Reports of increasing incidence and severity of invasive group A streptococcal (GAS) infections come mainly from affluent populations where exposure to GAS is relatively infrequent. We conducted a 6-year retrospective review of GAS bacteraemia in the Northern Territory of Australia, comparing the Aboriginal population (24% of the study population), who have high rates of other streptococcal infections and sequelae, to the non-Aboriginal population. Of 72 episodes, 44 (61%) were in Aboriginal patients. All 12 cases in children were Aboriginal. Risk factors were implicated in 82% of episodes (91% in adults) and there was no significant difference in the proportion of Aboriginal compared to non-Aboriginal patients with at least one risk factor. Genetic typing of isolates revealed no dominant strains and no evidence of a clone which has been a common cause of these infections elsewhere.

To estimate the change in the seroprevalence and risk factors for toxoplasmosis in The Netherlands, a study was conducted in the general population in 2006/2007, similarly designed as a previous study in 1995/1996. Testing 5541 sera for IgG antibodies against Toxoplasma gondii showed a marked decrease of the overall seroprevalence to 26·0% [95% confidence interval (CI) 24·0–28·0], compared to 40·5% (95% CI 37·5–43·4) in 1995/1996. In women of reproductive age the seroprevalence decreased from 35·2% (95% CI 32·9–38·6) in 1995/1996 to 18·5% (95% CI 16·2–20·7) in 2006/2007, leaving the majority of pregnant women susceptible to primary infection with T. gondii and their babies to congenital toxoplasmosis. In participants aged ⩾20 years, Toxoplasma seropositivity was associated with living in the Northwest, living in urban areas, low educational level, consumption of raw pork, keeping a cat, and not having occupational contact with clients or patients. For younger participants, risk factors were keeping sheep or cattle, consumption of raw unwashed vegetables and putting sand in the mouth.

Syphilis is a chronic, multi-stage infectious disease that is usually transmitted sexually by contact with an active lesion of a partner or congenitally from an infected pregnant woman to her fetus. Although syphilis is still endemic in many developing countries, it has re-emerged in several developed countries. The resurgence of syphilis is a major concern to global public health, particularly since the lesions of early syphilis increase the risk of acquisition and transmission of infection with human immunodeficiency virus (HIV). Because there is no vaccine to prevent syphilis, control is mainly dependent on the identification and treatment of infected individuals and their contacts with penicillin G, the first-line drug for all stages of syphilis. The emergence of clinically significant azithromycin resistance in Treponema pallidum subsp. pallidum, the syphilis agent, has resulted in treatment failures, thus precluding the routine use of this second-line drug. Information is presented here on the diagnosis and recommended antibiotic treatment of syphilis and the challenge of macrolide-resistant T. pallidum.

Invasive pneumococcal disease (IPD) is of concern in Japan, where the heptavalent pneumococcal conjugate vaccine (PCV7) is unavailable. We determined serotypes, genotypes indicating β-lactam resistance, and antibiotic susceptibilities of 496 isolates from normally sterile sites in patients (193 children, 303 adults) from 186 institutions between August 2006 and July 2007. Disease presentations included sepsis (46·2%), pneumonia (31·5%), and meningitis (17·5%). Mortality was 1·4% in children and 22·1% in adults, many of whom had underlying diseases. In children, serotype 6B (22·5%) was followed by 19F (14·1%), and 14 (13·1%); potential coverages of PCV7 and PCV13 were 75·4% and 93·7%, respectively. In adults, serotype 12F (14·3%) was followed by 3 (11·3%), and 6B (10·3%); 23-valent polysaccharide vaccine (PPV23) coverage was 85·4%. Most serotype 12F strains were gPISP, with pbp2b gene alteration; carbapenem had an excellent MIC90. PCV7 is recommended for children and PPV23 for adults to increase prevention against IPD.

1. Bacteriological surveys of more than forty popular bathing beaches around the coasts of England and Wales have been made during the past 5 years. The great majority of the beaches studied were subject to contamination with sewage.

