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ViralJapanReport #50
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HIV/AIDS

艾滋病

591
Total Cases
2012-09 – 2026-08
Data Span
Report period: May 2025May 2026
Surveillance Analysis

Summary

HIV/AIDS recorded 591 cases in this reporting window. In the latest observation 2026-08-30, it reported 15 cases, +9 cases versus 6 in previous observation 2026-08-23 (+150%). The latest four observations changed -16% versus the prior four, so this is not just a one-period twitch. The combined judgement is Rising fast, with low risk (34).

Highlights

  • Current movement: Rising fast; latest 15 cases, +9 cases versus the previous observation (+150%)
  • Recent momentum: latest four observations versus prior four -16%; long-window change +10%
  • Seasonal context: No same-season baseline; same-season median ratio no same-season baseline, based on — same-season baselines
  • Historical position: latest value is at the no historical percentile of prior observations
  • Scope limit: This source is sentinel surveillance; counts reflect reported sentinel signals and should not be read as total national infections. The current source does not provide death-count fields, so missing values should not be interpreted as absence of mortality burden.

Key Findings

  • The short-term rise has case-volume support: the latest observation is +9 cases above the previous observation, not merely a low-denominator percentage artifact.
  • Seasonal context is No same-season baseline: YoY +50%, same-season median ratio no same-season baseline. The historical percentile is not extreme, so this reads more like a rapid rise within a seasonal upswing that needs confirmation over subsequent observations.
  • Risk is low, but not the highest priority tier; keep it in active review rather than classifying it as an event-level outbreak from this signal alone.
  • This source is sentinel surveillance; counts reflect reported sentinel signals and should not be read as total national infections.

Figures

Figure 1. Epidemic curve for HIV/AIDS. Monthly reported cases over the full surveillance period.
Figure 2. Monthly distribution of cases by year.

Trend Analysis

Trend judgement: Rising fast. The important point is not simply that the latest count is high; three pieces of evidence line up. First, the latest observation is +9 cases above the previous one. Second, the latest four observations changed -16% versus the prior four, indicating a steeper recent slope. Third, the long-window change remains +10%, so the background is also moving upward. With a same-season ratio of no same-season baseline and historical position at the no historical percentile, this should be treated as a seasonal/elevated rise that needs confirmation. Review prefecture distribution, age groups, sentinel coverage or reporting completeness, and any school or childcare-cluster signals next.