(1) As far as is at present known, the great majority of the fleas infesting Mus rattus and Mus decumanus in different parts of the world, belong to either the species Xenopsylla cheopis, Ceratophyllus fasciatus, Ceratophyllus anisus, Ctenopsylla musculi or Ctenophthalmus agyrtes or are comprised of some admixture of these five species.

(2) Xenopsylla cheopis is the most prevalent in the tropics and sub-tropical regions and often occurs there to the almost complete exclusion of other species. It is common during summer and autumn in some of the warmer parts of the temperate zone, more especially in ports which have maritime intercourse with the tropics.

(3) In the cooler regions Ceratophyllus fasciatus is the most universally distributed flea and is associated with more or less of Ctenopsylla musculi and Ctenophthalmus agyrtes according to the locality and the habitat of the particular rats.

(4) In Japan Ceratophyllus fasciatus is replaced by Ceratophyllus anisus, a closely allied species.

(5) The numerous other fleas which have been captured off rats are only occasional visitors.

(6) Ceratophyllus fasciatus, like Xenopsylla cheopis, readily bites man. Out of 517 experiments 308 fed, or 59% were positive. In 101 experiments, under identical circumstances with a rat, 59, or 58.4% of the fleas fed.

(7) The experiments with Ceratophyllus fasciatus were made upon eight persons and evidence was obtained of preference on the part of the insects for particular individuals.

(8) 111 experiments were made with 46 specimens of Ctenopsylla musculi; only 4 fed=3.6% whereas 9 out of 11 fed on a mouse.

(9) 68 specimens of Ctenophthalmus agyrtes were tried, in some cases upon three persons. None fed, whereas 11 out of 19 of the same fleas fed on a rat under identical conditions.

During the first wave of the severe acute respiratory syndrome-coronavirus-2 epidemic in the Netherlands, notifications consisted mostly of patients with relatively severe disease. To enable real-time monitoring of the incidence of mild coronavirus disease 2019 (COVID-19) – for which medical consultation might not be required – the Infectieradar web-based syndromic surveillance system was launched in mid-March 2020. Our aim was to quantify associations between Infectieradar participant characteristics and the incidence of self-reported COVID-19-like illness. Recruitment for this cohort study was via a web announcement. After registering, participants completed weekly questionnaires, reporting the occurrence of a set of symptoms. The incidence rate of COVID-19-like illness was estimated and multivariable Poisson regression used to estimate the relative risks associated with sociodemographic variables, lifestyle factors and pre-existing medical conditions. Between 17 March and 24 May 2020, 25 663 active participants were identified, who reported 7060 episodes of COVID-19-like illness over 131 404 person-weeks of follow-up. The incidence rate declined over the analysis period, consistent with the decline in notified cases. Male sex, age 65+ years and higher education were associated with a significantly lower COVID-19-like illness incidence rate (adjusted rate ratios (RRs) of 0.80 (95% CI 0.76–0.84), 0.77 (0.70–0.85), 0.84 (0.80–0.88), respectively) and the baseline characteristics ever-smoker, asthma, allergies, diabetes, chronic lung disease, cardiovascular disease and children in the household were associated with a higher incidence (RRs of 1.11 (1.04–1.19) to 1.69 (1.50–1.90)). Web-based syndromic surveillance has proven useful for monitoring the temporal trends in, and risk factors associated with, the incidence of mild disease. Increased relative risks observed for several patient factors could reflect a combination of exposure risk, susceptibility to infection and propensity to report symptoms.

We reviewed the first 21 years (1991–2011) of Australia's National Notifiable Diseases Surveillance System (NNDSS). All nationally notified diseases (except HIV/AIDS and Creutzfeldt–Jakob disease) were analysed by disease group (n = 8), jurisdiction (six states and two territories), Indigenous status, age group and notification year. In total, 2 421 134 cases were analysed. The 10 diseases with highest notification incidence (chlamydial infection, campylobacteriosis, varicella zoster, hepatitis C, influenza, pertussis, salmonellosis, hepatitis B, gonococcal infection, and Ross River virus infection) comprised 88% of all notifications. Annual notification incidence was 591 cases/100 000, highest in the Northern Territory (2598/100 000) and in children aged <5 years (698/100 000). A total of 8·4% of cases were Indigenous Australians. Notification incidence increased by 6·4% per year (12% for sexually transmissible infections and 15% for vaccine-preventable diseases). The number of notifiable diseases also increased from 37 to 65. The number and incidence of notifications increased throughout the study period, partly due to addition of diseases to the NNDSS and increasing availability of sensitive diagnostic tests. The most commonly notified diseases require a range of public health responses addressing high-risk sexual and drug-use behaviours, food safety and immunization. Our results highlight populations with higher notification incidence that might require tailored public health interventions.

