An emerging infection is defined as an infection which has newly appeared in a population while a re-emerging infection is one which has existed in the past but its incidence is rapidly increasing. The reasons for the emergence and re-emergence of infections are not well understood but appear to be associated with factors that involve the pathogen, the host and the environment. These factors are often inter-related and act together in a complex manner to bring about changes in patterns of infection. Pathogens are extremely resourceful and possess mechanisms to adapt to new hosts and environments as well as to acquire new virulence traits. Host factors include herd immunity, social behaviour and demographics. Environmental factors like the climate, deforestation and new technologies have an impact on the emergence of infections. The challenge is to contain an infection when it emerges but more importantly to prevent its emergence in the first place. As the emergence of an infection is complex and multifactorial, a multidisciplinary approach is required. Health based strategies alone are insufficient. Social, economic and environmental measures and the political will to implement appropriate policies are equally important.
Infection is an important cause of morbidity and mortality in immunocompromised patients. The high risk of infection is not only the consequence of the underlying disease but also the result of the diagnostic, monitoring and therapeutic procedures performed on these patients. Infections may be exogenous or endogenous in origin. The prevention of exogenous infections requires a high standard of hygiene. As many infections are acquired in hospitals, an effective control of nosocomial infection programme is crucial in preventing infections in the immunocompromised. Prevention of endogenous infections involves suppression of the aerobic bacterial flora (selective decontamination) and measures to maintain gastrointestinal epithelial integrity to reduce risk of translocation of intestinal flora. Boosting the host immunity through passive and active immunisation should also be considered. Prevention of infection in the immunocompromised is no easy task and requires a multidisciplinary approach.
Staphylococcal infection is common in Malaysian hospitals. A recent survey of 22 Malaysian hospitals revealed that staphylococci were isolated from almost 40% of positive blood cultures. A more detailed analysis of such cases in our own hospital showed that almost 70% of Staphylococcus aureus and about 16% of coagulase-negative staphylococcal isolates were associated with clinically-significant disease. Staphylococcal bacteraemia was seen mainly in neonatal sepsis, skin and soft tissue infections, pneumonia, arthritis, osteomyelitis, endocarditis and postoperative sepsis. Multiply-resistant S. aureus were encountered in all the hospitals surveyed. Resistance rates to penicillin ranged from 40% to almost 100% while methicillin resistance rates of up to 25% were reported from several hospitals.
Leptospirosis is a re-emerging zoonotic infection. In developing countries large outbreaks have occurred in urban slums and following floods. Individuals from developed nations are also now more frequently exposed to the infection as a result of international travel and greater participation in certain outdoor recreational activities. Leptospirosis remains a diagnostic challenge since it often presents as a non-specific febrile event and laboratory diagnosis is still currently inadequate. Rapid tests may not be sufficiently sensitive in early disease and culture facilities are not widely available. A severe pulmonary haemorrhagic form of the infection is increasingly being encountered in many countries including Malaysia. The control of leptospirosis is largely dependent on general hygienic measures and rodent control. An effective human vaccine is still not available. There remains much that is unknown about this disease and there is scope and opportunity for good quality research.
Many infections are associated with occupations. Involvement in a particular occupation may place the person at higher direct risk of contracting certain infections. In some instances the life-style associated with the occupation results in a higher risk of exposure to the infection. The link between the infection and the workplace is often missed by the attending physician. This may be due to a lack of awareness on the part of the physician. Sometimes a direct link can be difficult to prove without the use of sophisticated molecular epidemiological tests. This has led to gross under-diagnosis and under-reporting of such cases. It is however important that occupational infections be diagnosed as adequate preventive measures need to be implemented. Furthermore the patient may be eligible for monetary compensation under the relevant occupational safety laws of the country.
Infectious diarrhoea is the second most common cause of morbidity and mortality worldwide. The WHO estimates that about 2.5 million people die annually as a result of infectious diarrhoea, most of them children. In 2002 about 1.6 million children under the age of five in developing countries died from diarrhoeal disease. In the United States between 211- 375 million episodes of diarrhoeal disease occur annually resulting in 73 million physician consultations and 1.8 million hospitalisations with over 3,000 deaths.
