[Prevalence of canine filariasis by Dirofilaria immitis and Dipetalonema reconditum in Maceió, Alagoas State, Brazil]. / Prevalência da filariose canina causada por Dirofilaria immitis e Dipetalonema reconditum em Maceió, Alagoas, Brasil.

A survey on the prevalence of Dirofilaria immitis and Dipetalonema reconditum was conducted in 1,519 dogs from Maceió and two coastal areas in the State of Alagoas, Northeast Brazil, from 1995 to 1999, by testing for microfilariae in blood. All blood samples were from exclusively domiciled dogs with a known history, showing that the infections were autochthonous, confirming transmission of canine filariasis in these areas. In Greater Metropolitan Maceió, 15 (1.3%) microfilaremic dogs were detected with D. immitis and 15 (1,3%) with D. reconditum. In the southern coastal area there was an estimated prevalence of 12.7% for D. immitis. D. immitis and D. reconditum microfilaria were 298.1 micrometer and 249.2 micrometer long and 7.3 micrometer and 4.4 micrometer wide, respectively. A Witness immunotest that detects D. immitis antigen was used to confirm parasitological results and reveal occult dirofilariasis cases. Of the total 6,579 females examined, 8 (0.1%) Culex quinquefasciatus were observed to be naturally infected with D. immitis larvae. These results proved dirofilariasis transmission in Maceió and demonstrated D. reconditum in the same geographic area.

[Bancroftian filariasis in urban areas of Alagoas State, Northeast Brazil: study in the general population]. / Filariose bancroftiana em áreas urbanas do Estado de Alagoas, nordeste do Brasil: estudo em populaçao geral.

In order to assess the present status of lymphatic filariasis in Alagoas State, Brazil, hemoscopic surveys were carried out in the human population of the three different physiographic regions of the State. Blood samples were collected by thick smear technique taken after 10:00 p.m. From a total of 101 cities of the State, 10 were randomly selected, Bancroftian filariasis was only found in Maceió, the capital of Alagoas State. In a cross-sectional survey conducted among the general population of 4 neighborhoods in the city, 10,973 individuals were examined, 226 were microfilaraemic with prevalence in the city neighborhoods ranging from 0 to 5.4%. Prevalence rates and microfilariae density were significantly higher in males. Among the examined inhabitants born out of Maceió, microfilariae carriers had lived a significantly longer time in endemic areas than the amicrofilaraemic subjects. Based on the data obtained in the present study, measures to avoid expansion of bancroftian filariasis in the region were established.

[Present status of bancroftian filariasis in Maceió, State of Alagoas, Brazil]. / Situação atual da filariose bancroftiana na cidade de Maceió, estado de Alagoas, Brasil.

Epidemiological and entomological surveys were carried out in the human and mosquito populations in Maceió, Alagoas, in order to assess the present status of bancroftian lymphatic filariasis. Examination of thick blood smears of 10,450 students from different areas of the city revealed 0.66% Wuchereria bancrofti microfilaria carriers. The distribution of filariasis is focal in the city, 80% of the individuals with patent infection living in two neighboring areas with 1.24% and 5.25% prevalence. Parallel studies performed with samples of all age groups in the human population showed similar microfilaria prevalence rates observed previously in the student survey. However, thick blood smears taken from members of families with at least one subject with patent infection gave a prevalence six times greater suggesting, increased transmission in households. The percentage of carriers was higher in the youngest age group (< 20 years). Culex quinquefasciatus mosquitos caught at the locations where the autochthonous cases were found presented natural infection rates ranging from 0.28% to 4.62%. The combination of all these findings indicates occurrence of active transmission of W. bancrofti in the urban area of Maceió, Alagoas State. Based on these data, measures for the potential control of filariasis were planned.

Experimental infections of simians with human malaria: attempts to infect Callithrix penicillata with Plasmodium falciparum.

After reviewing the use of non-human primates of the Old and New Worlds for human malaria research, we concluded that another experimental animal which is easily available to use and possible to rear indoors is needed. Thus, we studied the susceptibility of the marmoset Callithrix penicillata to Plasmodium falciparum erythrocytic infections. The marmosets received various P. falciparum human isolates, directly from a patient and from continuous cultures. The Palo Alto strain, which has been adapted to the night monkey Aotus trivirgatus and further maintained in the squirrel monkey Saimiri sciureus was also used. In a total of 20 marmosets we performed 31 inoculations, with 10(5) to 10(9) parasites, intraperitoneally, intracardiacly or intravenously. Blood samples from each animal were examined daily up to day 90 post-inoculation. None of the intact marmosets developed patent infections. Four out of 19 C. penicillata, previously splenectomized, showed circulating parasites for up to five days after intravenous inoculation with the Palo Alto strain, becoming negative thereafter. Neither the addition to the simian diet of p-aminobenzoic acid, essential for the parasite metabolism, nor drug-immunosuppression, improved the marmoset susceptibility to P. falciparum.