IN the admirable pioneer studies of Griffith and his colleagues on the epidemiology of streptococcal infections in schools, “no systematic attempt was made to discover the distribution of streptococci amongst the healthy residents. And the observations on carriers were in general confined to those who were suspected to have some catarrhal infection of the upper air passages” (Griffith, 1938). In this paper we report the results of weekly swabbings of the throats of all children in a single dormitory or ward of an orphanage with 350 inmates, during an outbreak of scarlet fever due to Streptococcus pyogenes, serologically type 2 (Griffith). All haemolytic streptococci were typed by the slide agglutination technique, so that fluctuations in the distribution of the epidemic and non-epidemic strains could be followed.

In a Nicaraguan population-based cohort, SARS-CoV-2 seroprevalence reached 28% in the first 6 months of the country's epidemic and reached 35% 6 months later. Immune waning was uncommon. Individuals with a seropositive household member were over three times as likely to be seropositive themselves, suggesting the importance of household transmission.

Nosocomial transmission of COVID-19 among immunocompromised hosts can have a serious impact on COVID-19 severity, underlying disease progression and SARS-CoV-2 transmission to other patients and healthcare workers within hospitals. We experienced a nosocomial outbreak of COVID-19 in the setting of a daycare unit for paediatric and young adult cancer patients. Between 9 and 18 November 2020, 473 individuals (181 patients, 247 caregivers/siblings and 45 staff members) were exposed to the index case, who was a nursing staff. Among them, three patients and four caregivers were infected. Two 5-year-old cancer patients with COVID-19 were not severely ill, but a 25-year-old cancer patient showed prolonged shedding of SARS-CoV-2 RNA for at least 12 weeks, which probably infected his mother at home approximately 7–8 weeks after the initial diagnosis. Except for this case, no secondary transmission was observed from the confirmed cases in either the hospital or the community. To conclude, in the day care setting of immunocompromised children and young adults, the rate of in-hospital transmission of SARS-CoV-2 was 1.6% when applying the stringent policy of infection prevention and control, including universal mask application and rapid and extensive contact investigation. Severely immunocompromised children/young adults with COVID-19 would have to be carefully managed after the mandatory isolation period while keeping the possibility of prolonged shedding of live virus in mind.

The Japanese investigators (Inada and Ido) who discovered the Spirochaeta icterohaemorrhagiae, the cause of infectious jaundice, showed that the serum of patients who had recovered from the disease contained immune substances which were capable of destroying the spirochaetes in the blood and tissues of an experimentally infected guinea-pig. They found that if the serum were injected into the guinea-pig prior to the appearance of icterus the disease was inhibited in all cases. The same result was obtained with the serum of immunised goats.

No published studies have discussed details of the prognosis and survival of patients with severe avian influenza A(H7N9) infection. In this study we analysed 128 laboratory-confirmed cases of severe H7N9 infection in Zhejiang province, the most affected region during the H7N9 epidemic in mainland China. We found that an increase in patient age by 5 years was associated with a 1·41 [95% confidence interval (CI) 1·19–1·67] times odds ratio for fatality. In addition, the time interval between the first clinical visit after symptom onset and hospital admission was inversely associated with survival time since admission. Of the 47 patients who died of the disease, when the time interval between the first clinical visit and hospital admission increased by 1 day, the duration of survival was 0·78 times (95% CI 0·62–0·98) as long. Our results suggest that patients with severe influenza H7N9 infection at older ages were at a higher risk of fatality, and that a delay in hospital admission was associated with more rapid death. More studies are required to corroborate our major findings.

We recruited 1591 patients who presented to our fever clinics from 23 January 2020 to 16 February 2020. The different imaging findings between COVID-19 pneumonia and influenza A viruses, influenza B virus pneumonia were also investigated. Most patients were infected by influenza A and B viruses in the flu-season. A laboratory kit is urgently needed to test different viruses simultaneously. Computed tomography can help early screen suspected patients with COVID-19 and differentiate different virus-related pneumonia.

