Rhesus monkey erythrocytes when incubated in vitro under similar conditions to those used for the cultivation of Plasmodium knowlesi-infected erythrocytes in vitro, exhibit an increase both in their osmotic fragility and in the activity of their acetylthiocholinesterase. No effect was observed on the catabolism of glucose through the glycolytic pathway or through the primary dehydrogenases of the pentose phosphate pathway. The ATP content of normal monkey erythrocytes was also unchanged during incubation in vitro. These observations indicate that incubation of erythrocytes in vitro primarily causes membrane changes. Infection of normal erythrocytes by P. knowlesi was reduced markedly by preincubation in vitro at 37 °C for 24 and 48 h. These results suggest that the maintenance of integrity of the surface of the eythrocyte in vitro is a necessary prerequisite for an efficient culture system for the malaria parasite.

Trichinella spiralis is the nematode causative agent of trichinellosis, an intestinal and tissular parasitosis. Even though an early diagnosis during the intestinal phase is essential to limit the infection in humans, to date, there are no available tests to achieve this goal. Based on the immune response generated by the host's intestinal mucosa, the aim of this work was to develop ELISAs to assess the presence of coproantigens (CAgs), coproantibodies (CAbs) and faecal immune complexes in stool samples of 18 individuals belonging to different outbreaks that have arisen in Argentina. By the methodologies developed in this work it was found that anti-muscle larva excretory-secretory products (ML-ESP) CAbs were detected in 89% of the samples analysed regardless of the time p.i. Anti-ML-ESP IgA, IgG, IgE and IgM were detected in 56%, 56%, 28% and 22% of the individuals respectively. Those samples negative for anti-ML-ESP total immunoglobulins proved positive for anti-adult worm-ESP CAbs. No CAgs were detected in any of the samples. The results obtained in this work indicate that the intestinal immune response in human trichinellosis is featured by all the isotypes of specific immunoglobulins. Furthermore, the detection of antibodies in stool samples, in either the free or complexed form, could be applied to confirm early human trichinellosis.

Among the recent advances in our knowledge of the aetiology of human diseases, one of the most interesting is the discovery of a new group of somewhat problematic organisms which have been grouped together under the generic name Rickettsia. Up to now their presence has been shown, more or less satisfactorily, to be associated with three types of human fevers, viz. typhus, trench fever and possibly Rocky Mountain spotted fever, and in the last few years a certain number of papers have appeared on this subject, the most comprehensive of which are those published by the British War Office Committee and the American Commission on trench fever. In addition it has been suggested that many other human diseases are caused by these organisms, but the evidence is so very unsatisfactory that it may be disregarded.

The identity of Hyalomma lusitanicum K. and H. anatolicum K. is discussed. The male and female of the two species are described. H. anatolicum is considered as species inquirenda, but distinct from H. anatolicum anatolicum (sensu Pomeranzev) and H. anatolicum excavatum (sensu Pomeranzev). H. anatolicum anatolicum and H. anatolicum excavatum are considered to be one polymorphic species. This species should be called H. excavatum as it tallies with the still existing type specimen of H. excavatum Koch; it should not be called H. anatolicum as it does not correspond to Koch's description of H. anatolicum. The name H. anatolicum should for the present be reserved for a species resembling H. excavatum, but characterized by the light yellow colour of the anterior part of the scutum. It remains to be determined by breeding experiments whether this character is constant.

The host–parasite relationships of several notoedrid and teinocoptid mites of two Malaysian bats, Cheiromeles torquatus (the hairless bat) and Cynopterus brachyotis (the common fruit bat), were studied.

C. torquatus is parasitized by five species of Notoedres (family Sarcoptidae)—N. alexfaini, N. longisetosus, N. elongatus, N. rajamanickami and N. cheiromeles. Two, N. alexfaini and N. longisetosus, are responsible for generalized mange, which affects mainly the trunk. The three remaining species produce small, discrete lesions, each having a distinctive morphology and polarity.

Notoedres elongatus causes papilliform swellings, usually over the bony parts of the wing. It inhabits deep burrows in the swellings, which consist largely of hyper-plastic connective tissue heavily infiltrated with round cells. The lesions produced by N. rajamanickami resemble those of N. elongatus, except that they are located on the head in the neighbourhood of the vibrissae and are not elevated. N. cheiromeles dwells in cupules in the stratum corneum on various parts of the body, including the wings. These cupules are formed as a result of an intense hyper-keratosis in the immediate vicinity of the mites.

The reaction of the skin of Cynopterus brachyotis to the teinocoptid mite, Teino-coptes asiaticus (family Teinocoptidae), expresses itself chiefly as an extensive acanthosis. There is little or no thickening of the stratum corneum except on the lips of the epidermal cupule in which the anterior end of the mite rests. The dermis underlying the mite undergoes moderate fibroblastic proliferation.

