Hepatitis-B infection is a global health problem. The spectrum of the disease is highly variable ranging from mild disease to chronic liver diseases including hepatocellular carcinoma. There are approximately 350 million chronic Hepatitis-B surface antigen (HBsAg) carriers in the world. Till date there is no effective therapy against this disease. Hence, prevention of the disease through vaccination is the only means to control the disease. Passive immunization is recommended for certain accidental exposures. Hepatitis-B immunoglobulin (HBIG) contains high titers of anti-HBs prepared from pooled plasma. HBIG has been shown to be highly effective in preventing post exposure transmission. HBIG induces immunity for a short period only hence, it is recommended to have a course of active immunization following passive immunization. Active immunization is achieved using vaccination. Two generations of vaccines, 1st generation plasma derived and 2nd generation recombinant DNA vaccines are available. Both these vaccines have been used extensively in all age groups all over the world. The studies have shown that HB vaccines are clinically well tolerated, safe and highly immunogenic. Normally 3 doses of HB vaccines are recommended in 0, 1, 2 and 12 or 0, 1, 6 months schedule. The dosages and schedules may vary in certain special groups, such as infants and neonates, chronic renal failure patients on hemodialysis. Advisory committee on immunization practices (ACIP) has given several guidelines regarding HB vaccination. Universal immunization of all infants and integration of HB Vaccine in the expanded program of immunization has been recommended by World Health Organization. Universal infant immunization is cost effective. Universal immunization of infants is the only strategy that will lead to the control and eradication of HBV infection in all regions of the world. Several countries have adopted this policy. But in India we have several problems in implementation of this policy. The high cost of the presently available vaccine is one of the major factors. The future consideration for hepatitis vaccines are focussed on multivalent combination vaccines with other childhood vaccines, and use of immunomodulators in conjunction with vaccine to increase the efficacy of vaccines in immunocompromised hosts.

Isolation of diarrhoea causing Aeromonas was carried out in the division of Active Surveillance, National Institute of Cholera and Enteric Diseases (NICED), Kolkata for a period of 12 months from January 1999 to December 1999. Out of 602 stool samples collected from patients with acute diarrhoea admitted in Infectious Diseases (ID) Hospital, Kolkata, 64 (10.6%) samples were identified positive for Aeromonas as the pathogen. The different isolated and identified species from patients with acute diarrhoea were A. hydrophila (60%), A. caviae (20%), A. veronii (10%), A. schubertii (4%), A. jandaei (3%), and A. trota (3%). Most of the isolated Aeromonas strains showed resistance to commonly employed antibiotics. All the clinical isolates of Aeromonas possessed virulence genes encoding for aerolysin and cytotonic enterotoxin genes. Except A. schubertii and A. jandaei, all the other species possessed the gene for haemolysis.

Cutaneous tuberculosis forms a small proportion of extrapulmonary tuberculosis. The incidence of cutaneous tuberculosis has fallen from 2% to 0.15% in India whereas it is rare in developed countries. The present study is an attempt at finding out the Mycobacterium species associated with cutaneous tuberculosis. A total of 51 cases of clinically suspected cutaneous tuberculosis were studied over a period of 18 months from July 1997 to December 1998. Of these, 32 (62.75%) were Scrofuloderma cases, 12 (23.52%) cases of Lupus vulgaris and 7 (13.73%) were Tuberculosis verrucosa cutis (TBVC) cases. Twenty nine mycobacterial isolates from 51 specimens gave an isolation rate of 56.86%. These were subjected to a battery of biochemical tests for identification to species level. Twenty six out of 29 isolates were identified as Mycobacterium tuberculosis, two were identified as Mycobacterium Scrofulaceum and one Mycobacterium avium complex was isolated. Sixteen Mycobacterial isolates were recovered from Scrofuloderma cases, 9 were isolated from Lupus vulgaris and 4 from TBVC cases. The three atypical mycobacterial isolates were recovered from Scrofuloderma cases. Though Mycobacterium tuberculosis was the most common isolate, Mycobacterium scrofulaceum and Mycobacterium avium complex were also isolated in the present study.

