Virologic surveillance of poliomyelitis in Delhi

OBJECTIVE

Virologic surveillance of poliomyelitis to monitor the transmission of wild polio virus in the community.

STUDY AREA

All major hospitals of Delhi and surrounding area.

METHODS

Stool samples were collected from 1221 cases of acute flaccid paralysis during 1992-1994 and were subjected to virus isolation on RD and HEp2 cell line. Viruses isolated were analyzed further by microneutralization test using polio and nonpolio antisera. The polio isolates were further characterized as vaccine or wild type using ELISA and probe technology.

RESULTS

Out of the 1221 cases tested, virus was isolated in 57.4%. Among the virus positive cases, polio was isolated in 57% and in 43% non polio entero viruses were detected. The most prevalent was polio virus type 1. Most of the strains were wild type.

CONCLUSION

Wild polio virus was prevailing in the community under study between the years 1992-1994.

Current status of Takayasu arteritis in India

The clinical features of 106 patients of Takayasu arteritis (TA) seen over a period of 16 years are documented (65 females and 41 males). The mean age was 27.3 +/- 9.2 years. Hypertension was the commonest mode of presentation (51.3%) and was detected in 82 patients (77.4%) at the time of presentation. Vascular bruits were heard in 72 patients (67.9%) and 13 patients (12.3%) were in congestive heart failure. Aortography was performed in 95 patients. Based on the extent of involvement, Type I (branches of aortic arch) was seen in 7 (6.6%) patients, Type II (aortic arch, its branches and descending thoracic aorta) in 7 (6.6%) patients, Type III (descending thoracic aorta and abdominal aorta) in 4 (3.8%) patients, Type IV (abdominal aorta only) in 29 (27.3%) patients and Type V (aortic arch, descending thoracic aorta and abdominal aorta) in 59 (55.7%) patients. Therapeutic modalities included antihypertensive drug therapy in 81 patients, antitubercular drugs in 8 patients, steroids in 16 patients and cyclophosphamide in one patient. Response to steroids was satisfactory in 5 of these 16 patients while the lesions of vasculitis healed in the patient who was treated with cyclophosphamide. Surgical interventions included nephrectomy and autotransplantation of kidney in 3 patients each and revascularization in 4 patients and angioplasty in 4 patients. In the area of pathogenesis of this disease, a high activity of protein kinase C(PKC), an increased intracellular calcium and inositol 1,4,5 triphosphate in both unstimulated and stimulated T cells of TA was observed. These findings suggest an activation of PKC-calcium pathway in TA.

Alteration of peripheral blood lymphocyte subsets in essential hypertension

OBJECTIVE

To assess lymphocytic subpopulation by labelled monoclonal antibody technique in a small group of patients with untreated essential hypertension (EH) and to detect any alteration with control of blood pressure.

DESIGN

Prospective study with phenotypic estimation of lymphocytes at presentation and a minimum of two weeks after the control of blood pressure.

SETTING

Referral, tertiary care hospital.

PATIENTS

Group 1, normotensive controls (n = 10); group 2, mild to moderate essential hypertension (n = 10); group 3, severe (accelerated/malignant) hypertension (n = 10). All the secondary causes of hypertension were ruled out by a thorough history, physical examination and appropriate radiological and biochemical investigations.

TESTS

Venous blood samples, taken at entry and a minimum of two weeks after control of blood pressure, were analyzed by alkaline phosphatase antialkaline phosphatase (APAAP) antibody technique for CD4, CD3, CD8 and CD22. Peripheral lymphocytes were separated and cocultured with phytohemagglutinin (PHA) for 72 h and assayed for CD25 by the APAAP technique.

MAIN RESULTS

In untreated patients with EH (groups 2 and 3), there was a significant down regulation of CD3, and CD4 lymphocytes whereas the proportion of mature CD22 cells increased. In group 3 there was a significant down regulation of CD25 with PHA stimulation. A negative correlation was observed between CD25 and diastolic pressure upon pooling the results of groups 2 and 3. No significant alteration in these parameters was observed following control of blood pressure with drugs for up to two weeks.

