39: Curious Congenital Conundrums - Seal of Approval - podcast episode cover

39: Curious Congenital Conundrums - Seal of Approval

Apr 25, 202239 minSeason 2Ep. 39
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Episode description

Drs. Ella Dzora and Jason Brophy discuss a case of congenital toxoplasmosis in the second case of the Febrile “Curious Congenital Conundrums” series.

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Transcript

Sara Dong

Hello everyone. Welcome to Febrile- a cultured podcast about all things infectious disease. We use consult questions to dive into ID clinical reasoning, diagnostics, and antimicrobial management. I'm Sara Dong, your host and an adult and pediatric ID fellow. Here on Febrile, we use patient cases and consult questions to learn about high yield ID topics. We'll present pieces of the story of a patient's case, and then pause along the way to hear from our guest consultant.

I am excited to welcome you back to our Febrile series entitled Curious Congenital Conundrums. This is our second case, and I'm fortunate to be here with Ella and Jason. Dr. Ella Dzora is a pediatric registrar in South Yorkshire, England. She is an interest in infectious diseases in global health, particularly migrant health. Our guest discussant today is Dr. Jason Brophy.

He is a pediatric ID specialist and researcher at the Children's Hospital of Eastern Ontario, and an Associate Professor of Pediatrics at the University of Ottawa. His research and clinical interests are pediatric HIV and congenital infections, and he also works as a pediatric HIV clinical advisor with a Clinton Health Access Initiative, supporting the uptake and optimal pediatric HIV care in west central Africa and Southeast Asia. Thanks so much for being here, guys.

Ella Dzora

Thanks for having us.

Jason Brophy

Thanks very much.

Sara Dong

Uh, I'm so glad you're here. Um, before we jump into the case, I always like to do a quick pause and just see if you could share a piece of culture or something that you've enjoyed recently.

Jason Brophy

So I have one, it's not, I didn't enjoy it recently, but I've been thinking a lot about it over the course of the pandemic. This book called "Polio: An American Story", which I think should be required reading for any infectious disease fellow or physician. Uh, it's about the history of polio in the US, years of this yearly summer pandemic or epidemics, uh, and then the race to find a vaccine. And then people being worried about taking the vaccine.

It's very reminiscent of what we're going sounds, and it's really well written. It won a Pulitzer Prize. So. I've given it to our ID fellows as, as Christmas gifts for some time.

Sara Dong

That's a good idea.

Ella Dzora

I've actually just been reading a, a similar book, but, um, a bit broader called Plague's Progress, which charts, um, kind of humanities rise and fall on the background of the different plagues that have swept us through the centuries, which is very, very, very interesting as well. That wasn't gonna be my cultural point, but it was

Sara Dong

You can share another one if you have.

Ella Dzora

Well, I, I I'm actually Scottish, although I, uh, live and work in south Yorkshire at the moment in England. Um, but we had Burns night recently who-- Robbie Burns is our national poet. Um, and it was really nice for the first time in three years, to be able to get together with some other Scots and just have some tunes and some haggis and just reminisce and celebrate actually, uh, you know, being Scottish and getting together and doing that.

So that was the first time we've done that in one, it was really lovely. Yeah.

Sara Dong

Oh, that's wonderful. I actually had not heard of Burns night before, I will say. until one of my co-fellows, uh, suggested one for our fellow group. Um, so that's awesome. Great. Well, uh, I'm gonna throw it over you Ella, to walk us through the case.

Ella Dzora

So our case today, Jason, you receive a consult on the ward for a 23 day old baby who's been admitted with seizures. The infant was flown down from the Northern Canadian territory of Nunavut two days earlier, due to clusters of generalized tonic, chronic movements. A CT head has been done on arrival at your hospital, and that demonstrates intracranial calcifications and ventriculomegaly. And, and the peds team is concerned about congenital infection as a cause of the infant seizures.

Can you describe your initial approach in gathering additional history in this case and what you'd be looking for in physical exam to work through your differential diagnosis?

Jason Brophy

Yeah. So these are very interesting consults to get our, uh, trainees very, very excited, cuz they don't come along very often, thankfully, but I think there's a broad history that you would need to consider, but the, the first thing would just be what's gone on during this pregnancy? What kinds of exposures has the mom had, uh, in terms of illnesses, febrile illnesses, mono like illnesses, in particular rash illnesses.

