus in patients with inflammatory bowel disease: prevalence, clinical significance and outcome.

Despite frequent use of immunosuppressive drugs in patients with inflammatory bowel disease (IBD) and reports of cytomegalovirus (CMV) infection following post-transplant immunosuppression, data on the frequency and clinical significance of CMV in patients with IBD are scant. Sixty-three patients with IBD (61 ulcerative colitis and two Crohn's disease) were evaluated for CMV using serology (IgM antibody, mu-capture ELISA), PCR for CMV DNA in colonic biopsy and histological assessment of haematoxylin and eosin-stained colonic biopsy. Positive result in any test was considered as CMV infection. Various parameters associated with CMV infection were analysed using univariate and multivariate analysis. Ten of 63 (15.8 %) patients (age 36.0 +/- 11.2 years, 31 female) were infected with CMV (DNA alone in four, IgM antibody alone in two and both in four, inclusion body in one). Patients with CMV infection were more often female (8/10 vs 23/53, P < 0.05), had pancolitis (10/10 vs 33/53, P < 0.05), histological activity (9/10 vs 17/53, P < 0.005) and used azathioprine (5/10 vs 7/53, P = 0.04; Fisher exact test for all). On multivariate analysis, female gender, pancolitis and histological activity were the independent factors associated with infection. Patients with CMV infection more often required surgical treatment for IBD (4/10 vs 4/53, P = 0.01) and had fatal outcome (3/10 vs 0/53, P = 0.003). CMV infection in patients with IBD may be common and is associated with poor outcome. PCR of rectal biopsy was the most sensitive method of detection followed by IgM antibody for diagnosis.

Neurocysticercosis in clinically suspected and MRI proven cases: evidence of sub-optimal antibody response.

Neurocysticercosis (NCC) has a worldwide distribution mainly in the developing countries like India. The study was done to find the seroprevalence of anti-cysticercus antibodies in clinically suspected and MRI proven cases and to corroborate the serological findings with radiological findings (MRI). A hospital based study among 204 suspected patients during January, 1996 to August, 2001 showed that 77 (32.2%, M:F = 2.2:1) had serological evidence of NCC. Of the total 189 sera, tested at 1:100 dilution 68 (35.9%) and of the total 50 CSF, tested at 1:5 dilution 9 (18%) were positive for anti-cysticercus IgG antibodies. In 35 cases where both were tested 13 sera (37.1%), 9 CSF (25.7%) and in 7 (20%) both sera and CSF were positive. In CSF from 62 patients with tubercular meningitis (disease control) 2 (3.2%) samples whereas in sera of 60 normal blood donors (normal control) 7 (11.7%) samples had anti-cysticercus IgG antibodies. In 33 MRI-positive cases, anti-cysticercus antibodies were seen in 15 (45.4%) patients. Antibodies were seen in 6 of 14 (42.8%) cases with single cortical cyst, 4 of 11 (36.3%) with 2-3 cysts and in 5 of 8 (62.5%) with multiple cysts. Alternatively, 18 of 33 (54.5%) MRI positive cases lacked anti-cysticercus antibodies. Six MRI negative cases were found to be seropositive and were treated successfully. Hence, immune response was sub-optimal even in MRI positive cases and conversely, few MRI negative cases were seropositive. Since positive response with MRI or serology depends on the stage of the disease, therefore both tests should be done together to confirm or to rule out NCC.