NIÑOSALUDCLIMATE × EPIDEMIOLOGY × AI
Public-health research prototype
Release 1.2 · Retrospective evidence · Not medical advice
AI for climate-resilient healthcare in Peru

Explore disease patterns. Test the evidence behind AI.

An exploratory platform combining official Peruvian epidemiological surveillance, environmental observations and territorial exposure information. It tests whether machine learning can improve early warning rather than claiming it already does.

Independent research projectCristian Daniel Medina Gomez
MINSA CDC PerúCENEPREDINEIRENIPRESS2017 / 2023 historical comparison
44,275
Piura dengue notifications · 2017
79,304
Piura dengue notifications · 2023
116
Northern districts in CENEPRED + INEI extracts
1,729
Active geocoded RENIPRESS listings in 3 regions · 2026

Research overview

An exploratory research prototype, not an operational warning system.

Explore the weekly EDA benchmark in 04, inspect the regional source audit in 06, and read the uncertainty and sensitivity analysis in 08. Models are run offline in Python; this interface displays their saved outputs.

Research note (PDF) · One-page project brief · Verification record

What actually changed in Piura?

Trends from the official MINSA historical files. Dengue and leptospirosis show notifications; EDA is a count of reported episodes, not individual people.

Legacy open-data annual series to 2024; the EDA 5+ series excludes the demonstrably incomplete 2024 historic CSV. The separate, newer CDC age-specific annual totals and updated all-age weekly series are in the research data bundle and tab 04. A rise in notifications does not establish that El Niño caused the rise.

Underlying annual series

*2024 EDA 5+: not comparable. The MINSA export contains zero entries after week 15, inconsistent with a CDC Peru dashboard export reporting 57,363 in 2024 and the DIRESA Piura SE52 report of 56,726. See the source-audit table below.

Independent source audit: Piura EDA, over age 5 (2019–2024)

The CDC Peru dashboard export provides a second official series for the same displayed indicator. It differs slightly from the older national open-data extract in 2019–2023 and dramatically in 2024. The original files are preserved; no missing weekly values have been imputed.

2024 · CDC dashboard export
57,363 episodes
2024 · MINSA historical CSV
15,451 episodes
YearOlder MINSA CSVCDC dashboard ExcelDifference
201941,71041,935+225
202020,08520,271+186
202124,69425,294+600
202232,69932,894+195
202354,31154,509+198
202415,45157,363+41,912

Root symptom: in Piura, the older national CSV records zero EDA episodes for over-age-5 from weeks 16–52 of 2024. The CDC dashboard shows nonzero weekly activity throughout that period. Zero in the CSV therefore indicates missing/incomplete surveillance content, not no disease.

Methodological boundary: the 57,363 figure is a validated annual dashboard total, not an imported district-week series. It is deliberately not inserted into the weekly machine-learning dataset; weekly 2024 EDA over-age-5 remain excluded pending a trustworthy complete export. Small differences in 2019–2023 may reflect surveillance revisions; their causes have not been determined.

Independent source audit: EDA under age 5 (2019–2024)

The October 2026 CDC Perú annual indicator download confirms 33,216 episodes and 307 hospitalizations in 2024, compared with 33,059 episodes and 297 hospitalizations in the older MINSA CSV. Both age groups are reviewed below; these are different publication snapshots, not counts to sum across sources.

2024 · Under age 5 · CDC dashboard
33,216 episodes
2024 · Under age 5 · Older MINSA CSV
33,059 episodes
YearOlder MINSA CSV, under 5CDC dashboard Excel, under 5Difference
201927,18127,386+205
202014,71814,846+128
202119,42419,603+179
202224,37024,519+149
202330,60430,778+174
202433,05933,216+157

Important distinction: all 52 weeks in the 2024 MINSA under-5 series have nonzero episode counts, unlike the incomplete older age-5+ series. Under-5 annual differences are below 1% across 2019–2024, but the reason for the differences is not yet established. The annual chart above still presents the older MINSA series, and its 2024 under-5 value of 33,059 has not been silently overwritten with the CDC annual total.

2024 admissions alert for research: the CDC dashboard records 307 under-5 hospitalizations (2023: 77). This is a substantial surveillance change that warrants investigation of referral, admission, and reporting practices; it is not proof of increased disease severity or an El Niño effect.

Evidence: CDC Perú – EDA situation dashboard · National MINSA historical open dataset · annual CDC Excel downloaded October 2026. See CDC_EDA_Piura_2019_2024_source_comparison.csv and audit_eda_piura_both_age_groups_2019_2024.csv.

Dengue surveillance update: official CSV through 2025

Original MINSA open-data extract updated 21 October 2026. The 2000–2024 national and Piura annual counts match the older file; 2025 is newly available. Notification counts are not unique patients or rates.

