The short version
- Three different clocks govern illness reporting into a US port, and they are set by passenger count, not by vessel size or flag[1].
- Every ship destined for a US port must report immediately any death or ill person among passengers or crew in the 15 day period before expected arrival[1].
- A ship carrying 13 or more passengers owes a second report: acute gastroenteritis case numbers 24 hours before arrival[1].
- Cases arising after that go in a further report not less than 4 hours before arrival[1].
- CDC’s Vessel Sanitation Program only reaches cruise ships with 13 or more passengers on a foreign itinerary with US ports[2]. Cargo, fishing, towing and OSV tonnage carry the duty with no programme behind it.
- Search results for vessel outbreak planning surface 33 CFR 155.1045, which is an oil pollution response plan rule[4]. It has nothing to do with disease.
Google answers this question with an oil spill regulation
Search for vessel outbreak response plan requirements and page one returns cruise specific CDC material, IMO and WHO guidance, and 33 CFR 155.1045. That last one is the vessel response plan rule for ships carrying oil[4]. It sits in the pollution subchapter, it is administered by the Coast Guard, and it does not mention communicable disease.
The confusion is understandable and expensive. An operator following that thread builds a plan against the wrong regulation, in the wrong subchapter, answerable to the wrong agency. The rules that actually govern illness arriving at a US port live in 42 CFR part 71, under 42 U.S.C. 264[3].
The three clocks, and what starts each one
42 CFR 71.21 is one short section carrying three separate duties. Most operators know the first and have never read the other two[1].
42 CFR 71.21(a), Report of death or illness
“The master of a ship destined for a U.S. port shall report immediately to the quarantine station” any death or any ill person among passengers or crew “within the 15-day period preceding the date of expected arrival.”[1]
| Clock | Trigger | Deadline | Who it binds |
|---|---|---|---|
| Death or ill person | Any death, or any ill person, in the 15 days before expected arrival[1] | Immediately | Every ship destined for a US port. No passenger threshold, no tonnage floor |
| AGE case count | Acute gastroenteritis cases aboard[1] | 24 hours before arrival | Ships carrying 13 or more passengers |
| AGE update | Cases arising after the 24 hour report[1] | Not less than 4 hours before arrival | Same ships, same voyage |
The first clock is the one that catches cargo operators. It has no passenger threshold. A towing vessel, a fishing vessel or a tank vessel with a crew of eight owes exactly the same immediate report as a cruise ship[1].
The 15 day lookback is the detail most often missed. The duty is not limited to someone sick on the day you arrive. If a crew member was ill fifteen days ago and recovered, the report still attaches. We cover the definition question and what counts as an ill person in CDC death and illness reports at sea.
Why thirteen passengers is the line that decides your plan
Thirteen is the number that appears in both places. It sets the AGE reporting duty in 42 CFR 71.21(c)[1], and it sets the jurisdictional limb of CDC’s Vessel Sanitation Program, which reaches cruise ships carrying 13 or more passengers on a foreign itinerary with US ports[2].
Two limbs, both required for VSP. Thirteen passengers, and a foreign itinerary touching US ports. Fail either and the programme does not reach you, although the reporting duty still does.
| Vessel | 71.21(a) immediate report | 71.21(c) AGE clocks | Inside VSP? |
|---|---|---|---|
| Cruise ship, foreign itinerary | Yes[1] | Yes[1] | Yes, inspections and standards apply[7][8] |
| Passenger vessel, domestic only, 13+ passengers | Yes[1] | Yes[1] | No. The itinerary limb fails[2] |
| Cargo, tanker, bulk | Yes[1] | No, under 13 passengers | No programme, no inspection regime, duty stands |
| Fishing, towing, OSV | Yes[1] | No | No programme, duty stands |
What CDC can do when the report lands
Reporting is not the end of it. 42 CFR 71.31 gives CDC authority to inspect a carrier[6], and 42 CFR 71.33 provides for provisional detention of persons, carriers and things[5]. Within its jurisdiction VSP also runs unannounced operational inspections against a published standard[7][8].
The practical exposure is schedule, not fine. A vessel held at anchor while a quarantine officer works through a case costs more per day than any penalty in the section. That is the argument for having the report drafted before it is needed, with the clinical detail a quarantine officer will ask for already gathered.
Note where the sanitation rules stop. 42 CFR part 71 subpart D builds a vessel sanitation inspection and control scheme[9], but it is scoped to the same cruise population as VSP[2]. A cargo operator reading part 71 will find a reporting duty that binds them and a control scheme that does not.
