This study assessed the impact of integrating NPE into the EPIWATCH® epidemic intelligence system and to determine whether this linguistic inclusion would enhance outbreak signal detection relevant to Nigeria. Our results demonstrated a 315% increase in EPIWATCH® outbreak reports in March 2024 NPE post-integration compared to the March median for the preceding period, highlighting the value of adapting AI surveillance tools to reflect the linguistic realities of diverse populations. This is particularly important in Nigeria, where the Nigerian healthcare system’s limited ability to quickly identify, diagnose, and contain outbreaks is compounded by language diversity and communication barriers.

The overall pattern of outbreaks during the 2018–2023 review period illustrates the high infectious‑disease burden in Nigeria, with the northern region disproportionately affected. This aligns with prior reports linking environmental, climatic, and infrastructural factors to disease persistence in the region [4, 23, 38]. As in earlier studies, Lassa fever and cholera were consistently prominent [6, 48], while emerging spikes in diphtheria [42] and Mpox [35, 43] show the evolving nature of outbreak threats. By comparing our findings to historical national data, we note that the integration of NPE did not just replicate known trends, in some cases, it surfaced earlier or more granular outbreak signals than traditional systems capture.

The findings also align with a growing body of evidence that local language integration in AI‑driven surveillance improves both reach and timeliness of epidemic intelligence. For example, MacIntyre et al. [33] emphasizes that multilingual data processing is crucial for effective early detection of infectious disease outbreaks. Similarly, Joshi et al. (2020) [16] found that language integration with social media data, specifically tweets, improved identification of early community‑level outbreak signals during the 2014 West African Ebola epidemic. Additionally, Silenou et al. [36] described how digital tools like SORMAS can support language integration in epidemic surveillance.

Our results contribute to this literature by providing quantitative evidence that adding NPE, a lingua franca widely understood across Nigeria, can meaningfully increase outbreak signal capture. As seen in other contexts, linguistic familiarity fosters greater public engagement with reporting channels, particularly in multilingual, resource‑limited settings where a single official language does not reflect daily communication norms. This mirrors patterns noted in culturally adapted OSINT projects elsewhere, where lowering language barriers improved both the volume and timeliness of detection.

By reframing the discussion to focus on these parallels, we emphasise that the benefit of Indigenous‑language integration is not limited to a single country or pathogen. Instead, it represents a scalable, evidence‑based strategy to strengthen epidemic preparedness globally. Future research should explore the integration of multiple Nigerian Indigenous languages, such as Hausa, Yoruba, and Igbo, into AI surveillance systems to assess further gains in sensitivity and inclusivity.

The findings in this study, demonstrate the high number of infectious diseases outbreaks in Nigeria, especially in the northern region [5, 34]. During the five-year period, some diseases displayed an increasing trend, while others showed a declining trend. These differences could be attributed to advancements in disease surveillance, raised public awareness of health issues, and the use of focused interventions [6, 10, 35,36,37].

Generally, outbreaks tend to peak during the dry season, correlating with increased rodent activity and food scarcity [38, 39]. As shown in Fig. 1 above, the fewest outbreaks were reported in 2020, which was probably caused by the COVID-19 era reporting gap or delayed surveillance systems that was linked to overburdened health systems in low resourced countries [40, 41]. The pattern of the trend of reported outbreaks over the five-year period was not consistent [42]. Apart from the increased reported diphtheria outbreak in 2023[43] and that of Mpox in 2022 [44], Lassa fever and cholera outbreaks were reported nearly year-round during the five-year period [45, 46].

The increase in outbreak detection following the integration of NPE into EPIWATCH® matches findings from other contexts where adapting language or culture, improved surveillance capacity. For instance, involving multiple languages has been shown to increase participation and reporting in multilingual health systems [21, 25, 27, 28]; supporting our observed post-NPE integration observations. Similarly, reports from other culturally specific OSINT and syndromic surveillance projects [14, 15, 25] indicate that lowering language barriers can enhance case capture efficiency and timeliness.

The geographic concentration of outbreaks in northern Nigeria reflects patterns mentioned by Ibrahim et al. [4, 23] and Redding et al. (2021) [38] i.e. environmental, climatic, and infrastructure factors that drive high disease burden in this area. The prominence of Lassa fever and cholera in our dataset corresponds with the endemic profiles described by Dalhat et al. (2022) [6] and Elimian et al. (2020) [48]. However, our results suggest more consistent year-round reporting, likely showing that OSINT-based detection is more sensitive than traditional methods.

In contrast, our discovery of a sharp rise in reported diphtheria in 2023 stands out from the longer-term national decline noted by Abdulrasheed et al. (2023) [43]. This difference may stem from both a real outbreak resurgence and better case identification due to expanded NPE search capabilities. Likewise, although Mpox was reported sporadically in both our study and Silenou et al. (2020) [36], our spike in 2022 was proportionally larger. This could be due to increased media attention and OSINT sensitivity following global case rises.

These comparisons indicate that the NPE integration did not just mirror trends found in earlier studies; in some instances, it uncovered more detailed or earlier signals. This implies that culturally and linguistically adapted OSINT platforms can support, and in some situations, surpass traditional reporting systems in both speed and thoroughness. This improvement enhances the overall surveillance structure in resource-limited areas.

