After a tick bite, how long for disease transmission?
A single tick bite can transmit several diseases. But investigators continue to debate how long a tick must be attached before it can transmit the Lyme disease bacterium. While many believe a tick must be attached for at least 36 to 48 hours before transmission can occur, others say it can happen within several hours.
People often ask: How long does it take for disease transmission to occur after a tick bite? According to investigators, Lyme disease may be transmitted faster if the tick previously fed on another host.
In a 2014 article entitled “Lyme borreliosis: a review of data on transmission time after tick attachment,” Michael J Cook explored the topic. “It is frequently stated that the risk of infection is very low if the tick is removed within 24 to 48 hours with some claims that there is no risk if an attached tick is removed within 24 hours or 48 hours.”
However, in animal models, Cook found, “transmission can occur in less than 16 hours, and the minimum attachment time for transmission of infection has never been established.”
Have you been bitten by a partially fed tick?
Investigators suggest that transmission time may be shorter if a tick has already fed on a host. A study by Shih and colleagues, found that, “Partially fed nymphal ticks transmit spirochetal infection more rapidly than do ticks that have never been attached to a host.”¹
So, how quickly a tick can transmit Lyme disease may depend on whether the tick had been partly fed BEFORE it attached to its second host.
Shih et al. demonstrated that partially fed nymphal ticks (84%) were capable of transmitting spirochetes to a non-infected mouse within 24 hours. The authors discovered it took less time for an infected nymphal deer tick to transmit Lyme spirochetes to a mouse if the tick was partially fed.
Ticks spontaneously detach from hosts
Individuals may mistakenly believe that once a tick bites it will remain attached throughout the entire feeding or until it is removed. But this isn’t the case.
In the mouse study, Shih found that ticks can spontaneously detach during the feeding process. And this action can profoundly impact the time it takes for spirochetes to infect the host.
“Virtually all nymphal ticks that previously had fed for 16 hours reattached efficiently.”¹
“We found that nymphs do detach spontaneously from free-ranging mice in the laboratory, perhaps as frequently as 15% of the time,” the authors report.
“Indeed, about [one tenth] of questing nymphs in nature seem to be distended, and reattachment by partially fed sub-adult ticks commonly occurs.”
In the laboratory, partially fed ticks would reattach to a second host and commence feeding. “Virtually all nymphal ticks that previously had fed for 16 hours reattached efficiently.”
What happens in partially fed ticks?
The tick attaches to a host, feeds and the Lyme bacteria multiply rapidly in the tick’s mid-gut. Normally, the tick eliminates all of the bacteria, leaving behind only those spirochetes that survive in the mid-gut before they molt into an adult.
But, in a partially fed tick, spirochetes multiply in the mid-gut and then move to the salivary glands.
If the tick bites again, the spirochetes residing in the salivary glands can be transmitted more quickly. “Partially fed nymphs [ticks] are able to reattach to another host and Lyme disease spirochetes may be transmitted by partially fed nymphs more rapidly than by nymphs that have not already fed.”
Pet owners: be wary
Their findings are particularly relevant to people who own pets. “These partially fed ticks may already have acquired spirochetal infection and avidly seek other hosts,” writes Shih.
“Pet ownership appears to be a risk factor for human Lyme disease, and this may reflect contact with ticks that have detached from a cat or dog within the household.”
If an unfed tick attaches it can take up to 36 hours to transmit the Lyme spirochetes to a mouse, Shih claims. “The chain of events that culminates in migration of the spirochetes from the gut of the tick to its salivary apparatus begins within the first day of attachment and requires at least another day for completion.”
Note: The study by Shih and colleagues was conducted only with mice and has not been replicated with humans.
Related Articles:
References:
- Shih CM, Telford SR, 3rd, Pollack RJ, Spielman A. Rapid dissemination by the agent of Lyme disease in hosts that permit fulminating infection. Infect Immun, 61(6), 2396-2399 (1993).
