IMMUNOLOGY AND HOST-PARASITE INTERACTIONS - ORIGINAL PAPER Parasitic infections in Malaysian aborigines with pulmonary tuberculosis: a comparative cross-sectional study Weng-Kin Wong 1 & Norazmi Mohd-Nor 1 & Rahmah Noordin 2 & Phiaw-Chong Foo 1,3 & Zeehaida Mohamed 4 & Jalaluddin Ashraful Haq 5 & Armando Acosta 1 & Maria E. Sarmiento 1 & Puvaneswari Subramaniam 6 & Jiloris F. Dony 7 & Mohamad-Noor Mohamad-Roze 1 & Sabariah Osman 2 & Boon-Huat Lim 1,2 Received: 18 February 2019 /Accepted: 19 July 2019 # Springer-Verlag GmbH Germany, part of Springer Nature 2019 Abstract The geographical distribution of tuberculosis (TB) overlaps with various parasitic infections. Uncovering the characteristics of coinfecting parasites that potentially affect the host susceptibility to TB is pertinent as it may provide input to current TB therapeutic and prophylactic measures. The present study was aimed at examining the types of parasitic infections in TB patients and healthy TB contacts (HC) in Orang Asli, Malaysian aborigines, who dwelled in the co-endemic areas. Stool and serum samples were collected from Orang Asli who fulfilled the selection criteria and provided written informed consents. Selected parasitic infections in the two study groups were determined by stool examination and commercial serum antibody immunoas- says. The prevalence of parasitic infections in TB and HC participants were 100% (n = 82) and 94.6% (n = 55) respectively. The parasitic infections comprised toxocariasis, trichuriasis, amoebiasis, toxoplasmosis, hookworm infection, ascariasis, strongyloi- diasis, and brugian filariasis, in decreasing order of prevalence. Overall, helminth or protozoa infection did not show any significant association with the study groups. However, when the species of the parasite was considered, individuals exposed to trichuriasis and toxoplasmosis showed significant odds reduction (odds ratio (OR) 0.338; 95% confidence interval (CI) 0.166, 0.688) and odds increment (OR 2.193; 95% CI 1.051, 4.576) to have active pulmonary TB, respectively. In conclusion, trichuriasis and toxoplasmosis may have distinct negative and positive associations respectively with the increase of host susceptibility to TB. Keywords Pulmonary tuberculosis . Parasitic infections . Healthy contact . Host susceptibility . Trichuriasis . Toxoplasmosis Introduction Tuberculosis (TB), an airborne transmitted disease caused by Mycobacterium tuberculosis (Mtb), is one of the major four infectious diseases (apart from malaria, HIV/AIDS, hepatitis) that leads to millions of deaths each year (Chen et al. 2015; WHO 2018). Owing to the common predisposing risk factors such as low socioeconomic status and poor hygiene practice, the geographic distribution of TB overlaps with various para- sitic diseases, which are either worldwide or region-specific (Torgerson et al. 2015; Tegegne et al. 2018). It is speculated that a parasitic coinfection could be a risk that increases the host susceptibility to TB, as the elicited immune response to counter a parasitic infection might in turn reduce the host TB immunity (Elias et al. 2008; Afifi et al. 2015; Mashaly et al. 2017; Taghipour et al. 2019). The infection outcome upon exposure to Mtb, i.e. clear- ance, containment/latent infection and progressive TB, varies from one individual to another, wherein the host innate and Section Editor: Xing-Quan Zhu * Boon-Huat Lim limbh@usm.my 1 School of Health Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia 2 Institute for Research in Molecular Medicine, Universiti Sains Malaysia, George Town, Malaysia 3 Acarology Unit, Infectious Disease Research Centre, Ministry of Health, Institute for Medical Research, Putrajaya, Malaysia 4 Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, George Town, Malaysia 5 Department of Microbiology, Ibrahim Medical College, Dhaka, Bangladesh 6 Tuberculosis and Leprosy Control Unit, Ministry of Health, Perak State Health Department, Ipoh, Malaysia 7 Tuberculosis & Leprosy Sector, Ministry of Health, Putrajaya, Malaysia Parasitology Research https://doi.org/10.1007/s00436-019-06406-7