Typing of Streptococcus pneumoniae to determine the serotype prevalence has paved the way for polyvalent vaccines to prevent invasive pneumococcal infection. Variation of serotype prevalence in different geographical areas necessitates typing of strains from these areas for effective vaccine protection. High cost of antisera very often is a hindering factor in undertaking this exercise. We have tried to evaluate typing by co-agglutination to reduce cost. Clinical isolates of S.pneumoniae from Pondicherry and surrounding Tamil Nadu were serotyped using antisera coated Staphylococcus aureus Cowan I strain and compared with standard quellung reaction. There was hundred percent correlation. By this method we could determine the serotypes causing invasive infections in this area. A commercially available Pneumotest kit was used as source of type specific antisera. Serotype 1 was found to be the major isolate (20.1%) by both the tests. Twenty-four isolates (13%) belonged to the nonvaccine types. Rest of the isolates was made up by serotypes 6, 5, 19, 23 and 12. Co-agglutination method was found to be a simple rapid and economical technique. Ten milliliters of the reagent could be made, using 0.1 ml of standard antisera. Shelf life was found to be six months at 40C.

Eighty eight patients of chronic lung diseases (CLD) attending TB and Chest department of J.N. Medical college Hospital were studied to find out the prevalence of Aspergillus in Broncho-alveolar Lavage (BAL) and anti- aspergillus antibodies in their sera. Direct microscopy and fungal culture of BAL was done. Antibodies were studied by immunodiffusion (ID) and Enzyme linked immunosorbent assay (ELISA). Dot blot assay for anti-aspergillus antibodies was also performed in sera of patients which were either positive by ID or by ELISA. Aspergillus was isolated in culture from 13(14.7%) cases of CLD, while, 30.6% cases showed anti-aspergillus antibodies by serological methods. Aspergillus fumigatus was the predominant species isolated. 17(19.3%) cases of CLD showed antibody against Aspergillus by ID, 22(25%) by ELISA, while 19 of 27 seropositive cases also showed positive results by Dot Blot assay. In cases of bronchogenic carcinoma and pulmonary tuberculosis, anti-aspergillus antibodies were detected equally by ID and ELISA in 21.42% and 21.05% cases respectively. In bronchial asthma, the antibodies could be detected in 60% cases by ELISA, while, in only 10% cases by ID. ELISA was found more sensitive than ID for detection of anti-aspergillus antibodies. The sensitivity of Dot Blot lies some what between ID and ELISA. It is concluded that prevalence of Aspergillosis is quite high in chronic lung diseases, culture and serological test should be performed in conjunction and more than one type of serological tests should be performed to establish the diagnosis.

A case of mixed infection due to Leptospira and Dengue in a two and a half-year-old girl with pyrexia is reported. Early detection and institution of appropriate therapy is crucial and lifesaving.

We report here 5 bacteriologically proven cases of Brucellar epididymoorchitis. Four cases presented with unilateral epididymoorchitis and with bilateral presentation in one case. Blood culture grew Brucella melitensis in all 5 cases. B.melitensis was isolated in testicular aspirate of 4 patients. Brucella agglutinins were demonstrated in testicular aspirate of 4 patients and semen of 2 patients. To our knowledge this is the first report of bacteriologically proven cases of brucellar epididymoorchitis in the world literature.

Bile Cultures for aerobic and anaerobic bacteria were carried out on 125 samples from patients with chronic cholecystitis with cholelithiasis. Cultures grew 71(56.8%) aerobes and 17(13.6%) anaerobic microorganisms. Polymicrobial infection was seen in 7(16.2%) cases. E. coli (45.07%) and Klebsiella (25.35%) were predominant among the aerobes and Bacteroides fragilis (58.82%) was predominant among the anaerobes. Highest incidence of the disease was observed in the fourth decade of life and females predominated in this study.

