Search

Despite increasing resistance in the pneumococcus over the past 30 years, there are few cases of treatment failure of non-meningeal infections with high-dosage parenteral penicillin G, which still remains highly effective for many pneumococcal diseases. This is reflected by the new 2008 CLSI breakpoints for parenteral penicillin G of susceptible, /=8 microg ml, for non-meningeal infections. For meningitis and oral penicillin V use, the old penicillin breakpoints of susceptible, /=2 microg/ml, will remain in place. Clinically relevant susceptibility breakpoints have also been developed for virtually all relevant antimicrobial agents used to treat pneumococcal diseases, based on clinical studies and pharmacokinetic and pharmacodynamic parameters. Although pneumococcal resistance to beta-lactams, macrolides and co-trimoxazole is now common worldwide, we are still able to treat almost all pneumococcal infections adequately. An exception is the oral treatment of multidrug-resistant serotype 19A strains in children in the USA, as these are resistant to amoxicillin, oral cephalosporins, macrolides, clindamycin and co-trimoxazole. While there is a need to develop new agents, judicious use of antimicrobial agents is the best long-term approach. Empiric treatment guidelines should reflect the emerging threats from increased drug resistance and the possibility of increased virulence in replacement serotypes following vaccine use. Compliance with guidelines by physicians and patients is important to prevent further development of resistance.

The 4th case of botulism in South Africa is reported. Unusual features are the detection of toxin in the patient's serum 7 weeks after the onset of the illness and the need for 14 weeks' intermittent positive pressure ventilation. Symptomatic treatment and meticulous nursing resulted in complete recovery. The microbiology, pathophysiology, clinical features, diagnosis and management of botulism are briefly reviewed.

Two clinical isolates of Yersinia enterocolitica biotype 1, positive for indole and lecithinase production, xylose and salicin fermentation, and aesculin hydrolysis, are reported. One strain, serotype 0 6, was recovered from a healthy food handler, while the other, serotype 0 5, was associated with a diarrhoeal illness in a 1-year-old child. This is the first report of either of these serotypes from human material in South Africa.

This article documents 53 cases of Salmonella paratyphi C infections in humans in the Eastern Transvaal (47 cases) and South West Africa (6 cases). Ninety-two percent of patients (49 cases) had enteric fever, 1 patient was asymptomatic, and 3 had localized urinary infections or were carriers. Most patients were successfully treated with chloramphenicol and only 1 relapsed. The South West African strains were identified as S. paratyphi C var. east africa. The organism is probably spread by water, and 70% of patients who had enteric fever were under the age of 20 years.

Sixteen cases of group B streptococcal (GBS) infections in neonates and infants aged up to 3 months were detected from November 1973 to January 1977. Three patients presented with pneumonia, 10 with meningitis and 3 with both pneumonia and meningitis. All diagnoses were confirmed by positive blood and/or cerebrospinal fluid cultures. The serotypes involved were type Ia (2 cases), type II (4 cases) and type III (10 cases). Ten patients died (62.5%). Early antibiotic treatment did not appear to affect the outcome, but low peripheral leucocyte count indicated a uniformly fatal outcome in 6 cases where leucopenia was documented, and this appeared to be associated with late-onset disease. The current status of GBS disease is presented, with particular reference to the control measures at present available and the possibility of immunotherapy and vaccination.

An indirect fluorescent antibody survey of the prevalence of Toxoplasma antibodies was carried out on sera from 4 regions of Southern Africa (Natal, Eastern Cape, Western Cape, and South West Africa and Botswana). The overall prevalence of seropositivity at a titre of 1/16 or higher was 20% (of 3379 sera tested), the highest prevalence occurring in Blacks (34%) and Indians (33%) of Natal, and the lowest in San (Bushmen) (9%) and Whites (12%) of South West Africa and Botswana. Differences in prevalence in these areas, and between different ethnic groups, are discussed and compared with previous studies in Southern Africa. Climatic factors affecting prevalence and transmission are compared in relation to cyst and oöcyst survival. The marked differences in prevalence between the San (9%) and the Negroid Dama (27%), both inhabiting the arid Kalahari Desert, are discussed with reference to the lifestyles of these groups.

The primary antibody response of iron-deficient children to diphtheria and typhoid immunization was measured. In 5 children immunized with diphtheria toxoid, there was no increase in antitoxin titre. Of 8 children who were given typhoid vaccine, 6 showed an increase in Salmonella typhi O agglutinin titre. All the iron-deficient children had normal isohaemagglutinin titres.

Two cases of gastro-enteritis in South African adults are reported. Stool cultures performed on both patients yielded pure growths Escherichia coli. One isolate was shown to have invasive ability, and the other to produce heatstable enterotoxin. Neither strain belonged to a 'classic' enteropathogenic serotype associated with infantile gastro-enteritis.

During the period August 1977 to April 1978, 14 Black patients in Johannesburg area had systemic infections caused by Listeria monocytogenes. Nine of these patients were neonates who presented with septicaemia (5 cases) or septicaemia and meningitis (4 cases) and 5 were adults, all of whom had meningitis. The mortality rate was 43% (6/14), with 4 neonatal and 2 adult deaths. All isolates of L. monocytogenes were type 4b. Only sporadic cases of human listeriosis have previously been reported in South Africa, and the cases reported here constitute the first epidemic in this country.

In vitro studies on the antibacterial activity of nitroxoline and sulphamethizole, alone and in combination, were undertaken and minimal inhibitory concentrations (MICs) determined on a range of urinary pathogens. Eighty per cent of the strains tested were sensitive to less than or equal to 16 mg/l of nitroxoline, and all strains, including Pseudomonas aeruginosa and Streptococcus faecalis, were sensitive to less than or equal to 64 mg/l of nitroxoline. No synergism could be demonstrated with sulphamethizole, but the combination was antagonistic when tested against strains of Ps. aeruginosa and Strep. faecalis. An in vivo study on 10 volunteers showed excellent urinary levels of nitroxoline and sulphamethizole after an oral dose of 160 mg of each agent, and 6-hour urinary nitroxoline levels were greater than or equal to 64 mg/l in 9 of the 10 subjects, and sulphamethizole levels were greater than or equal to 64 mg/l in all 10 subjects. Laboratory findings suggest that nitroxoline and sulphamethizole are both suitable agents for use in urinary tract infections caused by organisms sensitive to these agents, but there appears to be litte advantage in using them in combination.