Impact of insecticide-treated bed nets on malaria transmission indices on the south coast of Kenya

<p>Abstract</p> <p>Background</p> <p>Besides significantly reducing malaria vector densities, prolonged usage of bed nets has been linked to decline of <it>Anopheles gambiae </it>s.s. relative to <it>Anopheles arabiensis</it>, changes in host feeding preference of malaria vectors, and behavioural shifts to exophagy (outdoor biting) for the two important malaria vectors in Africa, <it>An. gambiae </it>s.l. and <it>Anopheles funestus</it>. In southern coastal Kenya, bed net use was negligible in 1997-1998 when <it>Anopheles funestus </it>and <it>An. gambiae </it>s.s. were the primary malaria vectors, with <it>An. arabiensis </it>and <it>Anopheles merus </it>playing a secondary role. Since 2001, bed net use has increased progressively and reached high levels by 2009-2010 with corresponding decline in malaria transmission.</p> <p>Methods</p> <p>To evaluate the impact of the substantial increase in household bed net use within this area on vector density, vector composition, and human-vector contact, indoor and outdoor resting mosquitoes were collected in the same region during 2009-2010 using pyrethrum spray catches and clay pots for indoor and outdoor collections respectively. Information on bed net use per sleeping spaces and factors influencing mosquito density were determined in the same houses using Poisson regression analysis. Species distribution was determined, and number of mosquitoes per house, human-biting rates (HBR), and entomological inoculation rate (EIR) were compared to those reported for the same area during 1997-1998, when bed net coverage had been minimal.</p> <p>Results</p> <p>Compared to 1997-1998, a significant decline in the relative proportion of <it>An. gambiae </it>s.s. among collected mosquitoes was noted, coupled with a proportionate increase of <it>An. arabiensis</it>. Following > 5 years of 60-86% coverage with bed nets, the density, human biting rate and EIR of indoor resting mosquitoes were reduced by more than 92% for <it>An. funestus </it>and by 75% for <it>An. gambiae </it>s.l. In addition, the host feeding choice of both vectors shifted more toward non-human vertebrates. Besides bed net use, malaria vector abundance was also influenced by type of house construction and according to whether one sleeps on a bed or a mat (both of these are associated with household wealth). Mosquito density was positively associated with presence of domestic animals.</p> <p>Conclusions</p> <p>These entomological indices indicate a much reduced human biting rate and a diminishing role of <it>An. gambiae </it>s.s. in malaria transmission following high bed net coverage. While increasing bed net coverage beyond the current levels may not significantly reduce the transmission potential of <it>An. arabiensis</it>, it is anticipated that increasing or at least sustaining high bed net coverage will result in a diminished role for <it>An. funestus </it>in malaria transmission.</p

The monitoring of hematopoietic stem cell transplant donors and recipients from endemic areas for malaria Monitoramento de doadores e receptores provenientes de áreas endêmicas para malária em transplante de células-tronco hematopoiéticas

Malaria is an unusual complication after hematopoietic stem cell transplantation in non-endemic countries. However, transplant candidates, recipients and donors living in endemic regions frequently report previous episodes of malaria. This fact could represent an important risk for immunosuppressed recipients that could develop severe malaria cases. We report a case of hematopoietic stem cell transplant (HSCT) in which the donor had a history of previous malaria, and close monitoring was performed before and after procedure by parasitological and molecular tests. The donor presented Plasmodium vivax in thick blood smears one month after transplant and was treated according to Brazilian Health Ministry guidelines. The polymerase chain reaction (PCR) was able to detect malaria infection in the donor one week earlier than thick blood film. Even without positive results, the recipient was pre-emptively treated with chloroquine in order to prevent the disease. We highlight the importance of monitoring recipients and donors in transplant procedures with the aim of reducing the risk of malaria transmission.<br>A malária é complicação incomum após o transplante de células-tronco hematopoiéticas em países endêmicos. No entanto, candidatos a transplantes, receptores e doadores que vivem em regiões endêmicas frequentemente relatam episódios anteriores de malária. Este fato pode representar um risco importante para receptores imunossuprimidos, que podem desenvolver casos de malária grave. Relatamos um caso de transplante de células-tronco hematopoiéticas (TCTH) em que o doador teve história de malária anterior e um monitoramento por meio de exames parasitológicos e moleculares foi realizado antes e após o procedimento. O doador apresentou Plasmodium vivax na gota espessa um mês após o transplante e foi tratado de acordo com as orientações do Ministério da Saúde brasileiro. A reação em cadeia da polimerase (PCR) foi capaz de detectar a infecção por malária no doador uma semana mais cedo do que a gota espessa. Mesmo sem resultados positivos, o receptor foi preventivamente tratado com cloroquina, a fim de prevenir as formas sanguíneas assexuadas. Destacamos a importância do monitoramento de receptores e doadores em procedimentos de transplante, com o objetivo de reduzir o risco de transmissão da malária

Reclaiming humanity for asylum-seekers - A social work response

This article explores the role of social work with asylum-seekers in the UK and Australia. It raises the questions of the contradictions for the profession in the light of increasingly repressive policies in both countries. Comparing the policies in the two countries, questions are asked about current social work engagement and the potential for an enhanced role