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J Alvar

Publications and source records attributed to J Alvar.

67 records · Page 4Linked to original sources
PubMed1987

[A case of chloroquine-resistant malaria of type R3 originating in Cameroon].

World areas with chloroquine-resistant falciparum malaria are progressively spreading, in Africa from East to West. We are reporting here a new case of resistance, grade III, from Cameroon, carried out in vitro by the WHO standard macrotest. Resistance is determined by the ability of trophozoites to develop into schizonts when therapeutic doses of chloroquine have been administered.

Africa, Western↗
PubMed1985

Leishmaniasis or AIDS?

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Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Infectivity of dogs naturally infected with Leishmania infantum to colonized Phlebotomus perniciosus.

A study was carried out on the infectivity to sandflies of 16 dogs naturally parasitized by Leishmania infantum. All dogs were seropositive and the parasite had been isolated from all except one. They were divided into 3 clinical groups: 5 asymptomatic, 4 oligosymptomatic, and 7 polysymptomatic dogs. The dogs were exposed to female Phlebotomus perniciosus from a local colony and 7 d later the fed females were dissected in order to determine their rate of infection. There was wide variability of the percentage of fed and infected sandflies within each clinical group of dogs, with no significant difference between the 3 groups; the infectivity to sandflies was independent of the extent of symptoms in the dogs.

Animals↗
PubMedDate not supplied

HIV--Leishmania infantum co-infection: humoral and cellular immune responses to the parasite after chemotherapy.

Specific serum antibodies, peripheral blood T-cell subsets, cellular response in vitro to soluble Leishmania antigens, phenotype of stimulated cells, and serum levels of tumour necrosis factor (TNF)-alpha and transforming growth factor (TGF)-beta 1 were studied in Spain in 17 patients co-infected with HIV and Leishmania infantum who had been previously treated with pentavalent antimony. Both humoral and cellular responses to Leishmania sp. appeared diminished, 8 out of 17 patients were positive by indirect immunofluorescence, and immunoblotting detected heterogeneous antibody-binding pattern in 11 out of 13 subjects. A blastogenesis test was positive in 4 cases; 2 of them presented proliferation of CD4+ cells while CD8+ cells proliferated in the other 2 patients. Serum levels of TNF-alpha were similar to those observed in patients infected with HIV only, while serum levels of TGF-beta 1 were significantly lower in the co-infected patients. The inability of antibody response to control the parasite and the absence of specific T-cell immunity to Leishmania sp. would explain the high frequency of relapses reported in these patients. The decreased levels of TGF-beta 1 could have an important role in the interaction between the 2 pathogens.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

Molecular tracking of infections by Leishmania infantum.

Leishmania infantum is a major opportunistic parasite in patients with acquired immune deficiency syndrome and is very variable in these subjects. Isoenzyme characterization is not able to explain this variability, since half of the stocks isolated from patients co-infected with human immunodeficiency virus and Leishmania belong to zymodeme MON-1. Amplification of L. infantum minicircles by the polymerase chain reaction (PCR) and digestion of the amplified product to reveal restriction fragment length polymorphisms (RFLP) has proved very useful in distinguishing between relapses and reinfections in co-infected, treated patients. We have confirmed the existence of a leishmaniasis outbreak among intravenous drug users in north-east Spain, previously detected by isoenzymatic analysis. We have documented persistence of the same strain of Leishmania in 2 treated co-infected patients throughout several years, regardless of the theoretical rapid evolution ascribed to kinetoplast deoxyribonucleic acid minicircle sequences. We suggest using this PCR-RFLP technique to detect reinfections in treated co-infected subjects.

AIDS-Related Opportunistic Infections↗