Background: Tuberculosis (TB) is of high public health importance in Malaysia. Sabah State, located on the island of Borneo, has previously reported a particularly high burden of disease and faces unique contextual challenges compared with peninsular Malaysia. The aim of this study is to describe the epidemiology of TB in Sabah to identify risk groups and hotspots of TB transmission. Methods: We conducted a retrospective review of TB cases notified in Sabah, Malaysia, between 2012 and 2018. Using data from the state's 'myTB' notification database, we calculated the case notification rate and described trends in the epidemiology, diagnostic practices and treatment outcomes of TB in Sabah within this period. The Chi-squared test was used for determining the difference between two proportions. Results: Between 2012 and 2018 there were 33 193 cases of TB reported in Sabah (128 cases per 100 000 population). We identified several geographic hotspots, including districts with > 200 cases per 100 000 population per year. TB rates increased with age and were highest in older males. Children < 15 years accounted for only 4.6% of cases. Moderate or advanced disease on chest X-ray and sputum smear positivity was high (58 and 81% of cases respectively), suggesting frequent late diagnosis. Multi-drug resistant (MDR) TB prevalence was low (0.3% of TB cases), however, rapid diagnostic test coverage was low (1.2%) and only 18% of all cases had a positive culture result. Treatment success was 83% (range: 81-85%) in those with drug-sensitive TB and 36% (range: 25-45%) in cases of MDR-TB. Conclusion: Between 2012 and 2018, TB notifications in Sabah State equated to 20% of Malaysia's total TB notifications, despite Sabah representing only 10% of Malaysia's population. We found hotspots of TB in urbanised population hubs and points of migration, as well as evidence of late presentation and diagnosis. Ensuring universal health coverage and expansion of GeneXpert® coverage is recommended to reduce barriers to care and early diagnosis and treatment for TB.

Animal and human studies show that exposure to solar-simulated UVR is immunomodulatory. Human studies that used natural sun exposure and controlled for confounding are rare. We immunized 217 healthy adults (age range ¼ 18e40 years) with a T-celledependent antigen, keyhole limpet hemocyanin, and measured personal clothing-adjusted UVR exposure (for 5 days before and after immunization), lifetime cumulative UVR exposure, serum 25-hydroxyvitamin D concentration at immunization, and potential confounding factors. We tested cellular and humoral immune responses in relation to UVR exposure. The delayed-type hypersensitivity response to keyhole limpet hemocyanin recall challenge was lower in individuals with higher personal clothing-adjusted UVR exposure on the day before immunization (P ¼ 0.015) and during intervals spanning the day before to 2e3 days after immunization. There was an incremental increase in T helper type 17 cells (as a proportion of CD4 þ T cells) from preimmunization to postimmunization in the high, compared with the low, personal clothing-adjusted UVR exposure group (0.31% vs. e0.39%, P ¼ 0.004). Keyhole limpet hemocyaninspecific antibody titers were not associated with acute or cumulative UVR exposure or serum 25hydroxyvitamin D levels. Higher UVR exposure at antigen sensitization was associated with a reduced delayed-type hypersensitivity response and altered T helper type 17 kinetics. This has implications for the effectiveness of vaccinations and susceptibility to infections that rely on cell-mediated immune responses.

Setting: Outpatient clinics, Kota Kinabalu, Malaysia; January–April 2018. Objectives: To identify barriers to full participation in tuberculosis (TB) contact investigation. Methods: Cross-sectional study of knowledge, perceptions, and behaviours among TB contacts. This study was conducted among contacts who attended an initial clinic visit to explore retention in care. During this first visit, contacts were approached for participation in a questionnaire at a follow-up visit. Contacts who consented but did not subsequently attend were interviewed at home. Associations between questionnaire findings and attendance were tested using logistic regression. Results: Of the total 1436 identified contacts, 800 (56%) attended an initial clinic visit. Of 237 consenting TB contacts, 207 (87%) attended their follow-up appointment. In univariable analyses, the odds of attendance were highest for people notified to attend the TB clinic directly by a health inspector; close relatives of TB patients; non-students; people with higher incomes and smaller households; older individuals; males; and people not perceiving TB as stigmatising. In multivariable analysis, mode of notification to attend and having a close relative with TB remained significant. Conclusions: Health inspectors provide an effective role in TB contact investigation through direct personal communication to encourage the completion of the TB screening process, but this requires further integration with clinical processes, and with workplace and school-based investigations.

Contact investigation and TB preventive treatment of children under five years of age who are close contacts of a TB case is a key component of TB prevention. However, the uptake of TB preventive treatment is low in many high-TB burden settings. This study explores factors affecting the implementation of TB contact investigation and preventive treatment among children in Malaysia’s city of Kota Kinabalu, Sabah State. This study was conducted in three primary health clinics between 2019 and 2020. We purposively sampled 34 parents and guardians of child contacts eligible for TB preventive treatment, and 25 healthcare providers involved in the management of child contacts. We conducted thematic analysis of semi-structured interviews and focus group discussions to illicit factors affecting implementation and uptake of TB contact investigation and TB preventive therapy. Six main themes emerged from the analyses–four of these relating to contact investigation and two relating to TB preventive therapy. Factors affecting TB contact investigation were addressed under system related factors (external factors, stakeholder collaboration, healthcare workers’ and clients’ concerns), clinic related factors (perceived performance, clinic schedule, and space), healthcare worker related factors (cooperation, commitment, knowledge, misconception, counselling and communication) and patient and contact related factors (cooperation and commitment). Factors affecting TB preventive treatment delivery were addressed under guardian related factors (cooperation, commitment, knowledge and misconception) and treatment related factors (child-friendly form and adverse effects). To address gaps and barriers identified in our study, we recommend developing system capacity to maintain routine contact investigation and preventive treatment in the context of external program risks, providing training to healthcare workers to address misconceptions, safeguarding vulnerable clients against the risk of detention and deportation while accessing care, ensuring public and private services are provided regardless of migration status, and improving processes and resources for contact investigation and preventive treatment.