{
  "meta": {
    "title": "Project Wolbachia at ten",
    "version": "1.0",
    "checked": "2026-10-16",
    "published": "2026-10-18",
    "canonical": "https://sidc.ai/doodles/wolbachia/",
    "ogImage": "https://sidc.ai/doodles/wolbachia/og.png",
    "householdsPerSquare": 8000,
    "targetHouseholds": 800000,
    "author": "Siddhartha Chaturvedi",
    "site": "sidc.ai",
    "correctionsUrl": "https://linkedin.com/in/sidcai"
  },
  "note": "Every number shown in the Project Wolbachia at ten doodle, with its source. Coverage is in households unless the note says otherwise.",
  "beats": [
    {
      "year": null,
      "headline": "Fight mosquitoes with mosquitoes.",
      "text": "Male mosquitoes carrying Wolbachia don’t bite. When they mate with wild females, the eggs don’t hatch.",
      "sources": [
        "neaStrategy"
      ],
      "coverage": {
        "value": "800,000",
        "note": "households targeted by end-2026: half of Singapore’s households",
        "sources": [
          "mse2026"
        ]
      },
      "released": {
        "value": "None yet",
        "note": "first release on 18 October 2016",
        "sources": [
          "nea2016"
        ]
      }
    },
    {
      "year": 2016,
      "headline": "Day one.",
      "text": "On 18 October, NEA’s Environmental Health Institute releases about 3,000 males at Braddell Heights.",
      "sources": [
        "nea2016"
      ],
      "coverage": {
        "value": "4,200",
        "note": "households across three study sites",
        "sources": [
          "nea2016"
        ]
      },
      "released": {
        "value": "About 3,000",
        "note": "on day one",
        "sources": [
          "nea2016"
        ]
      }
    },
    {
      "year": 2017,
      "headline": "Half isn’t enough.",
      "text": "Phase 1 halves mosquito numbers. But mosquitoes from next door move in, and a few females slip through sorting.",
      "sources": [
        "neaPhase1"
      ],
      "coverage": {
        "value": "3",
        "note": "study sites, not counted in households",
        "sources": [
          "nea2016"
        ]
      },
      "released": {
        "value": "No figure",
        "note": "no published weekly total found",
        "sources": []
      }
    },
    {
      "year": 2018,
      "headline": "New partner.",
      "text": "Phase 2 begins in April. In September, Verily’s Debug team joins as a collaborator.",
      "sources": [
        "neaReleases",
        "mseSummit"
      ],
      "coverage": {
        "value": "2",
        "note": "Phase 2 study sites",
        "sources": [
          "neaPhase2"
        ]
      },
      "released": {
        "value": "No figure",
        "note": "no published weekly total found",
        "sources": []
      }
    },
    {
      "year": 2019,
      "headline": "Past 90%.",
      "text": "Phase 3 cuts the urban Aedes aegypti population by more than 90% across 144 residential blocks.",
      "sources": [
        "nea2019"
      ],
      "coverage": {
        "value": "144",
        "note": "residential blocks in Phase 3",
        "sources": [
          "nea2019"
        ]
      },
      "released": {
        "value": "No figure",
        "note": "no published weekly total found",
        "sources": []
      }
    },
    {
      "year": 2020,
      "headline": "The worst year.",
      "text": "Singapore’s largest dengue outbreak: 35,000+ cases. Releases cover about 8% of HDB blocks. Too few to bend the curve.",
      "sources": [
        "mseSummit",
        "malaymail",
        "nea2020"
      ],
      "coverage": {
        "value": "~8%",
        "note": "of HDB blocks covered",
        "sources": [
          "malaymail"
        ]
      },
      "released": {
        "value": "No figure",
        "note": "no published weekly total found",
        "sources": []
      }
    },
    {
      "year": 2021,
      "headline": "Fewer cases.",
      "text": "Study sites in four towns: up to 98% fewer mosquitoes and up to 88% fewer dengue cases. Observational, not yet randomised.",
      "sources": [
        "nea2021"
      ],
      "coverage": {
        "value": "860",
        "note": "HDB blocks in Yishun and Tampines by June 2021",
        "sources": [
          "nea2021"
        ]
      },
      "released": {
        "value": "No figure",
        "note": "no published weekly total found",
        "sources": []
      }
    },
    {
      "year": 2022,
      "headline": "The trial.",
      "text": "15 areas, about 724,000 residents. Eight are picked at random for releases. Seven get none.",
      "sources": [
        "nejm",
        "malaymail"
      ],
      "coverage": {
        "value": "About 300,000",
        "note": "households after the 2022 expansion",
        "sources": [
          "malaymail"
        ]
      },
      "released": {
        "value": "2 million",
