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Biomedical subjects

L P Samaranayake

Publications and source records attributed to L P Samaranayake.

At least 19 recordsLinked to original sources

Seroprevalence of hepatitis B surface antibody in South African dental personnel.

Because there are no data available on the seroprevalence of hepatitis B in dental personnel in South Africa, a study was performed to assess the antibody status to hepatitis B surface antigen among 129 dental (preclinical) students and 62 dental hygienists at the Western Cape Dental School of South Africa. A total of 11 dental students and nine hygienists were positive to hepatitis B surface antibody, indicating a seroprevalence of 8.5% and 14.5%, respectively. These results, reported for the first time in dental personnel in South Africa, imply that dental students and hygienists in this part of the world are exposed to a significant risk of contracting hepatitis B.

Adult

Oral mycoses in HIV infection.

Oral mycoses in human immunodeficiency virus (HIV) infection are becoming increasingly common. Of these, oral candidiasis is by far the most prevalent; fewer than 10 cases of cryptococcosis, histoplasmosis, and geotrichosis have thus far been reported. Oral candidiasis is one of the earliest premonitory signs of HIV infection and may present as erythematous, pseudomembranous, hyperplastic, or papillary variants, or as angular cheilitis. Cumulative data from 23 surveys (incorporating 3387 adults) suggest that in general, oral candidiasis may develop in one third to half of HIV-seropositive persons. Almost equal numbers of cases manifest with either erythematous or pseudomembranous variants. These and related concepts pertaining to oral mycoses in HIV infection are reviewed.

Acquired Immunodeficiency Syndrome

Oral care of the HIV-infected patient.

There are only a small number of specialized centres that cater for the dental care of the steadily increasing number of HIV-infected individuals. The responsibility will, therefore, be increasingly shared with the dental practitioner who should be knowledgeable on the basic oral management protocols involved in treating these individuals. This article summarizes some essentials of oral health care in HIV-infected individuals.

AIDS-Related Opportunistic Infections

Carriage of oral flora on irreversible hydrocolloid and elastomeric impression materials.

This study assessed the carriage and persistence of oral flora on irreversible hydrocolloid and elastomeric impression materials. In the first part of the study, a single isolate each of Streptococcus mutans, Escherichia coli, Staphylococcus aureus, and Candida albicans were inoculated onto each of two elastomeric and two irreversible hydrocolloid impression surfaces artificially created in vitro. Then the inoculum was discarded, samples of impression material (13 mm in diameter) were removed over a 5-hour period, and the remainder of viable organisms were estimated. In the second part of the study, impressions were made from 21 dentate and eight edentulous patients, and bacterial counts were estimated as described. The results showed twofold to fivefold retention of bacteria on the irreversible hydrocolloids compared with the elastomeric impression surfaces. With all impression materials, the number of viable bacteria retained within 5 hours decreased 65% to 98% except for the "disinfectant" irreversible hydrocolloid Blueprint Asept, which totally destroyed the organisms in less than 3 minutes. It is concluded that the total bacterial "load" on impression surfaces is relatively low and decreases rapidly after impression making. However, disinfection of impression surfaces should be mandatory to prevent cross-infection.

Adult

Oral candidosis in the elderly in long term hospital care.

A total of 137 patients in long term hospital care were interviewed and examined to determine the prevalence, nature and most important causes of oral candidosis in the hospitalized elderly. Oral candidal infection as determined by the imprint culture technique was present in 47% of patients with a further 31% being carriers of Candida. The prevalence of chronic atrophic candidosis in denture wearers was 38%, while 26% of all patients had angular cheilitis, 67% of which had an infective etiology. Microbiologic examination strongly indicated the upper denture as the major source of infection in those with dentures despite the existence of a ward policy which should have encouraged good oral and denture hygiene.

Aged

Systemic fluconazole therapy and in vitro adhesion of Candida albicans to human buccal epithelial cells.

The adhesion of Candida albicans to buccal epithelial cells (BEC) from four healthy dentate men was studied in vitro 1 wk before, during and after a course of systemic fluconazole (50 mg once daily for 1 wk). After 1 wk of fluconazole intake candidal adhesion to BEC was significantly reduced and this reduction persisted for a week following completion of therapy. Fluconazole, therefore, in addition to being an effective antifungal agent may also have a sustained action on reducing adherence of candidal species to the oral mucosa.

Adult

Chronic hyperplastic candidosis and secretor status.

A prospective study was undertaken of 22 patients with chronic hyperplastic candidosis and 50 age and sex matched individuals with no evidence of oral mucosal disease. Specifically the relationship between the inherited ability to secrete blood group antigens in saliva and chronic hyperplastic candidosis was investigated. The proportion of non-secretors of blood group antigens was significantly higher in patients with chronic hyperplastic candidosis (68%) compared to the control subjects (38%). The inability to secrete blood group antigens in saliva may therefore be a risk factor in the development of, or persistence of chronic hyperplastic candidosis.

ABO Blood-Group System

Angular cheilitis in a group of Sri Lankan adults: a clinical and microbiologic study.

The relative importance of various factors in the pathogenesis of angular cheilitis in a population of Sri Lankan adults was studied. Forty-nine patients with cheilitis were examined clinically and microbiologically. Only 5 of 49 patients were full denture wearers. The clinical presentation of the lesions could be categorized as mild (Type I), moderate (Type II) or severe (Type III) and the duration of the lesions ranged from 1 month to more than 4 yr. Hematologic investigations revealed 18 patients with low hemoglobin 8 of whom had hypochromic, microcytic anaemia. Pathogenic organisms were isolated from 59% of the lesions; Candida spp. in 24 patients and Staph. aureus in 11 patients. A significant positive relationship between commissural leukoplakia and an infective etiology of angles was noted. This study confirms the multifactorial etiology of angular cheilitis while highlighting the varied clinical presentation of the lesions in an Asian population.

