Negative interactions with humans resulting from livestock predation is a major factor influencing the decline of African lion Panthera leo populations across Africa. Here we investigate lion depredation within two Maasai communities in southern Kenya where people and lions coexist in the absence of any formal protected areas. We explore the factors that increase the frequency and severity of lion attacks on pastoralists and their livestock and assess the effectiveness of livestock guarding to reduce damage. Finally, we examine in which circumstances lion depredation triggers retaliation by people. Over a period of 26 months, lions attacked livestock 29 times, resulting in 41 livestock deaths and 19 injuries. There were also two attacks on people. Lions preferred cattle over the more numerous sheep and goats. Attacks on livestock occurred mostly during the dry season and were not affected by changes in prey density or variation in pastoral settlement that brought livestock into closer proximity with lions. Livestock were guarded during 48.2% of lion attacks. Active guarding at pasture disrupted the majority of lion attacks, resulting in lower mortality rates. Passive guarding in corrals at night also disrupted attacks but did not lead to lower livestock mortality.

Surveillance for acute flaccid paralysis (AFP) cases are essential for polio eradication. However, as most poliovirus infections are asymptomatic and some regions of the world are inaccessible, additional surveillance tools require development. Within England and Wales, we demonstrate how inclusion of environmental sampling (ENV) improves the sensitivity of detecting both wild and vaccine-derived polioviruses (VDPVs) when compared to current surveillance. Statistical modelling was used to estimate the spatial risk of wild and VDPV importation and circulation in England and Wales. We estimate the sensitivity of each surveillance mode to detect poliovirus and the probability of being free from poliovirus, defined as being below a pre-specified prevalence of infection. Poliovirus risk was higher within local authorities in Manchester, Birmingham, Bradford and London. The sensitivity of detecting wild poliovirus within a given month using AFP and enterovirus surveillance was estimated to be 0.096 (95% CI 0.055–0.134). Inclusion of ENV in the three highest risk local authorities and a site in London increased surveillance sensitivity to 0.192 (95% CI 0.191–0.193). The sensitivity of ENV strategies can be compared using the framework by varying sites and the frequency of sampling. The probability of being free from poliovirus slowly increased from the date of the last case in 1993. ENV within areas thought to have the highest risk improves detection of poliovirus, and has the potential to improve confidence in the polio-free status of England and Wales and detect VDPVs.

Non-tuberculous mycobacterium encephalitis is rare. Since 2013, a global outbreak of Mycobacterium chimaera infection has been attributed to point-source contamination of heater cooler units used in cardiac surgery. Disseminated M. chimaera infection has presented many unique challenges, including non-specific clinical presentations with delays in diagnosis, and a high mortality rate among predominantly immunocompetent adults. Here, we describe three patients with fatal disseminated Mycobacterium chimaera infection showing initially non-specific, progressively worsening neurocognitive decline, including confusion, delirium, depression and apathy. Autopsy revealed widespread granulomatous encephalitis of the cerebrum, brain stem and spinal cord, along with granulomatous chorioretinitis. Cerebral involvement and differentiation between mycobacterial granulomas and microangiopathic changes can be assessed best on MRI with contrast enhancement. The prognosis of M. chimaera encephalitis appears to be very poor, but might be improved by increased awareness of this new syndrome and timely antimicrobial treatment.

Entomophthora phytonomi Arthur, a pathogen recognized for many years under the name Entomophthora sphaerosperma Fres. as an important natural control agent in populations of the clover leaf weevil, Hypera punctata (Gyll.), has now been identified from the alfalfa weevil, Hypera postica (Gyll.). Both conidial and resting spore stages are described.

Early in the summer of 1973, the fungus was responsible for an epizootic in populations of the alfalfa weevil throughout much of east-central Ontario. In three study plots, mortality levels in larvae and cocoons ranged from 65–90% and 42–53%, respectively. This suggests that the fungus is capable of playing a significant role in the dynamics of weevil populations.

