Biomedical subjects

A M McNicholas

Publications and source records attributed to A M McNicholas.

5 recordsLinked to original sources

PubMed2001

C. trachomatis and N. gonorrhoeae surveillance in New Zealand: comparison of laboratory and clinic data.

OBJECTIVE: To determine the extent to which clinic-based sexually transmitted infection (STI) surveillance underrepresents the number of laboratory-confirmed cases of Chlamydia trachomatis and Neisseria gonorrhoeae in the Waikato and Bay of Plenty regions of New Zealand; and to estimate incidence rates for these two infections. METHODS: Data on C. trachomatis and N. gonorrhoeae were collected from diagnostic laboratories in the study regions for the year 2000, and compared with routine clinic-based STI surveillance data. RESULTS: Most laboratory-confirmed C. trachomatis (65.5%) and N. gonorrhoeae (55.7%) infections were diagnosed by healthcare providers outside the clinic-based STI surveillance system. The estimated incidence rate for C. trachomatis was 501 per 100,000, and 50 per 100,000 for N. gonorrhoeae. CONCLUSIONS AND IMPLICATIONS: Laboratory surveillance of C. trachomatis and N. gonorrhoeae provides a more complete picture of disease burden. Given the high infection rates reported, developing a national strategy for the management of STIs should be a public health priority in New Zealand.

Adolescent↗

PubMed1995

Is New Zealand's recent increase in campylobacteriosis due to changes in laboratory procedures? A survey of 69 medical laboratories.

AIMS: To evaluate the contribution of changing procedures in microbiology laboratories over the previous 5 years to the increase in campylobacteriosis notifications. To assess whether regional differences in notification rates are due to variations in laboratory procedures. METHODS: A questionnaire was sent to 69 New Zealand medical laboratories, requesting data on their identification procedures for enteric pathogens, including campylobacter. RESULTS: Changes over the last 5 years in laboratory techniques were insufficient to account for a marked increase in campylobacter isolations. On the basis of data provided by 12 laboratories, the number of specimens that grew campylobacter increased by 49% between 1992 and 1993. Differences in laboratory methods do not explain regional differences in campylobacter notification rates. CONCLUSION: Changes in laboratory methodologies over the last 5 years do not appear to account for the recent national increase in campylobacteriosis notifications.

Campylobacter↗

PubMed1994

Effect of ivermectin on infection with gastro-intestinal nematodes in Sierra Leone.

Levels of intestinal nematode infections were assessed six months after a two year trial of ivermectin for efficacy against onchocerciasis had ended. In the trial the inhabitants of six villages in Sierra Leone were offered treatment with ivermectin or placebo at six monthly intervals for four rounds in total. Quantitative faecal egg counts were carried out on stool samples provided by 202 subjects, all of whom had received all four rounds of treatment, in two of the villages (Dodo and Mogibisi). These data were analysed by a novel procedure in which a 3-way ANOVA with negative binomial errors enabled village and host gender influences on the outcome of treatment to be identified. Necator americanus was the most common species showing an overall prevalence of 90% but a higher intensity in Mogibisi relative to Dodo, particularly among male subjects. Neither prevalence nor intensity of infection were altered in ivermectin-treated compared with placebo-treated subjects. Trichuris trichiura was the least common species with a prevalence of 15%. It was concluded that there was no significant protection from infection with this species among the ivermectin relative to the placebo-treated subjects. Ascaris lumbricoides, with an overall prevalence of 39%, was more common among female (50%) compared with male (27%) villagers. Prevalence was not significantly affected by ivermectin but the intensity of infection declined by 91.3% in Dodo whilst in Mogibisi intensity was only reduced by 14.6%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

Coagulation abnormalities and ivermectin.

Prothrombin ratios were measured 13-16 days after treatment in 148 subjects from Sierra Leone taking part in a double-blind placebo-controlled trial of ivermectin. Prolonged prothrombin ratios were observed more frequently in the ivermectin group, although this difference was not significant and no patients suffered bleeding complications. Further investigation of these patients failed to reveal any abnormality of liver function, although factor VII and II levels were reduced in most affected individuals, suggesting interference with vitamin K metabolism. Ivermectin has a minimal effect on coagulation and concern about mass treatment for this reason appears to be unjustified.

Adolescent↗

PubMedDate not supplied

A field study of the effect of ivermectin on intestinal helminths in man.

A single stool specimen from each of 904 villagers participating in a placebo-controlled trial of ivermectin for onchocerciasis was examined for intestinal helminths by the formol-ether technique. Ivermectin had a significant effect on Ascaris infection, reducing prevalence and intensity for at least 3 months, but rapid reinfection occurred. There was no significant effect on Trichuris, Necator or Schistosoma mansoni infections. Incidental Strongyloides infections were not seen commonly in this population, but were significantly reduced in the ivermectin-treated group. Regular administration of ivermectin on a mass basis would reduce the prevalence of Ascaris infection and any attendant morbidity. This is a useful additional effect of the drug.

Animals↗