Infections caused by Gemella spp.: case reports from India

Human infections caused by Gemella spp. are rare. We report here our experience of the isolation of species of Gemellae from various clinical samples. Careful and complete identification of this organism will prevent diagnostic and therapeutic delays and bring more such cases to light.

Bioterrorism: a threat for which we are ill prepared

Of the weapons of mass destruction, the biological ones are the most feared and bioterrorism has become one of the most vicious threats to civilized society in recent times. Biological weapons have been sporadically used for centuries. Despite international regulations, there has been a global re-emergence of the threat of biological warfare. As many as 17 countries are suspected of either including or developing biological agents in their weapons programmes. In the past decade, a number of terrorist organizations with access to bioweapons technology have emerged. Current surveillance systems may be inadequate to detect biological attacks. The onset of illness is often delayed, thus the timing and location of such an event may be extremely difficult to identify. We are unfamiliar with most of the agents of biological warfare and are ill-equipped to handle the consequences of such an attack. In addition, there is no apparent coherent policy to handle a biological terrorist incident. Given the enormity of what is possible in the event of a biological attack, we must be prepared to detect, diagnose, epidemiologically characterize and respond appropriately to biological weapons. Of the potential biological weapons, smallpox and anthrax pose the greatest threats.

Botulism: An update

Botulism is a paralytic illness caused by the action of a neurotoxin elaborated by Clostridium botulinum. Other clostridial bacteria, like C.butyricum and C.baratii can also produce the toxin leading to signs and symptoms of botulism. Though rare, the illness is potentially fatal and can masquerade as other illnesses making diagnosis difficult. Physicians need to familiarize themselves with the disease as prompt recognition and early treatment can considerably curtail the fatal outcome in the affected and prevent additional cases in the unaffected. New diagnostic, therapeutic and preventive modalities to tackle the disease have come into focus. Botulinum toxin, generally considered a potent poison, is successfully being used for treatment of various neuromuscular disorders representing one of the most dramatic role reversals of modern times.

Infective complications of central venous catheters in cardiac surgical patients

Prospective randomised study was conducted over a 24 months period in a cardiac surgical intensive care unit to determine the incidence of infection associated with multilumen venous catheters. The influence of various factors including fever, peripheral blood culture, catheter site, catheter usage for monitoring central venous pressure and/inotrope therapy on infection rates were statistically evaluated. A total of 100 catheters submitted to the Microbiology laboratory were bacteriologically examined. Forty-nine of these were inserted into upper body sites, and 51 were inserted into the femoral vein. Twenty-one were triple-lumen catheters. Catheters were removed when a central line was no longer necessary. Catheter tips were cultured by semiquantitative technique for aerobic and anaerobic bacteria. Bacteremia occurred in 3% of catheter insertions; (Enterococcus faecalis, one; Enterobacter spp. One; Acinetobacter spp., one); and catheter colonisation developed in 24%. Neither catheter colonisation nor catheter related infection were associated with any of the risk factors evaluated. Our data indicates that central venous catheters are safe to use in our patients. The inability to identify "risk factors" for catheter infection emphasise the need to maintain a high index of suspicion.

Breast cancer survival by teaching status of the initial treating hospital

BACKGROUND

A number of studies have documented variation in treatment patterns by treatment setting or by region. In order to better understand how treatment setting might affect survival, we compared the survival outcomes of women with node-negative breast cancer who were initially treated at teaching hospitals with those of women initially treated at community hospitals.

METHODS

We constructed a retrospective cohort consisting of a random sample of 938 cases, initially diagnosed in 1991, drawn from the Ontario Cancer Registry. Exposure was defined by the type of hospital in which the initial breast cancer surgery was performed. Outcomes were ascertained through follow-up of vital statistics.

RESULTS

The crude 5-year survival rate was 88.7% for women who had their initial surgery in a community hospital and 92.5% for women who had their initial surgery in a teaching hospital. Women in higher income neighbourhoods experienced better survival at 5 years regardless of which type of hospital they were treated in. Multivariate proportional hazards regression modelling demonstrated a 53% relative reduction in risk of death among women with tumours less than or equal to 20 mm in diameter who were treated at a teaching hospital (relative risk [RR] = 0.47, 95% confidence interval [CI] 0.23-0.96), whereas among those with larger tumours there was no demonstrated difference in survival (RR = 1.32, 95% CI 0.73-2.32). Other variables that were significant in the model were age at diagnosis, estrogen receptor status and the use of radiation therapy.

INTERPRETATION

Women with node-negative breast cancer and tumours less than or equal to 20 mm in diameter who were initially seen at a teaching hospital had significantly better survival than women with similar tumours who were initially seen at a community hospital. Survival among women with larger tumours was not statistically significantly different for the 2 types of hospital.

