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A 12-months study on bancroftian filariasis was carried out in the Igwun basin, Nigeria. A total of 1,418 individuals (768 males, and 650 females) were examined for microfilaremia and clinical filarial stigmata. There were 14.3% and 11.1% male and female point prevalence rates, respectively, and an overall prevalence of 12.8%. Prevalence rates and microfilarial density increased with age. The highest mff density of 35 mff/20 ml blood occurred in the 40-49 year old male individuals. Disease rates of 55.5 and 65.3% were recorded for males and females respectively. Chyluria (9.3% males, 16.7% females), hydrocele (17.8%), elephantiasis (15.9% males, 29.2% females), and enlarged groin glands (16.4% males, 19.4% females) were the major clinical signs, all associated with microfilaremia. Anopheles gambiae and Cules pipiens were the principal vectors. The estimated mean daily, weekly, and monthly per capita biting densities were 26, 161, and 753 respectively. The overall infection rate of mosquitoes was 22.3%, with a mean mff density of approximately 5 mff/mosquito. These vector parameters were indicative of active transmission in the area, and may be responsible for the high prevalence of infection, the diversity of clinical signs, and high morbidity rates.

The digestive tract of a fully formed free-swimming cercaria of Echinostoma revolutum (Froelich, 1802) Dietz, 1909 was studied by electron microscopy. The oral sucker and pharynx are covered by a tegument. The oesophagus and the caeca are not luminized. They are packed with giant epithelial cells with electron-dense granules of irregular shape, rough endoplasmic reticulum and its cisterns, and Golgi apparatus. The tegument of the oral sucker cavity contains numerous uniciliate receptors.

In the years 1985-1988, a total of 254 specimens of the roach, Rutilus rutilus, captured in 23 localities of South Bohemia, were examined for the presence of protozoan parasites. Only 17 specimens (6.7%) were free of infection, whereas the others were infected at least with one parasite species, mixed infections were observed most frequently. The following species were found rarely: Myxidium rhodei Leger, 1905 in the liver and muscles, Pleistophora mirandellae Vaney et Conte, 1901 in ovaries, Trichodina nemachili Lom, 1960 on the skin, Trichodina prowazeki Grupcheva et Lom, 1980 on the skin (the first finding in Czechoslovakia). The data concerning localization of individual parasites and their prevalence are presented and five protozoan species described in detail.

The effects of infections of Trichinella spiralis on 10 specific-pathogen-free Beagles were examined. Eight puppies received either 100, 500, 1,000, or 5,000 larvae, and 2 adult dogs received 1,000 larvae. Blood was drawn every 4 days, beginning 5 days before infection, for the determination of relative eosinophil numbers. Creatine kinase levels were monitored before infection, two weeks after infection, and one month after infection. The dogs were euthanized 1 month postinfection, and larvae were counted in muscle digests of 10 gram samples of diaphragm, pectoralis superficialis, masseter, biceps brachii, and vastus lateralis. The dogs displayed minor signs of gastrointestinal upset during the first week after infection. The dogs also developed a slight eosinophilia with a magnitude that was dependent on the number of larvae the dog received. All infected dogs, but one that had received 500 larvae, had a positive reaction with larval excretory-secretory products of T. spiralis; adult dogs had the greatest immunologic response. The creatine kinase levels were found not to be related to either the time postinfection or the magnitude of the larval dose. The number of larvae recovered from the muscles (maximum of 70 per gram) was dependent on the dosage of larvae received, but there was no significant predilection of the larvae for any of the five examined muscle groups.

Effect of temperature on the sporogonic cycle of Plasmodium berghei (NK 65) has been studied in vector Anopheles stephensi. To determine the optimum temperature for development of parasite, fed mosquitoes were kept at 16 +/- 1 degree C, 19 +/- 1 degree C and 26 +/- 1 degree C temperature. The temperature 19 +/- 1 degree C was found to be optimum for normal development of parasite within the vector. Sporulated oocysts were observed on the 10th day post feed and salivary glands were loaded with thousands of sporozoites on day 14. Temperature 16 +/- 1 degree C, though did not exert any deleterious effect on the morphology of parasites it delayed the development of sporozoites in the oocysts by 5 days as compared to control group. In the case of long exposure to this temperature, the sporozoites obtained from salivary glands became non-infective. Temperature 26 +/- 1 degree C was responsible for deterioration of all the stages of sporogonic cycle and it also checked the formation of sporozoites in the oocysts.