2. A rough grading of the beaches studied gave a similar ranking order whether the results of the presumptive coliform test or faecal coli counts were used as the basis of grading.

3. Grading of beaches was valid only when surveys were carefully planned to ensure representative sampling from the areas on the beaches concerned where bathing actually took place.

4. The coliform test as used in the bacteriological examination of drinking waters was the main test procedure used but had certain limitations. Promising results with plate counts on relatively non-inhibitory media were obtained.

5. Various salmonella serotypes, notably Salm. paratyphi B, were isolated in small numbers from a high proportion of sea-water samples. The proportion of positive results for salmonella isolation increased from 13·3% in samples with less than 1000 coliform organisms per 100 ml. to 40·1% in samples with over 10,000 coliforms per 100 ml. Comparison of the numbers of salmonellae isolated with what is known of the minimum infective doses of these organisms suggested that very large volumes of sea water would require to be ingested for infection to occur.

6. Poliovirus was not isolated from a small series of sea-water samples examined. Because of the very large dilution factor, special concentration procedures would probably be required to isolate this virus from sea water.

7. Four cases of paratyphoid fever probably due to bathing were recorded. Surveys of the two associated beaches had given median presumptive coliform counts of more than 10,000 per 100 ml., and both showed gross macroscopic pollution with sewage.

8. A statistically controlled study of the bathing histories of 150 poliomyelitis cases in children living permanently by the seaside gave no evidence that bathing had played any part in causing the disease.

The occurrence of Shiga toxin-producing Escherichia coli (STEC) was studied on four cattle farms. STEC were detected in 29–82% of the cattle. STEC with additional EHEC markers were detected on all farms. The occurrence of the complete virulence marker pattern (stx1 and/or stx2, eae, EHEChlyA, katP, espP) was correlated with the presence of known STEC serotypes. STEC O26[ratio ]H11 and O165[ratio ]H25 with the complete pattern of virulence markers were the most prevalent. STEC O157 (H7/H-) STEC O103[ratio ]H2 and STEC O145[ratio ]H- were found sporadically. Five clonal subgroups of the STEC O26[ratio ]H11 isolates were identified by pulsed-field gel electrophoresis. STEC O26[ratio ]H11 were present in three groups of cattle. This serotype was detected in a single group over the entire fattening period. Most STEC O26[ratio ]H11 with the complete pattern of potential virulence markers were found in clinically healthy cattle. These animals may represent a risk factor for farmers and consumers.

From 1 January 1992 to 31 December 2000, 27 milkborne general outbreaks of infectious intestinal disease (IID) were reported to the Public Health Laboratory Service (PHLS) Communicable Disease Surveillance Centre (CDSC). These outbreaks represented a fraction (2%) of all outbreaks of foodborne origin (N=1774) reported to CDSC, but were characterized by significant morbidity. Unpasteurized milk (52%) was the most commonly reported vehicle of infection in milkborne outbreaks, with milk sold as pasteurized accounting for the majority of the rest (37%). Salmonellas (37%), Vero cytotoxin-producing Escherichia coli (VTEC) O157 (33%) and campylobacters (26%) were the most commonly detected pathogens, and most outbreaks were linked to farms (67%). This report highlights the importance of VTEC O157 as a milkborne pathogen and the continued role of unpasteurized milk in human disease.

A novel enzyme-linked immunosorbent assay (ELISA) and a confirmatory Western blot (WB) to detect human antibodies against Francisella tularensis were evaluated. The ELISA was based on partially purified lipopolysaccharide (LPS), the WB on whole antigen of F. tularensis. Positive WB showed a typical LPS ladder. Sensitivity and specificity of the ELISA, as assessed in 104 positive sera and 1149 ‘normal’ sera from healthy young adults, were 99·0% and 97·1% respectively. Sensitivity of the WB was close to 100%, whereas specificity was 99·6%. Antibodies against the LPS of F. tularensis were detected in four of the ‘normal’ sera in both ELISA and WB. The assays were further evaluated using sera of individuals from Norway, Sweden and Kosovo suspected to be infected in tularemia outbreaks. Results revealed that the combination of ELISA and WB is suitable for laboratory confirmation of tularemia as well as for large-scale epidemiological studies.

