Numbers of leucocytes in squirrels with gametocytes of Hepatozoon in their blood (infected) were compared with animals without gametocytes (uninfected). Typical values for leucocytes/mm3 blood in uninfected squirrels were: leucocytes 5·7×103, granulocytes 3·4×103, lymphocytes 2·0×103 and monocytes 0·3×103 cells. Infection caused an increase in monocytes, lymphocytes and granulocytes, and there was a significant positive association between parasitaemia level and numbers of both total leucocytes and monocytes. Infected animals had more uninfected monocytes/mm3 blood than did uninfected animals. The proportions of monocytes were more variable over time in infected animals, but no shift between infected and uninfected status was detected. Transfer of serum from infected squirrels to mice resulted in elevated counts of total blood leucocytes, monocytes and granulocytes, but not of lymphocytes, as compared with controls. Serum from squirrels with high parasitaemias had a more marked effect than serum from squirrels with low parasitaemias. Results indicate an infection-related monocytosis, possibly controlled by cytokines, that increases the number of cells available for invasion by gametocytes, thus enhancing the chances of parasite transmission.

Cyclin-dependent kinases (CDKs) have important roles in regulating key checkpoints between stages of the cell cycle. Their activity is tightly regulated through a variety of mechanisms, including through binding with cyclin proteins and the Cdc2/Cdc28 kinase subunit (CKS), and their phosphorylation at specific amino acids. Studies of the components involved in cell cycle control in parasitic protozoa are limited. Trichomonas vaginalis is the causative agent of trichomoniasis in humans and is therefore important in public health; however, some of the basic biological processes used by this organism have not been defined. Here, we characterized proteins potentially involved in cell cycle regulation in T. vaginalis. Three genes encoding protein kinases were identified in the T. vaginalis genome, and the corresponding recombinant proteins (TvCRK1, TvCRK2, TvCRK5) were studied. These proteins displayed similar sequence features to CDKs. Two genes encoding CKSs were also identified, and the corresponding recombinant proteins were found to interact with TvCRK1 and TvCRK2 by a yeast two-hybrid system. One putative cyclin B protein from T. vaginalis was found to bind to and activate the kinase activities of TvCRK1 and TvCRK5, but not TvCRK2. This work is the first characterization of proteins involved in cell cycle control in T. vaginalis.

On Hawai‘i Island, an increase in human neuroangiostrongyliasis cases has been primarily associated with the accidental ingestion of Angiostrongylus cantonensis L3 in snails or slugs, or potentially, from larvae left behind in the slug's slime or feces. We evaluated more than 40 different treatments in vitro for their ability to kill A. cantonensis larvae with the goal of identifying a safe and effective fruit and vegetable wash in order to reduce the risk of exposure. Our evaluation of treatment lethality was carried out in two phases; initially using motility as an indicator of larval survival after treatment, followed by the development and application of a propidium iodide staining assay to document larval mortality. Treatments tested included common household products, consumer vegetable washes and agricultural crop washes. We found minimal larvicidal efficacy among consumer-grade fruit and vegetable washes, nor among botanical extracts such as those from ginger or garlic, nor acid solutions such as vinegar. Alkaline solutions, on the other hand, as well as oxidizers such as bleach and chlorine dioxide, did show larvicidal potential. Surfactants, a frequent ingredient in detergents that lowers surface tension, had variable results, but dodecylbenzene sulfonic acid as a 70% w/w solution in 2-propanol was very effective, both in terms of the speed and the thoroughness with which it killed A. cantonensis L3 nematodes. Thus, our results suggest promising directions for future investigation.

In the course of recent work on the pathogenicity of Trypanosoma vivax in bovines, cases have occurred at the Veterinary Laboratory, Entebbe, when it has been difficult to diagnose the species of trypanosome occurring in the blood. This difficulty arose because many of the trypanosomes were too small to be typical T. vivax and the possible occurrence of T. uniforme had to be considered, and also because many abnormal degenerate forms appeared at irregular intervals. A more detailed study of the trypanosomes present in the infection was therefore undertaken and, although in many aspects this work is still incomplete, the course of the infection in goats and sheep has been sufficiently interesting to merit this preliminary report.

The examination of a vast number of ticks, collected in late years from various hosts in many parts of the world, has resulted in the addition of several new species to the genus Haemaphysalis. Though only 13 of the species admitted by Neumann in his “Révision” (Pt. II, 1897) still stand, the number of recognised good species now reaches 43.

The differences noted between these Sarcoptes from cattle and those from the horse, described by Buxton, are as follows:

There are two lateral setae in all stages. The spines are notched or V-shaped at the ends. There are three cones in the larva as well as in all other stages. There is a pair of setae analogous to that found on the genital apron of the male at the corresponding location in the immature female. In the immature female the ridges on which are located the third ventral setae (V 3) run backward without returning forward on the opposite side. In the adult female, immature female and male, the two short setae on the terminal joint of the first leg, P 7 and 8, are represented by a single seta on the second leg. The third leg in all stages is furnished with four short setae on the terminal joint. The end joint of the fourth leg of both adult and immature females has four short setae. In the nymph none are present on the fourth leg.