You'd also want to know was there any, uh, any findings on her prenatal investigations such as her antenatal ultrasounds? And many of the congenital infections will have some typical findings on these, those antenatal fetal ultrasounds, uh, that can be telling. And that may or may not actually lead to findings later at the time of birth, but maybe clues that we could, uh, have recognized a congenital infection earlier during the pregnancy.

We'd wanna know what were the findings at delivery with respect to the, the growth parameters, uh, and things like hepatosplenomegaly or rash or eye findings in particular, uh, head growth. So microcephaly or macrocephaly, and then you would want to know what had gone on with the baby, since birth, uh, if they were growing well, if they were having any, uh, ongoing concerns that had been bringing them to medical attention or that the parents themselves had recognized as being a concern.

And then lastly would be a good exposure history. So what's gone on in the mom's life, uh, with respect to her exposures in her environment, as well as her diet and, and in particular, uh, things like food intake that we know has/is associated with, uh, specific infections, like, uh, raw undercooked meat or unpasteurized dairy products, like goats milk.

For this, this case in particular, we know that there are some specific cultural practices or cultural habits in terms of eating, uh, with respect to raw meat that we know put, uh, patients at risk. Lastly, I always like to ask about travel because, um, we always think of what's local or what's local to, uh, where the person's coming from, but they may have traveled during pregnancy.

We all remember what happened about five or six years ago with, uh, Zika, uh, and how that kind of took over the world, knowing what, well it took over the world in terms of panic. I don't know that we saw that many cases, uh, but having that kind of full history is really important.

Ella Dzora

Uh, just shows how important it is to understand the cultural context that your patients are coming from for those exposures. Yeah. Um, so thankfully the baby hasn't seized since admission. Um, they've been loaded with phenobarbital. The peds neurology team is involved. They've done a basic panel of blood work, including a CBC, electrolytes, renal function and liver enzymes, and that's all come back as normal.

The CRP measures 19, blood and urine cultures were taken prior to starting ampicillin, cefotaxime, acyclovir at the Northern referral center. They've done a blood HSV PCR. Um, but an LP was deferred because it was noticed that the child's head circumference was greater than the 99th centile (%ile).

When considering congenital infections in the differential diagnosis in a sick neonate, what would your approach be to requesting diagnostic tests and what are other specialties may be required to help you with further investigations?

Jason Brophy

So these patients, it it's very, there's a big tendency to throw the book at them, because there are so many things that it could be, uh, but a differential diagnosis in a case like this would, would take you to specific congenital infections, uh, particularly toxoplasmosis, uh, cytomegalovirus or CMV, other things like I talked about Zika virus, uh, West Nile virus is known to cause congenital infection rarely, but it's been described.

More common things like HSV and VZV can affect the brain as well. So, so those are the things we would be thinking about in the infectious world. There's like a, a broad non-infectious differential. Um, but really that should be guided by your initial investigations.

And so, uh, for a child like this, you would want to start minimally with having some, uh, head imaging to know what's going on and in terms of the baby's seizing , and in particular , noting that the, that if the head circumference is, is elevated, uh, is there, is there hydrocephalus , happening, which in itself would require further management. And so having, uh, having a good start with head imaging.

And head ultrasound is a very nice, uh, modality to start with in that there's no radiation involved and it's actually very good at picking up things like ventriculomegaly and calcifications, uh, as well as other potential things like bleeds, which could be playing a role in a patient like this. We would also, uh, want to think about a lumbar puncture to have the information of what's going on there. Um, especially if, if it's a, a child who presents with additional features like fever.

So not to forget the, the more common things like bacterial meningitis, uh, HSV encephalitis, particularly at this baby's age. Uh, and then the, the less common causes of infection, things like Listeria meningitis, for example. Having those initial investigations, depending on what you find in your initial TORCH investigation. So say we do find on that initial workup with, uh, with head head ultrasound, that there is, uh, signs of calcification or hydrocephalus.

Obviously we would go on to other imaging like MRI or, or CT scan. CT scan in the past would've been one of the most common investigations because it's very nice at picking up calcifications. But we are more conscious of radiation exposure, uh, at this young age nowadays, and we're more inclined to get an MRI. In a patient of this age, we, we can often bundle them and they would not require a general anesthetic. So these are kind of the practicalities of working up these patients.