CONCLUSION

In this small group of patients with untreated EH, a significant alteration in the lymphocytic repertoire was observed. Whether this will be found in large groups of hypertensives remains to be seen.

Hepatitis B--potential of perinatal transmission in India

To estimate the frequency of perinatal hepatitis B virus (HBV) infection, 850 pregnant females were tested for HBsAg and HBeAg using RPHA kits. Frequency of HBsAg positivity was 4.6% by RPHA and 6.34% by micro-ELISA. HBeAg was detected in 18% of the HBsAg positive pregnant females. Presuming a perinatal HBV infection rate of 90% amongst infants born to HBsAg and HBeAg positive pregnant females and 17% amongst infant born to HBsAg positive but HBeAg negative mothers, we estimated that 1.17% to 1.64% infants out of 24 million births occurring annually in this country would be infected with HBV. In other words every year 2.8 to 3.9 lakh infants are being infected by HBV perinatally, 90% of whom will eventually develop chronic HBV infection. Urgent control measures are necessary to circumvent this problem.

Low prevalence of human immunodeficiency virus type-1 (HIV-1) infection in population attending a major hospital in New Delhi, India

During 4 year period between April 1990 and March 1994, 4120 specimens from the patients attending out patient departments of Medical, Surgical and Antenatal units of a major city hospital were tested for HIV infection as a part of an on-going sentinel surveillance programme. In addition, 1440 specimens from the patients attending STD clinic of the same hospital and 862 females seeking termination of pregnancy from a near by hospital were included for comparison. It was found that only 3 individuals with high risk behaviours out of 2002 females attending antenatal clinic showed evidence of HIV infection (rate 1.49 per 1000). The corresponding rate for the group of patients attending STD clinic and seeking termination of pregnancy were 3 out of 1440 (rate 2.15 per 1000) and 1 out of 862 (rate 1.16 per 1000) respectively. It was noted that prevalence of HIV infection in the hospital attending population with unspecified risk factor (medical, surgical and antenatal clinics) was not a matter of serious concern. The importance of finding out risk factors in females attending antenatal clinic is evident from the study.

Coxsackie B virus in the etiology of heart diseases in Delhi

Coxsackie B group of viruses have been long considered as the precipitating factor in heart diseases. Their association with various heart diseases especially pericarditis, myocarditis and myopericarditis is known, but now their association is also known with cardiomyopathy and ischaemic heart diseases. A study was carried out on 87 patients suffering from various heart diseases and the role of Coxackie B virus infection was studied. The study included 25 control subjects. Thirty patients (34.5%) were found to be having high antibody titre for at least one of coxsackie B virus group with coxsackie B3 and B4 being the two commonest types. Serum IgM immunoglobulins were raised in acute infective disorders like pericarditis, myocarditis and myopericarditis but IgG, IgA and IgM levels were normal in ischaemic heart diseases and cardiomyopathy.

Diagnostic utility of the estimation of mycobacterial Antigen A60 specific immunoglobulins IgM, IgA and IgG in the sera of cases of adult human tuberculosis

SETTING

An ELISA assay based on mycobacterial Antigen A60 for the estimation of Mycobacterium-specific immunoglobulins in the serum has been used successfully for the rapid diagnosis of tuberculosis in studies done in the Western countries. There are hardly any similar large scale studies in India.

OBJECTIVE

To evaluate the utility of this ELISA test for rapid diagnosis of different clinical forms of tuberculosis in an adult Indian population.

DESIGN

ELISA test based on mycobacterial antigen A60 (Anda Biologicals, France) was used to estimate specific IgM, IgA and IgG antibodies in the sera obtained from 337 cases of tuberculosis and 131 controls in the population of Delhi (India).

