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Choice of methodology in the diagnosis of parasitic infections
ABSTRACTS OF A N N U A L S C I E N T I F I C MEETING
1971
67
'T' mycoplasmas were present in 85",, of males with clinical nongonococcal urethritis and in almost the same proportion of patients with gonorrhoea. This isolation rate was significantly higher than that in a group of subjects in the same age groups, with similar sexual habits but without symptoms of urethritis. 'T' mycoplasmas were not found in a group of males that did not have urethritis or a history of casual intercourse. The incidence of 'T' mycoplasmas in females with gonorrhoea, or in those with nongonococcal vaginal discharge, was comparable with males with gonorrhoea or with nongonococcal urethritis. Females without symptoms had a lower isolation rate but, when compared with the above 2 female groups, the difference was not significant. The effect of tetracycline therapy was followed in a group of male patients with nongonococcal urethritis. As symptoms subsided 'T' mycoplasmas were eliminated or reduced in number. It is concluded that 'T' mycoplasmas occur frequently in men suffering from nongonococcal urethritis, in men and women with gonorrhoea1 infection and in promiscuous females. Tetracycline generally cures nongonococcal urethritis and postgonorrhoeal urethritis (A'eisseria gomrrhoea negative) and eliminates 'T' mycoplasmas.
CHOICE OF METHODOLOGY I N THE DIAGNOSIS OF PARASITIC I N FECTIONS
MCILIILLAN, B. South Wales
School o j Public Heulrh uird Tropical Medicine, Sydtre?', New
Diagnosis of parasitic infection requires an cpidcmiological history and the corrclation of clinica! and laboratory findings so that commensal infection can be differentiated from disease process With malaria, the preparation of blood films and their staining in an alkaline medium is important. T h e specific identification of the parasite depends on the experience of the pathologist, keeping in mind that the diagnosis of the young malaria ring is difticult. In demonstrating drug resistance of a particular strain of malaria parasite, serial parasite counts are necessary. T h e demonstration of Enrumoebu hisrcrlvticu (and other alimentary protozoa) may depend upon the intensitv and frequency of examination a!though the finding of 1:. hisrolyricn is indicative of clinical amoebiasis only under certain circumstances. Full assessment of metozoan infections requircs specialized techniques including quantitation by egg counting. For example, the excretion of 1,000 hookworm eggs g. of stool is not significant but the excretion of, say, 150,000 eggs g. of stool may indicate a mortal infection. Reference was made to the use and limitations of serology in the diagnosis of parasitic diseascs. Serological procedures are often requested unnecessarily, because of a lack of understanding of the dlseasc process.
CURRENT EPIDEMIOLOGICAL PROBLEMS I N RUBELLA IMMUNIZATION
FISHER, S . Dieiisioir qf 1~pideiiiio/ogyqf Departmetit of Health, $Jjdne.y, il'rw South Wules If the mass campaigns, a t prescnt aimed at girls aged 12-14 yr., are the sole means of immunization and if the acceptance rare in 1972 in N.S.W. i.e. 76",,, is csperienced in the whole country, then in 1991 more than 1 3rd of those becoming pregnant will still be unimmunized. T h e rate of immunization in wonn-n over 15 yr. is unlikely to have exceeded 2",, yr. of those at risk, since the vaccine was released here in late 1969. Titrations of rubella antihaemagglutinin on 5,079 serum samples from pregnant women in N.S.W., in 1968-70, by Mr A. M. Murphy (I.C.P. 81 M.R. Lidcornbe) have shown the following proportions of those without demonstrable antibody: ages 20-29 yr., 20""; 30-34 yr., 13",,;and 35-39 yr., 3",,. It follows that during the 5 yr. from ages 25-20 to 30-34 nonimmune fertile women have a chance of 7 , 2 0 of contracting rubella, and the chancc of the first trimester of a pregnancy coinciding with the 1 in 57. Further, the average age for first birth is 23.7 yr and 3 out of 4 women infection is 7 2" x 1 2o who have had one child will have a second one; nonimmune primigravidas therefore appear to be a group of high risk.