Due to human error, drinking water supplied to a new housing estate in The Netherlands was contaminated with grey water. The cohort of 921 accidentally exposed households (area A) had a higher attack rate for diarrhoea (54·1%) than a non-exposed cohort of 1529 households from an adjacent area (B) (24%) (RR 2·3, 95% CI 1·9–2·7). Household water score showed a dose-response with illness, in both areas A and B. For each 1000 inhabitants, 19·8 cases in area A, 7·0 cases in control area B (RRAB 2·2, 95% CI 1·3–3·8) and 3·3 cases in a more distant control area C (RRAC 4·6, 95% CI 2·7–8·0) were diagnosed with gastroenteritis by their general practitioner. A gastroenteritis outbreak associated with consumption of contaminated drinking water was observed in the exposed area. The use of grey water was banned in 2003, with the exception of rainwater use for flushing toilets. The risk of rainwater use is currently being investigated.

The aim of this study was to review microbiology results from testing >2500 raw drinking milk and dairy products made with unpasteurised milk examined in England between 2013 and 2019. Samples were collected as part of incidents of contamination, investigation of infections or as part of routine monitoring and were tested using standard methods for a range of both pathogens and hygiene indicators. Results from testing samples of raw cow's milk or cheese made from unpasteurised milk for routine monitoring purposes were overall of better microbiological quality than those collected during incident or investigations of infections. Results from routine monitoring were satisfactory for 62% of milks, 82% of cream, 100% of ice-cream, 51% of butter, 63% of kefir and 79% of cheeses, with 5% of all samples being considered potentially hazardous. Analysis of data from cheese demonstrated a significant association between increasing levels of indicator Escherichia coli with elevated levels of coagulase positive staphylococci and decreased probability of isolation of Shiga toxin-producing E. coli. These data highlight the public health risk associated with these products and provide further justification for controls applied to raw drinking milk and dairy products made with unpasteurised milk.

Using animal inoculation, three out of six Lebanese and three out of nine Argentinian and two out of two Pakistan separate commercial consignments of bone meal imported during 1970 were found to be infected with anthrax.

Tyzzer (1917), who described an epidemic that had appeared in his mouse colony, named the causative organism Bacillus piliformis, giving an inclusive description of its behaviour and morphology. Both natural and experimental infections were studied. The high susceptibility of the Japanese waltzers as contrasted with the relative immunity of the common mice suggests that the disease susceptibility may be linked with the waltzing factor.

The aim of this study was to estimate transmission parameters of enterotoxigenic F4+ Escherichia coli F4 (F4+ E. coli) in groups of early weaned piglets with F4-receptor-positive (F4R+) and F4-receptor-negative piglets (F4R−). Transmission of F4+ E. coli was quantified in four heterogeneous groups of F4R+ and F4R− piglets. Infectiousness was determined by the number of F4+ E. coli/g faeces shed during 8 days. Transmission parameters were estimated using generalized linear models assuming a stochastic SIR model. F4R+ piglets were found to be more susceptible than F4R− piglets, but F4R+ and F4R− piglets were not different in infectiousness. The reproduction ratios for homogeneous F4R+ and F4R− populations were estimated as 6·37 (95% CI 1·89–21·48) and 0·02 (95% CI 0·00–1·13) respectively. The implication of these results is that in order to prevent major outbreaks, the fraction of F4R+ piglets should be small (approximately 10% or less). Therefore, selective breeding programmes could contribute to reducing F4+ E. coli-related diarrhoea and transmission.