It's a balance between having the best investigation and having the one that you can get easily, or that has the least, uh, potential complications. If we were to find, calcifications in the head or hydrocephalus, uh, ventriculomegaly, then we would go down the TORCH pathway, thinking about, serologic investigations, mostly, uh, for things like toxoplasmosis, cytomegalo virus. And HSV, VZV, syphilis.

And then if there were additional potential exposures, like the travel part, then you think about Zika virus. For CMV and Zika virus, PCR testing is often better investigation, at least if you know that there's been an exposure. Like if the, if the CMV IgG is positive, then you know, that mom had CMV at some point. And then you would want a urine or saliva PCR as the most sensitive test, uh, to have a sense of, if CMV was playing a role.

Likewise, for, for Zika virus, we can do, uh, blood or urine PCR for Zika to know if there was a congenital Zika infection. Not a lot of Zika up in Nunavut, being close to the Arctic circle or in the Arctic circle. Um, but, um, but yeah, People travel. So, uh, if that was part of the history, then you would want to look at that. And, and I didn't mention eye exam, but eye exam is very helpful in these patients because so many of these infections have eye manifestations.

And so, uh, things like chorioretinitis, uh, either active or healed or inactive, or scarred as well as cataracts. And I've seen all three in, in patients with multiple of these infections

Ella Dzora

And Dr. Brophy, would you mind maybe just touching on, you mentioned about maternal serology, um, but particularly thinking about toxoplasmosis, um, maybe just run us through serology in the neonate and maybe the use of IgA, which is a bit more unusual in toxoplasmosis, maybe than in other infections.

Jason Brophy

Yeah. And so, so we usually start with a Toxoplasma IgG/IgM done locally, uh, which can be done on a number of different standard serology platforms. And, uh, and that could be done on mom and baby. Uh, and that would tell you if there's been toxoplasma infection in the past for mom. Of course IgM doesn't pass from mom to baby. So if a baby had an IgM, uh, that would be very suggestive. And likewise, if mom had an IgM positive, then that would be very suggestive as well.

But the problem with, with IgM is (a) it's not very sensitive or not a hundred percent sensitive in infants, uh, they don't reliably make serology responses, especially in the, in premature babies. Uh, that would not be the end of the story in terms of working them up. And the other part is if a mom has an IgM, you, you need to think about the timing. Because, uh, IgM can remain positive for a long period of time.

So in a patient like this, where a baby's already born, if the mom had an IgM positive, and we know that it can stay positive for up to a year, uh, then that would be very suggestive that something happened during the pregnancy. But regardless, when you have this setup, you would want to go on to more definitive testing. For most of us that requires sending it out to a reference lab.

The most common lab that's used is the, the laboratory in California, which provides really detailed serology, including IgA , which is a very sensitive test for toxoplasma. It provides the reference IgM ISAGA uh, which is also very helpful. And then you can compare mom and babies, uh, IgG, uh, titers with the dye test. Uh, and as we say with most infections, uh, congenital infections, if baby has a fourfold higher titer of IgG than mom, then that's very suggestive.

Lastly, we can do PCR tests on amniotic fluid during pregnancy on placental tissue, uh, on baby CSF or blood. Uh, I've seen it offered on urine as well. And all of these are very helpful. If we were getting involved during the pregnancy prior to the delivery of the baby, uh, and say it was either a setup where we knew mom had an exposure or mom had a, a suggestive illness, like a, uh, mononucleosis type illness, for example, or eye disease.

And we were thinking about toxoplasma and mom had positive, uh, serologic testing with IgG/IgM, then you can do the avidity testing on IgG, which, uh, gives us a sense for the timing of the infection. Uh, and if predated the pregnancy, if there was high avidity versus, um, if it was likely in the last four months of pregnancy, uh, in the case of low validity. And so that would be very helpful. And then you need to figure out what is going on with the baby.

And so, uh, if the baby has no findings on ultrasound, then you don't know, has the infection happened yet or not? So having an amniocentesis at, it's recommended at, at, or after 18 weeks, ideally to tell us if there is, uh, already congenital infection or not. That is the recommendation when we know that a mom has had an infection of pregnancy.

Ella Dzora

Thank you. That's really comprehensive. That's great. Um, so back to our case, uh, the general peds team, uh, has helped to arrange some diagnostic testing of the infant, including getting a neurosurgical consult and an urgent MRI is scheduled and that confirms severe hydrocephalus. And, uh, so the neurosurgical team have placed an emergency shunt.

