: Persistent trachoma is a growing concern to trachoma control programs globally and programs serving Ethiopia specifically. Persistent trachoma is defined as a district with two or more trachoma impact surveys (TISs) at which the prevalence of trachomatous inflammation-follicular (TF) among children ages 1–9 years is ≥5%, the elimination threshold. Because the global target for trachoma elimination as a public health problem is 2030, research is needed to better characterize persistent trachoma. This study described the epidemiology of ocular Chlamydia trachomatis infection, the causative bacteria of trachoma, in seven contiguous districts experiencing persistent trachoma. In 2019, multistage cluster random sampling TISs were conducted in the seven districts after 10 years of interventions. All individuals ages ≥1 year were examined for trachoma clinical signs by certified graders, and conjunctival swabs were collected from children ages 1–5 years to test for C. trachomatis infection. The district TF prevalence ranged from 11.8% (95% CI:7.6–16.0%) to 36.1% (95% CI:27.4–44.3%). The range of district-level C. trachomatis infection prevalence was between 2.7% and 34.4%. Statistically significant spatial clustering of high-infection communities was observed in the study districts, and children with infection were more likely than those without to be found in households with clinical signs of trachoma and those without latrines. These seven districts appear to constitute a persistent hotspot in Amhara, where an additional 3–5 years or more of interventions will be required. The global program will need to strengthen and enhance intervention strategies within persistent districts if elimination by 2030 is to be achieved.

: Sudan is endemic for multiple neglected tropical diseases, including trachoma, onchocerciasis (OV), lymphatic filariasis (LF), and schistosomiasis (SCH). In 2019, dried blood spot samples were collected for a baseline trachoma serosurvey in three localities (El Seraif, Kotom, and Saraf Omrah) in North Darfur State. None were classified previously as OV- or LF-endemic, although low levels of SCH had been identified in all three. Approximately 30 households from 25 communities in each locality were selected by multistage cluster random sampling. Collections of DBSs were analyzed by multiplex bead assay for antibodies to multiple pathogens. This paper presents data on OV (Ov16), LF (Wb123, Bm14, Bm33), and SCH (soluble egg antigen [SEA], Sm25) antibodies among 8,322 individuals from 2,119 households. The survey-adjusted seroprevalence estimates for Ov16 were <0.3% in all localities. Lymphatic filariasis–antigen seroprevalences were discordant. Seroprevalence estimates ranged from 4.6–6.0% (Wb123), 0.99–1.4% (Bm14), and 29.2–33.3% (Bm33). Schistosomiasis seroprevalence estimates among school-aged children ranged from 2.7–8.0% (SEA) and 10.9–15.6% (Sm25). Ov16 seropositivity was low and supported the localities’ classification as nonendemic. The results suggested LF exposure, but discordance between antigens, challenges defining seropositivity thresholds, and the absence of programmatic guidance based on antibody serology alone for Wuchereria bancrofti indicate a need for remapping surveys to confirm transmission. Schistosomiasis antibody levels were high enough to warrant further mapping to guide treatment decisions. The lack of gold standards limited interpretation of results, particularly for LF, but in resource-challenged areas, integrated serological surveillance offers the possibility of efficient monitoring of exposure to multiple diseases.

Trachoma recrudescence is a serious concern for trachoma control programs. Programs define recrudescence as the return of trachomatous inflammation-follicular (TF) prevalence above elimination threshold (≥5%) on district-level trachoma surveillance surveys (TSSs). This study aimed to determine potential correlates of trachoma recrudescence within a historically highly endemic region. Between 2015 and 2021, population-based TSSs were conducted in 51 districts of Amhara, Ethiopia. District estimates were calculated accounting for multistage design; logistic regression was used to estimate the association of key correlates with recrudescence at the district level. Among the 51 districts, 17 (33%) were recrudescent. Correlates of recrudescence included indicators of historic trachoma burden, such as higher trachomatous inflammation-intense (TI) prevalence (odds ratio [OR]: 2.6, CI: 1.4–5.3) and higher Chlamydia trachomatis (Ct) infection prevalence (OR: 2.9, CI: 1.1–9.9) at the first recorded impact survey. The increased prevalence of children with clean faces (OR: 0.4, CI: 0.21–1.0) and the increased prevalence of travel time to a water source ≤ 30 min (OR: 0.5, CI: 0.2–1.1) at the TSS were associated with a protective effect from recrudescence. Data on historical trachoma burden as well as current water and sanitation conditions may help programs predict where recrudescence is more likely to occur and thus help programs sustain elimination as a public health problem.