Piura · 2025 notifications
1,117
Piura · 2024 notifications
32,246

All 1,117 Piura records in 2025 have the confirmed diagnostic label (C), including three records classified as severe dengue. The marked decrease from 2024 does not establish a causal climatic effect. Weekly numbers are by symptom-onset week; surveillance is provisional. This addition does not retrain or validate the existing climate model.

Data source: MINSA dengue open-data catalog. Supporting reproducible extracts: dengue_piura_departamento_semanal_2016_2025.csv and data/dengue_piura_provincia_anual_2016_2025.csv.

Climate-informed early warning: does AI help?

Four-week-ahead dengue forecasting experiment for Piura. Training: 2018–2022. Held-out evaluation: 2023–2024.

ObservedSimple persistenceMachine learning + climate
Source: MINSA and CDC climate data, processed by NiñoSalud. Predictor week t versus target week t+4.

Piura precipitation history

Population-weighted mean of weekly precipitation across 65 districts; this is not the total rain volume of the region.

Where could physical exposure constrain healthcare?

CENEPRED 2026 physical-risk scenarios: flooding and mass movements. These levels are not forecasts of disease outbreaks.

District risk register

Diarrheal surveillance — Piura province-week data

Official CDC Peru 2018–2025 EDA episodes with observed climate, presented at province level. This panel uses all-age EDA; age-stratified data are available as annual summaries only.

Weekly diarrheal episodes

Number of episodes, not people or incidence rate.

Observed weekly precipitation

Rainfall cannot by itself prove that a change in EDA was caused by El Niño. Missing climatic observations are not treated as zero.

Does machine learning beat a simple baseline?

Out-of-time retrospective test, four epidemiological weeks ahead. Same province, target week and evaluation sample for both methods.

Observed vs retrospective predictions

ObservedLast observedRandom Forest

Overall retrospective evaluation

What does observed climate actually add?

Controlled retrospective ablation: identical 992 province-weeks (2023-2025), same four-week-ahead prediction target, Random Forest configuration and training years (2019-2022). Only the climate predictors change. The chart and all release documents now use this same matched experiment (climate Random Forest MAE 50.29).

MethodMAE (episodes)Interpretation
Last observed week45.09Best of tested methods
Four-week trailing average46.67Simple baseline
Random Forest + observed climate50.29Lower observed error within this RF comparison
Random Forest, EDA-only52.76Identical algorithm, without weather
Previous-year same week71.95Seasonal naive baseline
Research finding: weather features lower Random Forest error by approximately 4.7% on this evaluated sample, but the climate model still does not beat last-week persistence. This is not evidence of operational early warning.
Evaluation caution: 2023-2025 was already used to inspect a previous model. This analysis is exploratory, not an untouched final evaluation. Climate gaps excluded some 2025 observations. No validated warning thresholds or causal conclusions.

Reproduce with python research/eda_climate_ablation.py. Download detailed metric comparison. Methodological references: US CDC - Appraising models; WHO EWARS.

What the overall score conceals: differences by province

The fixed v0.8 out-of-time climate Random Forest has different error profiles by province. Positive % means the climate forest reduces MAE relative to simple persistence, not that climate alone caused the difference. All 2023–2025 exploratory observations and algorithm parameters remain unchanged.

Piura provinceEvaluationsPersistence MAERF + climate MAEChange vs persistence
Ayabaca12419.217.6+8.2%
Huancabamba12416.616.0+4.2%
Morropon12431.228.3+9.3%
Paita12428.825.6+11.3%
Piura124138.1180.4-30.7%
Sechura12411.712.0-2.7%
Sullana12473.782.6-12.1%
Talara12441.439.9+3.8%
These province-specific estimates are descriptive and based on only 124 retrospective predictions per province, from a period previously inspected in model development. This is not prospective generalization, clinical utility or a validated locality-specific warning tool.

Recalculate from the existing matched ablation predictions. Download province-level error metrics.

Why northern Peru? Historical climate-health context

El Nino is historical context for this project. No 2027 climate or epidemic forecast is generated or validated here. Consult official authorities for current forecasts.

What NinoSalud can support: a transparent review of historical surveillance, climatic anomalies, source discrepancies and district exposure classifications. It cannot generate certified outbreak warnings or predict 2027 case counts.

Official sources for current context: ENFEN announcements · MINSA CDC Peru · IMARPE coastal El Nino index (ICEN). Official outlooks are time-sensitive.

When did reported EDA depart from its historical reference?

Exploratory weekly comparison, not an epidemic detector. For each province and target week in 2023–2025, the historical reference is computed from 2018–2022 only, using observations from the same week plus/minus two weeks. Week 53 is mapped to week 52 in the historical reference. The 90th percentile is a descriptive threshold, not an estimated probability.