CSF from the shunt demonstrates an elevated protein of 1.9 g/dL, and further testing reveals a normal CBC, normal electrolytes, liver enzymes and bilirubin. Toxoplasma serology is positive, so the dye titer is 1:256 and the IgM is positive. Moms current toxoplasma serology is 1:64. Blood toxoplasma PCR remains pending at present. It's been sent to the reference lab. Um, and unfortunately, no maternal lesion serum samples or placenta remains for testing.

The audiology exam is normal, uh, but ophthalmology exam, uh, reveals a large active retinal lesion, just adjacent to the fovea of the left eye. So, Dr. Brophy, can you discuss your approach, uh, to treatment of congenital toxoplasmosis? How do you approach treatment discussions with your patient with parents?

Jason Brophy

The treatment of congenital toxo is a bit fraught in that, um, it's a, I usually introduce it to parents as being tough. Uh, it's a very long treatment course, uh, in that they're, they should be treated for one year and it requires multiple medications with side effects that require at minimum, blood work monitoring.

And so, in a case of moderate to severe infection in a, in congenital infection, you would want to use a combination of pyrimethamine and sulfadiazine, and these are, uh, two medications that have been shown to work best for congenital infection. In other scenarios, uh, like in adults with reactivation disease or, uh, with toxoplasma lymphadenitis, other other forms and there are, uh, other options for treatment, including trimethoprim sulfamethoxazole, uh, clindamycin and macrolides.

But in this setting of congenital infection, uh pyrimethamine and sulfadiazine are their recommended treatments. Both of them can have side effects of, of, uh, marrow suppression, pyrimethamine in particular, causing anemia, macrocytic anemia, uh, and sulfadiazine in particular causing neutropenia.

We usually, uh, recommend in addition to these two medications, the addition of folinic acid or leucovorin three days a week, and that will help reduce the, the risk of pyrimethamine associated anemia and, and marrow suppression generally. Uh, but these three medications need to be monitored closely with blood work, including complete blood count, as well as liver and renal screening for proteinuria, uh, as a side effect of pyrimethamine.

So it's recommended to do those more frequently in the first month of therapy and then, um, a monthly for the duration of the 12 months of treatment. Uh, sulfadiazine is, uh, before you start it, you should check for a G6PD deficiency, uh, in that it's one of the G6PD triggers and, um, the medication dosing should be followed closely along with the child's weight over time. One significant issue that has really plagued us, over the last number of years.

Not only in Canada, but in multiple countries around the world is, is a lack of these medications availability, uh, in particular sulfadiazine and so for example, we don't have, uh, any companies that make that product in Canada. So we need to go through, through our federal regulatory agencies to bring in products from other countries. And this is often a very difficult, uh, endeavor in that, uh, they're not made by very many companies.

It's not a very lucrative product I think, uh, and that is part of the, the issue. And there's often a delay for us in terms of getting to start these medications because of these access issues. And it, it really, I, in my mind, this is an advocacy issue for us in pediatric infectious disease. In that these are, uh, medications that are the treatments of choice for this very severe infection at times. And, uh, we need to have secure access for our programs.

Ella Dzora

And can I just clarify something you said earlier that if there was a suggestion that mom had, uh, exposure, you might do an amniocentesis at 18 weeks. If that showed a potential infection, would you start treatment at that point? If so, would it run for a year, from 18 weeks gestation or a year after delivery?

Jason Brophy

Right. If a mom is diagnosed with acute toxo in pregnancy, uh, and that, like I said, those diagnoses can come in a variety of ways, either mom with an illness, uh, that triggered testing, um, mom with a finding on ultrasound that triggered testing, mom with a known exposure, uh, say to, cat feces, which I, I failed to mention earlier, which was the one that, the one thing that everybody knows, uh, about

Ella Dzora

It's probably in this side of the pond is definitely the bigger exposure compared to raw meat, I think.

Jason Brophy

Yeah. Yeah. And, and I have to say in, in the past, in patients who are local, like who haven't traveled, then the main risk factor is, uh, if they have a cat and they changed their litter before they knew they were pregnant, uh, or. The, the main, the main, uh, risk factor I've always found in those patients is not so much that because everybody knows you're not supposed to change cat litter when you're pregnant. Uh, but rather gardening.