Salmonellosis is a disease that represents a major public health concern in both developing and developed countries. The aim of this article is to evaluate the public health burden of Salmonella illness in Lebanon. The current scope of the Salmonella infection problem was assessed in relation to disease incidence and distribution with respect to age, gender and district. Factors that provide a better understanding of the magnitude of the problem were explored and highlighted. Data reported to the Epidemiologic Surveillance Department at the Lebanese Ministry of Public Health between 2001 and 2013 was reviewed. Information obtained was compared to information reported regionally and globally. The estimated true incidence was derived using multipliers from the CDC and Jordan. A literature review of all published data from Lebanon about Salmonella susceptibility/resistance patterns and its serious clinical complications was conducted. The estimated incidence was 13·34 cases/100 000 individuals, most cases occurred in the 20–39 years age group with no significant gender variation. Poor and less developed districts of Lebanon had the highest number of cases and the peak incidence was in summer. Reflecting on the projected incidence derived from the use of multipliers indicates a major discrepancy between what is reported and what is estimated. We conclude that data about Salmonella infection in Lebanon and many Middle Eastern and developing countries lack crucial information and are not necessarily representative of the true incidence, prevalence and burden of illness.

Multisystem inflammatory syndrome in adults (MIS-A) is a hyperinflammatory illness related to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The characteristics of patients with this syndrome and the frequency with which it occurs among patients hospitalised after SARS-CoV-2 infection are unclear. Using the Centers for Disease Control and Prevention case definition for MIS-A, we created ICD-10-CM code and laboratory criteria to identify potential MIS-A patients in the Premier Healthcare Database Special COVID-19 Release, a database containing patient-level information on hospital discharges across the United States. Modified MIS-A criteria were applied to hospitalisations with discharge from March to December 2020. The proportion of hospitalisations meeting electronic health record criteria for MIS-A and descriptive statistics for patients in the potential MIS-A cohort were calculated. Of 34 515 SARS-CoV-2-related hospitalisations with complete clinical and laboratory data, 53 met modified criteria for MIS-A (0.15%). The median age was 62 years (IQR 52–74). Most patients met the severe cardiac illness criterion through either myocarditis (66.0%) or new-onset heart failure (35.8%). A total of 79.2% of patients required ICU admission, while 43.4% of patients in the cohort died. MIS-A appears to be a rare but severe outcome of SARS-CoV-2 infection. Additional studies are needed to investigate how this syndrome differs from severe coronavirus disease 2019 (COVID-19) in adults.

1. Between September 1941 and January 1942 haemoglobin estimations were made by the Haldane method on 544 women and 530 children, aDd the values obtained compared with those for similar groups investigated before the war. 2. The women investigated were grouped as follows: (a) 353 nurses and students at a London teaching hospital and its base in the country, (b) 159 workers at a factory in a small town near London, and (c) 32 housewives, mothers of children attending a hospital in the East End of London. 3. The mean haemoglobin value of the 544 women was 89·5 % and the range was from 56 to 120%. The mean is very similar to that obtained by Davidson et al. in 1937 for a group of nulliparous women from the poorest class in Aberdeen. In contrast Price-Jones's (1931) mean figure of 98·3% for 100 supposedly healthy nurses and women students, and Jenkins & Don's (1933) mean figure of 100·5% for 116 women are significantly higher than the mean of the present series. The percentage haemoglobin was below 90 in 54 %, and below 80 in 10 % of our cases. In Price-Jones's series no haemoglobin value was below 90 %, though in Jenkins and Don's series it was below 90 in 9 % and below 80 in 1 % of the cases. 4. The mean haemoglobin value of all the nurses and students was 87·2 %. The mean for those working in London was 90.6 % and for those working in the country was 84·1 %: the difference between these means is significant. The mean values of the nurses and students working at the same hospital approximated closely, as did the mean value for the auxiliary nurses to that of the professional nurses at the same hospital. 5. The mode of life and conditions of work in the two hospitals did not differ materially. A comparison of the diets of the nurses at the two hospitals showed that in London, over a period of 3 months, the average daily intake yielded 1865 calories and 63·5 g. of protein, of which 41 g. were first-class protein; whereas in the country, for the same period, the diet yielded 1662 calories daily and 46·7 g. of protein, of which 28 g. were first-class protein. It was estimated that the London group had a daily iron intake of 10.8 mg. and the country group one of 9·2 mg. 6. The mean haemoglobin values of the factory workers and the London housewives were 94·0 and 89·6% respectively. 7. A small number of nurses and students with low haemoglobin values had regular iron medication and the majority showed a satisfactory response to treatment. 8. There were in the present, series 364 children aged 6 months to 5 years. They were examined at welfare centres, diphtheria immunization clinics and day-and residentialnurseries. The curve of their mean haemoglobin values at successive ages approximates to corresponding curves of 10 years ago for British children not receiving medicinal iron. In our present series the average haemoglobin level at 6–12 months was 75·4%. Between 1 and 2 years of age the level had dropped to 72·8%, and thereafter it gradually rose, reaching 81·8% between 4 and 5 years of age. The lowest levels were found in children under 2 years of age. Since iron treatment of such infants will not only raise their mean haemoglobin level, but also halve their morbidity rate (Mackay & Goodfellow, 1931), the haemoglobin level of these untreated babies must be considered pathologically low. The incidence of severe anaemia was lower in the welfare group than in the other groups and was highest among the children in the residential nurseries. 9. The mean haemoglobin level of 90 school children aged 5–13 years was 80·3% (about 10% lower than Davidson's (1935) mean for poor children in Aberdeen), of 38 school children aged 13–15 years 89·3% and of 38 adolescent girls working at the factory already mentioned 98·7 %. 10. In all the groups of women and older children, with the exception of the small group of girls working in a factory, the mean haemoglobin values were significantly lower than those of previous groups with which we could compare them. We believe that this general lowering of the mean haemoglobin values of the older subjects and the low curves obtained for the younger children are the expression of a nutritional anaemia. We also believe that iron deficiency is one important aetiological factor, but that other factors have also played a part in the production of this anaemia. It is probable that among women and school children other dietetic deficiencies are implicated, and that in nurseries a high incidence of infection has increased the incidence and severity of an anaemia primarily due to an iron deficiency. 11. We believe that the bearing of this anaemia on the health of the nation is of sufficient importance to call both for official action at the present time, and for further investigation.