Antimicrobial resistance (AMR) remains a critical public health problem that pervades hospitals and health systems worldwide. The ongoing AMR crisis is not only concerning for patient care but also healthcare delivery and quality. This article outlines key components of the origins of AMR in the United States and how it presents across the American healthcare system. Numerous factors contributed to the crisis, including agricultural antibiotic use, wasteful prescribing practices in health care, conflicting behaviours among patients and clinicians, patient demand and satisfaction, and payment and reimbursement models that incentivize inappropriate antibiotic use. To combat AMR, clinicians, healthcare professionals, and legislators must continue to promote and implement innovative solutions, including antibiotic stewardship programmes (ASPs), hand hygiene protocols, ample supply of personal protective equipment (PPE), standardized treatment guidelines for antibiotic prescribing, clinician and patient educational programmes, and health policy initiatives. With the rising prevalence of multi-drug resistant bacterial infections, AMR must become a greater priority to policymakers and healthcare stakeholders.

In general, tuberculosis (TB) is more common in men than women. However, for reasons currently not understood, women are 1·5–2 times more likely to report TB compared to men in Pashtun region (Afghanistan, adjacent provinces Pakistan and Iran). We explored whether or not gender disparity in TB notifications in the Pashtun region of Pakistan can be explained by Pashtun ethnicity. Using an ecological linear regression design, we estimated the effect of Pashtun ethnicity on female-to-male ratio (FMR) in TB notifications after adjusting for other determinants of women's health, in Pakistan. Districts with a high proportion of women of Pashtun ethnicity had a 44% (95% confidence interval 27–61) increase in FMR of notified TB cases compared to those with low proportions, after controlling for confounders. Genetic predisposition and distinct socio-cultural determinants could be possible causative factors. However, these hypotheses need further evaluation through rigorous longitudinal studies.

Of the ordinary infections sustained by children during the first 5 years of life 56% were common colds, 16·5% other infections of the respiratory tract, 16% gastro-intestinal catarrhs, 6% infections of the skin and mucous membranes and 5·5% infectious diseases in a strict sense.

Common colds were most frequent in the second year, namely, an average of 4·3 common colds per child per year. As the child grew older the number of colds decreased. Adults showed an average of two common colds per year.

Of the ‘other infections of the respiratory tract’, 42% were undifferentiated respiratory tract infections, 23% febrile affections without definite localization, 17% otitis, 11% pharyngitis and 7% influenza. The frequency of these ‘other infections of the respiratory tract’ rose from 0·3 in the first to 1·8 in the fifth year of life. After the fifth year the frequency diminished to one infection every 2 years in adults.

The frequency of gastro-intestinal catarrhs in the first year of life, namely, 0·6 per child per year, was doubled in the second year, and then remained constant for a few years. After the fifth year a decrease was observed in this figure too.

Fifty-four per cent of the 116 index children sustained at least one suppurative skin affection during the first 5 years of their lives, 28% had more than one. Most pyodermias occurred in the first few months of life, a second maximum being observed in schoolchildren, 21% of the index children had stomatitis in the first 5 years, 42% conjunctivitis.

By their fifth birthday, 49% of the 116 children had had measles, 46% chicken pox, 26% rubella, 24% exanthema subitum, 17% mumps, 3% whooping cough, while 2 of the 116 children had had scarlatina, 1 child hepatitis, 1 poliomyelitis and 1 bacterial meningitis.

No difference in morbidity was found between boys and girls in respect of respiratory tract infections. The boys had skin infections distinctly more often than the girls, and infections of the mucous membranes and of the gastro-intestinal tract were also slightly more frequent in boys. Apart from infections of the skin and mucous membranes, which were more often observed in mainly bottle-fed children, ordinary infections were equally frequent in this latter category and in children mainly breast-fed.

