The collection of Panstrongylus geniculatus bugs by inhabitants of dwellings in Caracas city (Metropolitan District) and in the neighboring Miranda and Vargas Sates, Venezuela, allowed for the gathering of data on the potential role of this sylvatic triatomine bug as a vector of Chagas disease in this area. The natural infection by Trypanosoma cruzi was recorded by examining fresh and stained faeces of the bugs. Additionally, a random amplification of polymorphic DNA technique for parasite identification and group typing was employed. A dot-ELISA test was used to identify the gut content of the triatomine bugs with the aim of assessing and quantifying the vector-human contact. Sixty-seven specimens (76.1%) were positive to T. cruzi (identified as T. cruzi I) and 60.2% (53/88) gave a positive reaction to the human antiserum. The human blood-positive samples included mixed blood meals with domestic animals (dog, pig and cow) (9.4%) and with mouse (3.8%). The overall Human Blood Index, measured as the percentage of bugs whose gut contents reacted with human antiserum on the total numbers of bugs that reacted with all the antisera tested, was 98.1%. Almost 41% of the bugs that had fed on humans were also positive for T. cruzi. These data show that the feeding of P. geniculatus on humans does not seem to be accidental and that its rate of infection by T. cruzi is high in this area which is not regarded as endemic for Chagas disease by the National Control Programme. This situation is particularly striking because it occurs in and around Caracas, the capital city, where 20% of the whole population of Venezuela live, human migrations from endemic areas are continuous, people in the crowded shantytown as well as people living in high-quality country houses are equally at risk and the epidemiological cycle Didelphis marsupialis/Rattus rattus-P. geniculatus-human does appear to occur successfully.

Sixty-eight health care workers were enrolled in a double-blind clinical trial and randomized to receive either mupirocin calcium ointment or placebo, intranasally bid for 5 days. Nasal cultures were taken immediately before starting treatment, 1 and 2 during treatment, at the end of treatment, 3 days later, weekly for 1-5 weeks and then monthly for 2-6 months after treatment. Mupirocin eliminated nasal carriage with Staphylococcus aureus in 58% of subjects within two days and 86.7% subjects by the end of therapy compared to 9.4% subjects at the end of treatment with placebo (P < 0.001). Post-treatment colonization rates of 43%, 56% and 67% were attained after 1 month, 2-4 and 6 months treatment with mupirocin respectively and recolonisation with the same strain of S. aureus that had been isolated before treatment was noted in 32%, 40% and 48%. No resistance to mupirocin developed and the drug was well tolerated. Mupirocin is safe and effective in suppressing nasal carriage of S. aureus.

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This study attempted to quantify the transmission of Trypanosoma cruzi in children less than 15 years of age in Barinas State, Venezuela and investigate risk factors for infection. Among 3,296 children, 4 (0.12%) were seropositive. The mother of one child also was also seropositive, which suggested that congenital transmission is a possible risk factor for Chagas disease in this area. Seroprevalence among the dwellers of 10 localities was 3.3%. Rhodnius prolixus was detected in 7 localities and in 8% of 125 dwellings. A multivariate logistic regression model showed that infection was associated with age, a dirt floor, and distance from houses to palm trees. The risk of infection is increased by the presence of adventitious sylvatic R. prolixus and transient or residual colonies. Insecticide spraying does not seem justified in this scenario, a finding that was also observed in other Latin American countries. New methods are therefore needed for Chagas disease control programs.

We studied the antibacterial activity of amoxycillin, clavulanic acid and the combination, against 1210 clinical isolates with plasmid-mediated ampicillin resistance, isolated at the Zaragoza Clinical University Hospital during 12 years. MICs were determined by an agar dilution technique with an inoculum of 10(4) cfu per spot. MIC50 values of amoxycillin/clavulanate ranged from 8 to 16 mg/l. The antibacterial activity of amoxycillin/clavulanate did not show any statistically significant variation during the 12-year period.

BACKGROUND The transmission routes for American cutaneous leishmaniasis (ACL) are in flux, so studies examining its transmission in humans, mammalian hosts, and sand fly vectors are urgently needed. OBJECTIVES The aim of this work was understand the epidemiological cycles of Leishmania spp., which causes ACL in the Andean Region of Venezuela, by identifying the Leishmania and the sand fly species involved in human and dog infections. METHODS Thirty-one biopsies from patients in Mérida and Táchira states with suspected ACL were studied by both parasitological tests (cultures and hamster inoculation) and a molecular test [Internal transcribed spacer 1 (ITS1) nested polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)]. We also conducted a survey to detect Leishmania infection in dogs (Immunifluorescence antibody test and ITS1 nested PCR-RFLP) and sand flies (ITS1 nested PCR-RFLP) from El Carrizal, a highly endemic focus of ACL in Venezuela. FINDINGS Three different Leishmania species were identified in the clinical samples from humans (Leishmania braziliensis, L. guyanensis, and L. mexicana) and dogs (L. guyanensis and L. mexicana). The predominant sand fly species found were those from the Verrucarum group (infected with L. mexicana) and Lutzomyia migonei (infected with L. guyanensis and L. mexicana). MAIN CONCLUSIONS We show that Lu. migonei may be the putative vector in two ACL epidemiological cycles, involving L. guyanensis and L. mexicana. We also report for the first time the presence of L. guyanensis in domestic animals.

We studied the susceptibility to the amoxycillin/clavulanate combination (2:1), and the characteristics of the beta-lactamases, of 1410 amoxycillin-resistant strains of Enterobacteriaceae (785 of Escherichia coli and 625 of Klebsiella spp.). Of the E. coli strains, 97.07% were susceptible to the combination and 98.85% produced plasmid-mediated beta-lactamases. Of the Klebsiella spp. strains, 87.84% were susceptible to the combination and 75.36% produced plasmid-mediated beta-lactamases. In both cases, the differences in MIC values, according to the characteristics of the beta-lactamases of the strains, were statistically significant. Of the 99 strains of E. coli and Klebsiella spp. that were not inhibited by amoxycillin 16 mg/l with clavulanate 8 mg/l, 19 hyperproduced chromosomal beta-lactamase; five produced a plasmid-type beta-lactamase as well. Fifty-seven strains produced two plasmid-type beta-lactamases.

Background Little is known about the prevalence of asymptomatic leishmaniasis in Venezuela. The objective of this study was to quantify Leishmania asymptomatic infection in six endemic foci of cutaneous leishmaniasis (CL) in Portuguesa State, Venezuela, where no previous data were available. Methods Study of the prevalence of Leishmania asymptomatic infection was carried out in 841 individuals from six endemic foci of CL in the municipalities Sucre and Ospino, Portuguesa State. We applied the leishmanin skin test (LST) and the internal transcribed spacer 1 (ITS1) PCR to DNA from sera and blood clots of all LST-positive and 20% of LST-negative patients. Results Of 841 inhabitants tested by LST, 197 returned a positive reaction (23.42%); all of the LST-positives (197) and 121 negatives were screened by nested PCR using serum and blood clots. Among the LST-positive group, 2.54% were PCR-positive with sera, while 44.67% were positive with blood clots. In the LST-negative group, PCR was positive in 2.48% of serum samples and in 38.84% of blood clots. Conclusions It is recommended that LST and PCR on blood clots are used together to detect exposure and asymptomatic infection and for identification of the Leishmania species.