Acute respiratory tract infections in Indian children with special reference to Mycoplasma pneumoniae

A total of 70 Indian children of either sex and under 5 years of age who were admitted to the All India Institute of Medical Sciences, New Delhi during a 1-year period (January 1994-December 1994) with complaints suggestive of acute respiratory tract infections (ARTI), were investigated for bacterial aetiology of infection with special reference to Mycoplasma pneumoniae. Microbial aetiology could be established in 44/70 (62.8 per cent) of cases of ARTI. Mycoplasma pneumoniae infection was seen in 21/70 (30 per cent), aerobic bacteria in 14/70 (20 per cent), Chlamydia pneumoniae in 2/70 (2.8 per cent), and mixed infection with mycoplasma either with bacteria and/or chlamydia in 7/70 (10 per cent). However, in 26/70 (37.1 per cent) cases no cause could be detected. Diagnosis of infection with M.pneumoniae was based on culture in 2/20 (10 per cent) cases, antigen detection in throat swab by indirect immunofluorescence assay using specific antibody in 16/70 (22.8 per cent) cases, and demonstration of IgM antibody in serum by serodia Myco II particle agglutination test in 17/70 (24.2 per cent). Streptococcus pneumoniae (9/70, 12.8 per cent) and Staphylococcus aureus (5/70, 7.1 per cent) were the aerobic isolates from blood in these patients. Results of this study indicate that M.pneumoniae plays a significant role in respiratory tract infection in an Indian paediatric population. Rapid diagnostic procedures, such as antigen detection and IgM antibody demonstration, should be used more widely to determine the infective aetiology early in the course of illness. The study also highlights the mixed aetiology in ARTI in children, which has important therapeutic implications.

The incidence of Legionella pneumophila: a prospective study in a tertiary care hospital in India

The prevalence of Legionella pneumophila causing community-acquired pneumonia (CAP) in patients who were admitted to hospital was investigated. Between April 1997 and December 1998, 60 patients admitted to the All India Institute of Medical Sciences with CAP, were included in the study. Aetiological diagnosis was based on the results of routine microbiological blood culture for bacteria and serological test by enzyme linked immunosorbent assay (ELISA) for L. pneumophila serogroup 1-7. Eight (13%) patients had a conventional bacterial aetiology and nine (15%) had serological evidence of recent infection with L. pneumophila. Legionella pneumophila may be an important cause of CAP in adults in developing countries. Empiric antimicrobial treatment should include a combination of agents to cover both atypical agents and bacterial pathogens.

Role of molecular typing in an outbreak of Salmonella paratyphi A

During the post monsoon season of 1996 an outbreak of human Salmonellosis caused by Salmonella serovar-paratyphi A occurred in New Delhi and had continued for over 2 months. A total of 36 clinically diagnosed enteric-fever cases were reported during this outbreak. The isolates were compared following their characterisation by biotyping, antibiogram-analysis, plasmid-profiling and IS200 probing, to study the relatedness in order to delineate a common source. The study included representative strains from both outbreak (15) and sporadic (7) cases for comparative analysis. Biotyping, antibiogram, whole cell protein-analysis and plasmid-profiling could not discriminate sporadic cases from outbreak strains, suggesting that a single clone/type (PT-1) may be prevalent in our region. In contrast, molecular-typing using IS200-probing revealed 2 clonally related strains circulating during the outbreak, as compared to the unrelated sporadic strains which exhibited considerable genetic diversity. Molecular analysis by IS200-probing, helped to assign an index case which provided a history of later outbreaks, since paratyphi A was repeatedly cultured in later outbreaks also. The study also suggests that genetic rearrangements can occur during the emergence of outbreaks. It reaffirmed the usefulness of IS200-probing in epidemiological investigations of Salmonella enterica serovars.

Mycoplasma pneumoniae and community-acquired pneumonia

BACKGROUND

Community-acquired pneumonia is an important cause of mortality and hospitalization in all age groups. In temperate climates, Mycoplasma pneumoniae is a common respiratory pathogen causing pneumonia. Information on human Mycoplasma infection in India is scarce.

METHODS

We aimed to determine the frequency of Mycoplasma pneumoniae infection among patients with community-acquired pneumonia in a prospective cross-sectional study. The assessment included clinical and radiological evaluation followed by microbiological evaluation for the specific pathogen. Microbiological investigations included aerobic and anaerobic blood culture, anti-Mycoplasma IgM antibody detection by gelatin particle agglutination test and ELISA, culture of respiratory tract secretions for Mycoplasma pneumoniae and other organisms, and detection of specific Mycoplasma pneumoniae antigen by indirect immunofluorescence.

RESULTS

Sixty-two patients (42 men and 20 women; mean age 41.7 years) with community-acquired pneumonia were investigated prospectively. They included 42 immunocompetent and 20 immunocompromised patients. Six patients had definitive evidence of Mycoplasma pneumoniae infection and an additional 16 patients had a probable diagnosis. In all, 22 (35.5%) patients with pneumonia had Mycoplasma pneumoniae infection. Of these, 12 patients belonged to the immunocompromised group and 10 to the immunocompetent group. Patients with Mycoplasma pneumoniae infection also had secondary bacterial infection as evidenced by organisms isolated from blood in 50% and from respiratory tract secretions in 68%.