The index child with older brothers and sisters contracted the ordinary infectious diseases younger than the index child who was the eldest child in the family. On account of the presence of older children in the family, a child was ill not more often, but earlier. The infections of the respiratory tract showed a distinct preference for the winter months, and the frequency of gastrointestinal infections was also slightly higher in that season.

Febrile affections without definite localization, as well as infections of the oral mucosa, occurred especially during the summer months.

Going to the kindergarten did not lead to an increase of the frequency of common colds and gastro-intestinal catarrhs, but the number of infectious diseases in a strict sense became higher. The ‘other infections of the respiratory tract’ became more frequent under the influence of school only in those index children who were the eldest in the family. The index children from families with a low level of hygiene experienced more infections of the skin and mucous membranes than those from families with a high hygienic level.

No difference between these two groups was demonstrable in regard to the other ordinary infections.

There was a parallelism between the frequency of common colds and of gasto-intestinal catarrhs but not with the other minor infections.

Data on coronavirus disease 2019 (COVID-19) prevalence in the Democratic Republic of Congo are scarce. We conducted a cross-sectional study to determine the seroprevalence of antibodies against anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the slum of Kadutu, city of Bukavu, between June and September 2021. The survey participants were all unvaccinated against SARS-CoV-2. The crude seroprevalence rate was adjusted to the known characteristics of the assay. Participants aged 15–49 years old made up 80% of the population enrolled in the study (n = 507; 319 women and 188 men). The overall crude and adjusted seroprevalence rates of antibodies for COVID-19 were 59.7% (95% CI 55.4–63.9%) and 84.0% (95% CI 76.2–92.4%), respectively. This seroprevalence rate indicates widespread dissemination of SARS-CoV-2 in these communities. COVID-19 symptoms were either absent or mild in more than half of the participants with antibodies for COVID-19 and none of the participants with antibodies for COVID-19 required hospitalisation. These results suggest that SARS-CoV-2 spread did not appear to be associated with severe symptoms in the population of these settlements and that many cases went unreported in these densely populated locations. The relevance of vaccination in these communities should be thoroughly investigated.

We present and analyse data collected during a severe epidemic of foot-and-mouth disease (FMD) that occurred between July and September 2000 in a region of northeastern Greece with strategic importance since it represents the southeastern border of Europe and Asia. We implement generic Bayesian methodology, which offers flexibility in the ability to fit several realistically complex models that simultaneously capture the presence of ‘excess’ zeros, the spatio-temporal dependence of the cases, assesses the impact of environmental noise and controls for multicollinearity issues. Our findings suggest that the epidemic was mostly driven by the size and the animal type of each farm as well as the distance between farms while environmental and other endemic factors were not important during this outbreak. Analyses of this kind may prove useful to informing decisions related to optimal control measures for potential future FMD outbreaks as well as other acute epidemics such as FMD.

A 9-month trial of a simple typing scheme for ‘thermophilic’ enteric campylobacter isolates at a large Public Health Laboratory is described. Resistotyping was performed with six agents in a method modified by Bolton and colleagues from an earlier scheme, and biotyping was performed by a modified Lior scheme involving three tests. Reproducibility was excellent in both schemes, with test variation < 2%. Five household clusters and one larger presumptive milk-borne outbreak were identified in this scheme, and confirmed in pyrolysis mass spectrometry. The 328 isolates from new patients, excluding duplication from these clusters, were divided into 35 resistotypes with the largest group comprising 22% of isolates. In combined bio- and resistotyping, 86 types were found, with the largest group comprising 9·5% of isolates. The results are contrasted with salmonella sero- and phage-typing, where, on the same basis, the 176 isolates in the same period were divided into 40 groups, with the largest comprising 45% of isolates. Resistotyping, with or without additional biotyping, proved to be a convenient, simple, rapid, highly discriminatory, reproducible and inexpensive method well suited to use in local laboratories. It is a strong candidate for first-line national and local surveillance of campylobacter infections, fulfilling a need for monitoring of this important cause of enteric disease.