And so I usually tell moms, uh, that, uh, uh, your garden looks like a giant litter box to a cat so, so there's, uh, that's like the main factor that are identified in local cases. Uh, and those that have traveled, like to, um, to Africa in particular south America, uh, or our Northern patients, it's more often eating exposure that, that we suspect.

Um, but yeah, I, if we do make that diagnosis in pregnancy, uh, before the amniocentesis, if there's no suggestion of an infection, uh, on the imaging, then the fetal imaging, then you would put the, start the mom on spiramycin, which is a macrolide that we know will prevent infection from passing from mom to baby.

Cuz the risk of transmission early on, uh, is, is lower, but with more grave side effects, uh, or, uh, sequelae in the baby vs later in pregnancy, uh, we know that the transmission risk is much higher though with often less effect on the baby, if it happens on the third trimester. So spiramycin until your amniocentesis is complete. If the amniocentesis is negative, then the mom would be recommended to continue her spiramycin until delivery.

Uh, if on the other hand, the amniocentesis suggests the fetus is infected, then the recommendation would be to switch to sulfadiazine and pyrimethamine. And I haven't had that scenario before where, uh, a baby did, uh, get that treatment prenatally. Um, but my understanding is that the fetus should be treated for a year or the newborn to be treated for a year postnatally.

Ella Dzora

Thanks for clarifying that.

Jason Brophy

And then the last, the last thing I didn't mention with the, the treatment is anti-inflammatory or steroid therapy. There are two criteria for the addition of a steroid like prednisone or prednisolone. Uh, one would be if there's active eye disease and the other would be, if there is a very high protein level in the, the, uh, CSF. Criteria would be, uh, one g/dL, um, or 10 g/L.

Ella Dzora

Good. Thank you for that. Um, so yeah, so our baby, um, is started on pyrimethamine +sulfadiazine uh, and some prednisolone for the significant eye disease, folic acid, as you said to cover up the marrow suppression and remains really stable. So the general peds team is considering discharge. What follow up would you, you recommend in that situation?

Jason Brophy

The followup should be quite close, uh, over time, be that with the infectious disease, uh, clinic or, uh, their primary care or pediatric, uh, care. Sometimes we'll do a shared care model if they're, uh, far from the hospital, such as in the Arctic. We would recommend the regular monitoring of, for those toxicities, uh, through blood work, uh, as well as close monitoring of their weight so that we can make dose adjustments.

I usually make a dose adjustment if, uh, there's been a 10% increase in the weight. Uh, so that, uh, they're never outside of the 90% of their recommended, uh, dosing. The steroids can be tapered, if they've been started, once the active eye disease resolves. I've never had to do a repeat lumbar puncture to reassess protein. But that would be, uh, I think it would be reasonable to, to wean the steroids after, uh, a certain period of time and, and notable improvement.

And obviously these patients need close follow up from, from the point of view of their eye disease. If they have active eye disease, uh, some of them may develop cataracts. It may require surgical intervention.

And then obviously neurologic and neurodevelopmental follow up, uh, so that we can identify any, uh, any problems that may arise and intervene as soon as we can with respect to therapies, speech therapy, uh, audiology, your hearing assessments would be very important as well, uh, to make sure that they can hear.

And if hearing is an issue, uh, then making sure that they have augmentation so that we really, I usually frame it to the families that we want to, we want to give them the best shot at being the best version of themselves. And so, uh, many of these kids will have sequelae with respect to vision or hearing or, uh, neurologic function.

So when we can intervene early with, um, with therapies like occupational or physiotherapies or, um, supporting their mobility with respect to gross motor dysfunction, support their vision so that they can see and learn, um, likewise support their hearing so that they can hear and learn. Um, then that is the best that we can do for them, and they can be the best versions of themselves.

Ella Dzora

And can I ask, uh, we don't have potentially the, um, as big a geographical area that we're covering as you over in England, how much-- cause it's quite a big burden of treatment for these kids. How much would you expect of that to happen locally in the Northern territories and how much would they have to travel for?

Jason Brophy

Yeah. So unfortunately I've had several of these patients over time. We try to be as, um, efficient as possible. And so, uh, I tend not to bring them back to see me alone. I, I prefer to have combined follow up with other specialties. So if the ophthalmologists or the neurosurgeons if they have, uh, shunts, uh, or the neurologists, uh, if they have neurologic complications like seizures, uh, I try to do a, a combined follow up with them.

