First Report of Widespread Wild Populations of Triatoma infestans (Reduviidae, Triatominae) in the Valleys of La Paz, Bolivia

Wild populations of Triatoma infestans, the main vector of Chagas disease in the Southern Cone countries, may be involved in reinfestation of human dwellings, limiting the success of vector-control campaigns in Bolivia. Knowledge of the distribution of these populations remains incomplete. We report here the detection of T. infestans wild populations in large areas in the department of La Paz, Bolivia. Among 18 sylvatic areas investigated, 17 were positive with T. infestans specimens. The infection rate of captured T. infestans with Trypanosoma cruzi was 85.7% in adult specimens. These results expand the geographical distribution of wild populations of T. infestans; it may be distributed throughout the Inter-Andean Dry Forest eco-region of Bolivia. The current information allows us to propose the hypothesis that a sylvatic origin of the reinfestation is located in the valleys of La Paz.     

Sexual violence

Gender-based violence is related to the power imbalance between men and women that is present, to a greater or lesser degree, in all societies. It was recognized as a human rights problem by the United Nations relatively recently. It includes emotional, physical and sexual violence. Sexual violence is the extreme form of gender-based violence, usually accompanied by the other types of violence. Its prevalence is difficult to determine, but it is likely to affect at least one-third of women at some time in their life. It has multiple effects on women's physical and gynaecological health, and these depend greatly on the quality of care that women receive immediately after the assault. Unfortunately, most emergency health services, including those in women's hospitals, are not prepared to provide the correct care for these women. Care should be multidisciplinary and should involve crisis treatment, meticulous clinical examination with complementary auxiliary methods, treatment of physical lesions, prevention of pregnancy and transmission of sexually transmitted infections, and follow-up for at least 6 months after the assault.     

New discoveries of sylvatic Triatoma infestans (Hemiptera: Reduviidae) throughout the Bolivian Chaco

Sylvatic populations of Triatoma infestans might be involved in the recolonization of human dwellings. We report here the discoveries of new T. infestans sylvatic foci in the Bolivian Chaco. Eighty-one triatomines were caught, 38 of which were identified as T. infestans. Triatoma sordida and Panstrongylus geniculatus were the other species collected. One T. infestans and one T. sordida were infected with Trypanosoma cruzi TcI; one T. infestans was infected with TcII. These discoveries add to the debate on the geographic distribution of sylvatic T. infestans populations, the geographic origin of the species, and the epidemiological role of these populations.     

Combination of cytochrome b heteroduplex-assay and sequencing for identification of triatomine blood meals

The identification of blood meals in vectors contributes greatly to the understanding of interactions between vectors, microorganisms and hosts. The aim of the current work was to complement the validation of cytochrome b (Cytb) heteroduplex assay (HDA) previously described, and to add the sequencing of the Cytb gene of some samples for the identification of blood meals in triatomines. Experimental feedings of reared triatomines helped to clarify the sensitivity of the HDA. Moreover, the sequencing coupled with the HDA, allowed the assessment of the technique’s taxonomic level of discrimination. The primers used to produce DNA fragments of Cytb genes for HDA had a very high sensitivity for vertebrate DNAs, rather similar for mammals, birds and reptiles. However, the formation of heteroduplex depended on blood meal’s quality rather than its quantity; a correlation was observed between blood meals’ color and the positivity of HDA. HDA electrophoresis profiles were reproducible, and allowed the discrimination of blood origins at the species level. However, in some cases, intraspecific variability of Cytb gene generated different HDA profiles. The HDA based on comparison of electrophoresis profiles is a very useful tool for screening large samples to determine blood origins; the subsequent sequencing of PCR products of Cytb corresponding to different HDA profiles allowed the identification of species whatever the biotope in which the vectors were captured.     

Cancer and cardiovascular-related perceived risk in a diverse cancer center catchment area

Cancer Causes & Control - Despite cancer and cardiovascular disease (CVD) sharing several modifiable risk factors, few unified prevention efforts exist. We sought to determine the association...     

