Acute blood samples from 120 children, attending the fever hospital in Alexandria and complaining of fever, were collected and examined for haemagglutination-inhibiting (HAI) and complement-fixing (CF) antibodies against the following arbovirus antigens; Sindbis, West Nile (WN), yellow fever, dengue 1, sandfly fever, Quaranfil, Chenuda and Nyamanini. Positive reactions in the acute sera were only detected against Sindbis (4·3%) and WN (4·3%) antigens. The convalescent sera obtained from 48 of these children showed a pronounced HAI titre against WN antigen in 14·6 % of them. The same sera showed a lower titre against yellow fever antigen (Asibi strain) which is due to cross-reaction between the two viruses. None of the acute or the convalescent sera showed CF antibodies against Quaranfil, Chenuda or Nyamanini antigens. The convalescent sera were not tested against dengue type 1 antigen. It is suggested that of the known arboviruses in Egypt, WN is the most important from the public health point of view.

1. Scarlatinal streptococci obtained from the throats of cases of scarlet fever can be divided into various groups by means of agglutination and absorption tests. The same type of streptococcus can on occasion originate at least five separate clinically distinguishable diseases, namely, scarlet fever, tonsilitis, erysipelas, puerperal fever, and broncho-pneumonia, and it would appear that, so far as streptococcic infections are concerned, the nature of the disease entity is determined by the toxigenic qualities of the type of streptococcus, by the susceptibility or insusceptibility of the individual as determined by the absence or presence of the specific antibodies in the blood, and by the site of the infection itself (see p. 330).

2. Strong corroboration for the view that the S. scarlatinae is the causal organism of scarlet fever is obtained from the following findings, viz.:

(a) S. scarlatinae have been isolated from the throat brushings of practically all acutely ill scarlet fever patients (see p. 329).

(b) The whole clinical picture of scarlet fever going on to marked desquamation is produced by the subcutaneous injection of the exotoxin derived from the S. scarlatinae, the exotoxin having been haeated to 55° C. for one hour, with a view to destroying any filterable living virus which might be associated with the filtered exotoxin (see p. 342).

(c) In the Schultz-Charlton reaction the blanching of the scarlet fever rash is caused by the serum of a horse immunised against S. scarlatinae and its toxins.

(d) Dick-positive and Dick-negative reactions as produced by the intradermal injection of the streptococcus toxin have the closet correspondence to the degree of susceptibility or immunity to scarlet fever of the respective reactors (see p. 334).

(e) Susceptible nurses once they are actively immunised by injections of scarlatinal streptococcus toxin have been shown to be immune to the toxin of scarlet fever (see p. 337), and susceptible school children similarly inoculated are likewise immune (see p. 338).

(f) Return cases of scarlet fever can be prevented by actively immunising susceptible contacts with scarlatinal streptococcus toxin prior to the scarlet fever patient being discharged from hospital (see p. 339).

(g) Susceptible contacts can be safeguarded from taking scarlet fever by passively immunising them with a sufficient does of antistreptococcus serum obtained from a horse wich has been immunised by injections of S. scarlatinae and its toxin (see p. 349).

3. The limitations of the Schultz-Charlton reaction as an aid in the diagnosis of scarlet fever have been confirmed (see p. 330).

4. Evidence has been obtained which firmly establishes the value of the Dick suseptibility test as a measure of susceptibility to scarlet fever (see p. 332).

5. Extensive corroboration of the value of the Schick test as a measure of susceptibility to diphtheria has been obtained (see p. 334).

6. The efficacy of active immunisation against scarlet fever by means of scarlatinal streptococcus toxin injections has been demonstrated by the fact that, while scarlet fever has been present in epidemic form in Aberdeen, no nurses or maids in Aberdeen City Hospital have contracted scarlet fever since June 1st, 1925, from which date the nursing and domestic staffs of the hospital have been actively immunised before being admitted for duty to the scarlet fever wards; whereas, prior to that date, an average of 8·5 nurses, or 9·5 per cent. of the nursing staff, and 1·4 maids, or 4·2 per cent. of the domestic staff. annually suffered from scarlet fever (see p. 337).

7. Coincident with the disappearance of scarlet fever in the immunised nursing staff of the City Hospital, there has been a notable increase in the incidence of streptococcic tonsilitis in these immunised nurses, and the streptococci obtained from these cases of tonsilitis in nurses commonly fall into one or other of the serological groups of scarlatinal streptococci; and accordingly it would appear to be proved that immunised nurses, while protected by immunisation from the toxic effects of the exotoxin of S. scarlatinae, are not protected against tonsilitis due to S. scarlatinae (see p. 338).

