A qualitative investigation into knowledge, beliefs, and practices surrounding mastitis in sub-Saharan Africa: what implications for vertical transmission of HIV?

BACKGROUND: Mastitis constitutes an important risk factor in HIV vertical transmission. Very little, however, is known on how women in sub-Saharan Africa conceptualise health problems related to breastfeeding, such as mastitis, and how they act when sick. We aimed at filling this gap in knowledge, by documenting the indigenous nosography of mastitis, health seeking behaviour, and remedies for prophylaxis and treatment in rural sub-Saharan Africa. METHODS: The study was conducted in the Nouna Health District, rural Burkina Faso. We employed a combination of in-depth individual interviews and focus group discussions reaching both women and guérisseuers. All material was transcribed, translated, and analysed inductively, applying data and analyst triangulation. RESULTS: Respondents perceived breast problems related to lactation to be highly prevalent and described a sequence of symptoms which resembles the biomedical understanding of pathologies related to breastfeeding, ranging from breast engorgement (stasis) to inflammation (mastitis) and infection (breast abscess). The aetiology of disease, however, differed from biomedical notions as both women and guerisseurs distinguished between "natural" and "unnatural" causes of health problems related to breastfeeding. To prevent and treat such pathologies, women used a combination of traditional and biomedical therapies, depending on the perceived cause of illness. In general, however, a marked preference for traditional systems of care was observed. CONCLUSION: Health problems related to breastfeeding are perceived to be very common in rural Burkina Faso. Further epidemiological research to assess the actual prevalence of such pathologies is urgently needed to inform the design of adequate control measures, especially given the impact of mastitis on HIV vertical transmission. Our investigation into local illness concepts and health care seeking behaviour is useful to ensure that such measures be culturally sensitive. Further research into the efficacy of local customs and traditional healing methods and their effect on viral load in breast milk is also urgently needed

The NlpD Lipoprotein Is a Novel Yersinia pestis Virulence Factor Essential for the Development of Plague

Yersinia pestis is the causative agent of plague. Previously we have isolated an attenuated Y. pestis transposon insertion mutant in which the pcm gene was disrupted. In the present study, we investigated the expression and the role of pcm locus genes in Y. pestis pathogenesis using a set of isogenic surE, pcm, nlpD and rpoS mutants of the fully virulent Kimberley53 strain. We show that in Y. pestis, nlpD expression is controlled from elements residing within the upstream genes surE and pcm. The NlpD lipoprotein is the only factor encoded from the pcm locus that is essential for Y. pestis virulence. A chromosomal deletion of the nlpD gene sequence resulted in a drastic reduction in virulence to an LD50 of at least 107 cfu for subcutaneous and airway routes of infection. The mutant was unable to colonize mouse organs following infection. The filamented morphology of the nlpD mutant indicates that NlpD is involved in cell separation; however, deletion of nlpD did not affect in vitro growth rate. Trans-complementation experiments with the Y. pestis nlpD gene restored virulence and all other phenotypic defects. Finally, we demonstrated that subcutaneous administration of the nlpD mutant could protect animals against bubonic and primary pneumonic plague. Taken together, these results demonstrate that Y. pestis NlpD is a novel virulence factor essential for the development of bubonic and pneumonic plague. Further, the nlpD mutant is superior to the EV76 prototype live vaccine strain in immunogenicity and in conferring effective protective immunity. Thus it could serve as a basis for a very potent live vaccine against bubonic and pneumonic plague