Common Outbreaks in Nigeria during the five-year Period

Lassa Fever: With outbreaks occurring frequently throughout Nigeria, Lassa fever remains a serious public health problem there. The incidence of Lassa fever outbreak reports from open sources has increased alarmingly over the past five years. Several factors contribute to the spread of the disease, such as inadequate healthcare infrastructure, poor sanitation and limited access to treatment and diagnostic services. Early detection, case management, and community-based interventions have been the mainstays of efforts to contain Lassa fever outbreaks; however, difficulties still exist in guaranteeing an efficient and prompt response to outbreaks.

Cholera: Another major threat to public health in Nigeria is cholera outbreaks, which are especially common during the rainy season. Over the past five years, there has been variability in the incidence of cholera, with periodic spikes in signals reported in different states. In afflicted communities, cholera is spread by poor sanitation, tainted water sources, and overcrowding. Clean water supply, hygienic education, immunization campaigns, and better case management in medical facilities are examples of control measures.

Yellow Fever: Although fewer often occurring, yellow fever outbreaks are still a concern in Nigeria. Over the previous five years, there has been fluctuation in the incidence of yellow fever, with intermittent outbreaks taking place in various areas. Initiatives to vaccinate high-risk groups have aided in slowing the disease’s spread.

Diphtheria: During the previous five years, there has been a decrease in the incidence of this vaccine-preventable disease in Nigeria. Diphtheria signals have decreased in part because of routine vaccination with the diphtheria-tetanus-pertussis (DTP) vaccine. To keep the spread of diphtheria under control, regular immunization programs must be strengthened, surveillance must be improved, and suspected signals must have prompt access to medical care.

Mpox: Over the past five years, there have been intermittent reports of Mpox outbreaks in Nigeria, despite the disease being comparatively uncommon in comparison to other illnesses. To stop the spread of Mpox, surveillance programs and public health initiatives like case isolation and contact tracing are crucial. Early detection and response to outbreaks can be facilitated by increasing public and healthcare provider knowledge of the signs, symptoms, and mode of transmission of Mpox.

The significant number of reported outbreaks recorded over the five-year study period poses a concern because many of those diseases have a high morbidity and death rate, especially when early diagnosis and proper treatment are lacking. These findings support earlier reports of endemicity in Nigeria and other West African countries [47]. The substantial number of outbreaks reported in Edo and Ondo could be caused by ecological and cultural practices, or by the reservoir’s existence in the states; besides having a sizable treatment facility in Edo State, where many of the country’s Lassa fever cases are handled, food is also dried outside [39, 48]. It is not recommended to rely solely on prior reports of seasonal variations in case occurrence for preparatory activities, considering the nearly year-round outbreak frequency during the five-year study period and the asymmetrical pattern of peak occurrence of confirmed cases. It also supports recorded accounts that different outbreaks can happen at any time of the year. To successfully monitor and respond to disease trends and guarantee ongoing advancements in disease control and prevention initiatives, it is essential to maintain improved surveillance measures. Our analysis illustrates the geographic distribution of reported outbreaks in all the 36 states and the geopolitical zones [39]. The geographical distribution pattern suggests that targeted public health interventions are needed in the northern region to mitigate the impact of outbreaks and improve overall health outcomes in these areas.

A review of health patterns in Nigeria over the previous five years indicates a complicated interaction between different infectious diseases. Effective immunization campaigns have led to a decline in some diseases, like diphtheria, but the public health remains seriously threatened by others, like Lassa fever and cholera [6, 49]. The persistence of these diseases is attributed to a few factors, including limited access to healthcare services, poor sanitation, and inadequate healthcare infrastructure. Furthermore, the periodic emergence of illnesses such as Mpox and yellow fever highlights the significance of strong surveillance systems and quick reaction times in managing infectious diseases in Nigeria [44, 50]. Comprehensive strategies that combine efforts in prevention, detection, and response are necessary to effectively address the burden of these diseases [4, 5]. This entails bolstering vaccination rates, boosting access to necessary services, encouraging good sanitation and hygiene habits, and fortifying healthcare systems. To reduce the burden of infectious diseases in Nigeria and achieve long-lasting improvements in public health outcomes, cooperation between government organizations, healthcare providers, and foreign partners is essential. Also, enhanced surveillance and early detection are essential to this collaboration because they allow for the prompt identification and containment of disease outbreaks, preventing the spread of infectious diseases and lessening their effects on the populace.

A major step toward enhancing disease surveillance in Nigeria is the integration of NPE into EPIWATCH®. This approach emphasizes inclusive strategies to effectively address health challenges, while acknowledging the significance of cultural and linguistic diversity in public health interventions. By comparing the common outbreaks from March 2024 with those from previous years using EPIWATCH®, one can gain insight into how Nigeria’s disease patterns are evolving. Since certain diseases may show consistent trends over time while others may show fluctuations or emerge as new challenges, an understanding of these temporal variations is crucial for customizing public health interventions to address evolving health needs and priorities. The results hold great significance for public health response tactics in Nigeria, as improved surveillance capacities allow officials to identify epidemics sooner, take immediate action, and deploy resources more effectively. This proactive strategy is essential for preventing the spread of disease, reducing morbidity and mortality, and eventually enhancing population health outcomes. The integration of NPE into EPIWATCH®, demonstrates the potential of using OSINT to improve disease surveillance and response.

While BBC News archives could, in theory, be used to retrospectively apply NPE search terms over the 2018–2023 period for a head to head comparison of detection rates, the limited prevalence of NPE in that source and its lack of extensive translation data reduce its suitability as a standalone comparator. However, the concept of a retrospective, same-period analysis remains compelling. A future study could implement this approach across a broader range of historical open source media and social platforms where NPE is more widely used, enabling a truer comparable evaluation of outbreak detection with and without NPE integration.