In 2015, Botswana introduced the quadrivalent human papillomavirus (HPV) vaccine as a two-dose schedule in girls aged 9–13 years. We sought to establish a baseline HPV prevalence in unvaccinated young adults in Botswana. HIV-uninfected men and women aged 18–22 years were recruited from the University of Botswana in Gaborone during October 2019–February 2021. Demographic and behavioural characteristics were self-reported during structured interviews. Self-collected vaginal and penile swabs were tested for 28 HPV types using Seegene Anyplex II HPV28. We compared any HPV type, quadrivalent vaccine (HPV 6, 11, 16, 18)-type and non-quadrivalent vaccine-type prevalence in men and women and evaluated the risk factors for prevalence of any HPV type. A total of 493 men and 500 women were included in the analysis. Compared to men, women had higher prevalence of any HPV type (63.0% versus 31.4%, P < 0.001), vaccine-type HPV (21% versus 9.7%, P < 0.001) and non-vaccine-type HPV (60.4% versus 28.4%, P < 0.001). Higher prevalence of any HPV type in men and women was associated with having ≥2 sex partners in the past 12 months; always using condoms in the past 3 months was associated with a lower HPV prevalence. These data provide baseline information for future evaluation of the population impact of the HPV vaccination programme, including potential herd effects in men.

The effect of varying conditions of inoculation and incubation on the growth of type C influenza virus in the allantoic cavity of the developing chick embryo were investigated. It was found that the highest yields of both virus haemagglutinin and infectious virus were obtained following the inoculation of chick embryos at 8 days with subsequent incubation at 32° C. Using the chick embryo allantoic cavity for titration of infectious virus, growth curves of allantoically propagated virus under varying inoculation and incubation conditions were determined.

For jurisdictions implementing measles elimination strategies, a minimum surveillance benchmark of 1/100 000 population per year measles-like illness (MLI) cases initially notified, but then rejected based on laboratory testing was proposed. We used this standard to assess the quality of the Victorian enhanced measles surveillance between 1998 and 2003. Victorian enhanced measles surveillance includes interviews with notified cases and confirmatory laboratory testing for notifications. We found 72% (918/1281) of measles notifications were discarded after testing. The median annual rate of discard was 2·9/100 000. The annual discard rate was inversely associated with the age of the notifications, and measles negative with no other diagnosis made was the most common laboratory outcome. The annual rates of discarded notifications in Victoria were consistently above the minimum recommended standard. The rate of discarded MLIs as a surveillance threshold should be useful in measles endemic regions, but may require modification where disease elimination has occurred.

The foregoing experiments conclusively show that a broth medium is quite unsuitable as a test culture medium to determine the vitality of anthrax spores in disinfection experiments, whereas agar is a suitable and delicate medium for the purpose, even when considerable traces of the disinfectant are carried over with the inoculation.

The reason for this inefficiency of broth is not obvious. We thought that it might be due to the absence of bacillar forms in the sporing material, but the emulsion of spores heated to 80°C. for 15 minutes and then inoculated directly into broth gave good growths.

Absence of oxygen might be another factor, but the results were the same when splinters of sterilised wood infected with anthrax spores were treated. The wood floated on the surface of the broth and so was subjected to a free supply of oxygen, yet no growths were obtained in broth when the splinters were soaked in the disinfectants, while good growths were obtained on agar. The control splinters gave good growths in broth. It may be that the anthrax spores are partially de-vitalised by the action of the disinfectant and that in this condition broth is a comparatively unsuitable culture medium for them. Prolonging the time of incubation of the broth cultures up to 10 or 14 days makes no difference. If a culture in broth shows no growth in 48 hours, a growth hardly ever appears with more prolonged incubation. Nor is this superiority of agar over broth as a culture medium confined to the emulsified disinfectants employed in these experiments, for similar results have been obtained with phenol, and with formaldehyde, the latter both in the fluid (formalin), and in the gaseous, conditions.