Adolescent

Superficial oral fungal infections.

Fungal infections in humans are provoked and exacerbated by defects in the cellular immune system. Hence, the emergence of novel clinical variants of oral candidoses and rare mycoses with the pandemic spread of human immunodeficiency virus infection is not surprising. The new clinical entities of oral candidoses that have been described in the past few years have had a significant impact on the classification of these diseases. Classification of oral candidoses is an issue addressed in some detail here. Angular cheilitis is a disease commonly associated with Candida infection. In the West, it is frequently seen in the elderly, but a report from Asia indicates that the disease may be prevalent in the young age groups due to factors such as anemia, despite the similarity of the infective agents. A novel cofactor implicated in infectious states has been the host blood group secretor status, and data from three studies suggest that the latter may play an intriguing role in the pathogenesis of oral candidosis. Finally, a new mouse model has been described as a substitute for the rat model in investigating the host-parasite interactions in oral candidosis, and its pros and cons are reviewed.

Acquired Immunodeficiency Syndrome

Oral care of HIV infected patients: the knowledge and attitudes of Irish dentists.

As the numbers of people with HIV infection and AIDS increase, so will the contribution required from dental practitioners. A postal questionnaire survey was therefore conducted among dental practitioners in Ireland to determine their knowledge and attitudes towards HIV infection and the issues it raises for them. Although a majority of dentists were aware of the facts related to AIDS and the spread and oral manifestations of HIV infection, there were considerable gaps in their knowledge with regard to dental management. Only 41% were prepared to be engaged in continued care of HIV infected patients while contradicting opinions were expressed on the risk of HIV transmission in dentistry and attitudes towards HIV seropositive patients and staff. Further educational efforts on HIV infection and its implications in dentistry should be directed towards dentists in Ireland.

Adult

Bacteraemia following incision and drainage of dento-alveolar abscesses.

Twenty-five patients undergoing routine incision and drainage of dento-alveolar abscesses were screened for bacteraemia during the procedure. In 13 patients, the abscesses were aspirated with a needle prior to incision and drainage, while needle aspiration was omitted in the remaining 12. A blood sample was taken from all individuals immediately before the surgical procedures and at one-minute intervals for a period of 5 minutes after surgery. Needle aspiration of pus resulted in a significant reduction (P less than 0.05) in the bacteraemic episodes (0 out of 13) during subsequent surgery as compared with incision and drainage, without aspiration (3 out of 12). Bacteraemia appeared to be transient, although in one case it was detected at 5 minutes. It is concluded that bacteraemic episodes occur during incision and drainage of dento-alveolar abscesses and this may be reduced by aspiration of the abscess contents prior to incision and drainage. In addition, the aspirates could serve as excellent microbiological samples, uncontaminated with salivary flora. The need for antibiotic cover in at risk patients, however, needs to be established by further studies.

Bacteria

Increasing acceptance of hepatitis B vaccine by dental personnel but reluctance to accept hepatitis B carrier patients.

Dental personnel in London were surveyed for their uptake of hepatitis B vaccine and willingness to provide dental care to carriers of hepatitis B virus (HBV). Most respondents were aware of current recommendations about vaccination, and three fourths of dentists had been vaccinated against HBV. However, only half of dental ancillary staff members had been vaccinated against HBV. Three fourths of the London dentists surveyed, despite their immunity against HBV, were unwilling to treat HBV carriers.

Attitude of Health Personnel

Patient perception of cross-infection prevention in dentistry.

A questionnaire survey was conducted among 301 dental hospital and general practice patients in the Glasgow region to assess their perception and awareness of cross-infection preventive methods used in dentistry. Sixty percent of the respondents were aware that dentists have been advised to wear gloves routinely, and a large majority thought that the gloves were for the dentists' own protection. Almost all the respondents did not mind the dentist wearing either gloves or masks during treatment. One third of the total population were ignorant about sterilization methods used in dentistry. One half of the hospital patients and one third of the general practice patients thought that infectious diseases could be contracted via the dentist or his instruments. Although two in three of the respondents surmised that transmission of AIDS in the dental clinic is unlikely, one half of the general practice patients were unwilling to visit the dentist if the latter was known to treat patients with AIDS. This survey indicates that there is a great deal of confusion and fear among the public on cross-infection in the dental clinic, which needs to be rectified by a properly targeted health education campaign.

Acquired Immunodeficiency Syndrome

Suppurative oral candidosis. Review of the literature and report of a case.

A case of a dento-alveolar abscess due to a polymicrobial infection with a yeast, Candida guilliermondii and two other oral bacteria are described. A review of the literature has revealed only a single case of an odontogenic abscess due to Candida species and we believe this to be the first report of a dentoalveolar infection where Candida guilliermondii is associated as a co-pathogen.

Adult

The relationship between colonisation, secretor status and in-vitro adhesion of Candida albicans to buccal epithelial cells from diabetics.

This study investigated whether oral candida infection in diabetics and adhesion of Candida albicans to buccal epithelial cells in vitro were related. Buccal cells from 50 patients with diabetes mellitus showed a significant increase in adhesion of C. albicans strain CDS 88 compared with those collected from 50 non-diabetic controls matched for age, sex and denture status. Oral candida carriage, candida infection and secretor status were also investigated in both groups. The frequency of carriage was increased, but not significantly, and there was a significantly higher incidence of candida infection in diabetic patients compared with controls. Diabetic patients who were non-secretors had a significantly increased frequency of oral candida carriage.

Candida albicans