RESULTS

Of the 131 controls, only 9.9% were positive for IgM, 7.6% for IgG, 6.1% for IgA and 9.9% when an IgA and IgG combination was considered. Of 122 cases of active pulmonary tuberculosis, 41% were positive for IgM, 86.8% for IgA, 88.5% for IgG and a very high positivity (98.3%) was seen when IgA and IgG estimations were combined. A relatively low seropositivity was observed in 25 cases of pleural tuberculosis. The corresponding figures in 130 cases of extrapulmonary tuberculosis were 22.3%, 68.4%, 73.8% and 86.15%. When 60 cases of pulmonary tuberculosis who had been successfully treated with antituberculosis drugs were analyzed the rates of seropositivity fell to 11.6%, 46.6%, 58.3% and 66.6% respectively.

CONCLUSION

Our findings point to a very good sensitivity (91.6%) and specificity (90.0%) of the test when combined IgA and IgG antibody titres are considered, to detect cases of adult tuberculosis. The role of IgM estimation can be restricted to the detection of cases of reactivation of tuberculosis.

Pregnancy induced hypertension: changes in coagulation profile of newborns

Coagulation parameters and platelet count were studied in 30 neonates of mothers with pregnancy induced hypertension (PIH). 30 neonates born to normotensive mothers were taken as controls. The test group was further subdivided as neonates born to mothers with gestational hypertension, pre-eclamptic toxemia and eclampsia. The values of Prothrombin Time, Partial Thromboplastin Time with Kaolin, Thrombin Time, Fibrinogen Degradation Products were significantly raised and Fibrinogen and Platelet count were reduced significantly in both term and preterm test groups as compared to controls. The derangement in coagulation parameters was more marked with increasing severity of PIH.

A bacteriological study in hospitalized children with pneumonia

A total of 110 consecutive hospitalized children with severe lower respirator tract infection were studied with the aim of determining the main bacterial pathogens responsible. Of these, 57 were classified as severe pneumonia and 53 as very severe pneumonia. Streptococcus pneumoniae was the most common organism identified in 24.6% and 32.1% of cases of severe and very severe pneumonia, respectively, followed by Haemophilus influenzae type b, which was seen in 17.5% and 20.8%, respectively. The highest diagnostic yield was with the latex particle agglutination test on serum and urine. Blood culture was positive in only ten of the 110 children. No difference was found between the aetiological agents identified in severe and very severe cases of pneumonia. Therefore, the use of different parenteral antibiotics for two clinically defined groups of pneumonia, as recommended by WHO in their standard case management guidelines for the ARI control programme, does not seem necessary.

Widespread emergence of Vibrio cholerae 0139 in India

The National Institute of Communicable Diseases (NICD) has been monitoring the incidence of laboratory confirmed cases of cholera in Delhi in collaboration with Infectious Diseases Hospital (IDH) since 1965. Cholera and cholera-like cases from all hospitals in Delhi are admitted in IDH and the rectal swabs of all such cases are processed for isolation of Vibrio cholerae at NICD laboratory. Since April 1993, there has been isolation of Vibrio cholerae serotype 0139, in increasing numbers (831 out of 2,830, 29.2%) The isolates have been characterized and enterotoxin studies carried out. As a referral laboratory NICD has also confirmed the causative role of Vibrio cholerae 0139 in diarrhea outbreaks from various parts of the country. The implications of establishment of this newer serotype of Vibrio cholerae, as a potential epidemic strain are discussed.