Periodic outbreaks of West Nile virus (WNV), Eastern equine encephalitis virus (EEEV) and to a lesser extent, California serogroup viruses (CSGV), have been reported in parts of Canada in the last decade. This study was designed to provide a broad assessment of arboviral activity in Quebec, Canada, by conducting serological surveys for these arboviruses in 196 horses, 1442 dogs and 485 humans. Sera were screened by a competitive enzyme linked immunosorbent assay and positive samples confirmed by plaque reduction neutralisation tests. The percentage of seropositive samples was 83·7%, 16·5%, 7·1% in horses, 18·8%, 0·6%, 0% in humans, 11·7%, 3·1%, 0% in adult dogs and 2·9%, 0·3%, 0% in juvenile dogs for CSGV, WNV and EEEV, respectively. Serological results in horses and dogs appeared to provide a meaningful assessment of risk to public health posed by multiple arboviruses.

1. By means of a new technique, using the “closed bowl” of the Sharpies-Super Centrifuge, in which the distance which the virus particles have to travel under the influence of a given centrifugal force until they are caught mechanically in an agar-gel lining the wall of the bowl amounts to only a few tenths of a millimetre, the potency of 5 c.c. of a foot-and-mouth disease virus suspension can be reduced by 90–99 per cent in 3 min. using a centrifugal force of 24,000 times gravity. The virus can be recovered without loss by extraction of the agar-gel either in fresh medium or even in the liquid layer or “supernatant”, thus showing that adsorption phenomena play no role whatever in the effects obtained by centrifugation.

2. The non-adsorbability of the virus by the agar, however, is determined by the presence of a certain though very small amount of impurities presumably protein which seem to have a “protective” effect. The limit of nonadsorption of the virus by the gel appears to be in that region of “purity” where the sulphosalicylic acid test for protein is negative whereas serological precipitation reactions for host protein are still positive. Virus purified beyond this limit is strongly adsorbed by an agar-gel.

3. Measurements of the sedimentation rate were made on three strains of virus of different type Vallee A, Vallee 0 and Waldmann C and no differences between the three strains were observed. The average diameter of the virus particles determined from the sedimentation rate data was 20 mμ. All the evidence now available for the monodispersity of the virus is discussed. The fact that the infective particles are uniform in size indicates that the measurements recorded here concern actually the single virus elements.

4. The sedimentation equilibrium of the virus has been estimated. The value calculated on this basis for the weight of a single virus particle is circ. 1 × 10−17 g. The diameter of a sphere of this weight and density 1·30 would be 25 mμ. The size values for the virus, 25 mμ estimated from sedimentation equilibrium data and 20 mμ estimated from sedimentation rate data, are discussed in relation to the possible shape of the virus particles.

5. The virus can be sedimented in sucrose and sucrose-salt solutions of densities up to 1·28. On the basis of the sedimentation rates in these media the specific gravity of the virus particles is estimated to be about 1·40. This value however may be abnormally high due to the dehydrating effect of the high concentration of salt or sugar. The application of the centrifuge technique described here to the concentration and purification of the virus of foot-andmouth disease in conjunction with ultrafiltration methods will be the subject of a second paper by Galloway & Schlesinger (1937).

A cross-sectional study was conducted from 2014 to 2017 in 13 organised pig farms located in eight states of India (Northern, North-Eastern and Southern regions) to identify the risk factors, pathotype and antimicrobial resistance of Escherichia coli associated with pre- and post-weaning piglet diarrhoea. The data collected through questionnaire survey were used to identify the risk factors by univariable analysis, in which weaning status, season, altitude, ventilation in the shed, use of heater/cooler for temperature control in the sheds, feed type, water source, and use of disinfectant, were the potential risk factors. In logistic regression model, weaning and source of water were the significant risk factors. The piglet diarrhoea prevalence was almost similar across the regions. Of the 909 faecal samples collected (North – 310, North-East – 194 and South – 405) for isolation of E. coli, pathotyping and antibiotic screening, 531 E. coli were isolated in MacConkey agar added with cefotaxime, where 345 isolates were extended spectrum β-lactamase (ESBL) producers and were positive for blaCTX-M-1 (n = 147), bla TEM (n = 151), qnrA (n = 98), qnrB (n = 116), qnrS (n = 53), tetA (n = 46), tetB (n = 48) and sul1 (n = 54) genes. Multiple antibiotic resistance (MAR) index revealed that 14 (2.64%) isolates had MAR index of 1. On the virulence screening of E. coli, 174 isolates harboured alone or combination of Stx1, Stx2, eaeA, hlyA genes. The isolates from diarrhoeic and post-weaning samples harboured higher number of virulence genes than non-diarrhoeic and pre-weaning. Alleviating the risk factors might reduce the piglet diarrhoea cases. The presence of multidrug-resistant and ESBL-producing pathogenic E. coli in piglets appears a public health concern.