Building the plan US law does not require
There is no federal requirement for a non-cruise US vessel to hold a communicable disease response plan. That is a gap, not a permission. The reporting clocks run whether or not anyone aboard knows they exist, and a master who has never read 42 CFR 71.21 will miss the 15 day limb every time.
- Put the three clocks in the SMS as three separate entries. One immediate, one at 24 hours, one at 4 hours[1]. Written as a single line about reporting illness, the second and third are always lost.
- Name the quarantine station for each intended port before sailing. The duty is to report immediately, and immediately does not allow time to find a number.
- Define who assesses the case. The master reports, but someone has to decide whether this is an ill person. That decision benefits from a physician on the line, which is where maritime medical consulting sits.
- Record the 15 day window continuously. A running illness log is the only way to answer the lookback honestly. It also feeds crew medical record obligations.
- Separate this from the medevac decision. Reporting and evacuation are different calls on different clocks, and we set the second out in when to medevac or disembark a seafarer.
- Do not confuse it with pollution response. 33 CFR 155.1045 is an oil rule[4]. Keep it in the pollution file where it belongs.
Where illness reporting sits in a vessel medical programme
This layer connects to the others in ways operators rarely map. An outbreak aboard draws on the medicine chest, which may hold scheduled medication governed by 21 CFR 1301.25[12]. Isolation draws on hospital space requirements. Waste from a case draws on vessel medical waste rules. Vessel hygiene draws on potable water and sanitation, and on the regimes that reach a foreign flag vessel in a US port.
Discovery Health MD maps those layers against a fleet’s flag and route, and says which apply and which do not, cited to the governing rule. Start with the six decisions or a vessel medical compliance audit. Speak to the team.
Common questions
Which vessels must report illness before arriving at a US port?
Every ship destined for a US port. 42 CFR 71.21(a) binds “the master of a ship destined for a U.S. port” with no tonnage floor, no passenger threshold and no flag distinction[1]. That includes Great Lakes traffic, offshore supply vessels and foreign flag tonnage. The AGE clocks in paragraph (c) are the ones limited to ships carrying 13 or more passengers[1].
What is the 15 day period in 42 CFR 71.21?
It is a lookback, not a forecast. The report covers any death or any ill person among passengers or crew “within the 15-day period preceding the date of expected arrival”[1]. A case that arose two weeks ago and resolved is still inside the window. This is the limb most often missed, because crews naturally think of the duty as reporting who is sick today. The report itself covers what has to go in it.
What are the 24-hour and 4-hour reports?
They are the acute gastroenteritis clocks for ships carrying 13 or more passengers. The number of AGE cases is reported 24 hours before arrival, and cases arising after that report go in a further report not less than 4 hours before arrival[1]. Both are separate from the immediate report under paragraph (a), and a vessel can owe all three on the same voyage[1].
Does my cargo ship need an outbreak response plan?
No US federal rule requires one for a cargo vessel. CDC’s Vessel Sanitation Program and its published standards reach cruise ships carrying 13 or more passengers on a foreign itinerary with US ports[2][8], and nothing equivalent exists outside that. The reporting duty under 42 CFR 71.21(a) still applies in full[1], so the sensible position is a short written procedure that names the clocks, even though no inspector will ask for it.
Is 33 CFR 155.1045 the vessel outbreak plan rule?
No, and this is a common and costly mix-up. 33 CFR 155.1045 sets response plan requirements for vessels carrying oil[4]. It is a pollution rule in a Coast Guard subchapter and contains no communicable disease provision. Disease reporting into a US port is governed by 42 CFR part 71 under 42 U.S.C. 264[1][3]. The same pattern of a search result pointing at the wrong instrument shows up in uninspected vessel first aid requirements.
What can CDC do after a report is made?
Inspect and detain. 42 CFR 71.31 provides the inspection authority over carriers[6], and 42 CFR 71.33 provides for provisional detention of persons, carriers, and things[5]. Within VSP jurisdiction, there are also unannounced operational inspections against a published standard[7][8]. The realistic cost is delay rather than penalty, which is why the clinical detail should be assembled before the call, not during it.
How does this differ from a ship sanitation certificate?
Completely. A sanitation certificate is an International Health Regulations instrument about vessel hygiene[11], and CDC does not require ships to present one at US ports[10]. Illness reporting is a US statutory duty about people, running on the three clocks above[1]. A vessel can hold a valid exemption certificate and still be detained under 42 CFR 71.33 because someone aboard is ill[5].