We would like to thank Mr Lim Boo Liat of the Institute for Medical Research, Kuala Lumpur, and Mr Eric Alfred of the National Museum, Singapore, who very kindly allowed us to examine material from their collections. Mr Lim also assisted in other ways and proved to be a genial and helpful host when we visited his laboratory at the IMR. We are also most grateful to Professor John Harrison, who so generously provided us with space in his department.

The present paper deals mainly with some new species of cestodes collected from birds commonly occurring in and near Nagpur, C.P., India.

Chagas disease (CD) is a neglected disease and endemic in Brazil. In the Brazilian Northeast Region, it affects millions of people. Therefore, it is necessary to identify the spatiotemporal trends of CD mortality in the Northeast of Brazil. This ecological study was designed, in which the unit of analysis was the municipality of the Brazilian northeast. The data source was the Information System of Mortality. It was calculated relative risk from socioeconomic characteristics. Mortality rates were smoothed by the Local Empirical Bayes method. Spatial dependency was analysed by the Global and Local Moran Index. Scan spatial statistics were also used. A total of 11 287 deaths by CD were notified in the study. An expressive parcel of this number was observed among 70-year-olds or more (n = 4381; 38.8%), no schooling (n = 4381; 38.8%), mixed-race (n = 4381; 62.3%), male (n = 6875; 60.9%). It was observed positive spatial autocorrelation, mostly in municipalities of the state of Bahia, Piauí (with high-high clusters), and Maranhão (with low-low clusters). The spatial scan statistics has presented a risk of mortality in 24 purely spatial clusters (P < 0.05). The study has identified the spatial pattern of CD mortality mostly in Bahia and Piauí, highlighting priority areas in planning and control strategies of the health services.

In the Samoan Islands, in the South Pacific, one frequently sees horses and donkeys disfigured by large tumours. These occur on the pasterns and fetlocks, and occasionally between the eye and the nostril, but never on other parts of the body. They are often multiple, and they cause much inconvenience because of their size; many of them are larger than the animal's hoof (Plate XXIII).

A strain of Plasmodium gallinaceum has been treated for 10 weeks with sulphadiazine (5 mg./20 g.) in the presence of p-aminobenzoic acid in doses (0·5 mg./ 20 g.) inhibiting the sulphadiazine. No resistance to paludrine or to sulphadiazine has developed.

Research and innovation in the diagnosis of infectious and parasitic diseases has led to the development of several promising diagnostic tools, for example in malaria there is extensive literature concerning the use of rapid diagnostic tests. This means policymakers in many low and middle income countries need to make difficult decisions about which of the recommended tools and approaches to implement and scale-up. The test characteristics (e.g. sensitivity and specificity) of the tools alone are not a sufficient basis on which to make these decisions as policymakers need to also consider the best combination of tools, whether the new tools should complement or replace existing diagnostics and who should be tested. Diagnostic strategies need dovetailing to different epidemiology and structural resource constraints (e.g. existing diagnostic pathways, human resources and laboratory capacity). We propose operational modelling to assist with these complex decisions. Projections of patient, health system and cost impacts are essential and operational modelling of the relevant elements of the health system could provide these projections and support rational decisions. We demonstrate how the technique of operational modelling applied in the developing world to support decisions on diagnostics for tuberculosis, could in a parallel way, provide useful insights to support implementation of appropriate diagnostic innovations for parasitic diseases.

Vector systematics research is being transformed by the recent development of theoretical, experimental and analytical methods, as well as conceptual insights into speciation and reconstruction of evolutionary history. We review this progress using examples from the mosquito genus Anopheles. The conclusion is that recent progress, particularly in the development of better tools for understanding evolutionary history, makes systematics much more informative for vector control purposes, and has increasing potential to inform and improve targeted vector control programmes.

To determine the involvement of the actin cytoskeleton in macrogametocyte growth and oocyst wall formation, freshly purified macrogametocytes and oocysts were stained with Oregon Green 514 conjugated phalloidin to visualize F-actin microfilaments, while Evans blue staining was used to detect type 1 wall forming bodies (WFB1s) and the outer oocyst wall. The double-labelled parasites were then analysed at various stages of sexual development using three-dimensional confocal microscopy. The results showed F-actin filaments were distributed throughout the entire cytoplasm of mature Eimeria maxima macrogametocytes forming a web-like meshwork of actin filaments linking the type 1 WFBs together into structures resembling ‘beads on a string’. At the early stages of oocyst wall formation, F-actin localization changed in alignment with the egg-shaped morphology of the forming oocysts with F-actin microfilaments making direct contact with the WFB1s. In tissue oocysts, the labelled actin cytoskeleton was situated underneath the forming outer layer of the oocyst wall. Treatment of macrogametocytes in vitro with the actin depolymerizing agents, Cytochalasin D and Latrunculin, led to a reduction in the numbers of mature WFB1s in the cytoplasm of the developing macrogametocytes, indicating that the actin plays an important role in WFB1 transport and oocyst wall formation in E. maxima.