A longitudinal study of nasal colonization and hand contamination of food handlers with Staphylococcus aureus commenced in 2002 prior to the outbreak of severe acute respiratory syndrome. In the follow-up in 2003 when hygiene measures were strictly implemented, significant reductions in carriage were observed. To investigate if this change was sustained, nasal and hand carriage rates were compared between the earlier studies and a further sampling in 2011. The initial nasal carriage rate was 35% and hand contamination 41·2%, decreasing to 23·5% and 11·6%, respectively in 2003 (P < 0·001). In 2011, nasal carriage was similar to 2003 (22·9%), while hand contamination dropped further to 3·7% (P < 0·001). Spa-typing revealed 39 types in 2002 and 42 in 2011. This study reveals that the marked reduction in colonization had been sustained. This may be attributed to reduced opportunities for spread due to enhanced hygiene and reinforces its importance for control of disease.

We undertook a retrospective descriptive comparison of the spectrum of pathogens responsible for bacteraemia and diarrhoea in HIV antibody positive and negative patients over 4 years (1988–92), in Nairobi, Kenya. The study population was recruited from primary to tertiary centers of clinical care and consisted of 2858 adults (15 years or older). There were 415 significant blood culture isolates, 192 from 1785 HIV negative patients and 223 from 953 HIV positive patients. There were 233 significant faecal isolates, 22 from 115 HIV negative patients and 211 from 531 HIV positive patients. The most common pathogens detected in blood were Streptococcus pneumoniae and Salmonella typhimurium and in faeces Shigella flexneri, S. typhimurium and Cryptosporidium parvum. The agents causing illness in HIV positive patients in Nairobi are similar to those prevalent in the HIV negative community and the investigation of a febrile illness with or wothout diarrhoea in an HIV positive patient should reflect this.

The co-existence of stroke and HIV has increased in recent years, but the impact of HIV on post-stroke outcomes is poorly understood. We examined the impact of HIV on inpatient mortality, length of acute hospital stay and complications (pneumonia, respiratory failure, sepsis and convulsions), in hospitalized strokes in Thailand. All hospitalized strokes between 1 October 2004 and 31 January 2013 were included. Data were obtained from a National Insurance Database. Characteristics and outcomes for non-HIV and HIV patients were compared and multivariate logistic and linear regression models were constructed to assess the above outcomes. Of 610 688 patients (mean age 63·4 years, 45·4% female), 0·14% (866) had HIV infection. HIV patients were younger, a higher proportion were male and had higher prevalence of anaemia (P < 0·001) compared to non-HIV patients. Traditional cardiovascular risk factors, hypertension and diabetes, were more common in the non-HIV group (P < 0·001). After adjusting for age, sex, stroke type and co-morbidities, HIV infection was significantly associated with higher odds of sepsis [odds ratio (OR) 1·75, 95% confidence interval (CI) 1·29–2·4], and inpatient mortality (OR 2·15, 95% CI 1·8–2·56) compared to patients without HIV infection. The latter did not attenuate after controlling for complications (OR 2·20, 95% CI 1·83–2·64). HIV infection is associated with increased odds of sepsis and inpatient mortality after acute stroke.

The growth of virulent strains of Bordetella pertussis in the brains of mice was studied by carrying out viable counts on mice killed at various times during the infection. The results suggested that this system conformed to the general model which postulates that the organisms causing death multiply in vivo at a rate which is constant for all doses and that death is certain to occur when the number of organisms reaches a certain constant figure.

Perhaps the most important factor in this route of infection is the lodgement of the parasite in the host, for if this is accomplished a single organism grows until the lethal level is reached. There is no sublethal infection.

In actively and passively protected mice, the growth of the organism is approximately the same as in unprotected controls for the first 4–5 days. At this time there is a striking change in protected animals and the viable count falls rapidly and progressively and the animals survive. At the same time the blood-brain barrier becomes permeable and circulating antibodies diffuse into the brain. In vitro, specific antisera plus complement are highly bactericidal.

