IN the first half of the year, 1941, an unusual number of cases of congenital cataract made their appearance in Sydney. Cases of similar type, which appeared during the same period, have since been reported from widely separated parts of Australia. Their frequency, unusual characteristics and wide distribution warranted closer investigation, and this report is an attempt to bring to notice some of the more important features of what might almost be regarded as a mild epidemic.

Fifty years ago in New South Wales the late Sir Norman Gregg [1] described congenital cataracts in 78 babies, 67 of whose mothers had had clinical rubella in early pregnancy; he concluded that the disease in the mother caused the abnormality in the baby. Gregg [1–3] and Swan [4, 5] and their colleagues reported that deafness, heart disease and microcephaly were also major components of the congenital rubella syndrome. The need to prevent this tragic outcome stimulated intensive work on laboratory diagnosis and vaccine development, leading to the isolation of rubella virus in 1962 and then to methods for antibody detection. These complementary advances established the two traditional pillars of virological diagnosis and opened the way to immunization, with the result that some countries are now on the verge of eliminating a disease which for over 100 years was regarded as no more than a mild and harmless exanthem of childhood.

The association between rubella in pregnancy and congenital anomalies was first reported 50 years ago, by N. McAlister Gregg, an Australian ophthalmologist [1]. During the next 20 years his findings were confirmed by others (reviewed in [2]). However, the first reports of the isolation of rubella virus in cell cultures and development of tests for neutralizing antibodies were not published until 1962 [3, 4]. Subsequent studies conducted in the UK and North America during a pandemic of rubella in 1963–4, were therefore able to make a more accurate estimate of the risks of maternal rubella at different stages of pregnancy. It was estimated that about 30000 rubella-damaged babies were born in the USA alone in 1963–4 [5]. This emphasized the importance of developing a vaccine to prevent infection in pregnancy and thereby, the birth of babies with rubella-induced congenital defects.

The first description of rubella in the UK was by an English physician, Dr William Maton, who reported an outbreak of an illness resembling a mild form of scarlatina in a boys' public school in 1815 [1]. Some years later, when observing the spread of a rash-associated illness in a large family, Maton described the characteristic clinical features of rubella, namely a mild prodromal illness followed by a generalized and often tingling rash lasting for a few days and associated with enlarged and tender glands in the occipital and postauricular regions. He also correctly identified the relatively long incubation period of rubella and noted the absence of fever and other signs of constitutional upset. Maton did not suggest an English name for this disease which had been previously described and called Rothëln by German physicians in the late 18th century. The term ‘rubella’ (Latin for ‘little red’) was first used in 1866 by another English physician, Dr Henry Veale, when describing an outbreak of Rothëln in a boys' school in India [2].

Postnatal rubella is a mild illness, a disease which was considered to be of only minor importance for many years. The first authors to write about the disease as distinct from other exanthemata were German physicians; they differentiated rubella from measles and scarlet fever in the latter part of the eighteenth century and called the disease Rotheln. Hence the common English language eponym is ‘German measles’. Some consider that the term ‘German’ in German measles is probably of literary rather than of geographical significance and that it came from the old French ‘germain’ (derived from the Latin ‘germanus‘), meaning ‘closely akin to’ measles [1]. That it is not generally called by its German name, Rotheln, is due to Veale, a Scottish physician who in 1866 described 30 cases of rubella in the Edinburgh Medical Journal, and proposed ‘rubella’ as a short and euphonius name that could be easily pronounced [2].

More than 25 years have passed since the last rubella epidemic in the United States. The rubella pandemic of 1964–5 demonstrated clearly the extraordinary teratogenic potential of the rubella virus. In the United States alone, it is estimated that more than 12500000 cases of rubella occurred during the winter and spring of 1964–5. Congenital rubella infection occurred in an estimated 30000 pregnancies, 10000 resulting in fetal death or therapeutic abortion and 20000 resulting in infants born with congenital rubella syndrome (CRS) [1]. In contrast, during 1988, only 225 cases of rubella were reported to the Centers for Disease Control (CDC) in Atlanta, the lowest annual total since rubella became a nationally notifiable disease in 1966 [2]. However, in 1989, this downward trend of reported cases was interrupted, with the number of reported rubella cases in the United States increasing nearly twofold, and in 1990, the total increased another threefold (to more than 1000 cases) [3]. Although the 1990 reports represent the highest total since 1982, the overall incidence of rubella in the United States has still declined by more than 98% since 1969, the year rubella vaccine was licensed (Fig. 1).