1971
67
'T' mycoplasmas were present in 85",, of males with clinical nongonococcal urethritis and in almost the same proportion of patients with gonorrhoea. This isolation rate was significantly higher than that in a group of subjects in the same age groups, with similar sexual habits but without symptoms of urethritis. 'T' mycoplasmas were not found in a group of males that did not have urethritis or a history of casual intercourse. The incidence of 'T' mycoplasmas in females with gonorrhoea, or in those with nongonococcal vaginal discharge, was comparable with males with gonorrhoea or with nongonococcal urethritis. Females without symptoms had a lower isolation rate but, when compared with the above 2 female groups, the difference was not significant. The effect of tetracycline therapy was followed in a group of male patients with nongonococcal urethritis. As symptoms subsided 'T' mycoplasmas were eliminated or reduced in number. It is concluded that 'T' mycoplasmas occur frequently in men suffering from nongonococcal urethritis, in men and women with gonorrhoea1 infection and in promiscuous females. Tetracycline generally cures nongonococcal urethritis and postgonorrhoeal urethritis (A'eisseria gomrrhoea negative) and eliminates 'T' mycoplasmas.
CHOICE OF METHODOLOGY I N THE DIAGNOSIS OF PARASITIC I N FECTIONS
MCILIILLAN, B. South Wales
School o j Public Heulrh uird Tropical Medicine, Sydtre?', New
Diagnosis of parasitic infection requires an cpidcmiological history and the corrclation of clinica! and laboratory findings so that commensal infection can be differentiated from disease process With malaria, the preparation of blood films and their staining in an alkaline medium is important. T h e specific identification of the parasite depends on the experience of the pathologist, keeping in mind that the diagnosis of the young malaria ring is difticult. In demonstrating drug resistance of a particular strain of malaria parasite, serial parasite counts are necessary. T h e demonstration of Enrumoebu hisrcrlvticu (and other alimentary protozoa) may depend upon the intensitv and frequency of examination a!though the finding of 1:. hisrolyricn is indicative of clinical amoebiasis only under certain circumstances. Full assessment of metozoan infections requircs specialized techniques including quantitation by egg counting. For example, the excretion of 1,000 hookworm eggs g. of stool is not significant but the excretion of, say, 150,000 eggs g. of stool may indicate a mortal infection. Reference was made to the use and limitations of serology in the diagnosis of parasitic diseascs. Serological procedures are often requested unnecessarily, because of a lack of understanding of the dlseasc process.
CURRENT EPIDEMIOLOGICAL PROBLEMS I N RUBELLA IMMUNIZATION
FISHER, S . Dieiisioir qf 1~pideiiiio/ogyqf Departmetit of Health, $Jjdne.y, il'rw South Wules If the mass campaigns, a t prescnt aimed at girls aged 12-14 yr., are the sole means of immunization and if the acceptance rare in 1972 in N.S.W. i.e. 76",,, is csperienced in the whole country, then in 1991 more than 1 3rd of those becoming pregnant will still be unimmunized. T h e rate of immunization in wonn-n over 15 yr. is unlikely to have exceeded 2",, yr. of those at risk, since the vaccine was released here in late 1969. Titrations of rubella antihaemagglutinin on 5,079 serum samples from pregnant women in N.S.W., in 1968-70, by Mr A. M. Murphy (I.C.P. 81 M.R. Lidcornbe) have shown the following proportions of those without demonstrable antibody: ages 20-29 yr., 20""; 30-34 yr., 13",,;and 35-39 yr., 3",,. It follows that during the 5 yr. from ages 25-20 to 30-34 nonimmune fertile women have a chance of 7 , 2 0 of contracting rubella, and the chancc of the first trimester of a pregnancy coinciding with the 1 in 57. Further, the average age for first birth is 23.7 yr and 3 out of 4 women infection is 7 2" x 1 2o who have had one child will have a second one; nonimmune primigravidas therefore appear to be a group of high risk.