Cefepime is a new cephalosporin antibiotic which is highly active against both Gram-positive and Gram-negative organisms. The purpose of this study was to establish the in-vitro activity of cefepime and three other cephalosporins against recent clinical isolates from patients at the General Hospital Kuala Lumpur. A total of 334 strains comprising Enterobacteriaceae, non-fermentative Gram-negative bacilli and Staphylococcus aureus were tested for their sensitivity to cefepime, cefotaxime, ceftriaxone and ceftazidime. Minimum inhibitory concentrations of the antibiotics were established using an agar dilution method. With the exception of some strains of Flavobacterium meningosepticum, Xanthomonas maltophilia and other non-fermentative Gram-negative bacilli, cefepime was found to be active against a wide range of Gram-negative organisms. Cefepime was as or more active than the other cephalosporins against Acinetobacter, Enterobacteriaceae and methicillin-sensitive Staphylococcus aureus. Strains of Klebsiella and Salmonella that were resistant to the third generation cephalosporins were sensitive to cefepime. Cefepime could be a valuable alternative for the treatment of nosocomial infections due to multiply resistant organisms.
Beta-lactamase production is one of the major mechanisms of resistance amongst bacteria especially the enteric bacilli. The purpose of this study is to assess the in-vitro activity of Sulperazon, a combination of cefoperazone and an irreversible beta-lactamase inhibitor, sulbactam, against the cefoperazone resistant isolates of aerobic gram-negative bacilli. A total of 92 such strains were tested. It was found that at a concentration of < or = 8 mg/l of sulbactam added to cefoperazone 82% of Klebsiella spp, 100% of E. coli, 100% of Enterobacter spp, 33% of Pseudomonas aeruginosa, 67% of Pseudomonas spp and 62% of Acinetobacter spp that were resistant to cefoperazone alone were susceptible to the combination. Hence it is concluded that the addition of sulbactam to cefoperazone does expand the spectrum of the in-vitro activity of cefoperazone.
A turnaround time study was conducted for bacteriological culture tests in seven Malaysian general hospitals. The turnaround times were determined using a specially designed form that was completed by the ward staff. Doctors at these hospitals were also polled to find out whether they were satisfied with the promptness of bacteriological test reporting in their hospitals. The turnaround times obtained from this survey were found to be satisfactory taking into account the constraints of laboratory methods employed. Nevertheless only about a third of doctors expressed satisfaction with the timeliness of the bacteriological test reporting. Doctors and microbiologists should get together and agree on acceptable standards of turnaround times that are practical and reasonable.
Over a 12 months period, out of 25,411 livebirths, 155 neonates (6.1 per 1000 livebirths) had proven septicemia by blood culture. The mortality rate was 26.5%. Septicemia was more common among the very low birthweight and preterm neonates of gestation of 30 weeks or less. 45.8% of the septicemia occurred during the first 48 hours of life. Staphylococcus epidermidis was the most common causative organism. However, mortality was highest among neonates who acquired multiresistant nosocomial infection during the later part of neonatal life.
A prospective survey of antibiotic prescribing patterns in six Ministry of Health general hospitals in Malaysia was undertaken. Information on antibiotic prescriptions including the types of antibiotics used and the purposes for prescription was obtained through the use of questionnaires. A total of 1,918 antibiotic prescriptions were available for analysis. About two-thirds of prescriptions were for therapeutic purposes. The most common infections treated were lower respiratory infection (31%), followed by skin and soft tissue infection (17%), and urinary tract infection (8%). Only 20% of the therapeutic prescriptions were based on microbiological test results. Prophylactic prescriptions were issued for a variety of indications, the most common being toilet and suture of wounds. Only 5% of prophylactic prescriptions were of less than 3 days duration. There was great diversity in antibiotics and antibiotic regimens employed. It was evident that there was a lack of compliance with guidelines on antibiotic use issued by the Ministry of Health.
A survey on the use of antibiotics in surgical prophylaxis was carried out in seven Malaysian hospitals. Details of antibiotic prescriptions were obtained through questionnaires completed by the prescriber. A total of 430 such prescriptions was analysed. A large number of different antibiotic regimens were used for a variety of surgical procedures. The majority of prescriptions (70%) were issued for procedures where such prophylaxis was probably not necessary. Antibiotics were also often prescribed for durations that were longer than necessary. There is an urgent need to educate surgeons and standardize surgical prophylactic regimens in order to reduce cost and combat the emergence of antibiotic resistance.