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Impaired fitness of Mycobacterium africanum despite secretion of ESAT-6
No full textBackground. When compared with Mycobacterium tuberculosis, individuals that live in the same household as an active case of smear-positive pulmonary tuberculosis exposed to M. africanum progress less frequently to active disease within 2 years. A putative ESX-1 secretion apparatus member, Rv3879c, is mutated in M. africanum, and individuals infected with M. africanum less frequently demonstrate T-cell responses to the ESX-1-secreted virulence factor ESAT-6 than those infected with M. tuberculosis. We hypothesized that less frequent progression is caused by impaired secretion of ESAT-6.Methods. We analyzed in vivo growth and in vitro secretion of ESAT-6 and CFP-10, comparing M. tuberculosis to M. africanum and a strain of M. africanum complemented with M. tuberculosis Rv3879c.Results. ESAT-6 and CFP-10 secretion were similar for all strains, although these were enriched in M. africanum cell lysates, suggesting a modest ESX-1 secretion defect unrelated to the Rv3879c mutation. In mice, M. africanum demonstrated smaller bacterial population sizes than M. tuberculosis but similar numbers and frequencies of ESAT-6-responsive T cells in the lungs.Conclusions. These results confirm impaired fitness of M. africanum in vivo and indicate that Rv3879c is not required for secretion of ESAT-6 or for its presentation as an antigen to T cells in vivo
An analysis of timing and frequency of malaria infection during pregnancy in relation to the risk of low birth weight, anaemia and perinatal mortality in Burkina Faso
No full textImpact of prenatal multiple micronutrients on survival and growth during infancy: a randomized controlled trial
No full textBACKGROUND: Although prenatal multiple micronutrients can improve fetal growth, their benefit on postnatal health remains uncertain. OBJECTIVE: We assessed the effect of the UNICEF/WHO/United Nations University multiple micronutrient supplement for pregnant and lactating women (UNIMMAP) compared with the usual iron and folic acid supplement (IFA) on survival, growth, and morbidity during infancy. DESIGN: In a double-blind, randomized trial, we followed 1294 singleton newborns whose mothers had prenatally received either the UNIMMAP or IFA. We assessed monthly anthropometric measures and health variables up to age 12 mo. Children were assessed again at a mean age of 30 mo. Mixed-effects models accounted for repeated measurements. RESULTS: The UNIMMAP resulted in a 27% (HR: 0.73; 95% CI: 0.60, 0.87; P = 0.002) reduction in the rate of stunting in 15,261 infant-months with a higher length-for-age z score of 0.13 (95% CI: 0.02, 0.24; P = 0.02) over the whole observation period. However, by age 30 mo, this difference was not observed. An effect of the UNIMMAP on weight-for-length (P-interaction = 0.004) and head circumference-for-age (P-interaction = 0.03) became apparent by the end of the first year of life. By the age of 30 mo, children from the UNIMMAP group had a higher weight-for-height z score of 0.20 (95% CI: 0.06, 0.34; P = 0.004). No difference in mortality or morbidity was identified in groups, except a 14% reduction in reported episodes of fever (95% CI: 1%, 28%; P = 0.04). CONCLUSIONS: Improved linear fetal growth with continuation into early life and enhanced postnatal growth were 2 mechanisms that mediated the effect of the prenatal UNIMMAP on infant nutritional status. Additional follow-up to assess long-term effects is warranted. This trial was registered at clinicaltrials.gov as NCT00642408
New foci of Rhipicephalus microplus in West Africa
No full textThe invasive character of Rhipicephalus microplus was observed in Benin, the second West-African country from which this ticks species has been collected after the initial confirmed record in Ivory Coast in 2007. A cross-sectional study was carried out in the Department of Mono to examine the presence of the tick R. microplus. The survey covered 9 herds (villages) in an agro-ecological zone inhabited by agro-pastoralists, including the State Farm of Kpinnou that imported Girolando cattle from Brazil. Almost 800 ticks were sampled from 36 cattle, on average four cattle per village. The morphological identification revealed ticks of two different genera: Rhipicephalus and Amblyomma. Rhipicephalus microplus was the only representative of the species previously known as Boophilus or blue ticks. Its taxonomic identity was confirmed molecularly by PCR-RFLP. A comparison was made with the situation of R. microplus in Brazil
Managerial supervision to improve primary health care in low- and middle-income countries [comment]
No full textTaenia solium infections in a rural area of eastern Zambia; a community based study