And so typically we would wanna see within a couple of months of discharge, minimally, uh, and then again, usually at three to four month intervals for the course, the, of the follow up. Um, here we're a bit lucky in that some of our specialists do traveling clinics and they go up to the Northern territories. So patients don't have to travel quite as far. So one 2-hour flight instead of two 2-hour flights uh, or three hour flights. Um, We try to be as practical as we can.

And with the advent of virtual care, it's really made a big difference. So doing, having that shared care model where we're supporting their, their local practitioners, or, uh, say their pediatrician who flies into their community, than it does help, um, make what's a very difficult situation, a bit more bearable for the families.

Ella Dzora

And just one more thing to clarify, cuz the eye disease can flare up, particularly adolescents and later in life. If the eye disease was quiet in that first year of, of life, how often would you have to follow it up or would you wait till they had symptoms?

Jason Brophy

Yeah, so I usually defer those decisions to ophthalmologists. I don't like telling people what to do. Um, but, but generally they want to see them on a regular basis, like on, uh, I, I think if they're local, they'll see them more closely. They'll follow 'em up more frequently. Uh, but I think minimally on a yearly basis, especially when they're young and maybe can't verbalize their complaints.

But yeah, the expectation with congenital infection is that, there's definitely a risk for future reactivation of eye disease. And that that risk is higher if, uh, they haven't been treated, like if the congenital infection wasn't diagnosed at the time, then it's very high risk of, of reactivation over their lifetime. That varies according to the geography or serotype or subtype of, of, toxo.

Uh, the South American versions tending to be more aggressive, uh, than the, than the European versions. Um, don't think we understand that as well for our Arctic versions. Um, but, um, the, that follow up over time should. Should be there. And, and typically the, the bigger risk would be re reactivation usually in adolescents.

Ella Dzora

Thanks. Um, so our neonate has done really well and the parents are shown how to crush and dissolve the medications for administration and infectious diseases follow up is arranged. Mom's really keen to, to return to her home community as she has three older children at home. And she's quite overwhelmed being so far away from home and alone and away from her family.

So infectious diseases, neurology, ophthalmology, audiology, and neurosurgery follow up is arranged and interim telehealth communication, as you suggested, is arranged to assess the progress. Follow up drug toxicity blood work is arranged locally and at telehealth follow up three weeks later, mom asks whether or not this infection could have been prevented.

Jason Brophy

So that's a very good question. We know that some jurisdictions of the world, uh, have prenatal testing that's routine for all. So that it's most commonly known in France, owing to their culinary proclivities, um, but in my experience, we, in, in Ottawa, we have a lot of, a lot of migrants from, uh, Francophone Africa as well as, uh, places like Morocco and Lebanon.

Uh, and it's interesting where most of those places have toxoplasma screening practices, very similar to France because they were influenced by French through colonization over time. In those, in those, uh, environments or jurisdictions, toxoplasma screening in pregnancy is routine. Uh, and what tends to happen is you have a toxoplasma test during, uh, your initial intake into prenatal care. If you're seropositive with an IgG positive and an IgM negative, then you'd be clear, in the clear.

If your IgG negative, then you'll be recommended to have, uh, repeat follow up over time and ideally a good counseling around what would be the things to do during pregnancy to reduce your risk, uh, primary infection during the pregnancy. So, interestingly we, because we've had had, uh, several cases, uh, in Nunavut over the last few years, we're actively in the process of introducing a prenatal, uh, screening program up there. The population is very small.

The number of births per year is something around 500 to 800, uh, depending on how much of the territory you're including. But we have a high number of cases, uh, and it makes sense because there's increasing research showing that it it's not, it's not cat exposure up there. There are no cats in the Arctic, uh, region, um, or well, I guess there are probably some domestic ones, uh, but there are no wild ones.

But we know that, uh, a number of animals that are consumed including marine mammals, like beluga and walrus and seal, well as, uh, ungulates like caribou, uh, and there's some findings from local researchers that show that, uh, some fish have, uh, evidence of, toxo uh, char and salmon and then Arctic goose as well apparently have toxo. So, uh, it just tells you that, um, We need to do a, a better job of counseling in pregnancy, uh, because serology's only gonna tell you if there's a problem.