Large-scale population-based studies have reported a significant increase in invasive pneumococcal disease (IPD) in those with underlying haematological or solid-organ malignancy, but limited condition-specific data are available on rates of IPD in the adult population. A retrospective chart review of all patients with IPD (identified prospectively) in the province of Alberta, Canada (population ~3·3 million) was conducted from 2000 to 2004 to study the epidemiology of IPD. Rates of IPD in patients with various haematological and solid-organ malignancies were determined by obtaining the number of these patients at risk from the provincial cancer registry. Compared to the attack rate of IPD in the adult population aged ⩾18 years (11·0 cases/100 000 per year, 95% CI 10·44–11·65), there were significantly increased rates of IPD in those with lung cancer (143·6 cases/100 000 per year, OR 13·4, 95% CI 9·3–19·4, P<0·001) and multiple myeloma (673·9 cases/100 000 per year, OR 62·8, 95% CI 39·6–99·8, P<0·001). More modestly increased rates of IPD were found in those with chronic lymphocytic leukaemia, acute myeloid leukaemia, acute lymphoblastic leukaemia, and Hodgkin's and non-Hodgkin's lymphoma. There was an increased prevalence of serotype 6A in those with these underlying malignancies, but no other serotypes predominated. Fifty-three percent (48/83) of cases were caused by serotypes in the investigational 13-valent pneumococcal conjugate vaccine (PCV13), and 57/83 (69%) of the cases were caused by serotypes in the 23-valent pneumococcal polysaccharide vaccine (PPV23). The incidence of IPD in adults with certain haematological and solid-organ malignancies is significantly greater than the overall adult population. Such patients should be routinely given pneumococcal polysaccharide vaccine; this population could also be targeted for an expanded valency conjugate vaccine.

The antibody responses of 194 volunteers were studied for up to 3 years after primary immunization with one, two or three doses of human diploid cell rabies vaccine, administered either in 0·1 ml volumes intradermally (i.d.) or as 1·0 ml intramuscularly (i.m.). Sero-conversion occurred in 95% of subjects after the first injection and in 100% after the second. The highest titres and most durable antibody responses were induced by three injections of vaccine.

Booster doses were administered either by the subcutaneous (s.c.) or i.d. route, after 6, 12 or 24 months to randomly grouped volunteers; these induced responses ≥ 5·0 i.u. per ml in 95% of subjects. The responses were rapid and were neither influenced by the primary regimen nor by the timing and route of the booster dose.

Antibody titres after i.d. immunization were only two-fold lower than those induced by the larger volume of vaccine. The findings suggest that the i.d. route is both effective and economic.

Forty-nine subjects were vaccinated with either live attenuated, detergent split, or oil adjuvant A2/Hong Kong influenza vaccines, or a saline influenza B vaccine as control. Respiratory symptoms occurred more frequently in subjects who received the live vaccine but in total there was little difference between the symptoms in the four groups. Antibody titres hi nasal washings and serum were measured by haemagglutination inhibition, neuraminidase inhibition and virus neutralization tests. The oil adjuvant vaccine stimulated larger antibody responses than the other procedures. Six weeks after vaccination the volunteers were challenged with partially attenuated live A2/Hong Kong influenza virus administered intranasally. The live attenuated and oil adjuvant vaccines provided the best protection against challenge.

Previous studies of boys at Christ's Hospital school have indicated that annual immunization with influenza virus vaccines did not significantly reduce the total incidence of influenza infection compared to unimmunized subjects. In view of the implications of this result, a similar study was conducted in ferrets to clarify these findings. Groups of ferrets were immunized or infected with a series of influenza A (H3N2) viruses over an 18-month period, and the immunity to subsequent live virus challenge was measured after each virus or vaccine exposure. The results indicated that live virus infection gave a more solid immunity than immunization with inactivated vaccine; and the serum haemagglutination-inhibiting antibody response was greater following immunization than following infection. In addition, differences in immunity could not be explained by measurements of cross-reacting and specific antibody, since the incidence of these antibodies was similar in both infected and immunized animals. The results do not suggest an explanation for the different levels of immunity induced following infection or immunization or the results obtained from the Christ's Hospital study. However, the relative contribution of various immune responses to virus or virus antigen is discussed, and it is suggested that the difference in immunity may lie in the ability of live virus infection to stimulate local antibody.