No full textBACKGROUND: Taenia solium taeniosis/cysticercosis is a parasitic infection occurring in many developing countries. Data on the status of human infections in Zambia is largely lacking. We conducted a community-based study in Eastern Zambia to determine the prevalence of human taeniosis and cysticercosis in a rural community. METHODS AND FINDINGS: Stool and serum samples were collected from willing participants. Geographical references of the participants' households were determined and household questionnaires administered. Taeniosis was diagnosed in stool samples by coprology and by the polyclonal antibody-based copro-antigen enzyme-linked immunosorbent assay (copro-Ag ELISA), while cysticercosis was diagnosed in serum by the B158/B60 monoclonal antibody-based antigen ELISA (sero-Ag ELISA). Identification of the collected tapeworm after niclosamide treatment and purgation was done using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). A total of 255 households from 20 villages participated in the study, 718 stool and 708 serum samples were collected and examined. Forty-five faecal samples (6.3%) were found positive for taeniosis on copro-Ag ELISA while circulating cysticercus antigen was detected in 5.8% (41/708) individuals. The tapeworm recovered from one of the cases was confirmed to be T. solium on PCR-RFLP. Seropositivity (cysticercosis) was significantly positively related to age (p = 0.00) and to copro-Ag positivity (taeniosis) (p = 0.03) but not to gender. Change point analysis revealed that the frequency of cysticercus antigens increased significantly in individuals above the age of 30. Copro-Ag positivity was not related to age or gender. The following risk factors were noted to be present in the study community: free-range pig husbandry system and poor sanitation with 47.8% of the households visited lacking latrines. CONCLUSIONS: This study has recorded high taeniosis and cysticercosis prevalences and identified the need for further studies on transmission dynamics and impact of the disease on the local people
High prevalence of HIV and sexually transmitted infections among male sex workers in Abidjan, Côte d'Ivoire: need for services tailored to their needs
No full textObjectives: To assess condom use and prevalence of sexually transmitted infections (STI) and HIV among male sex workers (MSW) in Abidjan, Cote d'Ivoire.MethodsA cross-sectional survey was conducted between October 2007 and January 2008 among MSW attending a sex worker clinic in Abidjan. A short questionnaire was administered in a face-to-face interview, and the participants were asked to provide a urine sample for STI testing and to self-collect transudate of the gingival mucosa for anonymous HIV testing, using a rapid test. A rectal swab for STI testing was taken by a physician. Molecular amplification assays were performed for the detection of Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis.Results96 MSW participated in the survey, their median age was 27 years and the median duration of sex work was 5 years. Consistent condom use with clients during the last working day was 86.0%, and consistent condom use with the regular partner during the last week was 81.6%. HIV infection was detected in 50.0% of the participants. The prevalence of N gonorrhoeae was 12.8%, chlamydia infection was present in 3.2% and T vaginalis in 2.1% of the study participants.ConclusionsHIV and STI rates found in this study confirm the high risk and vulnerability status of MSW in Cote d'Ivoire. There is a definite need for studies exploring risk and risk perceptions among MSW in more depth and for services tailored to their needs, including developing and validating simple algorithms for the diagnosis of STI in MSW and men who have sex with men
Return to normal life after AIDS as a reason for lost to follow up in a community-based antiretroviral treatment program
No full textOBJECTIVES: To understand reasons for lost to follow-up (LTFU) from a community-based antiretroviral therapy (ART) program in Uganda. STUDY DESIGN: Retrospective cohort of patients LTFU between May 31, 2001-May 31, 2010 was examined. A representative sample of 579 patients traced to ascertain their outcomes. METHODS: Mixed methods were used. Using "stopped care" as the hazard and "self-transferred" as the comparator we examined using Cox proportional multivariable model, risk factors for stopping care. RESULTS: Overall, 2933/3954(74.0%) patients were LTFU. Of 579/2933(19%) patients sampled for tracing, 32 (5.5%) were untraceable, 66(11.4 %) were dead and 481 (83.0%) found alive. Of those found alive, 232(40.0%) stopped care, 249(43.0%) self-transferred, while 61(12.7%) returned to care at ROM. In adjusted hazards ratios, born-again religion, originating from outside Kampala, resident in Kampala for one year, having school-age children who were out of school, non HIV disclosure, CD4 counts >250 cells/mm3 and pre-ART were associated with increased risk of stopping care. Qualitative interviews revealed return to a normal life as a key reason for LTFU.Of 61 patients who returned to care, their median CD4 count at LTFU was higher than on return into care (401/mm3 vs. 205/mm3, P<0.0001). CONCLUSION: Many patients become LTFU during the course of years, necessitating the need for effective mechanisms to identify those in need of close monitoring. Efforts should be made to improve referrals and mechanisms to track patients who transfer to different facilities. Additionally, tracing of patients who become LTFU is required to convince them to return