This highly topical book offers information on two groups of communicable diseases: the first being zoonoses, with animals playing an essential role in maintaining the infection in nature and man is only an accidental host. The second group comprises the diseases common to man and animals, where they generally contract the infection from the same source, and the animals may contribute in particular to the distribution and actual transmission of infections.

Ecological and social changes, along with the migration of large numbers of people between continents, have caused the spread of once endemic diseases, which can now pose a threat in distant communities. The risk of bio-terrorism has highlighted the need for detailed knowledge of those diseases in terms of their epidemiology, mechanisms of transmission to humans, diagnosis and control.

In each volume, the groups of communicable diseases are listed in alphabetical order, which makes it easy to use. The great asset of this publication is that a number of pages devoted to each disease follows its incidence rate and pathogenicity for humans and animals. Less serious infections are listed briefly while those possessing serious threat are described in great detail. Each chapter is followed by the list of most important references, though some of them are not the most up-to date.

What also makes it easy to use for a reader is the listing of the synonyms for each disease, and chapters divided into paragraphs with headings such as etiology, geographic distribution, occurrence in man and animals, symptoms, sources of infections and mode of transmission, and the role of animals in its epidemiology, diagnosis and control. However, the tables, figures and photographs are included unevenly in the volumes. The transmission cycles are mostly presented in the second volume, while in the third one regarding Parasitoses they are completely missing. And it is in particular in Parasitoses, where the life-cycles are often quite complicated and for a better understanding of the mode of transmission, such illustrations would be very suitable.

What might be rather confusing are a few listed synonyms, which in several cases are somewhat contradictory in terms of their suffixes – osis (-iosis) and -iasis, even if the agents have the same generic suffix – e.g. Balantidiasis versus Balantidiosis (Balantidium coli,) and Cryptosporidiosis (Cryptosporidium spp.).

In conclusion, the publication, primarily targeted at academics and students in schools of public health, medicine and veterinary medicine, researchers as well as the staff of public health and veterinary health institutions, provides an attractive read – not just for everyone who must or wants to be familiar with the subject, but also for all seeking a broad overview in the world of known and emerging zoonoses.

The following is a summary of our studies on population of head lice, adults and nits.

1. Out of a total of 8702 adult lice, the male population comprised 2031. The gross infestation rate per head was 129.9 and the maximum number found on a single head was 1434. A disproportion in the distribution of the two sexes was a marked feature.

2. Patients below the age of 11 showed a lower infestation rate than those above this age, and short-haired individuals were more heavily infested than long-haired ones.

3. Frequent combing of the hair and the use of oil did not seem to dislodge the adults or to prevent the females from laying eggs.

4. The maximum larval count on a single head was found to be 4260, the average number of larvae per single head was 418·8, and 9 to 1 was the maximum proportion of larvae to females.

5. The maximum number of nits on a single hair was found to be 17 and 5·06 was calculated as the average number per hair.

6. Treatment with kerosene and pyrethrum killed all the lice and nits, and reinfestation did not occur.

7. The infestation did not spread to healthy patients in the hospital ward; it is thought that the poor migratory habits of lice are responsible for this.

8. From studies on the reinfestation of an individual after treatment it is concluded that head-lice cannot establish themselves on any part of the body except the head, and if their access to the head is prevented, the lice will not survive for more than 24 hr.

Light and electron microscopy were used to study the ultrastructure of the cement apparatus, namely cement glands and cement ducts of mature specimens of the acanthocephalan parasite Pomphorhynchus laevis Müller, 1776, recovered from the digestive tracts of fish Leuciscus cephalus Risso, 1826. In addition, the cement glands of immature P. laevis found within the body cavity of the fish Alburnus alburnus alborella De Filippi, 1844 were examined. In a mature male of P. laevis the 6 cement glands are rounded to oval in shape and each of them has an outer cytoplasmic layer containing nuclei and surrounding a space for storage of the cement material within the gland. The nuclei have an irregular outline and the cytoplasm of the cells contains round, membrane-bound secretory granules approximately 1 μm in diameter. Nuclei surrounded by secretory granules were present inside the gland lumen. Within the gland ducts of mature males, granules were present within the wall thickness and, inside the luminal area, mitochondria were encountered. In contrast, within the cement glands of immature P. laevis there were no secretory granules and the chromatin of the nuclei appeared condensed. The nature of the secretory product of the cement glands was investigated with histological and electrophoretic methods. A protein with molecular weight of 23 kDa was recorded as a major component of cement.