Multiple introductions of methicillin-resistant Staphylococcus aureus (MRSA) strains occurred to a new hospital in Hong Kong. Two years of clinical microbiological surveillance of the resulting outbreaks was combined with laboratory investigation by phage and antibiogram typing, and plasmid profiling. The outbreaks on the special care baby (SCBU) and burns (BU) units were studied in detail, and colonization of staff and contamination of the environment were investigated. MRSA were spread by the hands of staff on the SCBU, where long-term colonization of dermatitis was important, but were probably transmitted on the BU by a combination of the airborne, transient hand-borne and environmental routes. Simple control measures to restrict hand-borne spread on the SCBU were highly effective, but control was not successful on the BU.

Annually for 4 years groups of young Australian wild rabbits have been captured during non-epizootic periods from areas in which myxomatosis has occurred during the previous summer. The intensity of the preceding epizootic was measured by testing a sample of survivors for antibody. The captured young rabbits were raised in the laboratory until they were about 4 months old and then inoculated intradermally with small doses of the slightly attenuated myxoma virus strain Aust/Corowa/12–52/2 (KM 13), all samples of virus being derived from the same batch which has been stored at -70°C.

The results show there is a significant negative correlation between the mortality rate and the degree of exposure to myxomatosis of the forbears of the tested animals. Passive and active immunization have been excluded and this result is ascribed to increased genetic resistance.

We are greatly indebted to Mr. F. N. Ratcliffe, Officer in Charge of the Wildlife Survey Section of the Commonwealth Scientific and Industrial Organization, and to his officers, especially Messrs W. E. Poole, K. E. Myers, G. Douglas, B. V. Fennessy, H. Frith and K. Keith for their invaluable assistance in collecting rabbits and serum samples.

We have had valuable discussions with Dr W. R. Sobey, Dr P. J. Claringbold and Dr G. S. Watson on genetical and statistical aspects of the problems under study.

Livestock feed is susceptible to contamination from wildlife excreta during on farm storage. Pathogens associated with diseases such as paratuberculosis, salmonella and cryptosporidiosis are present in wild rodent and bird excreta. Feed stores on four farms in the east of Scotland were monitored monthly over the winter of 1998/9 to quantify the levels of wildlife faecal contamination. A mean of 79·9 rodent (95% confidence interval: 37·5–165·9) and 24·9 (14·3–41·7) bird faeces were deposited per m2 of stored feed per month. It was estimated that individual cattle and sheep could encounter 1626 and 814 wildlife faeces over the winter.

A model based on the numbers of infected faeces consumed per annum was used to estimate ‘infectious probabilities’ (Pinf) required to account for the reported prevalence of paratuberculosis, salmonella and cryptosporidiosis in sheep and cattle in the east of Scotland in 1998. Based on empirical data for input variables [the number of faeces encountered (Fe), the number ingested (Fi) and the prevalence of infection in wildlife species (Ip)], Pinf estimates ranged from 1·6×10−8 for cryptosporidiosis in sheep to 8·2×10−6 for paratuberculosis in cattle. The model suggested that ingestion of feed contaminated by wildlife faeces could account for the prevalence of all three diseases. Wildlife faecal contamination of stored feed should be given serious consideration as a potential source of infection to livestock.

In 1934 a committee on the eradication of bed-bugs appointed by the Minister of Health issued its report (Report on the Bed-bug, 1934) in which recommendations for research into the biology of Cimex lectularius L. were made. The committee was struck by the lack of precise information on certain aspects of the bionomics and habits of the insect and suggested work along the following lines:

The effect of food supply and starvation at different seasons and at different stages of development.