Rosa
11/12/2023 (10:38 am)
I was bit by a tick 7 days ago that I sent in to Ticktest and it tested negative for everything. I have developed some symptoms of achey joints, nothing severe but I do feel concerned. Should I take antibiotics even though the tick tested negative? 7-10 days? 20 days? Is it too late since the bite was 7 days ago? Thank you Dr Cameron.
Dr. Daniel Cameron
11/13/2023 (10:45 am)
I have patients who developed tick borne infections despite a negative test from the tick. One study said that blood may interfere with the testing. The bacteria may not survive in transit. I am not a fan of a single dose of doxycycline as advised by the CDC. The single dose would have had to be given in 72 hours. I am not a fan of sitting any symptoms that occur within 6 weeks of a known tick bite. I typically treat as if there were an EM rash with followup. The duration would be determined by your doctor along with followup.
Naomi
07/24/2023 (4:40 pm)
My very worst case of Lyme happened after a dine and dash little one got me. Literally walked about 2 yards off a deck, into dirt/gravel drive where the car was parked. Couple little clumps of weeds I keep mowed down. Went back inside, took a shower with a loofah. By midday, I was feeling even worse than usual. Full disclosure, I have had over 40 latchons in my life, been dealing with it since way back when Lyme, et al, was lumped under Woodsman’s Disease or nothing, possible infection in vitro. But can trace back Sept 1976, three months before I turned 9.
By that night, I had a red patch. I had used the heating pad all day, and honestly thought I had a burn. It grew over the next couple weeks, could not see any indication of a bite of any sort. I ended up basically bed ridden, could not hold a fork to eat, and all my normal symptoms were exponentially worse.
Ended up at doc for regular appointment, showed the nurse, she said, “Lyme”. Ended up immediately on a PICCline with Ceftriaxone, because I had already been taking Doxy prior to the bite. It wasn’t until almost a week into the picc when the tiniest blister like spot appeared, barely visible, showing where it had hit me. PICC was 28 days, they would not give me a bigger dose or longer, but, oh man, did I feel better than I had for years and years. My BP and blood sugars started stabilizing on their own. Within two days of it being pulled, I went backwards. Couple months later I had a double bypass, which half failed, to where now, I have zero life. Good thing I have a smart aleck attitude, and can laugh at everything.
Sorry for all the typos and bad grammar, I cannot proof things and with brain fog and aphasia, I am lucky to even get something in writing.
Karen Diehl
07/24/2023 (12:45 pm)
My husband came down with a very severe debilitating headache with shooting pains on and off beside his ear which lasted 4 days. He thought he had a pinched nerve in his neck which was creating the headache. His couldn’t see his chiropractor for a few days. He had a treatment and initially felt somewhat better and the following day he broke out in a rash on his upper arm and torso. No bullseye. He then remembered removing a tick from behind his ear, the same area where the shooting pain occurred, the previous week prior to the start of the headache. The tick was NOT attached and it was crawling and he removed it but didn’t think to save it.
His doctor saw him the following day, began treatment of Doxy, 2xper day for 21 days. The test did come back positive for Lymes disease. I always thought the tick had to be imbedded but in my husband’s case, it must have just bit him and kept crawling.
Is this the most current treatment out there and is this the recommended treatment? We’re not sure if we should be doing something else.
Beth Pamela Mack
07/24/2023 (9:31 am)
My 17 year old son was diagnosed with potential lyme disease 3 weeks after a tick bite. He has Bell’s palsy secondary to Lyme which is what lead to the diagnosis. He also had a rash, but we didn’t put the two together until the Bell’s palsy started. He is now on 100 mg of Doxy twice daily for two weeks. They also gave him prednisone for the Bell’s palsy which I had him discontinue a few days later after learning that prednisone could prevent the eradication to Lyme. I’m concerned that without treating the Bell’s palsy with steroids he could have long term facial paralysis, but I obviously don’t want the Lyme to spread more throughout his body. Any information on this would be greatly appreciated.
Dr. Daniel Cameron
07/24/2023 (7:55 pm)
Doctor’s have continued to use steroids if they are concerned with a viral cause of Bell’s palsy. Lyme disease facial palsy appears to resolve with antibiotic treatment for most but not all patients.