Before Gregg's historic observation [1] rubella was not considered to have clinical or epidemiological importance in any country. In the western world epidemics occurred at varying intervals but with little morbidity and apparently only minor complications. Despite confirmation of Gregg's findings from many quarters, it was not until the worldwide outbreaks in the 1960s that the aftermath of rubella infection in pregnancy was fully realized. As a result of the 1964 outbreak in New York City, more than 1000 children were born with congenital rubella syndrome (CRS) and over 300 pregnancies either aborted spontaneously or were terminated for rubella infection [2]. The number of children affected represented 1% of births in the city; if extrapolated to the whole country this gave an estimated total of 30000 cases of CRS. No such disasters have so far been reported from the developing world.

Using ordinary least squares regression techniques this paper demonstrates, for the first time, that the classic association of war and disease substantially accounts for the presently observed geographical distribution of reported clinical AIDS cases in Uganda. Both the spread of HIV 1 infection in the 1980s, and the subsequent development of AIDS to its 1990 spatial pattern, are shown to be significantly and positively correlated with ethnic patterns of recruitment into the Ugandan National Liberation Army (UNLA) after the overthrow of Idi Amin some 10 years earlier in 1979. This correlation reflects the estimated mean incubation period of 8–10 years for HIV 1 and underlines the need for cognizance of historical factors which may have influenced current patterns of AIDS seen in Central Africa. The findings may have important implications for AIDS forecasting and control in African countries which have recently experienced war. The results are compared with parallel analyses of other HIV hypotheses advanced to account for the reported geographical distribution of AIDS in Uganda.

In March 1989 a large outbreak of acute gastroenteritis occurred simultaneously among schoolchildren and teachers at nine elementary schools in Toyota City, Japan. Illness was observed in 3236 (41·5%) of 7801 schoolchildren and 117 (39·4%) of 297 teachers. The main clinical symptoms were diarrhoea, vomiting, nausea and abdominal pain. Gastroenteritis was significantly associated with the consumption of school lunch served by one particular lunch preparation centre. One food handler at the centre suffered from gastroenteritis during the outbreak.Small round structured virus (SRSV) was detected in 4 of 8 stool specimens from sick persons. The school lunch contaminated by the infected food handler is the most probable source of this outbreak due to SRSV.

A group specific agar-gel immunodiffusion test was used to demonstrate that there is a frequent and widespread distribution of bluetongue virus throughout the Sultanate of Oman. The Culicoides midges C. imicola and C. schultzei, both capable of transmitting bluetongue group viruses, were recorded throughout the year. Although these studies did not establish that bluetongue is enzootic in Oman, type-specific neutralizing antibody results supported previous evidence for the existence of a Saudi Arabian bluetongue ecosystem. Variations in antibody evidence of virus activity within a restricted locality suggested a hot-spot theory concerning the perpetuation of the virus.