Information on the risk factors for community-associated skin and soft-tissue infections (SSTIs) due to methicillin-resistant Staphylococcus aureus in Asian populations is scarce. To this end we performed a case-control study of patients treated at two hospital-affiliated outpatient clinics in Taiwan to determine potential risk factors for MRSA SSTIs. S. aureus was isolated from 39 of 100 eligible patients, and 74% were MRSA. Apart from resistance to clindamycin and erythromycin, most MRSA isolates were susceptible to appropriate antimicrobials. The significant risk factors identified by multivariate analysis for MRSA SSTIs were male gender (P = 0·09), nasal carriage of MRSA (P = 0·02), exposure to an individual who had surgery within a year before infection (P = 0·02), and antibiotic treatment for SSTI in the year before infection (P = 0·04). The identification of such factors may assist provision of appropriate treatment to patients with suspected S. aureus SSTIs particularly in Taiwan.

Risky sexual behaviour (RSB) is defined as behaviours leading to sexually transmitted diseases and unintended pregnancies. According to the Joint United Nations Program on HIV/AIDS, HIV infection was very high among adolescents and youths living in sub-Saharan Africa including Ethiopia. This study was aimed to assess the prevalence of RSB and associated factors among undergraduate students at the University of Gondar.

An institution-based cross-sectional study was conducted from June to July 2019 and a simple random sampling technique was employed to select 420 students. Data were collected using a structured self-administered questionnaire, entered into Epi-info version 7.0 and exported to Statistical Package for Social Sciences (SPSS) version 25 for analysis, and presented in frequencies, percentages and tables. Bivariable and multivariable logistic regression analysis were carried out to identify variables having significant association with RSB.

The prevalence of RSB among undergraduate students at the University of Gondar was 44.0%. Age [adjusted odds ratio (AOR): 2.12; 95% confidence interval (CI) (1.19–3.79)], residence [AOR: 2.14; 95% CI (1.22–3.75)], living arrangement [AOR: 9.79; 95% CI (5.34–17.9)], daily religious attendance[AOR: 0.57; 95% CI (0.33–0.99)], drink alcohol [AOR: 9.19; 95% CI (3.74–22.59)] and having information about reproductive health and sexually transmitted diseases [AOR:3.05; 95% CI (1.00–9.27)] were factors significantly associated with RSB.