Weekly counts vs fixed historical reference

Observed EDA2018–2022 p902018–2022 median

Largest departures (descriptive only)

Transparent Python implementation in research/eda_reference_signals.py; download all province-week comparisons. Further database opportunities and limitations in docs/NORTHERN_PERU_SOURCE_RESEARCH.md.

Regional dengue · how long from symptom onset to recorded attendance?

A new independent audit of the GORE Piura regional dengue dataset (2023, 2025 and partial 2026), with source dictionary cross-checks. This measures the interval between the two recorded dates, not confirmed disease incidence, central reporting lag, treatment waiting time or forecast effectiveness.

Critical source mismatch: the dataset describes confirmed + possible cases without a diagnostic-status column. The 2023 snapshot ends in May, there is no 2024, and the 2026 snapshot ends June 30. It must not be merged with national confirmed-only totals.

Timing indicators

Valid interval: 0–90 days after recorded symptom onset. All exclusions are reported. The recorded attendance date may contain coding or surveillance errors.

Distribution of onset-to-attendance days

Count of records, not people or cases confirmed by laboratory testing.

Other provinces in the same cohort

Compare patterns cautiously: case definitions, rural access, incomplete reporting, epidemic timing, and date quality can all affect delays. These comparisons are descriptive, not causal.

What the data dictionary actually says

FieldDefinition in supplied official dictionaryResponsible interpretation
FECHA_INICIO_SINTOMASPatient's initial symptom dateSelf-reported or recorded onset date
FECHA_NOTIFICACIONDate patient attended health centerRecorded attendance proxy, not proven system notification timestamp
FECHA_INGRESODate entered into information systemChronology inconsistent in many rows; no reliable delay conclusion
ANOYear case was recordedNot always identical to calendar year of attendance

We found that the provided dictionary also describes UBIGEO using wording about a hydrological station and gives the notification-week field length as one character. These appear to be metadata-template errors and require source validation.

Method and aggregate-only exports in docs/REGIONAL_DENGUE_2026_AUDIT.md and data/regional_dengue_*.csv. Download province summaries. Original case-level rows are not bundled; source: GORE Piura open data.

Project background & contributions

Cristian Daniel Medina Gomez · Independent project informed by undergraduate studies in Economics and Management at Bocconi. No institutional supervision or endorsement is implied.

Project development: the project owner selected the Peru-focused direction, collected public source materials, requested iterative checks, reviewed the presentation and tested the interface.

AI-assisted research and implementation: generative AI provided substantial assistance with programming, analytical implementation, documentation and packaging. Methods, limitations and reproducible scripts are provided so that the outputs can be examined rather than accepted on trust.

The full contribution statement is included in docs/CONTRIBUTIONS.md.

Two distinct retrospective studies — do not confuse them

Dengue model: historical Piura-wide notifications, trained on 2018–2022 and tested on 2023–2024; displayed in tab 02. EDA model: provincial all-age episode counts, trained on 2019–2022 and tested on 2023–2025; displayed in tab 04. Both are exploratory and neither has demonstrated generalizable operational early warning. The 2026 exploratory ablation compares a matched EDA-only Random Forest against the same algorithm with observed weather features (tab 04).

EDA 2025 includes missing observed climate weeks. The EDA model evaluation excludes observations requiring those inputs, so its test metrics do not cover every week.

Research protocol

Research questionDo historical climate signals improve outbreak forecasting?
Unit of initial forecastPiura, weekly reported dengue notifications
Forecast horizon4 epidemiological weeks ahead
Model training2018–2022 (no random temporal split)
Evaluation years2023 and 2024
AI algorithmRandom forest, 200 trees, log-transformed counts
ComparisonPersistence (last reported week)
InputsPast counts, seasonality, past precipitation and temperature
Geospatial overlayCENEPRED 2026; not used in historical training
Medical validityNot validated for clinical or public-health deployment

Additional northern-Peru datasets identified (catalogued, not ingested)

Official sources below would support a next research phase. A new regionally scoped dengue dataset has now been audited (tab 06); other catalogued sources remain unintegrated.

SourcePotential questionStatus
DIRESA Piura · dengue notificationsSymptom onset vs recorded attendance intervalAudited; tab 06
GORE Piura · establishment EDAFacility distribution of weekly episodesCatalogue only; example 2024 file
SENAMHI · Piura station archiveWeather station coverage and qualityCatalogue only
CHIRPS v3 · rainfall gridsIndependent rainfall sensitivity checkCatalogue only
CDC Perú · October 2026 dengue dashboardCompare current surveillance across Piura, Tumbes, Lambayeque, La LibertadCatalogue only; not a historical predictor
SENAMHI · Río Piura hydrologyRiver gauge state and possible flood exposureCatalogue only

Full 11-source inventory and matching warnings in docs/NORTHERN_PERU_SOURCE_RESEARCH.md.