Parasite infection in young animals can affect host traits related to demographic processes such as survival and reproduction, and is therefore crucial to population viability. However, variation in infection among juvenile hosts is poorly understood. Experimental studies have indicated that effects of parasitism can vary with host sex, hatching order and hatch date, yet it remains unclear whether this is linked to differences in parasite burdens. We quantified gastrointestinal nematode burdens of wild juvenile European shags (Phalacrocorax aristotelis) using two in situ measures (endoscopy of live birds and necropsy of birds that died naturally) and one non-invasive proxy measure (fecal egg counts (FECs)). In situ methods revealed that almost all chicks were infected (98%), that infections established at an early age and that older chicks hosted more worms, but FECs underestimated prevalence. We found no strong evidence that burdens differed with host sex, rank or hatch date. Heavier chicks had higher burdens, demonstrating that the relationship between burdens and their costs is not straightforward. In situ measures of infection are therefore a valuable tool in building our understanding of the role that parasites play in the dynamics of structured natural populations.

Progarnia archosauriae nov. gen., nov. sp. (Haemosporina: Garniidae) is described in the blood of the South American caiman, Caiman crocodilus crocodilus (Archosauria: Crocodilia). The parasite undergoes merogony and gametogony principally in leucocytes and thrombocytes, but also invades erythrocytes in which it produces no ‘malarial’ pigment. It thus shares features of Fallisia and Garnia which are, respectively, intra-leucocytic and intra-erythrocytic haemosporines of the family Garniidae in present-day lizards. This, and the antiquity of the order Crocodilia, suggests that it was from such a parasite that the existing reptilian and avian haemosporines evolved. An overall evolutionary pattern is suggested.

The present report deals with the status of hepatic and splenic glutathione-S-transferase (GST) activities in mice during experimental infection with Plasmodium yoelii nigeriensis and subsequent treatment of infected mice with mefloquine (Mf) and menadione (Md). The infection caused significant decline in the hepatic and splenic glutathione-S-transferase (GST) activities of albino and db/+ mice. The decline was observed in the levels of both cytosolic and microsomal GST(s) of liver and spleen in both types of mice. Intraperitoneal administration of mefloquine at a dose of 5 mg/kg and menadione at a dose of 100 mg/kg, twice daily from day 1 p.i. (day 0) until day 10, caused restoration in the levels of hepatic as well as splenic GST(s), albeit to varying degrees. Mf was able to suppress parasitaemia by day 5 in the case of albino mice and by day 3 in the case of db/+ mice but was unable to cure both types of mice completely. On the other hand, Md caused a delay in maturation of infection in both cases, but could not cure the mice.

Cercaria strigata was first named and described briefly by Lebour (1908) from Tellina tenuis and Donax vittatus at Alnmouth, Northumberland. It was recorded again by the same author (1911) in 3% of Tellina tenuis at Millport. What was almost certainly the same cercaria had been previously noted by Giard (1907) between the mantle and shell in the same hosts. Giard did not name or describe the cercaria but suggested that it was the young stage of Gymnophallus oedemiae (Jameson) (= G. somateriae (Levins)) from the scoter Oedemia nigra L.

1. Atebrin given during the incubation period delays the appearance of parasites in the blood of birds infected by direct blood inoculation with Plasmodium relictum.

2. If given to birds infected by the bites of mosquitoes it does not retard the appearance of parasites in the blood, when given either before, or after, the infective bites, but it has some action in diminishing the severity of the attack and the degree of splenic enlargement.

3. Parasites appear in the blood of birds, infected by sporozoites, actually during the course of atebrin treatment if this is prolonged beyond the normal incubation period.

4. When asexual parasites appear in the blood of mosquito-infected birds after atebrin treatment they are abnormal in appearance and devoid of pigment grains; gametocytes are rarely seen in the blood of such birds, but if present they have normal pigment granules.

5. Treatment with atebrin produces peculiar bodies in the blood cells of canaries.

The development of the egg-shell of the trichuroid nematode, Trichuris muris, was observed by light and electron microscopy. Initial stages of shell formation occurred immediately following sperm entry into the oocyte in the spermatheca of the female worm. The external vitelline layer separated from the oolemma, reticulate oocyte granules were discharged into the resultant perivitelline space and stored glycogen contributed to the formation of the chitinous shell. A lipid layer developed between the inner surface of the chitinous layer and the oolemma. The fully formed egg-shell thus comprised an external vitelline layer, a middle chitinous layer and an inner lipid layer. The outer vitelline layer resembled a unit membrane with strands of particulate material attached to its outer surface. The middle chitinous layer was composed of chitin microfibrils encased in a protein coat; the sheets of microfibrils were arranged as parallel lamellae forming a helicoidal architecture. The inner lipid layer contained a variable number of loosely arranged strands of electron-opaque and less-opaque material.