Rabbit fleas for use in Myxomatosis investigations have been successfully bred on rabbits in an animal house. The timing of emergence appeared to be governed by a biological timing control interacting with different forms of disturbance. Yield was found to be related to litter size, the time the doe and her kittens were removed from the nest, the number of fleas put onto a doe before littering and the mean ambient temperature to which the doe was exposed in the week pre-partum. The survival rate of fleas in storage was affected by temperature, the degree of crowding, moisture content of the containers, whether fleas were fed or unfed and the source of fleas in terms of emergence times.

Prior to 2009 dengue fever had not been reported in the Andaman and Nicobar archipelago. In 2009, a few patients with dengue fever-like illness were reported, some of whom tested positive for dengue antibodies. In 2010, 516 suspected cases were reported, including some with dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS); 80 (15·5%) were positive for dengue antibodies. DENV RNA was detected in five patients and PCR-based typing showed that three of these belonged to serotype 1 and two to serotype 2. This was confirmed by sequence typing. Two clones of dengue virus, one belonging to serotype 1 and the other to serotype 2 appeared to be circulating in Andaman. Emergence of severe diseases such as DHF and DSS might be due to recent introduction of a more virulent strain or because of the enhancing effect of sub-neutralizing levels of antibodies developed due to prior infections. There is a need to revise the vector-borne disease surveillance system in the islands.

Malignant catarrhal fever (MCF) herpesvirus was isolated from the nasal secretions of 4/11 young wildebeest calves. In two cases virus was demonstrated in filtered secretions. The presence of cell-free MCF virus would suggest that the virus can be transferred from wildebeest to wildebeest and into cattle in nasal secretions.

Occasional cases of classical bovine spongiform encephalopathy (BSE) still continue to occur within the European Union (EU) for animals born after reinforced feed bans (BARBs), which should in theory have eliminated all risk of infection. The study aimed to determine (i) whether a common rate of decline of BSE infection was evident across EU member states, i.e. to determine whether control measures have been equally effective in all member states, (ii) whether there was any evidence of spontaneous occurrence of BSE in the data and (iii) the expected date for the last BSE case in UK. It was found that there was no significant difference in the rate of decline of BSE prevalence between member states, with a common rate of decline of 33·9% per annum (95% CI 30·9–37%) in successive annual birth cohorts. Trend analysis indicated an ultimate decline to 0 prevalence, suggesting that spontaneous occurrence does not explain the majority of cases. Projecting forward the trends from the back-calculation model indicated that there was approximately a 50% probability of further cases in the UK, and should the current rate of decline continue, there remains the possibility of further occasional cases up until 2026.

The United States has been fortunate in never having had any extensive epidemics of plague. With the exception of a few cases, not over a dozen, that are directly chargeable to the infection of the indigenous rodents (ground squirrels), the disease has been confined to the two largest and most important cities on the Pacific Coast, San Francisco and Seattle. In each city the disease has yielded promptly to vigorous sanitary measures carried out by the public health arm of the Federal Government. Under the political organization of the Government, direct control of measures for the suppression of a disease is taken by the central sanitary authority only when a request is made by the local authorities, but it has been the experience that local authorities are prompt to make requests for assistance whenever any serious epidemic appears.

Pharyngeal micro-organisms of 131 Australian and Malaysian children and adults were compared by analysis of aerobic culture of throat swab specimens. Enteric Gram-negative bacilli were commonly isolated in small numbers from Malaysian adults whether they had sore throats (28%) or not (36%), but were detected in only 9% of Australian adults without sore throats and in only 12% and 4% of Malaysian children with and without sore throats respectively. In other respects microbiological findings were similar in the different groups of subjects studied.

It is concluded that the pharyngeal carriage rate of enteric Gram-negative bacilli may differ substantially between different groups of normal individuals. Our findings also suggest that these micro-organisms do not have a pathogenic role in pharyngitis.

The European Sero-Epidemiology Network 2 (ESEN2) aimed to compare serological results of vaccine-preventable diseases across Europe. To ensure direct inter-country comparability of hepatitis A virus antibody (anti-HAV) measurements, a standardization panel of 150 sera was developed by a designated reference laboratory and tested by participating national laboratories using assays of choice; each country's results were subsequently regressed against those of the reference laboratory. Quantitatively, the assays were generally highly correlated (R2>0·90). Nevertheless, qualitative comparisons indicated that results obtained with different assays may differ despite the usage of well-established international and local standards. To a great extent standardization successfully alleviated such differences. The generated standardization equations will be used to convert national serological results into common units to enable direct international comparisons of HAV seroprevalence data. The results of this study are expected to contribute to the evaluation and potential improvement of the currently employed immunization strategies for hepatitis in Europe.

