Diarrhea in Children with Plasmodium falciparum Malaria: A Case-Control Study on the Prevalence and Response to Antimalarial Treatment

Biomarkers of Intestinal Injury and Dysfunction: Adding New Possibilities to Current Methods for Risk Stratification of Children with Malaria Disease

Malaria remains, in 2022, a major cause of pediatric preventable mortality, with its major burden disproportionately circumscribed to sub-Saharan African countries. Although only ~1 to 2% of malaria cases can be considered severe and potentially life threatening, it is often challenging to identify them so as to prioritize adequate health care and resources. In a recent investigation, M. L. Sarangam, R. Namazzi, D. Datta, C. Bond, et al. (mBio 13:e01325-22, 2022, https://journals.asm.org/doi/10.1128/mbio.01325-22) studied intestinal barrier dysfunction and injury in Ugandan children hospitalized with severe malaria and in healthy community controls. By measuring circulating levels of four different and complementary biomarkers of gut barrier dysfunction and microbial translocation, they demonstrated that intestinal injury is common in pediatric severe malaria (18% of all cases) and is associated with increased mortality, acute kidney injury, acidosis, and endothelial activation. This commentary discusses the prognostic implications of these results, knowledge gaps that remain to be filled, and how findings could be potentially translated into effective interventions to improve outcomes in children with malaria.

Intestinal inflammation and increased intestinal permeability in Plasmodium chabaudi AS infected mice

Background: Gastrointestinal symptoms are commonly associated with acute Plasmodium spp infection. Malaria-associated enteritis may provide an opportunity for enteric pathogens to breach the intestinal mucosa, resulting in life-threatening systemic infections. Methods: To investigate whether intestinal pathology also occurs during infection with a murine model of mild and resolving malaria, C57BL/6J mice were inoculated with recently mosquito-transmitted Plasmodium chabaudi AS. At schizogony, intestinal tissues were collected for quantification and localisation of immune mediators and malaria parasites, by PCR and immunohistochemistry. Inflammatory proteins were measured in plasma and faeces and intestinal permeability was assessed by FITC-dextran translocation after oral administration. Results: Parasitaemia peaked at approx. 1.5% at day 9 and resolved by day 14, with mice experiencing significant and transient anaemia but no weight loss. Plasma IFN-γ, TNF-α and IL10 were significantly elevated during peak infection and quantitative RT-PCR of the intestine revealed a significant increase in transcripts for ifng and cxcl10. Histological analysis revealed parasites within blood vessels of both the submucosa and intestinal villi and evidence of mild crypt hyperplasia. In faeces, concentrations of the inflammatory marker lactoferrin were significantly raised on days 9 and 11 and FITC-dextran was detected in plasma on days 7 to 14. At day 11, plasma FITC-dextran concentration was significantly positively correlated with peripheral parasitemia and faecal lactoferrin concentration. Conclusions: In summary, using a relevant, attenuated model of malaria, we have found that acute infection is associated with intestinal inflammation and increased intestinal permeability. This model can now be used to explore the mechanisms of parasite-induced intestinal inflammation and to assess the impact of increased intestinal permeability on translocation of enteropathogens.

Intestinal inflammation and increased intestinal permeability in Plasmodium chabaudi AS infected mice

Background: Gastrointestinal symptoms are commonly associated with acute Plasmodium spp infection. Malaria-associated enteritis may provide an opportunity for enteric pathogens to breach the intestinal mucosa, resulting in life-threatening systemic infections. Methods: To investigate whether intestinal pathology also occurs during infection with a murine model of mild and resolving malaria, C57BL/6J mice were inoculated with recently mosquito-transmitted Plasmodium chabaudi AS. At schizogony, intestinal tissues were collected for quantification and localisation of immune mediators and malaria parasites, by PCR and immunohistochemistry. Inflammatory proteins were measured in plasma and faeces and intestinal permeability was assessed by FITC-dextran translocation after oral administration. Results: Parasitaemia peaked at approx. 1.5% at day 9 and resolved by day 14, with mice experiencing significant and transient anaemia but no weight loss. Plasma IFNγ, TNFα and IL10 were significantly elevated during peak infection and quantitative RT-PCR of the intestine revealed a significant increase in transcripts for ifng and cxcl10. Histological analysis revealed parasites within blood vessels of both the submucosa and intestinal villi and evidence of mild crypt hyperplasia. In faeces, concentrations of the inflammatory marker lactoferrin were significantly raised on days 9 and 11 and FITC-dextran was detected in plasma on days 7 to 14. At day 11, plasma FITC-dextran concentration was significantly positively correlated with peripheral parasitemia and faecal lactoferrin concentration. Conclusions: In summary, using a relevant, attenuated model of malaria, we have found that acute infection is associated with intestinal inflammation and increased intestinal permeability. This model can now be used to explore the mechanisms of parasite-induced intestinal inflammation and to assess the impact of increased intestinal permeability on translocation of enteropathogens.