Nearly half of the respondents engaged in risky sexual activity. This prevalence is high and the students are at high risk of exposure to sexually transmitted diseases that need reproductive health intervention like counselling and discussion. Creating awareness is needed for the students regarding reproductive health and the risk of sexually transmitted diseases. In addition, giving special attention is required for students who use alcohol, who did not live with family and who have urban residence.

The spread of COVID-19 is recent in India, which has within 4 months caused over 190 000 infections, as of 1 June 2020, despite four stringent lockdowns. With the current rate of the disease transmission in India, which is home to over 1.35 billion people, the infection spread is predicted to be worse than the USA in the upcoming months. To date, there is a major lack of understanding of the transmission dynamics and epidemiological characteristics of the disease in India, inhibiting effective measures to control the pandemic. We collected all the available data of the individual patients, cases and a range of parameters such as population distribution, testing and healthcare facilities, and weather, across all Indian states till May 2020. Numerical analysis was conducted to determine the effect of each parameter on the COVID-19 situation in India. A significant amount of local transmission in India initiated with travellers returning from abroad. Maharashtra, Tamil Nadu and Delhi are currently the top three infected states in India with doubling time of 14.5 days. The average recovery rate across Indian states is 42%, with a mortality rate below 3%. The rest 55% are currently active cases. In total, 88% of the patients experienced symptoms of high fever, 68% suffered from dry cough and 7.1% patients were asymptomatic. In total, 66.8% patients were males, 73% were in the age group of 20–59 years and over 83% recovered in 11–25 days. Approximately 3.4 million people were tested between 1 April and 25 May 2020, out of which 4% were detected COVID-19-positive. Given the current doubling time of infections, several states may face a major shortage of public beds and healthcare facilities soon. Weather has minimal effect on the infection spread in most Indian states. The study results will help policymakers to predict the trends of the disease spread in the upcoming months and devise better control measures.

HBV genotypes have specific geographical distributions and can serve as epidemiological markers. Accumulated data have shown that the major HBV genotypes in China are B and C. Here, the HBV genotypes were examined from 6817 blood samples, which were collected from patients with chronic HBV infection in Fujian Province during 2006–2013; genotype B was identified in 3384 patients (49·6%), while genotype C was identified in 3430 patients (50·3%). The percentage of patients infected with genotype C gradually increased with age from 39·5% (patients aged <20 years) to 63·9% (patients aged >50 years), reaching a peak of 67·3% in the 45–50 years age group. These results clearly demonstrate that the genotype distribution of HBV in Fujian Province has significantly changed in recent years with almost equal numbers of genotype B and genotype C infections existing in the entire patient population, while higher incidence of genotype C infection exists in older patients, but genotype B is no longer dominant in the Fujian area as previously reported.

Rheumatic fever (RF) is an important public health problem in New Zealand (NZ). There are three sources of RF surveillance data, all with major limitations that prevent NZ generating accurate epidemiological information. We aimed to estimate the likely RF incidence using multiple surveillance data sources. National RF hospitalization and notification data were obtained, covering the periods 1988–2011 and 1997–2011, respectively. Data were also obtained from four regional registers: Wellington, Waikato, Hawke's Bay and Rotorua. Coded patient identifiers were used to calculate the proportion of individuals who could be matched between datasets. Capture–recapture analyses were used to calculate the likely number of true RF cases for the period 1997–2011. A range of scenarios were used to correct for likely dataset incompleteness. The estimated sensitivity of each data source was calculated. Patients who were male, Māori or Pacific, aged 5–15 years and met the Jones criteria, were most likely to be matched between national datasets. All registers appeared incomplete. An average of 113 new initial cases occurred annually. Sensitivity was estimated at 80% for the hospitalization dataset and 60% for the notification dataset. There is a clear need to develop a high-quality RF surveillance system, such as a national register. Such a system could link important data sources to provide effective, comprehensive national surveillance to support both strategy-focused and control-focused activities, helping reduce the incidence and impact of this disease. It is important to remind clinicians that RF cases do occur outside the well-characterized high-risk group.

1. The average number of guinea-pigs born in albino litters is 3·000 as against 3·097 in the case of the mixed group, but the difference between the mean values is not statistically significant. Hence, it will be seen that there is little or no relationship between the colour of guinea-pigs and the number of their progeny.

