Seroepidemiology of human toxoplasmosis in Chile

A series of already published and unpublished seroepidemiological surveys for toxoplasmosis, carried out in Chile in 1982-1994, is reviewed, expanded and analyzed. The surveys included 76,317 apparently healthy individuals of different ages (0.57% of the country's total population), from 309 urban and rural-periurban localities. Urban groups were integrated by blood donors, delivering mothers and middle grade schoolchildren, while rural-periurban individuals corresponded to unselected family groups. Blood samples were collected in filter paper. The presence of antibodies to Toxoplasma gondii was determined by the indirect hemagglutination test (IHAT), titers > 16 were considered positive. The test resulted positive in 28,124 (36.9%) of the surveyed people. Two hundred and six (0.3%) individuals presented IHAT titers > 1000, probably corresponding to acute or reactivated infections. A progressive increase of positive IHAT from northern to southern regions of the country was noted, phenomenom probably related to geographical conditions and to a higher production and consumption of different types of meat in the latter regions. It is postulated that ingestion of T. gondii cysts by humans is epidemiologically as important as ingestion of oocysts. The results presented stress the epidemiological importance of toxoplasmosis in humans, and warn about eventual implications in immunocompromised patients and in transplacental transmission, organ transplants and transfusions.

HEMAGGLUTINATION TEST FOR THE DIAGNOSIS OF HUMAN NEUROCYSTICERCOSIS: DEVELOPMENT OF A STABLE REAGENT USING HOMOLOGOUS AND HETEROLOGOUS ANTIGENS

A hemagglutination (HA) test was standardized using formalin- and tannin-treated gander red blood cells sensitized with a total salt extract of C. cellulosae (HA-Cc) and an antigenic extract of Cysticercus longicollis (HA-Cl) vesicular fluid. A total of 61 cerebrospinal fluid (CSF) samples were assayed, 41 from patients with neurocysticercosis and 20 from a control group, which were, respectively, reactive and non-reactive to ELISA using C. cellulosae. The CSF samples from the control group did not react and 35 (85.4%) and 34 (82.9%) CSF samples from patients were reactive to the HA-Cc and HA-Cl tests, respectively. The reagents ready for use were stable up to 6 months when stored at 4°C in 50% glycerol. The present results confirm that the reagent using Cysticercus longicollis stabilized with glycerol can be used as an alternative in the immunological diagnosis of neurocysticercosis

POSSIBLE ROLE OF LUTZOMYIA MARANONENSIS AND LUTZOMYIA ROBUSTA (DIPTERA: PSYCHODIDAE) AS VECTORS OF HUMAN BARTONELLOSIS IN THREE PROVINCES OF REGION NOR ORIENTAL DEL MARAÑON, PERU

Human bartonellosis is found predominantly in Perú2, 6, 8, 12, 15, as well as in Ecuador3, 7, 10 and Colombia13, 15. In Peru, the disease is restricted to the valleys of the western-side and a few inter-andean and eastern-slopes of the andean valleys6, 15, 18 at altitudes between 1000 and 3200 masl. Most human cases are reported from the regions of Chavin, Nor Oriental del Marañon and Lima16. Lutzomyia verrucarum is presumed to be the only vector of human bartonellosis in the valleys of Peru1, 2, 8, 11, 17, 19/ Our research objetive was to detect the presence of Lu. verrucarum in various localities known to be endemic for human bartonellosis in three provinces of Region Nor Oriental del Marañon. Sandfly collections were made between 1987 and 1992 during four visits to bartonellosis-endemic provinces: San Ignacio (districts of San José de Lourdes: 1020-1260 m and La Coipa: 1200-1560 m), Jaén (districts of Santa Rosa: 1300-1680 m and Jaén: 1220-1680 m) and Utcubamba (districts of Lonya Grande: 1200 m and El Milagro: 1200-1540 m)

Human infection with Trypanosoma cruzi in Nasca, Peru: A seroepidemiological survey (1)

We estimated the proportion of seropositivity for infection with Trypanosoma cruzi (Chagas’ disease) in a sample of the rural population of the Province of Nasca, Department of Ica, southwestern Peru. Although Triatoma infestans, the only vector species identified in the Department of Ica, is often found in domestic environments, data of the extent of human infection with T. cruzi are scant. This study comprised 446 houses, known to be infested with triatomines, distributed in 19 rural localities. While visiting those houses we collected filter paper bloodspots from 864 occupants (of both sexes, aged one year or over). By means of the indirect fluorescent antibody test (IFAT), we detected anti-T. cruzi IgG antibodies in samples from 178 individuals (20.6%). Seropositivity was significantly more frequent in females (23.8%) than in males (17.5%). Among the 410 individuals in the 1- to 10-year-old age group (47.5% of the population sample), 85 (20.7%) were found seropositive, which is indicative of an early acquisition of the infection. Within this group no significant differences in seropositivity were associated with sex

A case of human rabies in the Urban Area of Ribeirão Preto, SP, Brazil

A 39-year old male patient was admitted to the University Hospital of the Faculty of Medicine of Ribeirão Preto with signs and symptoms of sudden dyspnea, generalized myalgia and behavioral disorders. The initial suspicion was alcohol abstinence syndrome and the patient was referred for psychiatric and neurologic care. The evolution of the patient with a worsening of signs and symptoms, presence of crises of tachypnea, agitation, difficulty to swallow, irritability and hydrophobia, and his report of having been bitten by a suspected dog raised the hypothesis of rabies. The diagnosis was confirmed by examination of a corneal impression, biological tests in the cerebrospinal fluid (CSF) and saliva and visualization of Negri bodies in nervous tissue (direct immunofluorescence). The patient evolved with agitation, aggressiveness, and worsening tachypnea intercalating with apnea, and died on the 4th day after admission