Studies of experimentally induced respiratory infections and illnesses showed that influenza impaired performance on a visual search task but had no effect on a simple motor task, whereas colds impaired the motor task but not the search task. The effect of influenza on the search task was observed in both volunteers with significant clinical symptoms and volunteers who were shown, by virological techniques, to be infected but who had no significant clinical illness. Performance was also impaired during the incubation period of this illness, which confirms that subclinical influenza virus infections can have behavioural effects. In contrast to influenza, the effects of colds were restricted to volunteers who had significant clinical symptoms, and the impairments in performance were observed only when the symptoms were apparent.

In experiments designed to investigate transmission, cerebrospinal fluid (CSF) from patients with schizophrenia and neurological disease (Huntington's chorea and multiple sclerosis) which had been found to induce cytopathic effects in human embryonic fibroblast cell culture was injected intracerebrally into mice, hamsters and marmosets (small New World primates). No evidence was obtained of transmission to mice or hamsters. A total of 15 marmosets (Callithrix jacchus) was injected intracerebrally with CSF [8 with samples from 4 patients with schizophrenia. 3 with samples from patients with neurological disease (2 with Huntington's chorea and 1 with multiple sclerosis) and 4 with samples from 3 patients without neurological or psychiatric disease] and was observed over a period of 2½ years.

Analysis of variance on data obtained from behavioural observations averaged over 6-month periods revealed that animals injected with CSF from patients with schizophrenia and neurological disease became progressively more inactive when compared with animals injected with CSF from control patients. The change detected by behavioural observation was confirmed as a difference 2 and 2½ years after injection by automated activity monitoring.

There was an incidence of reproductive anomalies (including two occipital encephalocoeles) in the females in the experimental group, but the numbers are too small to draw firm conclusions from this observation.

Many reported differences in biological samples from schizophrenic patients and normal controls have subsequently been found to be due to factors unrelated to the disease state. This may prove to be the case with the changes observed in this experiment. Nevertheless, the fact that marmosets injected with CSF from patients suffering from neuropsychiatric disease, including schizophrenia, subsequently differed in their behaviour from those injected with control CSF warrants further investigation.

In experiments designed to investigate transmission, cerebrospinal fluid (CSF) from patients with schizophrenia or neurological disease (Huntington's disease) which had been found to induce a cytopathic effect (CPE) in human embryonic fibroblast cell culture was injected intracerebrally into common marmosets. Behavioural observations were made on the animals during a period of 2½ years prior to injection and for 2½ years after injection. In an earlier study (Baker et al. 1983 b) we found that animals injected with CPE + ve CSF became progressively more inactive when compared with those injected with non-cytopathic (CPE – ve) CSF from control patients. In the present study we were unable to replicate this finding. No difference in behaviour emerged between animals injected with control CSF and animals injected with CSF from schizophrenics or patients with neurological disease, nor between animals injected with CPE + ve CSF and animals injected with CPE – ve CSF. The numbers of offspring produced and surviving did not differ between the groups. We conclude that the original findings were due to factors unconnected with the nature of the injected material.

Results from two studies involving challenge with respiratory syncytial viruses showed that volunteers who developed colds were more sensitive to a visually distracting pattern presented prior to virus challenge than were volunteers who did not get a cold. Volunteers with sub-clinical infections reported more illusions after virus challenge than they had done before, whereas uninfected volunteers and those with colds tended to report fewer illusions on the second test. These effects did not occur when volunteers were challenged with either a coronavirus or rhinovirus. Overall, the results confirm that behavioural measures may be related to susceptibility to subsequent illness, and that viral infections may influence visual perception. They also show that the effects vary according to the nature of the infecting agent, which agrees with results from studies looking at other aspects of behaviour.

The specific humoral immune response of 17 volunteers to infection with human rhinovirus type 2 (HRV-2) has been measured both by neutralization and by ELISA. Six volunteers who had HRV-2-specific antibodies in either serum or nasal secretions before HRV-2 inoculation were resistant to infection and illness. Of the remaining 11 volunteers who had little pre-existing HRV-2-specific antibody, one was immune but 10 became infected and displayed increases in HRV-2-specific antibodies. These antibodies first increased 1–2 weeks after infection and reached a maximum at 5 weeks. All six resistant volunteers who had high pre-existing antibody and eight of the volunteers who became infected maintained their HRV-2-specific antibody for at least 1 year. At this time they were protected against reinfection. Two volunteers showed decreases in HRV-2-specific antibodies from either serum or nasal secretions. They became infected but not ill after HRV-2 inoculation 1 year later.