2. It may be said that there is a relationship between fertility and the period of the year. There is a tendency for fewer litters to be born during the quarter, January to March, and likewise for the fertility to be lowest during this period, as the mean number of births per litter is 2·65 for albino guineapigs and 2·67 for the mixed class, both values being significantly below the mean for the whole period.

3. The mean weight of the albino guinea-pigs at birth is 81·2 ± 0·36 grm., the corresponding value for the cream, cream and white class is 82·6 ± 0·43, but the difference is of no statistical importance. Hence we conclude that the weight of a guinea-pig at birth is not affected by its colour. Once again attention is centred on the January–March quarter as the most unfavourable period, since there is a tendency for guinea-pigs of either colour born in these months to be below the normal weight.

4. When allowance was made for the effects of selection on our data, there was no material difference between the rates of growth for the two types of guinea-pigs and, furthermore, the period of the year at which littering occurred exercised no apparent influence.

5. The rate of mortality during the first thirteen days of life amongst albino guinea-pigs is 5·58 per 1000 per day, and amongst cream, cream and white guinea-pigs 4·73 per 1000 per day, but the difference probably represents nothing fundamental because, when the mortality is studied according to the size of the litter, the rates are sometimes in the reverse direction.

6. Finally, there is, in the present data, nothing to suggest that albino guinea-pigs are as regards fertility, growth and mortality, significantly different from cream, cream and white guinea-pigs.

A large outbreak of cholera reported during April–July 2009 in the Kendrapada district of Odisha, India was investigated. Forty-one rectal swabs and 41 water samples, collected from diarrhoeal patients and from different villages were bacteriologically analysed for the isolation of bacterial enteriopathogens, antibiogram profile and detection of various toxic genes. The bacteriological analysis of rectal swabs and environmental water samples revealed the presence of V. cholerae O1 Ogawa biotype El Tor. The V. cholerae strains were resistant to ciprofloxacin, co-trimoxazole, chloramphenicol, streptomycin, ampicillin, furazolidone and nalidixic acid. The multiplex polymerase chain reaction (PCR) assay on V. cholerae strains revealed the presence of ctxA and tcpA genes. The mismatch amplification of mutation assay (MAMA) PCR on clinical and environmental isolates of V. cholerae revealed that the strains were El Tor biotype, which harboured the ctxB gene of the classical strain. The random amplified polymorphic DNA PCR analysis and pulsed-field gel electrophoresis results indicated that the V. cholerae isolates belonged to the same clone. This investigation gives a warning that the El Tor variant of V. cholerae has spread to the coastal district causing a large outbreak that requires close monitoring and surveillance on diarrhoeal outbreaks in Odisha.

1. In the course of this investigation we have dealt with many cases of refection, but during a period of several years we never obtained the condition except when raw potato starch was the carbohydrate in the synthetic diet. Recently, in the exceptional circumstances described in the text, we have had a few cases with rice starch.

2. Like other authors, we have always found that in refected rats the caeca are always enlarged and their contents the seat of specially great bacterial activity. The nature of the dominant organisms present has varied from case to case, and in one it was apparently a yeast. Nevertheless, there is a suggestion that certain organisms are more potent in promoting refection than others. In rice starch refection, such organisms seem to be present.

3. We have found that the administration of roughage in the manner described can, to a large extent, prevent the establishment of refection. The number of organisms in the caeca is then greatly reduced and the contents indeed may become nearly sterile.

4. Using potato starch as the carbohydrate of the diet, we have had no difficulty in reproducing the results of the early experiments published by one of us (Hopkins, 1912), but we found that to obtain a growth induced by administering very small quantities of milk to vitamin-free diets, the presence of this starch is necessary. Indeed, the growth so promoted calls for the same particularity in the carbohydrate supply as does the establishment of refection.

5. Nevertheless, we have obtained what seems to be conclusive evidence showing that the growth with milk is wholly independent of refection.

6. We have obtained some evidence that potato starch contains growth factors in association with protein which only becomes soluble when liberated by treatment with pepsin HCl. As our experimental results bearing on this, for some reason at present unexplained, have lacked constancy, we can only claim, that they are suggestive.