Serum samples from 14 patients whose burns had become infected with streptococci of groups A (11 patients), C (one patient) or G (two patients), and from 19 burned patients without bacteriological evidence of streptococcal infection were examined for anti-streptococcal antibodies. Tests were made for anti-streptolysin O (ASO), anti-hyaluronidase (AH), anti-deoxyribonuclease B (anti-DNAase B) and antibody against M-associated protein (MAP). Sera from the patients with streptococcal infections were also examined, when this was practicable, for ‘bactericidal’ (anti-M) antibody and for antibody against the opacity factor (OF) of the infecting serotype.

In patients infected with group A streptococci, the ASO response was generally poor, except in patients infected with strains of type T12/M12, and the AH response was rather similar, but most of the patients gave a rapid and vigorous anti-DNAase B response, except when the burn was small or colonization occurred very late. Antibody to the M and MAP antigens, and to OF (when the infecting strain formed this), was weak and transient, or absent, except in three of four patients infected with streptococci of type T12/M12.

Two strains of B. dysenteriae isolated from cases of asylum dysentery, were found to be readily agglutinable with stock Flexner-Y serum but serum prepared from the one had only a feeble action on the other. Absorption experiments revealed a like specificity. They differed in certain particulars in their action on certain carbohydrate media, and the attempt was made to obtain, by various procedures, variants from each strain giving fermentation reactions as alike as possible.

In the course of this work, an interesting and probably hitherto undescribed type of variation was met with, viz. the capacity exhibited by one strain which fairly promptly fermented the substance employed (isodulcite), of throwing off variants having no action on the substance. These variants appeared as white papillae on the surface of the original red ancestor and the description and analysis of this “reversion” process form the main interest of this paper. Though a fairly close approximation in fermentation characters was realised by selection of variants from each of the original strains, little or no approximation was apparent in respect of the serological affinities of these final variants.

Patients with methicillin-resistant Staphylococcus aureus (MRSA) clones, which were traditionally seen in the community setting (USA400/CMRSA7 and USA300/CMRSA10), are often identified as hospital-acquired (HA) infections using Infection Prevention and Control (IPC) surveillance definitions. This study examined the demographics and healthcare risk factors of patients with HA-MRSA to help understand if community MRSA clones are from a source internal or external to the hospital setting. Despite USA300/CMRSA10 being the predominant clone in Alberta, hospital clones (USA100/CMRSA2) still dominated in the acute care setting. In the Alberta hospitalized population, patients with USA400/CMRSA7 and USA300/CMRSA10 clones were significantly younger, had fewer comorbidities, and a greater proportion had none or ambulatory care-only healthcare exposure. These findings suggest that there are two distinct populations of HA-MRSA patients, and the patients with USA400/CMRSA7 and USA300/CMRSA10 clones identified in hospital more greatly resemble patients affected by those clones in the community. It is possible that epidemiological assessment overidentifies HA acquisition of MRSA in patients unscreened for MRSA on admission to acute care.

Two hundred and ninety-three milk ring test-positive individual milk samples were examined by whey complement fixation and agglutination tests and the results were compared with the isolation of B. abortus by cultures made from the milk.

There was a closer correlation between whey CF tests and isolation of the organism than between whey AG tests and isolation. Brucella organisms were not isolated from 116 MRT-positive milk samples when the whey CF titre was < 1/10; whereas 9/104 (9%) isolations were made from milk when the whey AG titre was < 1/20.

Because of its closer correlation with culture results it is suggested that the whey CF test would be valuable in an eradication programme for the detection of infected udders.

The limitations of the milk ring test for the examination of individual milk samples are emphasized and it should be used only as a preliminary screening test. In the individual milk samples examined, 32% of the MRT-positives showed no evidence of infection by either the whey AG, whey CF, or culture tests.