In order to assess the HIV prevalence in healthcare workers (HCWs) in Burkina Faso, we conducted a national survey in 97 health facilities from urban and rural areas. Of 1570 HCWs who agreed to participate, 1013 (64·5%) provided a urine sample for HIV testing. The crude prevalence of HIV in HCWs was 3·5% (95% CI 2·3–4·6). HIV prevalence was 0·7% in students and trainees, 3·8% in nurses and midwives, 4·5% in administrative workers, and 4·6% in laboratory workers. After age and area standardization, men from the Demographic Health Survey (DHS) had a similar HIV prevalence (2·3%, 95% CI 1·4–2·9) as male HCWs (2·5%, 95% CI 1·1–4·0), while female HCWs were more infected (4·5%, 95% CI 2·5–6·0) than women from the DHS (2·1%, 95% CI 1·3–2·4). A voluntary counselling and testing (VCT) programme should be specifically implemented and adapted for female HCWs.

This study aimed to assess the ability of a real-time reverse transcription polymerase chain reaction (RT-PCR) with multiple targets to detect SARS-CoV-2 and its variants in a single test. Nasopharyngeal specimens were collected from patients in Granada, Spain, between January 2021 and December 2022. Five allele-specific RT-PCR kits were used sequentially, with each kit designed to detect a predominant variant at the time. When the Alpha variant was dominant, the kit included the HV69/70 deletion, E and N genes. When Delta replaced Alpha, the kit incorporated the L452R mutation in addition to E and N genes. When Omicron became dominant, L452R was replaced with the N679K mutation. Before incorporating each variant kit, a comparative analysis was carried out with SARS-CoV-2 whole genome sequencing (WGS). The results demonstrated that RT-PCR with multiple targets can provide rapid and effective detection of SARS-CoV-2 and its variants in a single test. A very high degree of agreement (96.2%) was obtained between the comparison of RT-PCR and WGS. Allele-specific RT-PCR assays make it easier to implement epidemiological surveillance systems for effective public health decision making.

Tuberculosis (TB) contact tracing and TB preventive treatment are key tools in preventing the transmission of TB with the aim of eliminating the disease. Our study seeks to demonstrate how the infection spread from an individual patient to the entire community and how proactive contact tracing facilitated prompt diagnosis and treatment. Our work was conducted as a retrospective analysis of the spread of TB infection within the Roma community in the Czech Republic, following the case of an index patient who succumbed to pulmonary TB. Several levels of care and preventive and treatment measures are outlined. Confirming the identity of the Mycobacterium tuberculosis strain was achieved using molecular methods. Among the 39 individuals examined, TB disease was detected in eight patients and TB infection was detected in six patients. The investigation of contacts within this group yielded positive results in 36% of cases, necessitating treatment. The study’s findings provide evidence that actively tracing individuals at risk can lead to early detection of cases, prompt treatment, and prevention of further disease transmission. The study also indicates that the highest risk of infection occurs within the sick person’s household and that young children under the age of 5 are most susceptible to falling ill.

Coronavirus disease 2019 (COVID-19) is a newly emerged disease with various clinical manifestations and imaging features. The diagnosis of COVID-19 depends on a positive nucleic acid amplification test by real-time reverse transcription-polymerase chain reaction (RT-PCR) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, the clinical manifestations and imaging features of COVID-19 are non-specific, and nucleic acid test for SARS-CoV-2 can have false-negative results. It is presently believed that detection of specific antibodies to SARS-CoV-2 is an effective screening and diagnostic indicator for SARS-CoV-2 infection. Thus, a combination of nucleic acid and specific antibody tests for SARS-CoV-2 will be more effective to diagnose COVID-19, especially to exclude suspected cases.

The most important of the proteid constituents of milk is casein. From 70 to 90% of the total proteids of milk consists of this substance1. In milk, casein exists as a soluble calcium compound, which is not precipitated by boiling, but from which casein is deposited by the addition of acid or by the action of rennet2. This phenomenon is known as the curdling of milk and is a preliminary to its gastric digestion, both the acid in the stomach and the rennet being capable of producing it. By artificially influencing the nature of its curd we can influence the digestibility of the milk. In human gastric digestion and in the experiments detailed below both acid and rennet are present. The curdling of milk is a necessary preliminary to its digestion in an acid medium, and by influencing this process we can also influence the digestibility of the milk.

