Apicomplexan parasites cause devastating diseases in humans and livestock. Previously we demonstrated that antibodies targeting transmissible forms of the apicomplexan parasite, Eimeria, are effective at reducing parasite shedding thus preventing the transmission of the disease. However, the mechanisms responsible have not been fully defined. Moreover, there is no direct evidence that the parasite-specific IgG antibodies can reach the parasite developing in the enterocytes of the infected chicken host. This study summarizes our efforts using host immunity, parasite proteomics and 3D microscopy to provide a step forward in our understanding of how this immune response works. Eimeria maxima is an important pathogen of poultry and used as a surrogate for a number of human pathogens including Toxoplasma and Plasmodium. Our studies demonstrate that immunization with the purified wall forming bodies (WFBs) results in a production of parasite-specific IgG antibodies, which have the ability to reach in situ gametocytes in the intestinal lumen and permeate the enterocyte/parasite membranes in order to bind to the cytoplasmic Type 1 and Type 2 WFBs. This raises the intriguing possibility that via this process antibodies block the development of Eimeria maxima in vivo.

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 May 1912 when on the way with our Floating Laboratory to Rejaf, en route for the sleeping sickness district in what was formerly the Lado Enclave (now part of Mongalla Province), the late Colonel Mathias shot, near Renkwood station on the White Nile, two specimens of the Senegal or red-fronted gazelle—Gazella rufifrons. I found one of these animals, a female in good condition, heavily infected with sarcosporidiosis, the diaphragm, the intercosted muscles and those of the thigh being specially affected, though the striped muscle fibre everywhere contained cysts in varying numbers. In the light of the observations made by Probst and Francis (1910) the blood was carefully examined but no sarcosporidial spores were found in it nor were any blood parasites present.

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.

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.

Saccocoelioides is a genus of trematodes associated with fishes from the Americas. In the current research, morphologically distinct specimens of Saccocoelioides spp. were collected from six countries in Middle America. Specimens were sequenced using three molecular markers, the domains D1–D3 of the large subunit (LSU) from the nuclear rDNA, the cytochrome c oxidase subunit 1 (cox1) and nicotinamide adenine dinucleotide dehydrogenase subunit 1 (nad1) from mitochondrial DNA. A total of 74 new sequences were compared and aligned with other sequences available in GenBank. Maximum likelihood and Bayesian inference analyses were inferred from the LSU and cox1 datasets, revealing unequivocally that all the specimens correspond to S. lamothei. A haplotype network was built with 119 sequences of the nad1 gene. The network detected 57 distinct haplotypes divided into three haplogroups. To explore morphological differences among samples of S. lamothei, 17 morphological features were measured from 53 specimens from three fish families: Eleotridae, Mugilidae and Gobiidae. Principal component analysis yielded three main polygons that corresponded with each family analysed, suggesting host-induced phenotypic plasticity. The current evidence suggests that S. lamothei infects at least five fish families along the Pacific coasts of Mexico, Guatemala, El Salvador, Honduras, Nicaragua and Costa Rica.

Aminopeptidase activity was detected in Encephalitozoon intestinalis using a fluorometric assay. The aminopeptidase was capable of hydrolysing different amino acids bound to 7-amino-4-trifluoromethyl coumarin, with maximal activity against the amino acid, leucine. Aminopeptidase activity was localized in E. intestinalis spores and in intracellular stages. Enzymatic activity was inhibited by the traditional aminopeptidase inhibitors, bestatin and its analogue, nitrobestatin. Inhibition with the chelating agents, EDTA and 1,10-phenanthroline, suggested that the enzyme activity belongs to the metalloaminopeptidase class. Subcellular fractionation demonstrated that maximal enzyme activity was localized in the cytosolic fraction. Direct fluorogenic substrate analysis by native polyacrylamide gel electrophoresis estimated a molecular weight of 70·8 kDa. Direct fluorogenic analysis by polyacrylamide ampholyte gel electrophoresis indicated an isoelectric point of 4·8. The enzyme was both heat (>37 °C) and cold (<0 °C) labile with an optimal activity at pH 7·2. This is the first report characterizing a cytosolic aminopeptidase in microsporidia.

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.

The Japanese observers Ido, Hoki, Ito and Wani (1916) state that in Infectious Jaundice the infective organism—the Spirochaeta icterohaemorrhagiae—is transmitted probably from rats to man by means of the urine of rats, directly or indirectly.

(1) There is very little, if any, abnormal destruction of erythrocytes in cases' of infection with East Coast Fever. This is proved by blood counts, haemoglobin estimations, and the condition of the bloodforming and blood-destroying organs, all remaining practically normal. This is in marked contrast to what obtains in piroplasmosis.

(2) The hypothesis advanced by Nuttall fits all the facts. According to this hypothesis the invasion of the corpuscles occurs in the internal organs where the parasites develop, and the corpuscles only act as carriers of the parasites in the blood, thereby conveying them to the tick which serves as the vector.

(3) Since few, if any, of the corpuscles are destroyed they rapidly become charged with an increasing number of parasites which are being continuously produced in the internal organs as evidenced by Koch's blue bodies which form and break up in the lymphatic glands, spleen, liver, bone-marrow, etc. (Gonder, Nuttall).

(4) There is a marked leucopenia in East Coast Fever, the polymorphs decreasing less rapidly than the other elements. This is in contrast with the leucocytosis observable in piroplasmosis.

Habitat and record. The animal under consideration, a copepod of the Family Caligidae, has up to the present received three notices: by Norman and T. Scott (1906), A. Scott (1907), and T. and A. Scott (1913). (For further particulars see References at end of this paper, p. 409.) Norman and Scott stated that “the specimens were taken forty years ago on the dory by Laughrin, and by him sent to A. M. N.” Consequently, the specimens were forty years old before they were described, which would, even in the absence of other reasons, excuse a little scepticism as to the description. Scott gives a bare record of capture, with a copy of Norman and Scott's diagrams. These diagrams and the original of Norman and Scott are republished by Scott and Scott with the addition of a few errors. Considering these facts, and also that no satisfactory description is given of the appendages of the male, or of the maxillae or swimming legs of the female, and that the animal is very common, occurring on nearly every dory, I feel that there is some justification for a further description.

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.

For the opportunity to examine the material on which the following descriptions are based I am indebted to the courtesy of Dr P. A. Buxton and Miss E. Sikes of the London School of Tropical Medicine, where the life-history of certain fleas is being studied. A detailed examination of the parasite showed it to be referable to the Pirenine tribe of the Miscogasteridae—a family of Chalcidoid wasps. The genus and species appeared to be new. The fact, however, that the parasite had been bred from a species of flea known to have been recently introduced into Britain suggested the advisability of comparison with American representatives of the Pirenine group. This has now been done by my friend Mr A. B. Gahan of the Bureau of Entomology, Washington, D.C., to whom my hearty thanks are due. As the result we are agreed that a new genus is required. Bairamlia n.g. has obvious affinities with Pirene Hal., but differs in antennal, neurational and propodeal characters. Ecrizotes Forst. (fide A. B. Gahan) may also be a nearly related genus. genus. As regards the species, I am satisfied that it is very different from anything described by Walker of which material is still extant in the British Museum. Mr Gahan, however, tells me that Pirene marylandensis Gir. (Canad. Ent. 48, p. 116, 1916) is a congeneric though distinct species.