The periods of survival of bed-bugs and their eggs under different conditions.

The extent to which bed-bugs can subsist on the blood of birds, bats, mice, etc., when deprived of human blood.

The position and types of harbourages most favoured by bed-bugs under different conditions.

The distance which bed-bugs will travel, the factors (warmth, smell, etc.) which attract them, and whether they habitually return to the same harbourage.

The indirect immunofluorescent technique has been used to study the specific immunoglobulin responses in twelve adult cases of acute uncomplicated rubella. IgG, IgA and IgM antibodies increased virtually simultaneously. IgG antibody persisted throughout the period of study but showed a slight tendency to fall in titre after 7 months. IgM antibody was detected in nine cases. In these patients it was present in high titre 5–15 days after the rash but was not detected after 20 days. IgA antibody was detected in all cases. It was present in high titre 5–20 days after the rash but was no longer detectable after 29 days except in one patient who had a very low titre at 78 days. The presence of specific IgA and IgM indicates recent rubella in uncomplicated cases, and if the immunofluorescent method is used both types of antibody should be sought.

We systematically reviewed the current understanding of human population immunity against SARS-CoV in different groups, settings and geography. Our meta-analysis, which included all identified studies except those on wild animal handlers, yielded an overall seroprevalence of 0·10% [95% confidence interval (CI) 0·02–0·18]. Health-care workers and others who had close contact with SARS patients had a slightly higher degree of seroconversion (0·23%, 95% CI 0·02–0·45) compared to healthy blood donors, others from the general community or non-SARS patients recruited from the health-care setting (0·16%, 95% CI 0–0·37). When analysed by the two broad classes of testing procedures, it is clear that serial confirmatory test protocols resulted in a much lower estimate (0·050%, 95% CI 0–0·15) than single test protocols (0·20%, 95% CI 0·06–0·34). Potential epidemiological and laboratory pitfalls are also discussed as they may give rise to false or inconsistent results in measuring the seroprevalence of IgG antibodies to SARS-CoV.

Giardia intestinalis is the leading parasitic aetiology of human enteric infections in the United States, with an estimated 1·2 million cases occurring annually. To better understand transmission, we analysed data on all giardiasis outbreaks reported to the Centers for Disease Control and Prevention for 1971–2011. The 242 outbreaks, affecting ~41 000 persons, resulted from waterborne (74·8%), foodborne (15·7%), person-to-person (2·5%), and animal contact (1·2%) transmission. Most (74·6%) waterborne outbreaks were associated with drinking water, followed by recreational water (18·2%). Problems with water treatment, untreated groundwater, and distribution systems were identified most often during drinking water-associated outbreak investigations; problems with water treatment declined after the 1980s. Most recreational water-associated outbreaks were linked to treated swimming venues, with pools and wading pools implicated most often. Produce was implicated most often in foodborne outbreaks. Additionally, foods were most commonly prepared in a restaurant and contaminated by a food handler. Lessons learned from examining patterns in outbreaks over time can help prevent future disease. Groundwater and distribution system vulnerabilities, inadequate pool disinfection, fruit and vegetable contamination, and poor food handler hygiene are promising targets for giardiasis prevention measures.

This study assesses the contribution of different sources of human campylobacteriosis in Denmark using two different source-attribution approaches. In total, 794 non-human isolates and 406 isolates from human cases (domestic, travel related, and cases with unknown travel history) were collected. Isolates were characterized by multilocus sequence typing, flaA typing and susceptibility to antibiotics. Both models used indicate that the major burden of human campylobacteriosis in Denmark originates from the domestic broiler chicken reservoir. The second most important reservoir was found to be cattle. The Asymmetric Island model attributed 52% [95% credibility interval (CrI) 37–67] to Danish chicken, 17% (95% CrI 3–33) to imported chicken, and 17% (95% CrI 7–28) to cattle. Similarly, the Campylobacter source-attribution model apportioned 38% (95% CrI 28–47) to Danish chicken, 14% (95% CrI 10–18) to imported chicken, and 16% (95% CrI 7–25) to cattle. The addition of flaA type as an extra discriminatory typing parameter did not change the attribution of cases markedly.