Pigment gallstone pathogenesis: Slime production by biliary bacteria is more important than beta-glucuronidase production

Pigment stones are thought to form as a result of deconjugation of bilirubin by bacterial β-glucuronidase, which results in precipitation of calcium bilirubinate. Calcium bilirubinate is then aggregated into stones by an anionic glycoprotein. Slime (glycocalyx), an anionic glycoprotein produced by bacteria causing foreign body infections, has been implicated in the formation of the precipitate that blocks biliary stems. We previously showed that bacteria are present within the pigment portions of gallstones and postulated a bacterial role in pigment stone formation through β-glucuronidase or slime production. Ninety-one biliary bacterial isolates from 61 patients and 12 control stool organisms were tested for their production of β-glucuronidase and slime. The average slime production was 42 for biliary bacteria and 2.5 for stool bacteria (P <0.001). Overall, 73% of biliary bacteria and 8% of stool bacteria produced slime (optical density >3). In contrast, only 38% of biliary bacteria produced β-glucuronidase. Eighty-two percent of all patients, 90% of patients with common bile duct (CBD) stones, 100% of patients with primary CBD stones, and 93% of patients with biliary tubes had one or more bacterial species in their stones that produced slime. By comparison, only 47% of all patients, 60% of patients with CBD stones, 62% of patients with primary CBD stones, and 50% of patients with biliary tubes had one or more bacteria that produced β-glucuronidase. Most biliary bacteria produced slime, and slime production correlated better than β-glucuronidase production did with stone formation and the presence of biliary tubes or stents. Patients with primary CBD stones and biliary tubes had the highest incidence of slime production. These findings suggest that bacterial slime is important in gallstone formation and the blockage of biliary tubes. Supported by a VA Merit Review Grant. Presented at the Fortieth Annual Meeting of the Society for Surgery of the Alimentary Tract, Orlando, Fla., May 16–19, 1999.     

Contact immunotherapy of resistant warts

Contact immunotherapy has been proved effective in the treatment of resistant warts. This report chronicles our experience with a new contact immunotherapy agent, diphenylcyclopropenone. We have achieved a cure rate of 62% in 45 patients with resistant warts of all types who came to our general dermatology clinic. Cure rates may be lower in patients who have experienced multiple treatment failures. The majority of cures were obtained within 3 to 4 months. Although it appears somewhat less effective than published reports of dinitrochlorobenzene contact immunotherapy, diphenylcyclopropenone contact immunotherapy is an effective treatment for resistant warts and avoids any potential problems from mutagenicity.     

Human Cytomegalovirus Nuclear Egress Complex Subunit,UL53, Associates with Capsids and Myosin Va,but Is Not Important for Capsid Localization towards the Nuclear Periphery

After herpesviruses encapsidate their genomes in replication compartments (RCs) within the nuclear interior, capsids migrate to the inner nuclear membrane (INM) for nuclear egress. For human cytomegalovirus (HCMV), capsid migration depends at least in part on nuclear myosin Va. It has been reported for certain herpesviruses that the nucleoplasmic subunit of the viral nuclear egress complex (NEC) is important for this migration. To address whether this is true for HCMV, we used mass spectrometry and multiple other methods to investigate associations among the HCMV NEC nucleoplasmic subunit, UL53, myosin Va, major capsid protein, and/or capsids. We also generated complementing cells to derive and test HCMV mutants null for UL53 or the INM NEC subunit, UL50, for their importance for these associations and, using electron microscopy, for intranuclear distribution of capsids. We found modest associations among the proteins tested, which were enhanced in the absence of UL50. However, we found no role for UL53 in the interactions of myosin Va with capsids or the percentage of capsids outside RC-like inclusions in the nucleus. Thus, UL53 associates somewhat with myosin Va and capsids, but, contrary to reports regarding its homologs in other herpesviruses, is not important for migration of capsids towards the INM.