Faecal oral spread is claimed by many to be the mode of transmission of the gastric pathogen Helicobacter pylori. This idea is based not on experimental data but because the epidemiology of H. pylori infection resembles that of other pathogens known to be spread by the faecal-oral route. This is in spite of the observation that no-one has been successful in culturing H. pylori from human stool. In this study, a series of transmission experiments are reported on animals infected with the gastric spirilla, Helicobacter felis and ‘Gastrospirillum hominis’. Germfree mice and rats infected with H. felis did not transmit their infection to uninoculated mice despite prolonged contact in the same cage nor could the bacterium be isolated from their intestinal contents. This was confirmed in specific pathogen free mice where infected dams did not pass the helicobacter to their progeny. Similarly, mice infected with a human isolate of ‘Gastrospirillum hominis’ did not transmit the infection while in close contact with uninoculated mice. In contrast, in a limited series of experiments, both H. pylori and H. felis were transmitted from infected gnotobiotic Beagle puppies to uninfected animals in the same enclosure. In addition, the gastric mucus from a cat with indigenous ‘Gastrospirillum’-like organisms was infectious for mice, whereas faecal content from the same animal was not. It is suggested that the difference between the murine and canine experiments is that the dogs are more likely to have oral-oral contact than rodents. Unlike dogs, mice and rats do not vomit and are coprophagous. It is concluded that the case for faecal-oral spread of Helicobacter species is ‘not proven’ and that the inter-oral route is more likely.

Samples of 216 pâatés were examined for the presence of Listeria spp. Between May and August 1989; 35% were contaminated with L. monocytogenes, 5% of samples having counts of > 104/g. L. innocua was recovered from 2% of samples but no other species was isolated. Five serotypes of L. monocytogenes were represented (1/2, 4b, 4b(X), 4 not 4b or 4b(X), and NT). 4b was the predominant serotype and multiple serotypes were found in eight pâatés. The incidence of contamination with L. monocytogenes was greater in stored pâté (46%) than display pâté (30%). Sampling over a 21-day period showed an apparent increase in numbers of L. monocytogenes in 6 of 7 samples with multiple serotypes represented. There was no correlation between contamination of pâté by L.monocytogenes and the presence of coliforms. Comparisons are made between the contamination of soft cheese and pˇaté.

Streptococcus suis types 1 and 2 were detected in nasal swabs taken from five litters of piglets sampled twice weekly from birth. The two types had been detected in all pigs by the time they were 38 and 25 days old respectively with mean ages of first detectable infection being 13·5 and 8·5 days. The prevalence of infection was not affected by housing conditions or the population density of pigs. Piglets originating from a sow with vaginal swabs positive for S. suis type 2 were infected earlier than piglets from non-vaginal carriers. It is concluded that infection of piglets with S. suis type 2 may occur during the birth process.

Following a case of Legionnaires' disease Legionella pneumophila of the same serogroup was isolated from the hot water system of the hotel which had been epidemiologically implicated as the source of the infection. Pyrolysis mass spectrometry (PyMS) was used to compare 11 isolates from the hotel water sample with the patient's strain. Epidemiologically unrelated isolates, both clinical and environmental, of the same serogroup and monoclonal antibody type of L. pneumophila were included in the same analysis, together with relevant reference strains. The patient strain was shown to be indistinguishable from seven of the hotel water isolates, but clearly different from other unrelated clinical isolates, the reference strains and some of the other environmental isolates. PyMS is a rapid and cheap method for inter-strain comparison for L. pneumophila.

Fourteen people living in or near the city of Gloucester fell ill with Legionnaires' disease caused by Legionella pneumophila serogroup (SG) 1 between 27 August and 27 October 1986. Another patient had fallen ill on 30 May. Nine of the 15 were diagnosed retrospectively during a case finding exercise. There were three deaths. Three cases of Pontiac fever were also diagnosed.

The source was probably one or more wet cooling towers. Nineteen premises in the city with such towers were identified, and three just outside Gloucester. Samples from 11 of the 22 premises grew Legionella spp.; from nine of these L. pneumophila SG 1 (Pontiac) was isolated. The efficacy of regular addition of biocide in addition to hypochlorite added at the time of disinfection in inhibiting the growth of Legionella spp. was demonstrated.

A survey of patients' movements during their likely incubation period showed that there was no single building that all patients had visited, but there were two areas of the city which nearly all had visited or passed through by car. A case-control study demonstrated an association with one of these areas.

Cooling towers near both areas may have been sources but the evidence is insufficient to incriminate any single one. The unexpected finding of L. pneumophila SG 1 (Pontiac) in nine towers supports the hypothesis that there may have been multiple sources. Cooling towers may have been contaminated by mains water or by drift from other towers.