Cloning, characterization, and functional expression of acs, the gene which encodes acetyl coenzyme A synthetase in Escherichia coli

Acetyl coenzyme A synthetase (Acs) activates acetate to acetyl coenzyme A through an acetyladenylate intermediate; two other enzymes, acetate kinase (Ack) and phosphotransacetylase (Pta), activate acetate through an acetyl phosphate intermediate. We subcloned acs, the Escherichia coli open reading frame purported to encode Acs (F. R. Blattner, V. Burland, G. Plunkett III, H. J. Sofia, and D. L. Daniels, Nucleic Acids Res. 21:5408-5417, 1993). We constructed a mutant allele, delta acs::Km, with the central 0.72-kb BclI-BclI portion of acs deleted, and recombined it into the chromosome. Whereas wild-type cells grew well on acetate across a wide range of concentrations (2.5 to 50 mM), those deleted for acs grew poorly on low concentrations (< or = 10 mM), those deleted for ackA and pta (which encode Ack and Pta, respectively) grew poorly on high concentrations (> or = 25 mM), and those deleted for acs, ackA, and pta did not grow on acetate at any concentration tested. Expression of acs from a multicopy plasmid restored growth to cells deleted for all three genes. Relative to wild-type cells, those deleted for acs did not activate acetate as well, those deleted for ackA and pta displayed even less activity, and those deleted for all three genes did not activate acetate at any concentration tested. Induction of acs resulted in expression of a 72-kDa protein, as predicted by the reported sequence. This protein immunoreacted with antiserum raised against purified Acs isolated from an unrelated species, Methanothrix soehngenii. The purified E. coli Acs then was used to raise anti-E. coli Acs antiserum, which immunoreacted with a 72-kDa protein expressed by wild-type cells but not by those deleted for acs. When purified in the presence, but not in the absence, of coenzyme A, the E. coli enzyme activated acetate across a wide range of concentrations in a coenzyme A-dependent manner. On the basis of these and other observations, we conclude that this open reading frame encodes the acetate-activating enzyme, Acs.

Role of calcium and protein kinase C in the activation of T cells in Takayasu's arteritis

The roles of protein kinase C and calcium in the T cells of patients suffering from Takayasu's arteritis (TA) in response to the mitogens phorbol-myristate acetate (PMA) and streptococcal antigens have been studied. In TA there was an increased basal activity of protein kinase C (1.074 +/- 0.223 nmoles/mg protein/min) as compared with that of controls (0.570 +/- .12) (p < 0.001). There was 75% translocation from the cytosol to membrane fraction in response to PMA. Intracellular calcium levels showed increased basal levels in TA (177.07 +/- 12.56 nmoles) compared with the controls (112.83 +/- 10.6 nmoles) (p < 0.001) and there was a further rise on stimulation, indicating the T cells were in an activated state. There was a positive correlation between the calcium levels and the activity of protein kinase C (r = 0.71, p < 0.05). Unlike the situation in patients with rheumatic fever, T cells in TA showed no stimulation in response to streptococcal antigens. The low level of cAMP (1.12 +/- 0.169 pmoles/million cells) compared with that of controls (1.4 +/- 0.03) further supports the role of PKC-calcium in the T cell activation process. These findings suggest activation of the PKC-calcium pathway in TA.

Seroprevalence of rubella in women of reproductive age

This study was conducted on 160 females of childbearing age and 40 girls of prefertility age group. The rubella immunity status was analysed according to their age, social class, geographical distribution and previous obstetric history. History of previous rubella infection was obtained in 12% cases only. The over all incidence of rubella immunity was found to be 55%. There was a gradual increase in the immunity status, with peak incidence of 66% between 30 to 34 years of age. Females of low socioeconomic status showed higher incidence of immunity (63%) compared to social class I (40%). Rubella immunity was higher in urban female population (57%), where-as only 49% of rural females were immune to rubella virus infection. The immunity status of women with previous BOH was higher (61%) as compared to those with normal obstetric performance (54.6%). From the above observations, it was concluded that a substantial number of women enter child bearing without immunity to rubella. A simple HAI test for rubella antibody (IgG) can be a good pointer to pick up susceptible female population and the seronegative females should be immunised against rubella before they contemplate pregnancy.

