<i>Helicobacter pylori–Plasmodium falciparum</i> co-infection in adults in Idah, Nigeria: Prevalence, risk factors, and molecular confirmation of <i>H. pylori</i>

Background: Co-infection with Helicobacter pylori and Plasmodium falciparum represents an important public health concern in sub-Saharan Africa, where both infections are associated with environmental, behavioural, and socioeconomic conditions that may facilitate their transmission. Although H. pylori infection can affect gastrointestinal health and malaria may contribute to anaemia and systemic inflammatory responses, evidence on the occurrence of their co-infection and associated risk factors remains limited in Kogi State, North-Central Nigeria. This study therefore investigated the prevalence, molecular confirmation, and factors associated with H. pylori and P. falciparum co-infection among adults attending Zonal Hospital, Idah. Methods: A hospital-based cross-sectional study was conducted among 110 consenting adult patients attending Zonal Hospital, Idah. P. falciparum was detected using Giemsa-stained thick and thin blood-film microscopy, while H. pylori infection was detected using a validated monoclonal antibody-based stool antigen immunoassay. Molecular confirmation of H. pylori was performed by conventional PCR targeting the 16S rRNA gene, with amplified products of approximately 670 bp resolved by agarose gel electrophoresis. Sociodemographic, clinical, environmental, and behavioural data were collected using a structured questionnaire. Data were analyzed using IBM SPSS Statistics version 26. Associations between categorical variables were assessed using the Pearson chi-square test or Fisher’s exact test, as appropriate, while Pearson’s correlation analysis was used to assess relationships between relevant continuous variables. Statistical significance was set at p < 0.05. Results: Among the 110 participants, 32 (29.1%) tested positive for P. falciparum, 52 (47.3%) tested positive for H. pylori, and 12 (10.9%) had confirmed co-infection. Hygienic cooking practices were significantly associated with H. pylori infection (p < 0.001), with a substantially higher positivity rate observed among participants reporting poor hygienic cooking practices (80.5%) than among those reporting hygienic practices (27.5%). In contrast, previous H. pylori diagnosis was not significantly associated with infection (p = 0.066). Similarly, living close to mosquito breeding sites (p = 0.087) and sleeping under treated nets (p = 0.151) were not significantly associated with malaria infection. However, insecticide use was significantly associated with malaria positivity (p < 0.001), with lower positivity among insecticide users (3.3%) than among non-users (61.2%). DNA concentrations among the selected samples ranged from 78.3 to 87.0 ng/µL, exceeding the PCR quality threshold of 73 ng/µL. PCR confirmed H. pylori DNA in 8 of the 12 selected antigen-positive samples (66.7%), with distinct amplification bands at approximately 670 bp following gel electrophoresis. Conclusion: The study demonstrated a notable burden of H. pylori and P. falciparum infection and confirmed co-infection among adults attending Zonal Hospital, Idah. The identified associations with hygiene practices, proximity to mosquito breeding sites, insecticide-treated net use, and previous H. pylori diagnosis highlight the importance of integrated preventive strategies targeting modifiable environmental and behavioural factors. Although nutritional and functional-food interventions were not directly evaluated, foods with potentially gastroprotective or immunomodulatory properties represent relevant areas for future research. Integrated screening, improved sanitation and hygiene, strengthened malaria vector control, and further investigation of culturally appropriate nutritional interventions are recommended to reduce the burden and potential consequences of H. pylori and P. falciparum co-infection. Novelty of the Study: This study provides locally relevant data on concurrent H. pylori and P. falciparum infection among adults attending Zonal Hospital, Idah, and incorporates molecular confirmation of H. pylori in a subset of antigen-positive samples. The findings also identify areas for future investigation, including the potential role of culturally appropriate nutritional strategies in populations affected by co-infection.  Keywords: Helicobacter pylori; Plasmodium falciparum; co-infection; functional foods; immunomodulatory bioactive compounds; PCR; malaria; 16S rRNA; Nigeria; Kogi State