Pf41 serological profiling reveals potential malaria exposure in low transmission setting in the Menoreh Hills, Central Java, Indonesia

Pf41 serological profiling may serve as an additional sero-epidemiological tool to characterize past malaria exposure, particularly in low-transmission settings where routine parasitological methods have limited capacity to detect historical exposure. In the Menoreh Hills, Central Java, where malaria transmission is low and unstable, such profiling can reveal exposure history that are not captured by conventional parasitological methods. This study evaluates the utility of Pf41 antibody responses as an exposure marker in a low-transmission context, with the Menoreh Hills serving as an epidemiologically relevant field site. A cross-sectional seroepidemiological study was conducted from January to June 2025 in four malaria-endemic villages: Sedayu, Kemejing, Kembaran, and Wadas. Serum samples from 120 individuals in malaria endemic villages and 24 healthy non-exposed controls were analyzed for anti-Pf41 IgG antibodies using a protein microarray. Demographic and behavioral data were collected through structured questionnaires, and statistical analyses were performed to assess differences in antibody responses and their associations with demographic and exposure-related factors. The results revealed a high overall Pf41 seropositivity rate of 71% (85/120) among individuals in malaria endemic villages, with marked heterogeneity across villages: Kembaran 93%, Sedayu 83%, Wadas 60%, and Kemejing 47%. Mean standardized MFI was significantly higher in all exposed groups compared to controls (p < 0.001). At the individual level, Pf41 antibody responses were significantly associated with selected behavioral factors in a site-specific manner. In Sedayu, behavioral factors showed a site-specific pattern, with frequent mosquito bites during outdoor activities at night being associated with higher Pf41 antibody levels. In Kemejing, higher antibody levels were observed among individuals who fed livestock at night. In the pooled analysis across all study sites, nighttime livestock feeding and the use of repellent was significantly associated with increased Pf41 antibody levels. These findings indicate that serological evidence of past malaria exposure remains detectable in the Menoreh Hills despite a decline in reported clinical cases, with antibody responses varying across villages and reflecting differences in behavioral risk profiles. The integration of Pf41 serology into malaria surveillance systems could complement existing approaches by contributing to the identification of populations or areas with serological evidence of prior malaria exposure in low-transmission settings. Osteoarthritis is more common in women than in men. Scientists have long known about this difference, but the reasons behind it are unclear. This study looked at whether the higher risk of osteoarthritis in women is linked to biological differences between the sexes or to pregnancy and parenting. We analyzed data from thousands of men and women in Germany, comparing those with children to those without. We found that childless men and women had similar rates of OA, suggesting that biological sex alone may not explain the difference. However, women with children were more likely to develop osteoarthritis than childless women. The risk of osteoarthritis also increased for women as the number of children they had grew. For men, having children did not seem to affect their osteoarthritis risk. These findings suggest that pregnancy and parenting may play a key role in why women are more likely to develop osteoarthritis. This study highlights the importance of considering reproductive history when studying health differences between men and women. By understanding these factors better, doctors and researchers can work toward improving prevention and treatment for osteoarthritis in men and women. ➝ Women have a higher risk of osteoarthritis (OA) compared to men, but this study found no significant difference in OA risk between childless men and women. ➝ Women with children have a significantly higher OA risk than childless women, while parental status does not affect OA risk in men. ➝ The number of children is directly associated with increased OA risk in women, but not in men. ➝ The sex difference in OA risk appears to be driven by the differential reproductive costs of pregnancy and parental care, rather than differences in biological development between sexes. ➝ These findings emphasize the importance of considering reproductive history to better understand sex differences in disease risks.