        "note": "produced a week",
        "sources": [
          "mseSummit"
        ]
      }
    },
    {
      "year": 2023,
      "headline": "A million residents.",
      "text": "Releases now reach more than 300,000 households and about 30% of HDB blocks.",
      "sources": [
        "mse2023",
        "debug2024"
      ],
      "coverage": {
        "value": "300,000+",
        "note": "households, about 30% of HDB blocks",
        "sources": [
          "mse2023"
        ]
      },
      "released": {
        "value": "7 million",
        "note": "a week: capacity",
        "sources": [
          "debug2024"
        ]
      }
    },
    {
      "year": 2024,
      "headline": "96% say yes.",
      "text": "In community surveys, 96% of residents accept releases in their neighbourhood. The trial ends in September.",
      "sources": [
        "mse2024a",
        "mse2024b",
        "debug2024",
        "nejm"
      ],
      "coverage": {
        "value": "480,000",
        "note": "households from March 2024",
        "sources": [
          "mse2024b"
        ]
      },
      "released": {
        "value": "11 million",
        "note": "a week: capacity",
        "sources": [
          "debug2024"
        ]
      }
    },
    {
      "year": 2025,
      "headline": "Quietest since 2018.",
      "text": "4,036 dengue cases nationwide. MSE credits no major outbreak, a global dip and mosquito control by everyone.",
      "sources": [
        "mse2026"
      ],
      "coverage": {
        "value": "580,000",
        "note": "households from April 2025",
        "sources": [
          "mse2026"
        ]
      },
      "released": {
        "value": "11 million",
        "note": "a week: capacity, latest published (2024)",
        "sources": [
          "debug2024"
        ]
      }
    },
    {
      "year": 2026,
      "headline": "The verdict.",
      "text": "71–72% lower dengue risk in release areas. 6% of tests positive, vs 21% in control areas.",
      "sources": [
        "nejm"
      ],
      "coverage": {
        "value": "580,000",
        "note": "households (April 2025). 740,000 planned by March 2026.",
        "sources": [
          "mse2026"
        ]
      },
      "released": {
        "value": "10 million+",
        "note": "Debug’s weekly releases (May 2026)",
        "sources": [
          "debug2026"
        ]
      }
    },
    {
      "year": 2026,
      "headline": null,
      "text": "2,351 estimated dengue cases averted during the trial (95% CI 1,968–2,735). Same trial, second analysis.",
      "sources": [
        "ebiom"
      ],
      "coverage": null,
      "released": null
    }
  ],
  "evidence": [
    {
      "label": "Field study",
      "year": "2016",
      "src": [
        "nea2016"
      ]
    },
    {
      "label": "Fewer mosquitoes",
      "year": "2017",
      "src": [
        "neaPhase1"
      ]
    },
    {
      "label": "Fewer cases, observational",
      "year": "2020",
      "src": [
        "nea2020"
      ]
    },
    {
      "label": "Synthetic-control studies",
      "year": "2024",
      "src": [
        "synth"
      ]
    },
    {
      "label": "Randomised trial",
      "year": "2026",
      "src": [
        "nejm"
      ]
    }
  ],
  "sources": {
    "neaStrategy": {
      "short": "NEA, Project Wolbachia",
      "title": "NEA: Wolbachia-Aedes mosquito suppression strategy (programme page, updated 13 Aug 2026)",
      "url": "https://www.nea.gov.sg/corporate-functions/resources/research/wolbachia-aedes-mosquito-suppression-strategy"
    },
    "nea2016": {
      "short": "NEA, 18 Oct 2016",
      "title": "NEA media release, 18 Oct 2016: small-scale field study begins at Braddell Heights",
      "url": "https://www.nea.gov.sg/media/news/news/index/nea-commences-small-scale-field-study-with-release-of-male-wolbachia-carrying-aedes-aegypti-at-braddell-heights"
    },
    "neaPhase1": {
      "short": "NEA, Phase 1 results",
      "title": "NEA: Phase 1 small-scale field study, results and lessons",
      "url": "https://www.nea.gov.sg/corporate-functions/resources/research/environmental_health_institute/wolbachia-aedes-mosquito-suppression-strategy/phase-1-small-scale-field-study"
    },
    "neaPhase2": {
      "short": "NEA, Phase 2",
      "title": "NEA: Phase 2 field study, carried out in Tampines West and Nee Soon East",
      "url": "https://www.nea.gov.sg/corporate-functions/resources/research/environmental_health_institute/wolbachia-aedes-mosquito-suppression-strategy/phase-2-field-study"
    },
    "neaReleases": {
      "short": "NEA, 18 Sep 2018",
      "title": "NEA media release, 18 Sep 2018: Verily joins the ongoing Phase 2 field study, which started in April 2018",
      "url": "https://www.nea.gov.sg/media/news/news/index/project-wolbachia-singapore-welcomes-new-collaborator-for-ongoing-phase-2-field-study"
