Correct diagnosis of childhood pneumonia in public facilities in Tanzania: a randomised comparison of diagnostic methods.

OBJECTIVE: This study compares two methods for clinical diagnosis of childhood pneumonia that aim to estimate rates of underdiagnosis and overdiagnosis of childhood pneumonia by examining the sensitivity of Integrated Management of Childhood Diseases implementation in routine care against lung ultrasound (LUS) diagnosis. SETTING: We conducted observations in 83 public health facilities (dispensaries, health centres and district hospitals) in Pwani, Dodoma and Tabora, Tanzania between October and December 2017. METHODS: We used a novel method to estimate rates of underdiagnosis and overdiagnosis of childhood pneumonia by comparing directly observed public provider diagnoses to the results of diagnoses made by trained clinicians using Mindray DP-10 ultrasound machines. We perform multivariate analysis to identify confounding effects and robustness checks to bound the result. We also explore a number of observable characteristics correlated with higher rates of agreement between provider diagnoses and ultrasound diagnoses. RESULTS: We observed 93 providers conducting exams on patients aged 2 months-5 years who presented respiratory symptoms or were given a respiratory diagnosis by the provider. Of these 957 patients, 110 were excluded from analysis resulting in a final sample of 847.17.6% of cases identified as pneumonia via LUS examinations in our sample were diagnosed as pneumonia by providers, suggesting that a significant number of pneumonia cases for which care is sought in the public sector go undiagnosed. Provider knowledge of breath counting and years of experience are positively correlated with higher agreement. While clinical examination rates are not statistically correlated with agreement, it is notable that providers conducted a clinical examination on only about one-third of patients in the sample. CONCLUSION: Our results suggest that provider training and knowledge of clinical examination protocols for pneumonia diagnosis are predictive of correct diagnosis of pneumonia and should be further explored in future research as a tool for improving quality of care.

Effect of gut microbes on olfactory behavior of Drosophila melanogaster larva.

The symbiotic relationship between an animal and its gut microbiota is known to influence host neural function and behavior. The mechanisms by which gut microbiota influence brain function are not well understood. This study measures the impact of gut microbiota on olfactory behavior of Drosophila larvae and explores possible mechanisms by which gut microbiota communicate with neural circuits. The microbiota load in Drosophila larvae was altered by treating them with antibiotics or probiotics. Control larvae and larvae with altered microbiota loads were subjected to olfactory assays to analyze the chemotaxis response of larvae to odorants. Larvae treated with antibiotics had reduced microbiota load and exhibited reduced chemotaxis response toward odorants compared to control animals. This behavioral phenotype was partially rescued in larvae treated with probiotics that resulted in partial recovery of microbiota loads. Expression levels of several olfactory genes in larvae subjected to different treatments were analyzed. The results suggest that the expression of certain components of the GABA signaling pathway is sensitive to microbiota load. The study concludes that the microbiota influences homeostatic mechanisms in the host that control GABA production and GABA-receptor expression, which are known to impact host olfactory behavior. These results have implications for understanding the bidirectional communication between a host organism and its microbiota as well as for understanding the modulation of olfactory neuron function.