Serum samples obtained from patients hospitalized in Barbados with severe leptospirosis were tested by the microscopic agglutination test (MAT), enzyme immunoassay (EIA) and immunoblotting with leptospires that had been isolated from these patients. While serum samples taken a few days after onset of symptoms often showed no apparent correlation between MAT and EIA, later sequential serum samples produced similar profiles in both tests during the course of infection. Immunoblotting sonicate from Leptospira interrogans serovars arborea, copenhageni and bim with patients' sera, revealed reactions with a number of bands that corresponded with outer envelope components. These components included lipopolysaccharide (LPS), flagella and other outer membrane proteins, in addition to a low-molecular-weight (MW) carbohydrate cross-reactive with members of the Leptospiraceae. IgM antibodies elicited in the first to second week after infection reacted mainly with LPS and the low-MW cross-reactive carbohydrate. Comparative analysis of isolates of the same serovar by sodium dodecyl sulphate polyacrylamide gel electrophoresis and immunoblotting showed that while two serovar arborea isolates were identical, serovar bim isolates differed significantly from each other. This difference was also observed in comparative MAT testing.

A containment laboratory unit for research with aerosols of group 2 pathogenic microorganisms is described. The design criteria are based on current UK guidelines, which imply containment at group 3 level during aerosol production, storage, exposure of animals and sampling. Within the aerosol laboratory, primary containment is provided by a Henderson apparatus operating at a negative pressure to the external environment. Flexible film isolators under negative pressure are used for all hazardous microbiological work, e.g. tissue homogenization, and for housing infected laboratory rodents. A novel feature of the animal isolator is the separate ventilation of each cage, which minimizes the risk of cross-infection by aerosol transmission and ensures a similar environment within each cage. The results of an intentional release of a cloud of non-pathogenic microorganisms are presented to show the effectiveness of the containment barriers. Recommendations are given for the safe operation of a containment unit based upon practical experience.

Aeromonas has been recognized as an important enteropathogen, but factors related to its virulence have not been clarified. For most enteric pathogens, attachment is a prerequisite for infection and for the effective delivery of toxins to the intestinal epithelial cells. We examined a total of 273 strains isolated from stool, food and environmental specimens by an assay for mannose-resistant adhesion to INT407 cells in vitro. Seventeen of the 102 faecal isolates were adhesive strains with more than 10 bacteria adhering per cell, while only 2 of the 118 isolates from foods and river water adhered to the cells (P < 0·001). It is possible that the adhesion might serve as a marker for discrimination between the pathogenic and nonpathogenic isolates. The 8 highly adhesive strains with more than 20 adhering organisms per cell were scrutinized for the mechanism of adhesion. No correlation was apparent between the adhesion to INT407 cells and hydrophobicity. It was noted that fucose inhibited the adhesion of four strains as well as haemagglutination by them. Electronmicroscopic studies showed the presence of flexible and curvilinear fimbriae in only 2 of the 8 highly adhesive strains.

A study was conducted to isolate and identify microorganisms of medical importance from cockroaches (Blattella germanica) and to ascertain their vector potential in the epidemiology of nosocomial infections. Bacteria, fungi and parasites of medical importance were isolated and identified. Important bacterial pathogens responsible for wound infections, were further studies by antibiograms. One hundred and fifty-eight out of 159 (99·4%) cockroaches collected from hospital (test) and 113 out of 120 (94·2%) cockroaches collected from residential areas (control) were carrying medically important microorganisms (P < 0·05). A significantly higher (P < 0·001) number of test cockroaches were carrying a higher bacterial load (1 × 104 and 1 × 105) as compared to control cockroaches. Multiple drug-resistant bacteria were isolated from test cockroaches. The diversity of drug-resistant bacterial species isolated from test cockroaches suggests their involvement in the transmission of drug-resistant bacteria. Various fungi and parasitic cysts of medical importance were also isolated from the test and control cockroaches, but the carriage rates were low. The findings suggest that cockroaches, in hospitals, can act as potential vectors of medically important bacteria/parasites/fungi.