Patrick Kirwan

Background: Malaria is a major cause of morbidity and mortality worldwide with over one million deaths annually, particularly in children under five years. This study was the first to examine plasma cytokines, chemokines and cellular immune responses in pre-school Nigerian children infected withPlasmodium falciparumfrom four semi-urban villages near Ile-Ife, Osun State, Nigeria.Methods: Blood was obtained from 231 children (aged 39–73 months) who were classified according to meanP. falciparumdensity per μl of blood (uninfected (n = 89), low density (10,000, n = 22)). IL-12p70, IL-10, Nitric oxide, IFN-γ, TNF, IL-17, IL-4 and TGF-β, C-C chemokine RANTES, MMP-8 and TIMP-1 were measured in plasma. Peripheral blood mononuclear cells were obtained and examined markers of innate immune cells (CD14, CD36, CD56, CD54, CD11c AND HLA-DR). T-cell sub-populations (CD4, CD3 and γδTCR) were intracellularly stained for IL-10, IFN-γ and TNF following polyclonal stimulation or stimulated with malaria parasites.Ascaris lumbricoideswas endemic in these villages and all data were analysed taking into account the potential impact of bystander helminth infection. All data were analysed using SPSS 15 for windows and in all tests,pP. falciparumparasitaemia was positively associated with plasma IL-10 and negatively associated with IL-12p70. The percentage of monocytes was significantly decreased in malaria-infected individuals while malaria parasitaemia was positively associated with increasing percentages of CD54⁺, CD11c⁺and CD56⁺cell populations. No association was observed in cytokine expression in mitogen-activated T-cell populations between groups and no malaria specific immune responses were detected. AlthoughA. lumbricoidesis endemic in these villages, an analysis of the data showed no impact of this helminth infection onP. falciparumparasitaemia or on immune responses associated withP. falciparuminfection.Conclusions: These findings indicate that Nigerian children infected withP. falciparumexhibit immune responses associated with active malaria infection and these responses were positively associated with increasedP. falciparumparasitaemia.

Background: Co-infection with malaria and intestinal parasites such asAscaris lumbricoidesis common. Malaria parasites induce a pro-inflammatory immune response that contributes to the pathogenic sequelae, such as malarial anaemia, that occur in malaria infection.Ascarisis known to create an anti-inflammatory immune environment which could, in theory, counteract the anti-malarial inflammatory immune response, minimizing the severity of malarial anaemia. This study examined whetherAscarisco-infection can minimize the severity of malarial anaemia.Methods: Data from a randomized controlled trial on the effect of antihelminthic treatment in Nigerian preschool-aged (6–59 months) children conducted in 2006–2007 were analysed to examine the effect of malaria andAscarisco-infection on anaemia severity. Children were enrolled and tested for malaria, helminths and anaemia at baseline, four, and eight months. Six hundred and ninety subjects were analysed in this study. Generalized linear mixed models were used to assess the relationship between infection status andAscarisandPlasmodiumparasite intensity on severity of anaemia, defined as a haemoglobin less than 11 g/dL.Results: Malaria prevalence ranged from 35-78% over the course of this study. Of the malaria-infected children, 55% were co-infected withAscarisat baseline, 60% were co-infected four months later and 48% were co-infected eight months later, underlining the persistent prevalence of malaria-nematode co-infections in this population. Over the course of the study the percentage of anaemic subjects in the population ranged between 84% at baseline and 77% at the eight-month time point. The odds of being anaemic were four to five times higher in children infected with malaria compared to those without malaria.Ascarisinfection alone did not increase the odds of being anaemic, indicating that malaria was the main cause of anaemia in this population. There was no significant difference in the severity of anaemia between children singly infected with malaria and co-infected with malaria andAscaris.Conclusion: In this cohort of Nigerian preschool children, malaria infection was the major contributor to anaemia status.Ascarisco-infection neither exacerbated nor ameliorated the severity of malarial anaemia.

Immunization against hepatitis B virus (HBV) is recommended for all sentenced prisoners and all new entrants to prison in the UK. In November 2008, acute hepatitis B was confirmed serologically in a 27-year-old man (Case 1) who had been incarcerated since February 2007. The cell mate of Case 1, a 26-year-old man was an established HBV carrier. A home-made tattoo gun was confiscated from their prison cell. In the absence of other clearly identifiable risk behaviours, tattooing was deemed to be a possible route of HBV transmission. Transmission of hepatitis B in a prison setting is a real concern and this report highlights the importance of immunizing prisoners against hepatitis B and should encourage health professionals to communicate the benefits of immunization to inmates to increase vaccine uptake.

Helminth infections can alter susceptibility to malaria. Studies need to determine whether or not deworming programs can impact on Plasmodium infections in preschool children.

The objective of this cross-sectional study was to determine the prevalence and intensity of soil-transmitted helminths (STHs) in children aged 0–25 months and to identify the associated risk factors for Ascaris lumbricoides infections. The study was conducted in three villages outside Ile-Ife, Osun state, Nigeria in May/June 2005. Stool samples (369) were processed by formol-ether concentration. Ascaris lumbricoides (12.2%) was the dominant infection. Age, father's occupation and dog ownership were identified as the significant risk factors in the minimal adequate model for A. lumbricoides. The odds of being infected with A. lumbricoides increased as the children got older. Children aged 12–17 months and 18–25 months were 8.8 and 12.4 times, respectively, more likely to harbour Ascaris than those aged 7–11 months. The odds of harbouring Ascaris for children whose families owned a dog were 3.5 times that of children whose families did not own a dog. Children whose fathers were businessmen were 0.4 times less likely to be infected with Ascaris than those whose fathers were farmers. The findings from this study suggest that many of these young children, who are at a critical stage of development, are infected with Ascaris and that the prevalence of infection with this parasite increases with age. This study has highlighted the need to incorporate preschool children into deworming programmes in endemic regions and to investigate innovative ways of delivering cost-effective deworming treatment to this high-risk age group.

Children aged between one and five years are particularly vulnerable to disease caused by soil-transmitted helminths (STH). Periodic deworming has been shown to improve growth, micronutrient status (iron and vitamin A), and motor and language development in preschool children and justifies the inclusion of this age group in deworming programmes. Our objectives were to describe the prevalence and intensity of STH infection and to investigate the effectiveness of repeated four-monthly albendazole treatments on STH infection in children aged one to four years.