The global incidence of Shigella infection has been estimated at 80–165 million episodes annually, with 99% of episodes occurring in the developing world. To identify contemporary gaps in the understanding of the global epidemiology of shigellosis, we conducted a review of the English-language scientific literature from 1984 to 2005, restricting the search to low and medium human development countries. Our review yielded 11 population-based studies of Shigella burden from seven countries. No population-based studies have been conducted in sub-Saharan Africa or in low human development countries. In studies done in all age groups, Shigella incidence varied from 0·6 to 107 episodes/1000 person-years. S. flexneri was the most commonly detected subgroup in the majority of studies. Case-fatality rates ranged from 0% to 2·6% in population-based studies and from 0% to 21% in facility-based studies. This review highlights the large gaps in data on the burden of Shigella infections for low human development index countries and, more specifically, for sub-Saharan Africa.

In simple epidemiological models that describe the interaction between hosts with their parasites, the infection process is commonly assumed to be governed by the law of mass action, i.e. it is assumed that the infection rate depends linearly on the densities of the host and the parasite. The mass-action assumption, however, can be problematic if certain aspects of the host–parasite interaction are very pronounced, such as spatial compartmentalization, host immunity which may protect from infection with low doses, or host heterogeneity with regard to susceptibility to infection. As deviations from a mass-action infection rate have consequences for the dynamics of the host–parasite system, it is important to test for the appropriateness of the mass-action assumption in a given host–parasite system. In this paper, we examine the relationship between the infection rate and the parasite inoculum for the water flee Daphnia magna and its bacterial parasite Pasteuria ramosa. We measured the fraction of infected hosts after exposure to 14 different doses of the parasite. We find that the observed relationship between the fraction of infected hosts and the parasite dose is largely consistent with an infection process governed by the mass-action principle. However, we have evidence for a subtle but significant deviation from a simple mass-action infection model, which can be explained either by some antagonistic effects of the parasite spores during the infection process, or by heterogeneity in the hosts' susceptibility with regard to infection.

Clinical descriptions of Epstein–Barr virus (EBV) positive infectious mononucleosis (IM) are rare and their results are inconsistent. Over a 4-year period, we prospectively studied 590 young adults with clinically suspected IM, all of whom were tested for the presence of EBV IgM antibodies. We investigated the demographical, clinical and laboratory features of subjects with positive EBV IgM serology and heterophile antibodies. Contrary to previous studies, we found a seasonal disease pattern with a peak incidence during summer months, and a lower-than-expected prevalence of lymphadenopathy (88·9%), leucocytosis (46·2%), atypical lymphocytosis (89·2%) and elevated liver enzymes (57·9%). The prevalence of hyperbilirubinemia was relatively high (14·9%). The classic triad of fever, sore throat and lymph-adenopathy had relatively low sensitivity (68·2%) and specificity (41·9%) for EBV infection. Our study provides a complete and updated description of the clinical and laboratory presentation of laboratory confirmed IM, which is important for both clinicians and epidemiologists.

Serological surveillance of measles immunity has been carried out in England since 1986/7. Results from sera collected in 1989–91 revealed that the proportion of school age children who were susceptible to measles was increasing, following the introduction of the measles, mumps and rubella vaccination programme in October 1988. Mathematical models are used to interpret these data and determine whether this increasing susceptibility is sufficient to allow a resurgence of disease from the low levels achieved by 1993. The models summarize serological profiles by a single parameter, the reproduction number R, which quantifies the level of herd immunity in the population. Results showed that there was cause for concern over the levels of susceptibility to measles, with an epidemic of over 100000 cases likely in 1995/6. These predictions are consistent with trends in the incidence and age distribution of measles and have enabled the planning of a major vaccination campaign.