CONCLUSION

Community-acquired pneumonia has a polymicrobial aetiology, of which the prevalence of Mycoplasma pneumoniae is 35%. The study has two implications: (i) Mycoplasma pneumoniae infection is frequently associated with secondary bacterial infection; and (ii) initial empirical antibiotic therapy for community-acquired pneumonia in India must include antibiotics with activity against Mycoplasma pneumoniae.

Busy physicians and preventive services for adults

OBJECTIVE

To study the relationship between overall productivity and the rates at which primary care physicians, in a fee-for-service setting, deliver or prescribe preventive services to adult patients.

PATIENTS AND METHODS

The charts of 452 adult patients treated by 8 family practitioners and 5 internists in a fee-for-service practice setting were randomly selected and abstracted for provision of 10 preventive services over a 27-month period. The percentage of eligible patients screened for each service was correlated with the production of each physician measured in relative value units (RVUs).

RESULTS

The correlation coefficient between RVUs and the aggregate of the 10 services was 0.23 (95% confidence interval [CI], -0.36 to 0.70). The individual correlation coefficients between RVUs and 9 of the 10 preventive services ranged from -0.05 to 0.43. For cervical cancer screening, however, the correlation coefficient was -0.72 (95% CI, -0.91 to -0.24).

CONCLUSION

With the exception of screening for cervical cancer, the data presented in this study do little to support physicians' common belief that lack of time is the reason they are unable to incorporate prevention strategies into their clinical practice.

Drug-resistant Salmonella enterica serotype paratyphi A in India

The incidence of enteric fever caused by Salmonella enterica serotype Paratyphi A has been increasing in India since 1996. In 1998, the incidence of enteric fever caused by drug- resistant S. Paratyphi A abruptly increased in the New Delhi region. In the first 6 months of 1999, 32% of isolates were resistant to both chloramphenicol and cotrimoxazole and another 13% were resistant to more than two antibiotics.

Incidence of Clostridium difficile infection: a prospective study in an Indian hospital

Clostridium difficile is the commonest cause of hospital-acquired diarrhoea. A prospective study comprising of 156 patients and 54 healthy controls was undertaken to assess C. difficile associated diarrhoea (CDAD) incidence in an Indian hospital. Methods used included C. difficile culture and enzyme linked immunosorbent assay (ELISA) for Toxin A. Attempts were made to type isolates by antibiogram and SDS-PAGE. Of the 210 stool samples tested, 12 gave positive results in at least one assay. Of these, 11 were positive by the ELISA method, eight by culture, and seven by both methods. Neither the organisms nor the toxin was found in healthy controls or neonates. The average disease incidence of CDAD estimated by using both methods was 15%. Two antibiotypes of the isolates were obtained and of the isolates characterized by SDS-PAGE, two had identical patterns. This study shows that CDAD is an emerging problem in Indian hospitals. Monitoring should enable the development and implementation of policies and procedures that minimize the risk of this nosocomial pathogen.

Clinical spectrum of bacteroidaceae in a tertiary care hospital

Members of Bacteroidaceae family are the most commonly isolated anaerobic pathogens in humans. This study summarises our experience of isolation and antimicrobial susceptibility pattern of these anaerobes from diverse clinical infections in a tertiary care hospital. Over a period of 5 years, 611 samples were received for anaerobic culture. Of these, 53 specimens yielded 62 anaerobic isolates. Thirty of the 62 isolates (48.4%) belonged to Bacteroidacea family obtained from 29 patients. They comprised of 14 (14/32; 43.7%) Prevotella spp., 13 (13/32; 40.6%) Bacteroides spp., 3 (3/32; 9.3%) Porphyromonas spp and Fusobacterium (2/32; 6.2%). In 14 of 27 patients (48%) the infection was polymicrobial. All the isolated strains were sensitive to metronidazole. This study highlights need for adopting anaerobic culture technique as a routine diagnostic procedure and constant monitoring of antimicrobial susceptibility of all anaerobic isolates.

Prevalence of Mycoplasma pneumoniae and Chlamydia pneumoniae in children with community acquired pneumonia

A prospective one year study was performed on 62 children admitted at the All India Institute of Medical Sciences with community acquired pneumonia (CAP) for the prevalence of Mycoplasma pneumoniae and Chlamydia pneumoniae. Diagnosis of infection with M. pneumoniae was based on serological tests viz microparticle agglutination test for detection of IgM antibodies and indirect immunofluorescence test for antigen detection from throat swabs (sensitivity 85.7%, specificity 93.3%). The indirect solid-phase enzyme immunoassay for detection of IgG antibodies was used to determine the prevalence of C. pneumoniae (sensitivity 88.8%, specificity 75.8%). Seventeen patients (27.4%) were found to have serological evidence of M. pneumoniae infection whereas only 4 (6.4%) patients were seropositive for C. pneumoniae. Results of this study indicate that M. Pneumoniae plays a significant role in CAP in infants and young children. Thus specialized laboratory testing for these agents should be more widely used thereby affecting empiric antibiotic regimens.