In earlier papers (Gordon, 1930) it was shown that congo red has an inactivating effect on serum complement, both haemolytic and bactericidal, and that this effect can be reversed by treating the serum and congo red mixture with charcoal, the charcoal removing the congo red and leaving the complement active again. A similar reversal of inactivation is obtained by using instead of the charcoal, heated serum (55° C. for 30 min.) or protein solutions. Later (Gordon, 1931), it was shown that congo red had an inactivating effect on the haemolysins of Streptococcus haemolyticus and B. welchii. The reversibility of this effect was not so easy to demonstrate as with complement. Charcoal had a destructive effect on the haemolysins and so could not be used. It was found, however, that when the concentration of congo red was just sufficient to neutralize the streptococcal haemolysin, the addition of cuprammonium artificial silk adsorbed the congo red and liberated the haemolysin. In the case of B. welchii this method of reversal was not suitable, as the artificial silk had a destructive effect on the haemolysin. Instead, reversibility was demonstrated by adding ox serum to the mixture of congo red and haemolysin. This brought about a redistribution of the congo red between the ox serum and the haemolysin and if the amount of congo red used had been only just sufficient to neutralize the haemolysin of B. welchii, then the haemolytic activity could again be demonstrated. Gordon and Robson (1933) showed that congo red interfered with the anaphylactic reaction tested both in vivo and in vitro, the guinea-pig uterus being used in the in vitro experiments, in which the inhibitory action of the dye was shown to be reversible. It was suggested that the congo red interfered with the entrance of antigen into the cell.

The antigenic response of guinea-pigs to live poliomyelitis viruses of all three types has been studied and the loss of antigenicity involved in inactivation by formaldehyde and by ultra-violet light have been determined.

We wish to acknowledge the debt we owe to the late Prof. M. van den Ende for his great help and interest in this work, and we are grateful for the assistance received from Dr H. Malherbe and Ruth Harwin in carrying out many of the titrations, and from Dr T. Mead for synthesizing some 1:4-diphenylbutadiene for use as a filter for ultra-violet light.

We also have to thank G. S. Turner, T. Norcott, Doreen Deeks and Margaret Pakes for their technical help.

Bile is often referred to as if its chemical composition was constant and that by treating samples of bile with extractives similar results would be obtained, whereas samples of human bile differ to such an extent that the term bile in itself signifies little. Two samples of human bile may differ to such an extent that while one sample has the qualities of true bile as regards its bile salt content the other may be entirely devoid of lytic action on red blood cells. Numerous experiments made with human bile obtained during life and from the post mortem room have shown this to be correct. The actual bile salt content of bile can be judged by boiling the bile to remove much of the protein, and also to destroy bacterial activity and then contrast the haemolytic activity of the treated sample with a 1 per cent, solution of bile salt in normal saline.

Antistreptolysin O titres in the sera of children in a rural population of Ceylon were determined, to establish the upper limit of the normal ASO titres in nonrheumatic children, and to compare these ASO titres with results of surveys done in other countries.

Swabs were taken from throats and ulcers of the children examined and cultured specifically for group A haemolytic streptoccoci. Of a total of 257 children, 29·5 % had ASO titres of over 166 Todd units. The greatest number of children showed ASO values between 100 and 166 units. The percentage of children showing values over 166 units increased with age until a maximum of 54 % was reached between 9 and 10 years. Group A haemolytic streptococci were isolated from five throat swabs, but there were no isolations from ulcers. The values obtained from this survey have been compared with those from a few other developing countries.

Puumala virus (PUUV) causes many human infections in large parts of Europe and can lead to mild to moderate disease. The bank vole (Myodes glareolus) is the only reservoir of PUUV in Central Europe. A commercial PUUV rapid field test for rodents was validated for bank-vole blood samples collected in two PUUV-endemic regions in Germany (North Rhine-Westphalia and Baden-Württemberg). A comparison of the results of the rapid field test and standard ELISAs indicated a test efficacy of 93–95%, largely independent of the origin of the antigens used in the ELISA. In ELISAs, reactivity for the German PUUV strain was higher compared to the Swedish strain but not compared to the Finnish strain, which was used for the rapid field test. In conclusion, the use of the rapid field test can facilitate short-term estimation of PUUV seroprevalence in bank-vole populations in Germany and can aid in assessing human PUUV infection risk.