Malaria-induced bacteremia as a consequence of multiple parasite survival strategies

Globally, malaria continues to be an enormous public health burden, with concomitant parasite-induced damage to the gastrointestinal (GI) barrier resulting in bacteremia-associated morbidity and mortality in both adults and children. Infected red blood cells sequester in and can occlude the GI microvasculature, ultimately leading to disruption of the tight and adherens junctions that would normally serve as a physical barrier to translocating enteric bacteria. Mast cell (MC) activation and translocation to the GI during malaria intensifies damage to the physical barrier and weakens the immunological barrier through the release of enzymes and factors that alter the host response to escaped enteric bacteria. In this context, activated MCs release Th2 cytokines, promoting a balanced Th1/Th2 response that increases local and systemic allergic inflammation while protecting the host from overwhelming Th1-mediated immunopathology. Beyond the mammalian host, recent studies in both the lab and field have revealed an association between a Th2-skewed host response and success of parasite transmission to mosquitoes, biology that is evocative of parasite manipulation of the mammalian host. Collectively, these observations suggest that malaria-induced bacteremia may be, in part, an unintended consequence of a Th2-shifted host response that promotes parasite survival and transmission. Future directions of this work include defining the factors and mechanisms that precede the development of bacteremia, which will enable the development of biomarkers to simplify diagnostics, the identification of therapeutic targets to improve patient outcomes and better understanding of the consequences of clinical interventions to transmission blocking strategies.

Rethinking the economic costs of hospitalization for malaria: accounting for the comorbidities of malaria patients in western Kenya

BACKGROUND

Malaria causes significant mortality and morbidity in sub-Saharan Africa, especially among children under five years of age and places a huge economic burden on individuals and health systems. While this burden has been assessed previously, few studies have explored how malaria comorbidities affect inpatient costs. This study in a malaria endemic area in Western Kenya, assessed the total treatment costs per malaria episode including comorbidities in children and adults.

METHODS

Total economic costs of malaria hospitalizations were calculated from a health system and societal perspective. Patient-level data were collected from patients admitted with a malaria diagnosis to a county-level hospital between June 2016 and May 2017. All treatment documented in medical records were included as health system costs. Patient and household costs included direct medical and non-medical expenses, and indirect costs due to productivity losses.

RESULTS

Of the 746 patients admitted with a malaria diagnosis, 64% were female and 36% were male. The mean age was 14 years (median 7 years). The mean length of stay was three days. The mean health system cost per patient was Kenyan Shilling (KSh) 4288 (USD 42.0) (95% confidence interval (CI) 95% CI KSh 4046-4531). The total household cost per patient was KSh 1676 (USD 16.4) (95% CI KSh 1488-1864) and consisted of: KSh 161 (USD1.6) medical costs; KSh 728 (USD 7.1) non-medical costs; and KSh 787 (USD 7.7) indirect costs. The total societal cost (health system and household costs) per patient was KSh 5964 (USD 58.4) (95% CI KSh 5534-6394). Almost a quarter of patients (24%) had a reported comorbidity. The most common malaria comorbidities were chest infections, diarrhoea, and anaemia. The inclusion of comorbidities compared to patients with-out comorbidities led to a 46% increase in societal costs (health system costs increased by 43% and patient and household costs increased by 54%).

CONCLUSIONS

The economic burden of malaria is increased by comorbidities which are associated with longer hospital stays and higher medical costs to patients and the health system. Understanding the full economic burden of malaria is critical if future malaria control interventions are to protect access to care, especially by the poor.

Trends in Empirical Treatment of Hospitalized Children with Acute Gastroenteritis in Nigeria

BACKGROUND

Acute gastroenteritis is a common infectious disease with a high rate of morbidity and mortality in children below five years of age. Appropriate empirical treatment is therefore vital for reducing the incidence of the disease.

OBJECTIVE

This study aimed at determining the trends in the empirical treatment of hospitalized children with acute gastroenteritis.

METHODS

The study involved the data analysis of 88 medical folders of children who were diagnosed with gastroenteritis from January to February 2020 (a period of gastroenteritis yearly outbreak) in Mile 4 Hospital Abakaliki, Ebonyi State, Nigeria. Socio-demographic data and administered antibiotics data were collected.

RESULTS

Out of the 88 children, a total of 54 (61%) children were males, while 34 (39%) were females. The ages of the children ranged between 1-51 months, while the mean age was seen at 14 months. About 58 (66%) were diagnosed with acute gastroenteritis alone, with children aged 7-12 months recording higher numbers [25 (28%)]. Severe dehydration was seen as the most common morbidity of children with acute gastroenteritis. The guardians/parents of these children stayed at home for an average of 3 days (1-6 days) before visiting the hospital. The children were treated for an average of 5 days (2-9 days) in the hospital. The most singly used antibiotics was ciprofloxacin [31 (35%)] followed by a combination of ciprofloxacin and ceftriaxone [21 (24%)]. About 12 (14%) of the children were treated using a single dose of the antimalarial drug while 10 (11%) were treated in double combination therapy. The lowest duration in hospitalization (4 days) was seen in the use of a single dose regimen, while the highest hospitalization time (6 days) was seen in the use of a triple dose regimen.

CONCLUSION

The best empirical treatment of acute gastroenteritis may involve the use of ciprofloxacin alone and its combination with ceftriaxone. The severity of gastroenteritis may also be exacerbated with malaria.