Many parents move from rural China to urban areas in search of job opportunities, and leave their children behind to be raised by relatives. We aimed to assess the immunisation coverage, including the 1:3:3:3:1 vaccine series (one dose of Bacilli Chalmette–Guérin vaccine; three doses of live attenuated oral poliomyelitis vaccine; three doses of diphtheria, tetanus and pertussis combined; three doses of hepatitis B vaccine; and one dose of measles-containing vaccine), in children aged 12–72 months and identify the determinants of immunisation uptake among left-behind children in Hubei Province, Central China, in 2014. In this cross-sectional study using the World Health Organization's cluster sampling technique, we surveyed 1368 children from 44 villages in 11 districts of Hubei Province. The socio-demographic and vaccination status data were collected by interviewing primary caregivers using a semi-structured questionnaire and reviewing the immunisation cards of the children. Univariate and multivariate analyses were used to identify the determinants of complete vaccination and age-appropriate vaccination. For each dose of the five vaccines, the vaccination coverage in the left-behind and non-left-behind children was >90%; however, the age-appropriate vaccination coverage for each vaccine was lower in left-behind than in non-left-behind children. For the five vaccines, the fully vaccinated rate of left-behind children were lower than those of non-left-behind children (89·1%, 92·7%; P = 0·013) and age-appropriate immunisation rate of left-behind children were lower than those of non-left-behind children (65·7%, 79·9%; P < 0·001). After controlling for potential confounders, we found that the parenting pattern, annual household income and attitude of the primary caregiver towards vaccination significantly influenced the vaccination status of children. Moreover, we noted a relatively high prevalence of delayed vaccination among left-behind children. Hence, we believe that the age-appropriate immunisation coverage rate among left-behind children in rural areas should be further improved by delivering and sustaining primary care services.

Pulsed field gel electrophoresis (PFGE) and random amplified polymorphic DNA (RAPD) methods were applied for molecular typing of 130 Mannheimia (Pasteurella) haemolytica serotype A1 isolates obtained from 13 prefectures in Japan. These isolates were divided into 15 ApaI PFGE profiles that formed six distinct clusters (clusters A–F). Fifty-three (40·7%) isolates were classified in cluster B, and 20·0, 13·8, 12·3, 6·9 and 6·1% of isolates were in clusters E, A, F, D and C, respectively. The isolates of cluster B were differentiated into seven subtypes (B1–B7) and subtype B5 contained 63% (34/53) of isolates. RAPD revealed four banding patterns (types I–IV), and among 130 isolates 60·7% (79/130) of isolates were RAPD type I. All of the RAPD type I isolates were grouped into clusters A–C by PFGE. There was no relationship between molecular typing and geographic origin of these isolates. These results indicate that isolates of M. haemolytica A1 strain with various molecular profiles have already spread in Japan and may have caused sporadic infections.

COVID-19 as an emerging disease has spread to 183 countries and territories worldwide as of 20 March 2020. The first COVID-19 case (i.e. the index case) in Iran was observed in the city of Qom on 19 February 2020. One of the cities of Markazi Province is Delijan, which shares a border with Qom. Consequently, COVID-19 has quickly spread in this city because a large population commutes daily between the two cities. This study aimed to report the challenges and considerations of community-based preparedness at the onset of COVID-19 outbreak in a city of Iran in 2020.

The emergence of human and animal rabies in Bali since November 2008 has attracted local, national and international interest. The potential origin and time of introduction of rabies virus to Bali is described. The nucleoprotein (N) gene of rabies virus from dog brain and human clinical specimens was sequenced using an automated DNA sequencer. Phylogenetic inference with Bayesian Markov Chain Monte Carlo (MCMC) analysis using the Bayesian Evolutionary Analysis by Sampling Trees (BEAST) v. 1.7.5 software confirmed that the outbreak of rabies in Bali was caused by an Indonesian lineage virus following a single introduction. The ancestor of Bali viruses was the descendant of a virus from Kalimantan. Contact tracing showed that the event most likely occurred in early 2008. The introduction of rabies into a large unvaccinated dog population in Bali clearly demonstrates the risk of disease transmission for government agencies and should lead to an increased preparedness and efforts for sustained risk reduction to prevent such events from occurring in future.