The isometric mechanical properties of diaphragm muscle were studied in mice infected with either Trichinella spiralis or Trichinella pseudospiralis. Measurements of muscle stress were taken at 15, 20, 30 and 40 days post-infection. Infected diaphragm muscle showed a significant (P < 0·001) reduction in muscle stress during both twitch and tetanic contractions when compared with muscle from control animals. T. spiralis caused a significant reduction in resistance to muscle fatigue. The consequences of these changes in muscle function to host pathology are discussed, and related to previous work on the effects of Trichinella on host biochemistry and the immune response.

Experiments to investigate the linked metabolism of L-serine and L-alanine by Moniliformis moniliformis in vitro were carried out by incubating adult worms aerobically for 3 h at 37 °C in Tyrode’s solution containing L-[U-14C]alanine and other amino acids. When present in the medium alone, alanine was totally removed by the worms and metabolized almost entirely to ethanol and a compound identified as carbon dioxide. When present in the medium with serine and no other amino acids, alanine was largely metabolized as before but additional alanine, believed to originate from serine, was excreted. The same results were obtained with serine and 16 other amino acids in the incubation medium.

Toxoplasma gondii is an apicomplexan intracellular protozoan parasite responsible for toxoplasmosis, a disease with considerable medical and economic impact worldwide. Toxoplasma gondii cells never lose the nuclear envelope and their chromosomes do not condense. Here, we tested the murine monoclonal antibody PL2-6, which labels epichromatin (a conformational chromatin epitope based on histones H2A and H2B complexed with DNA), in T. gondii cultured in human fibroblasts. This epitope is present at the exterior chromatin surface of interphase nuclei and on the periphery of mitotic chromosomes in higher eukaryotes. PL2-6 reacted with T. gondii H2A and H2B histones in Western blot (WB) assays. In addition, the antibody reacted with the nuclear fraction of tachyzoites, as a single band coincident with H2B histone. In the T. gondii tachyzoite stage, PL2-6 also had peripheral nuclear localization, as observed by epifluorescence/confocal microscopy and immunoelectron microscopy. Confocal analysis showed that epichromatin is slightly polarized to one face of the parasite exterior chromatin surface. In replicating tachyzoites, PL2-6 also labels the exterior chromatin surface, covering the face of both segregating nuclei, facing the plasma membrane of the mother cell. The possible role of epichromatin in T. gondii is discussed.

In November 1912, through the courtesy of Mr S. W. J. Scholefield, Prof. Nuttall received fourteen living nymphs of Argas brumpti from Kitui, British East Africa. As only the adults and later stage nymphs of this species are known, an attempt was made to raise the species in the laboratory.

Most mathematical models of malaria infection represent parasites as replicating continuously at a constant rate whereas in reality, malaria parasites replicate at a fixed age. The behaviour of continuous-time models when gametocytogenesis is included, in comparison to a more realistic discrete-time model that incorporates a fixed replication age was evaluated. Both the infection dynamics under gametocytogenesis and implications for predicting the amount parasites should invest into gametocytes (level of investment favoured by natural selection) are considered. It is shown that the many malaria models with constant replication rates can be represented by just 3 basic types. For these 3 types, it is then shown that under gametocytogenesis (i) in 2 cases, parasite multiplication and gametocyte production is mostly much too low, (ii) in the third, parasite multiplication and gametocyte production is mostly much too high, (iii) the effect of gametocyte investment on parasite multiplication is mostly too high, (iv) the effect of gametocyte investment on gametocyte production is nearly always too low and (v) with a simple approximation of fitness, the predicted level of gametocyte investment is mostly much too low. However, a continuous model with 48 age-compartments compares well to the discrete model. These findings are a further argument for modelling malaria infections in discrete time.

An in vitro method for studying radiorespiration has been adapted to single macrofilariae. Using this method viable (but not heat-killed) Dipetalonema viteae and Onchocera gibsoni macrofilariae evolved measurable amounts of 14CO2 from L-[U-14C]glutamine. Nonlinear and less uniform rates of 14CO2 evolution were demonstrated with D-[U-14C]glucose, [1-14C]acetate and [1-14C]octanoate. These findings led us to develop an in vitro screen in which inhibition of 14CO2 evolution from L-[U-14C]glutamine was used as a parameter for gauging macrofilaricidal activity. Using this screen we have examined the activity of 17 ‘so-called’ antifilarial standards and found a greater degree of sensitivity than shown by other biochemical criteria. Other data obtained suggest a role for radiorespirometry in determining the viability of fragments of Onchocerca tissue.

The present paper is mainly concerned with the records and descriptions of new species of parasitic acari obtained in Ceylon and sent to me during 1947 by Mr Gordon B. Thompson, of whose collection they form a part. The study of the specimens of the tropical rat mite, Echinolaelaps echidninus (Berl.), represented in this material led me to re-examine both the literature and the specimens of this species contained in my own collection, and I have included in the present paper the results of this investigation and have established various forms of the species which this necessitates besides showing the probable relationships existing between them.

Cercaria Ephemera Lebour belongs to the group of Monostome cercariae which have been proved to belong to the Notocotylidae. This species probably belongs to the genus Notocotylus.