Polyarteritis nodosa presenting as perirenal hemorrhage

Though renal involvement with microaneurysm formation is common in polyarteritis nodosa (PAN), spontaneous perirenal hematoma (SPH) is rare. We report a patient in whom SPH was the presenting manifestation of PAN. SPH is a potential life-threatening complication of PAN and its early recognition is emphasized.

Subacute sclerosing panencephalitis in Delhi

Between 1989 and 1992 (to October), 65 patients of subacute sclerosing panencephalitis were referred to the Virology Laboratory of the National Institute of Communicable Diseases, Delhi, from the major hospitals of Delhi. The cases were mainly residents of Delhi, but a few were from states bordering Delhi. The age group of affected cases ranged from 2 to 24 years. The disease (SSPE) was six times more common in males than in females. All but four patients below 3 years of age gave a past history of measles. No patient had history of measles vaccination. The titres of haemagglutination inhibition antibodies (HAI) to measles virus in serum of SSPE patients ranged from 1:8 to 1:2048 and in CSF it ranged from 1:4 to 1:64, while in the control group it ranged from 1:2 to 1:256 in serum and nil in CSF. The geometric mean titres in serum was 10-fold higher in serum and four-fold higher in CSF from SSPE cases as compared to control.

Brugia malayi: the diagnostic potential of recombinant excretory/secretory antigens

The diagnostic potential of recombinant E/S antigens of the lymphatic filaria Brugia malayi was investigated by Western blot. A cDNA expression library was constructed using B. malayi male adult worm mRNA, and E/S recombinants were identified with a rabbit antiserum raised against E/S products collected in vitro from B. malayi male and female adult worms. Two of these recombinants, Bm12 and Bm14L, were studied after subcloning the cDNA inserts in an Escherichia coli plasmid expression and purification vector, obtaining the inserts' nucleotide sequence, and purifying the expressed proteins. By homology of their deduced amino acid sequence with that of previously identified proteins, Bm12 was identified as the B. malayi gp 15/400 antigen, and Bm14 as a member of the hsp90 family of heat shock proteins. The antigenic cross-reactivity of the purified recombinant proteins was assessed with 28 serum samples from patients infected with Ascaris, Trichuris, or hookworm, and also with a few samples from patients with onchocerciasis and loiasis. For Bm12, the specificity for all of the intestinal helminthiasis together was 75%. Bm14L, on the other hand, cross-reacted with all of the ascariasis serum samples with which it was tested. Presence of antibodies cross-reactive with B. malayi was confirmed in all of these serum samples by examining their antibody reactivity with Western blots of extracts of whole B. malayi adult worms. A semiquantitative (+ or -) assessment of the sensitivity of Bm12 for antibody detection was performed using 6 serum samples from patients with chronic filariasis and 24 samples from patients with microfilaremia. All of these serum samples contained anti-Bm12 antibody (sensitivity of 100%). Finally, the ability of Bm12 to detect antibody before the onset of patency was established with a longitudinal collection of serum samples obtained from 2 African green vervets (Cercopithecus aethiops) and 3 rhesus macaques (Macaca mulatta), all of which were infected with B. malayi. Anti-Bm12 antibodies were detectable in all animals between 4 and 11 weeks before patency.

Nutrition and immunity: an overview

Historical accounts and recent epidemiologic studies have suggested a mutually aggravating relationship between malnutrition and infection. In protein-energy malnutrition, there is a significant impairment of several aspects of immunity, including cell-mediated immune responses, secretory immunoglobulin A antibody production, phagocyte function, complement system, antibody affinity and cytokine production. Several micronutrients play a crucial role in maintenance of optimum immune responses. On the other hand, excessive intake of nutrients also impairs immunity. Animals fed diets lacking in nucleotides have lower immune responses than controls but there is no enhancement of immunity when the diet contains large amounts of nucleotides. These observations have considerable practical importance in terms of designing feeding formulas.