Takem Ebako Ndip, Roca Anna, Cunnington Aubrey
Ministry of Health, BP 281 Buea, Cameroon.
Malar J. 2014 Oct 13;13:400. doi: 10.1186/1475-2875-13-400.
Plasmodium falciparum malaria and non-typhoid Salmonella (NTS) bacteraemia are both major causes of morbidity and mortality in children in sub-Saharan Africa. Co-infections are expected to occur because of their overlapping geographical distribution, but accumulating evidence indicates that malaria is a risk factor for NTS bacteraemia. A literature review was undertaken to provide an overview of the evidence available for this association, the epidemiology of malaria-NTS co-infection (including the highest risk groups), the underlying mechanisms, and the clinical consequences of this association, in children in sub-Saharan Africa. The burden of malaria-NTS co-infection is highest in young children (especially those less than three years old). Malaria is one of the risk factors for NTS bacteraemia in children, and the risk is higher with severe malaria, especially severe malarial anaemia. There is insufficient evidence to determine whether asymptomatic parasitaemia is a risk factor for NTS bacteraemia. Many mechanisms have been proposed to explain how malaria causes susceptibility to NTS, ranging from macrophage dysfunction to increased gut permeability, but the most consistent evidence is that malarial haemolysis creates conditions which favour bacterial growth, by increasing iron availability and by impairing neutrophil function. Few discriminatory clinical features have been described for those with malaria and NTS co-infection, except for a higher risk of anaemia compared to those with either infection alone. Children with malaria and NTS bacteraemia co-infection have higher case fatality rates compared to those with malaria alone, and similar to those with bacteraemia alone. Antimicrobial resistance is becoming widespread in invasive NTS serotypes, making empirical treatment problematic, and increasing the need for prevention measures. Observational studies indicate that interventions to reduce malaria transmission might also have a substantial impact on decreasing the incidence of NTS bacteraemia.
恶性疟原虫疟疾和非伤寒沙门氏菌（NTS）菌血症都是撒哈拉以南非洲儿童发病和死亡的主要原因。由于它们的地理分布重叠，预计会发生合并感染，但越来越多的证据表明疟疾是NTS菌血症的一个危险因素。进行了一项文献综述，以概述撒哈拉以南非洲儿童中这种关联的现有证据、疟疾-NTS合并感染的流行病学（包括高危人群）、潜在机制以及这种关联的临床后果。疟疾-NTS合并感染的负担在幼儿中最高（尤其是那些小于三岁的儿童）。疟疾是儿童NTS菌血症的危险因素之一，严重疟疾尤其是严重疟疾贫血时风险更高。没有足够的证据来确定无症状寄生虫血症是否是NTS菌血症的危险因素。已经提出了许多机制来解释疟疾如何导致对NTS的易感性，从巨噬细胞功能障碍到肠道通透性增加，但最一致的证据是，疟疾溶血通过增加铁的可用性和损害中性粒细胞功能，创造了有利于细菌生长的条件。除了与单独感染任何一种疾病的人相比贫血风险更高外，对于疟疾和NTS合并感染的人，几乎没有描述出有鉴别性的临床特征。与仅患疟疾的儿童相比，患有疟疾和NTS菌血症合并感染的儿童病死率更高，与仅患菌血症的儿童相似。抗菌药物耐药性在侵袭性NTS血清型中越来越普遍，使得经验性治疗存在问题，并增加了对预防措施的需求。观察性研究表明，减少疟疾传播的干预措施可能也会对降低NTS菌血症的发病率产生重大影响。
