The high endogenous urease activity of Campylobacter pylori was exploited in a non-invasive test for the presence of this organism in the stomach. When 13C-urea was administered orally after a test meal, urea-derived 13CO2 appeared in the respiratory CO2 of infected individuals at a constant rate for greater than 100 min. The test was validated in 26 individuals who underwent both the 13C-urea breath test and endoscopic biopsy of the antral mucosa for culture and histological examination. Each positive breath test proved to be correlated with a positive culture or Warthin-Starry silver stain of a mucosal biopsy specimen, or both.

As part of a project within the European Community research activities on acquired immunodeficiency syndrome (AIDS), infants born to human-immunodeficiency-virus-seropositive mothers are being followed up from birth. By October, 1986, 71 infants from Padua, Berlin, and Edinburgh had been followed up to a median age of 6 months (range 1-15 months). Symptoms of AIDS or AIDS-related complex (ARC) had developed in 5, 3 of whom had died. The median age at antibody loss was during the 10th month. An estimated 75% will have lost maternal antibody by 12 months, but loss of antibody did not exclude infection confirmed by virus culture. Numbers were too small to draw conclusions about the risk of AIDS/ARC and mode of delivery or breast-feeding. The study suggested that the risk of AIDS/ARC is higher in infants born to mothers who have AIDS symptoms during pregnancy.

188 schoolchildren aged 10-15 living in a malaria endemic area along the Thai-Burmese border were matched for age, splenomegaly, and weight and were then randomly assigned to receive either doxycycline (adult equivalent of 100 mg daily) or chloroquine (adult equivalent of 300 mg base weekly). All drugs were administered by the investigators and blood smears were done weekly. In 95 subjects taking doxycycline for 597 man-weeks there were 5 cases of falciparum malaria and in the 93 controls taking chloroquine for 488 man-weeks there were 31. Doxycycline was more effective than chloroquine in the prevention of falciparum malaria infections (p less than 0.0001). The doxycycline group did not have significantly more side-effects than the chloroquine group.

77 patients with a first attack of genital herpes were entered into a double-blind trial to compare the efficacy of acyclovir with that of inosine pranobex. 24 patients received acyclovir with that of inosine pranobex, and 28 both drugs. Patients treated with acyclovir or both drugs healed more quickly and had a shorter duration of viral shedding than those treated with inosine pranobex. The time to first recurrence and frequency of subsequent recurrences were similar in the three treatment groups. Acyclovir is the treatment of choice for patients with a first attack of genital herpes.

In a randomised cross-over study 12 patients with antibody deficiency and chronic lung disease received monthly infusions of either 0.6 g/kg or 0.2 g/kg intravenous immunoglobulin for six months, and were then switched to the alternative dose for a further six months. Although the incidence of infections did not differ greatly in the high-dose and low-dose phases, the frequency of acute infection was substantially reduced in those periods when serum IgG was 500 mg/dl or more. Pulmonary function worsened on the low-dose regimen and improved on the high-dose regimen.

Three doses, given within one week, of Ty21a attenuated Salmonella typhi oral vaccine in an enteric-coated formulation provided 67% efficacy for at least 3 years in a randomised, placebo-controlled field trial involving 109,000 schoolchildren in Santiago, Chile. Increasing the interval between doses to twenty-one days did not enhance protection. Significantly less protection followed administration of vaccine in gelatin capsules with sodium bicarbonate. Ty21a provides the same level of protection as the heat/phenol-inactivated whole cell parenteral vaccine but differs in not causing adverse reactions. Ty21a may now be regarded as a practical public health tool.

728 patients aged 50-75 years who had had Q-wave myocardial infarction 6-18 months previously were enrolled in a randomised, multicentre trial of low-dose heparin in prevention of reinfarction. The control group (365 patients) received their study centres' usual therapy; the heparin group (363 patients) also received subcutaneous calcium heparin (12,500 IU daily). Mean (SD) follow-up was 708 (265) days in the heparin group and 687 (251) in the control group. The reinfarction rate was 63% lower in the heparin than in the control group (4/303, 1.32% v 13/365, 3.56%). The difference in cumulative reinfarction rate between the groups was significant by both drug-efficacy (chi 2 = 3.99, p less than 0.05) and intention-to-treat analysis (chi 2 = 3.84, p = 0.05). Heparin treatment reduced the cumulative general mortality rates by 48% on drug-efficacy analysis (chi 2 = 3.88, p less than 0.05) and by 34% on intention-to-treat analysis (chi 2 = 2.05, not significant). Cardiovascular mortality was also reduced (33%) but not significantly. However, fatal events attributable to thromboembolism (fatal reinfarction, stroke, pulmonary embolism) were significantly less frequent in the heparin than in the control group (1 v 7, p less than 0.05). 60 patients (16.5%) discontinued heparin treatment, but only 23 patients (6.3%) stopped because of side-effects. Low-dose heparin appears to be effective, safe, well tolerated, and free from haemorrhagic risk for the prevention of myocardial reinfarction.