It was confirmed, after experimental infection of 24 weaned pigs with different doses (200,000 and 4 mil.) of Eimeria debliecki oocysts that the developmental cycle of E. debliecki occurs in the anterior jejunum and after a high dose of oocysts also in the duodenum and anterior parts of the middle jejunum. Pathological changes characterized by a light atrophy of the villi, scarcely dispersed minute erosions of the epithelium in upper parts of the mucosa and an inflammatory response in the propria of the anterior jejunum were found in the area of the largest occurrence of developmental stages of E. debliecki (from 50 cm to 100 cm from the pylorus). An inflammatory infiltrate in the propria of the anterior jejunum from 3 DPI to 5 DPI contained a conspicuously large number of plasma cells with Russell bodies. Cellular changes were detected only in enterocytes with developmental stages of E. debliecki. Changes of the microvillous zone were observed in infected enterocytes; dilated mitochondria, free ribosomes and an increased number of residual bodies were found in the cytoplasm of enterocytes. The degree of the cellular changes of enterocytes was dependent on the maturity of the developmental stage of E. debliecki. Based on pathological changes observed by the use of light and electron microscopy, the coccidium E. debliecki is considered to be pathogenic for weaned pigs in spite it does not provoke a clinical infection.

The prevalence of anti-Toxoplasma gondii antibodies in serum samples of 55 habitually aborting women, 46 women with normal pregnancies, 92 outpatient adults, and 150 University students from North Jordan was studied using the enzyme linked immunosorbent assay (ELISA). Sera from the habitually aborting group were also tested by the indirect immunofluorescent (IIF) test. No significant difference was found between the overall prevalence rates in University students, outpatient adults and women with normal pregnancies (25.3%, 22.8% and 26.1% respectively). The prevalence in habitually aborting women exceeded two times that in women with normal pregnancies or in outpatient females (58.2%, 26.1% and 25.0% respectively), and was approximately three times that in female University students (18.3%). The greatest difference in the prevalence rate between habitually aborting women and those with normal pregnancies or outpatient females was found in groups having the highest antibody level (greater than or equal to 100% of standard positive controls). A positive correlation between the results of the ELISA and those of the IIF test occurred at titres of greater than or equal to 1:40 of the latter test in habitually aborting women.

Six types of gland cells occurring in the body of developing Echinostoma revolutum cercaria are described at ultrastructural level. Three types of the gland cells, lateral, ventral and dorsal, release their secretion into the tegument of cercaria during its development in the media. Another three types, paraoesophageal, penetration and proper cytogenic gland cells are preserved in the body of the free-swimming cercaria. The paraoesophageal gland cells open on the tegument surface. Secretory granules of all types of gland cells and stratification of the body tegument arising by gradual release of the contents of the above mentioned three types of gland cells are characterized in detail.

Malaria was studied in the province of Takeo, Cambodia. In the hyperendemic region of Kirivong district, 49 (46.0%) of 105 suspected patients were found to be infected, 98% of them with Plasmodium falciparum and 2.0% with P. vivax. The highest prevalence (85.7%) was recorded in the group of 15-20-year-old patients. A total of 296 patients were examined in the hospital of Takeo during one year (1983-1984) and 77 (26.0%) of them were positive. P. falciparum infection was found in 76.6% and P. vivax in 23.4% of cases. The highest prevalence (42.3%) was also in the age-group of 15-20 years. The "7-day test" was used in vivo in 15 patients in order to detect the sensitivity of P. falciparum to Fansidar. The asexual forms of parasites disappeared within 4 days, while the gametocytes survived in two patients until 7th and 8th day, respectively. The observations could not be terminated, since the two patients will fully left the hospital.

755 sheep from 41 farms in the districts of Trebisov, Michalovce, Humenné and Roznava in the East Slovakian region were investigated on the presence of antibodies to Bhanja (neutralization test) and tick-borne encephalitis (haemagglutination-inhibition test) viruses. In respective districts 2.2%, 0.4%, 1.7% and 26.7% of animals (total 5.3%) were found to be positive on Bhanja virus, 4.4%, 1.5%, 1.7% and 5.0% (total 2.6%) on tick-borne encephalitis (TBE) virus. The considerable infection rate in sheep with Bhanja virus in the district of Roznava (mean 26.7%-on one farm as high as 63.9% serologically positive animals) can be explained by the local occurrence of the tick Haemaphysalis punctata, the main vector of this virus in Europe. The serologic screening conducted indicates a low activity of natural foci of TBE in eastern Slovakia today, and confirms the existence of a natural focus of infection with Bhanja virus in the district of Roznava. Recent circulation of Bhanja virus is indicated by antibodies detected in several one-year-old sheep.

Two pairs of hitherto unknown multiciliate sensory endings have been demonstrated in free-swimming cercariae of Echinostoma revolutum using transmission and scanning electron microscopy. This type of receptor consists of a bundle of 36--40 short, conically projecting cilia ensheathed by a collar formed by a circular evagination of tegument in shape of a cup. The cilia projecting from the centre of a widened nerve fibre, filled with electron-lucid vesicles, possess a well developed basal body and do not contain a ciliary rootlet. The function of this receptor is discussed.

The blood picture was studied in white mice experimentally infected with Ascaris suum, Toxocara cati, and Toxascaris leonina. In mice infected with A. suum, maximum number (17%) of eosinophiles occurred on day 28 p.i. In mice infected with T. cati, the eosinophilia increased already from the first day after infection, reaching the maximum (26%) on day 21 p.i. In mice infected with T. leonina, the eosinophilia increased from day 7 to day 28 p.i. and a slightly increased number of eosinophiles persisted during the whole experiment.