Enteric protozoal parasitic infection has become an important cause of morbidity in children and adults. In the developing countries the association of Cryptosporidium with acute and persistent diarrhoea has been striking. Stool samples from 1002 patients (800 adults and 202 children) suffering from diarrhoea or other gastrointestinal symptoms were examined for the presence of Cryptosporidium parvum oocysts by modified Ziehl Neelsen stained smears. C. parvum was detected in 2.99% of children and 0.12% adults. Other parasites detected were E. histolytica (6.18%), G. lamblia (1.49%), A. lumbricoides (1.49%), hookworm (1.39%), Strongyloides stercoralis (0.39%), and Taenia (0.09%).

To assess prevalence of acid fast bacilli (AFB) in Ajmer, a retrospective analysis of 8 years was done in 1905 AFB cultures in various clinical specimens. All specimens were cultured on Lowenstein-Jensen slants after decontamination and concentration using modified Petroff's method. Smears were stained by Ziehl-Neelsen technique with acid and alcohol to exclude rapid growers. Four hundred and twenty eight AFB positive cultures were reported using morphological, staining and microscopic characteristics. Over all, AFB positive culture rate was 22.46%. Maximum positive cultures were from urinary system (253) followed by respiratory system (151), female genital systems (9), reticuloendothelial system (6), CNS (6), GIT (2), and CVS (1).

A rapid test for diagnosis of malaria based on acridine orange staining of centrifuged blood samples in a microhematocrit tube (QBC) was compared with thick and thin peripheral blood smears in 2274 samples. Malaria was diagnosed in 239 (10.5%) patients by Leishman's staining technique and QBC method. The QBC method allowed detection of an additional 89 (3.9%) cases. Thus the prevalence rate of malaria during the study was 14.4%. In 1946 patients who were negative by the QBC technique, the Leishman's stained smears did not provide any help in malaria diagnosis. Analysis of the relative quantity of parasites in the specimens, in the QBC method, revealed that 80 out of 89 QBC positive but smear negative cases, had a very low parasite number (less than 10 parasites per QBC field). Although QBC method was superior to the smear for malarial parasite detection, species identification was not possible in 26 (7.9%) cases by this technique. In 95.7% (n = 314) QBC positive cases, the buffy coat in the QBC tube appeared pigmented (gray to black). The colour of the buffy coat was therefore considered by us as a predictor of positivity and could be taken as an indicator for a careful and more prolonged search for the parasites. Thus, the QBC technique has its advantages in terms of speed, sensitivity and ease, especially in an endemic area as ours, where the level of parasitaemia is low and more than 70 to 80 smears need to be examined per day. However, the age old Romanowsky stains still appear superior for species identification.

Resistance to a variety of antimicrobial agents is emerging in bacterial pathogens throughout the world. Since the accuracy of the antimicrobial susceptibility data is associated with the performance standard of the test, strict adherence to the standard procedures is essential. The Kirby-Bauer disc diffusion susceptibility test, performed in accordance to NCCLS method gives reliable results and hence predicts clinical efficacy of the antibiotic tested. To assess the standard of performance of the antimicrobial susceptibility test, a survey was conducted by National Institute of Biologicals during 1999-2000. The findings indicated an urgent need of setting up a national quality control laboratory to provide the performance standards, reference Q.C. strains and quality antibiotic discs to ensure reproducible and reliable results.

A study was conducted to isolate and identify bacterial pathogens/contaminants in paneer samples sold in Chandigarh. Fifty eight samples of paneer bought at random were cultured on several media. Bacterial colony counts were also done. The predominant organisms isolated were Staphylococcus species, aerobic spore bearers, Klebsiella pneumoniae, Campylobacter jejuni, Acinetobacter species and Streptococcus species. The viable bacterial counts obtained ranged from 3 x 102 to 9.7 x 1010 CFU/mL. Contamination of paneer by pathogenic bacteria could be an important factor of gastrointestinal illnesses in the consumers.