The subject I propose to discuss in the present and subsequent papers is of importance in two ways. Popular traditions have frequently implied that the age at which a parent begets offspring is not without influence upon the characters of the latter, the prevailing belief being humorously portrayed in the late W. S. Gilbert's ballad “The Precocious Baby.” Again, recent thinkers, notably Professor Karl Pearson, have asserted that elder born children differ markedly in liability to certain diseases from their younger brethren. Were this view to be accepted it would be relevant to enquire whether the difference might not be a function of the age of the parents at the time of birth of the offspring or at least whether such difference might not play a part in bringing about this result. Assuming that any such effect could be demonstrated, it is plain that a valuable stimulus would be given to the study of physiological changes in the reproductive system within the fertile period. These are the immediately interesting aspects of the subject, but with them I am less directly concerned than withcertain secondary consequences.

In works on Public Health and Water Analysis, it is a common observation that the amount of chlorine in inland surface waters near the seaboard is considerably higher than what obtains in samples from more inland parts.

Levels of maternally transferred antibodies against the surface antigen of the A/Texas/1/77 strain of influenza virus showed the expected decline during infancy when measured by complement fixation (CF). However, this decline was not observed when these antibodies were measured by haemagglutination-inhibition (HI). It has been postulated that this discrepancy is due to the acquisition, in the early days of life, of non-specific serum factors which increase the HI activity of sera. The levels of these factors were determined indirectly by calculating HI: CF ratios and it was shown that the factors are rapidly acquired by children between the fifth and twentieth week of life.

A series of spontaneous epidemics of a paratyphoid infection among guinea-pigs is described. It is shown that an epidemic may result from the introduction of a fresh susceptible population into an infected area and vice versa. Such epidemics developed only when the new population was exposed during certain months. The bringing in of a fresh population at the end of November was not followed at the time by an epidemic outbreak; the epidemic did not occur until the following July.

The observed seasonal occurrence was not due to a change in virulence. The strains isolated at the end of the 1926 epidemic did not differ in virulence from those cultivated at the height of the 1927 epidemic.

The guinea-pig may remain a carrier for a long time whilst eliminating bacteria in the faecal discharges only intermittently and in small numbers. In general, even in the case of infected animals, the discharge of pathogenic bacteria is relatively small, except a few days before death.

Attention is called to the parallelism between the seasonal prevalence of human typhoid epidemics in this country and the epidemics of paratyphoid observed in our guinea-pig stock.

It is pointed out that a sound theory of the epidemiology of certain diseases must take into account the seasonal variation in host susceptibility.

The bronchial constriction occurring in death from acute anaphylaxis has been demonstrated radiologically by the use of lipiodol.

1. An M-producing strain of Streptococcus pyogenes type-12 was shown to be carried on the surface of apparently healthy tonsils for at least 3 years.

2. Loss of M substance in a strain of type-3 in a tonsillar carrier was shown to be by gradual replacement of matt forms by glossy variants. This pair of naturally occurring variants showed very different growth rates as mixtures in liquid media.

3. Under suitable conditions, glossy variants regularly appeared and replaced the M-producing strain from which they were derived in these and all other strains of type-3 and type-12 tested from a wide variety of sources.

4. It is suggested that the selection of variants by the differential nutrient value of the micro-environment is the deciding factor in carrier strains showing loss of M substance.

In our previous paper in this Journal it was shown that the temperature of 46°C.1 recommended by Eijkman and Bulir in their fermentation test is excessively high, as in water cultures it has a destructive effect on Bact. coli. This was in accordance with the previous work of Brown and Skinner (1930) and Skinner and Brown (1934). At the same time we were able to show that in cultures in Bulir's medium at 43° not only is the destructive effect of the excessively high temperature on Bact. coli removed but the reproduction and fermentation activity of this organism is distinctly stimulated. At 43° Eijkman's and Bulir's tests effectively distinguish between true Bact. coli communis and other strains.

The preparation of a medium that would allow the bacillus of diphtheria to grow and exclude all other organisms would be an ideal medium for those whose work is concerned with that organism, but, as such a medium has not yet been devised, we must be content with the modifications of the ordinary media which we possess. Various varieties of media have been prepared for the purpose of favouring the growth of B. diphtheriae, but very little seems to have been done with regard to selective media.