    },
    "mseSummit": {
      "short": "MSE, 2022",
      "title": "MSE: Minister Grace Fu at the 5th Asia Dengue Summit, 15 Jun 2022 (2020 outbreak, Verily partnership, production of 2 million a week)",
      "url": "https://www.mse.gov.sg/latest-news/speech-by-minister-grace-fu-at-5th-asia-dengue-summit/"
    },
    "nea2019": {
      "short": "NEA, 7 Oct 2019",
      "title": "NEA media release, 7 Oct 2019: more than 90% suppression in Phase 3",
      "url": "https://www.nea.gov.sg/media/news/news/index/successful-study-paves-the-way-for-doubling-the-size-of-male-wolbachia-aedes-mosquito-release"
    },
    "malaymail": {
      "short": "NEA via Malay Mail, 2022",
      "title": "Malay Mail, 15 Jun 2022, quoting NEA: 2020 study sites covered about 8% of HDB blocks; 2022 expansion to 31% of blocks or 300,000 homes",
      "url": "https://www.malaymail.com/news/singapore/2022/06/15/as-dengue-cases-soar-singapores-mosquito-suppressing-project-wolbachia-to-be-expanded-to-about-a-third-of-hdb-flats/12554"
    },
    "nea2020": {
      "short": "NEA, 17 Jul 2020",
      "title": "NEA media release, 17 Jul 2020: 65–80% fewer dengue cases at Yishun and Tampines study sites in 2019 (preliminary); releases to cover both towns",
      "url": "https://www.nea.gov.sg/media/news/news/index/male-wolbachia-aedes-mosquito-releases-to-cover-entire-yishun-and-tampines-hdb-towns"
    },
    "nea2021": {
      "short": "NEA, 5 Jul 2021",
      "title": "NEA media release, 5 Jul 2021: up to 98% suppression and 88% fewer dengue cases at study sites",
      "url": "https://www.nea.gov.sg/media/news/news/index/project-wolbachia-singapore-suppresses-aedes-aegypti-mosquito-population-and-reduces-dengue-cases-at-release-sites"
    },
    "nejm": {
      "short": "NEJM, 11 Feb 2026",
      "title": "Lim JT et al. Dengue suppression by male Wolbachia-infected mosquitoes. N Engl J Med 2026;394:1175–83",
      "url": "https://doi.org/10.1056/NEJMoa2503304"
    },
    "mse2023": {
      "short": "MSE, 8 May 2023",
      "title": "MSE written reply, 8 May 2023: more than 300,000 households, about 30% of HDB blocks, 1 million residents",
      "url": "https://www.mse.gov.sg/latest-news/written-reply-to-pq-on-project-wolbachia/"
    },
    "debug2024": {
      "short": "Debug, 2024",
      "title": "Debug blog, 15 Apr 2024: weekly capacity from 7 million (2023) to 11 million (2024)",
      "url": "https://blog.debug.com/2024/04/expansion-of-project-wolbachia-in.html"
    },
    "mse2024a": {
      "short": "MSE, Feb 2024",
      "title": "MSE written reply, 16 Feb 2024: 96% of residents accept releases",
      "url": "https://www.mse.gov.sg/latest-news/written-reply-to-pq-on-project-wolbachia-phase-5/"
    },
    "mse2024b": {
      "short": "MSE, 2024",
      "title": "MSE written reply, 2024: 480,000 households covered since March 2024",
      "url": "https://www.mse.gov.sg/latest-news/written-reply-to-pqs-on-dengues/"
    },
    "mse2026": {
      "short": "MSE, 13 Jan 2026",
      "title": "MSE oral reply, 13 Jan 2026: 4,036 cases in 2025; 580,000, 740,000 and 800,000 households",
      "url": "https://www.mse.gov.sg/latest-news/oral-reply-to-parliamentary-question-on-dengue-and-project-wolbachia/"
    },
    "ebiom": {
      "short": "eBioMedicine, 10 Sep 2026",
      "title": "Impact of Wolbachia-mediated incompatible and sterile insect techniques on dengue incidence: a large-scale cluster randomised controlled trial. eBioMedicine, 10 Sep 2026",
      "url": "https://doi.org/10.1016/j.ebiom.2026.106476"
    },
    "debug2026": {
      "short": "Debug, May 2026",
      "title": "Debug blog, May 2026: over 10 million released weekly from its Singapore facility",
      "url": "https://blog.debug.com/2026/05/"
    },
    "synth": {
      "short": "Lancet Microbe; Lancet Planet Health, 2024",
      "title": "Lim JT et al., Lancet Microbe 2024, and Bansal S et al., Lancet Planetary Health 2024: synthetic-control studies, as cited in the NEJM paper",
      "url": "https://www.nea.gov.sg/docs/default-source/project-wolbachia/nejm_project-wolbachia.pdf"
    },
    "nejmPdf": {
      "short": "NEJM full text",
      "title": "NEJM full text with acknowledgements, hosted by NEA",
      "url": "https://www.nea.gov.sg/docs/default-source/project-wolbachia/nejm_project-wolbachia.pdf"
    },
    "neaAuto": {
      "short": "NEA, partners",
      "title": "NEA: automation and partnerships to scale capacity (Orinno, Verily)",
      "url": "https://www.nea.gov.sg/corporate-functions/resources/research/environmental_health_institute/wolbachia-aedes-mosquito-suppression-strategy/automation-and-partnerships-to-scale-capacity"
    }
  },
  "corrections": [
    {
      "version": "1.0",
      "date": "2026-10-18",
      "note": "First published. Figures checked on 16 October 2026."
    }
  ]
}