Primary prevention would be much better than secondary prevention. And so, yeah, as you said, if we do identify, uh, some, a woman with a primary infection of pregnancy then would use the medication approach of spiramycin, uh, and then if, uh, fetal infection confirmed sulfadiazine/pyrimethamine. And then, like I mentioned, the, the counseling part of, of when the mom's infection happens, uh, really dictates the risk of infection to the fetus with a lower risk of infection in first trimester.

But if that infection does happen, uh, then a very high risk of serious congenital anomalies, like brain and eye disease. Uh, whereas if the primary infection happens later in the pregnancy, then the risk of transmission is quite high. Um, but the risk of, uh, disease or obvious, uh, clinical sequelae in the child is lower. That's presuming that you'll make the diagnosis and treat the child once they're, once they're born.

Ella Dzora

I think the CDC website gives prevalence in 14 to 44 year old women as 9%, but that's across the states. Presumably there's hugely wide regional variation within that as you've highlighted.

Jason Brophy

Yeah. I think we know, uh, at least in, in certain parts of the world, like, um, central Africa, uh, those rates can be like 50, 60, 70, even 80% reported. I think it really varies around the world and according to cultural practices around food and what you do or don't do while you're pregnant.

Ella Dzora

That was really thorough. Thank you very much. To end, I just wanted to ask if there's any other kind of important points that you've not already highlighted that you'd like to just bring to our attention about congenital toxoplasmosis or other congenital infections in general.

Jason Brophy

Yeah, I it's interesting. I find that there's such a, a wide range of parents, um, level of concern, right? It ranges. It's all natural. I'm not gonna worry about anything to, uh, like a high level of anxiety, uh, and not knowing, uh, what, or if you can do anything during pregnancy. It's, it's good to be, uh, rational. Uh, and I think it's good to provide, uh, good prenatal counseling around high yield things.

And so with toxo, uh, it's around primary prevention strategies, like don't, don't take in, uh, raw or rare meats, avoid unpasteurized dairy products, like goats milk. If you do garden, then please wear gloves and wash your hands while after you've done. So, um, and if you have a cat, uh, consign your partner to, to that, in the pregnancy

Ella Dzora

and, and ongoing.

Sara Dong

Yeah.

Jason Brophy

Thank you very much. Um, but then other other things like, uh, I didn't touch much on congenital CMV, but, uh, in my mind, that's one area that we don't talk about nearly enough in pregnancy and that, uh, literally almost every child with congenital CNV I've ever seen, uh, has a two year old sibling at home who's in daycare. And so we know who to target our primary prevention strategies towards, and I don't think we're doing it.

And when we look at the other types of, um, infections that we screen for, or counsel around during pregnancy, uh, they're much lower prevalence than CMV. And, uh, I think we need to do a better job on, on that particular congenital affection. Here in Ontario, we've introduced a, an enhanced hearing screening program that includes CMV testing for every child born in the province. And so we've identified, um, like a tenfold or even higher numbers of infants with congenital CMV over time.

Ella Dzora

That's huge.

Jason Brophy

And, and just like, just like with this case where the mom asked, um, why didn't I hear about this? Or, or what could have been during the pregnancy? That's what every mom asks me, like, except for except for moms who are healthcare workers or microbiologists. No one else has ever heard of CMV uh, unless you've had, you've been touched by it in your own household already. And so I think we need to do a better job of, of talking about these things, uh, and making it routine.

Sara Dong

Well, thank you guys, both so much for being here today. I learned a ton and had a lot of fun.

Ella Dzora

Thank you so much for having me.

Jason Brophy

Yes. Thanks. I appreciate it.

Sara Dong

Thanks to Ella and Jason for this great discussion on congenital toxo. Please stay tuned for the rest of our Curious Congenital Conundrum series. You can find the introduction and case one in our previous episodes and be on the lookout for our third and fourth cases coming up next. Our usual disclaimer, all presented patients on this podcast are inspired by patient experiences, but cases are constructed or significantly altered and de-identified for learning purposes.

If you are new to febrile or haven't checked it out, I encourage you to take a peek at our website febrilepodcast.com to find Consult Notes, which are written complements to the show where there are links to references as well as our library of ID infographics that you can use to learn and teach others about ID. Thanks for listening, stay safe and I'll see you next time.

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