0:00 Hello, in this video, we're going to talk about neonatal infections, the unwell 0:08 child. 0:11 Signs and symptoms of an unwell or ill neonate includes lethargy, stiff limbs, 0:18 sinosis, 0:19 grunting, severe chest in drawing, capillary refill more than 3 seconds, and 0:25 this is checked 0:27 on the sternum, an increased respiratory rate greater than 60, high temperature 0:34 or low temperature 0:35 against stiff limbs, and movement only when stimulated. The first neonatal 0:43 infection or 0:44 condition we will look at is sepsis caused by bacteria, and sepsis is 0:49 essentially the 0:50 body's response to a systemic infection. It is common and commonly overwhelming 0:57 with high mortality. 0:58 The signs may be minimal, but usually the signs and symptoms are those that we 1:04 discussed in the 1:05 start of the video. Sepsis can be divided into early onset or late onset. Early 1:12 neonatal sepsis 1:15 means that this is occurring less than 48 hours after delivery. Late onset is 1:20 the neonate is already 1:22 older than 48 hours. Sepsis is often confused with bacterium. Now, bacterium is 1:31 defined as the 1:33 presence of bacteria in the blood, where sepsis is the response to the bacteria 1:37 , which includes 1:39 vasodilation, causing hypertension, tachycardia to compensate and to maintain 1:44 cardiac output. 1:45 Sepsis is caused usually secondary to an bacterial infection somewhere in the 1:52 body. 1:53 So the primary infection occurs somewhere in the body, such as the lungs, you 1:59 get pneumonia, skin, 2:01 cellulitis, urinary tract infection from pylonephritis, gastroenteritis or from 2:09 the bones, osteomyelitis. 2:10 All these primary infections can lead to dissemination of that bacteria causing 2:17 sepsis. 2:18 In infants, sepsis can be subtle, and any suspicion of sepsis should be 2:25 investigated and treated, 2:27 typically with empirical antibiotics such as gentamycin and benzylpenicillin. 2:33 One of the complications of sepsis is that the bacteria can go into the brain, 2:40 causing bacterial 2:41 meningitis, and this is the second condition we'll look at, bacterial mening 2:46 itis. Bacterial meningitis 2:49 is when the bacteria causes inflammation to the meninges. There is also viral 2:57 meningitis 2:58 but viral meningitis is often self-limiting. Bacterial meningitis is much more 3:03 serious. 3:04 So what is meningitis? The meninges are layers of protective sheaths that cover 3:12 the brain. 3:14 The brain is actually covered by many layers because the brain is so important 3:18 and needs protection. 3:21 So let us look at what actually surrounds the brain. From the outside, superfic 3:27 ially, 3:27 we have the scalp, which includes the skin, fat. Below the scalp, we have the 3:33 bone, the skull itself. 3:35 Then we have the meningiolayers, which includes the duramata, the arachnoid 3:41 membrane, the subarachnoid 3:42 space, which contains the cerebrospinal fluid, and then we have the piamata, 3:49 before we actually 3:50 have the brain tissue itself. In bacterial meningitis, the bacteria irritates 3:57 the meninges, 3:58 these layers causing inflammation. So what are the causative agents? Well, let 4:03 's look at the common 4:04 causes in neonates and in infants. Common causes of bacterial meningitis in the 4:11 newborns in the 4:12 neonates are E. coli, group B streptococcus, and misteria monocytogens. A group 4:18 B streptococcus, 4:19 an E. coli, essentially can be obtained from the mother during the delivery 4:26 when the baby 4:26 is delivered through the vagina. In infants, there are usually different caus 4:34 ative agents of 4:35 bacterial meningitis, such as nisteria meningitis, hemophilus influenza, and 4:41 streptococcus pneumoniae. 4:43 And these are the main causative agents also for young adolescents, as well as 4:48 young adults. 4:50 Now, the younger the patients, the more subtle the symptoms, if meningitis is 4:55 suspected, 4:56 blood cultures must be performed to identify the causative agent, as well 5:02 possibly a lumbar 5:03 puncture needs to be performed. The signs and symptoms of bacterial meningitis 5:09 include poor 5:10 feeding, seizures, lethargy, irritability, high-pitch cry, bulging of the font 5:20 anels, 5:20 because of increased intracranial pressure, fever, apnea, and vomiting. 5:25 Treatment includes 5:28 antibiotic empirically, which mainly involve the beta lactams plus amacrolide 5:34 or aminoglycoside. 5:37 Dexamethasone, which is a steroid, is usually administered before antibiotics, 5:42 because it is shown to have overall benefits. Vaccination is thus very 5:48 important as a preventive 5:49 measure, as vaccination against some of these causative agents have been shown 5:53 to reduce the 5:54 incidence of meningitis by those bacteria. The next infection you must know for 6:03 an ill 6:04 infant is pertussis, which is a ubiquitous, highly contagious infection. It's 6:09 caused by bacteria 6:11 known as borticellaptasis. Clinical feature, it's essentially known as the 100- 6:17 day cough, 6:17 and it's divided into three stages, so over this period of 100 days is divided 6:23 into three stages. 6:25 What happens is the bacteria or the teleptasis. It's a cocous bacillus, and 6:33 essentially it 6:34 infects the infant via air droplets. From here, the infant will develop signs 6:40 and symptoms, 6:41 such as peroxysmal coughing, inspiratory whoop, and post-tusive vomiting. 6:50 As mentioned, the clinical course is a classic 100-day cough, and the 100-day 6:57 cough can be 6:57 divided into three stages. Of course, there's an incubation period, which is 7:03 about one to two weeks, 7:04 before symptoms start coming up. So the first stage is the catarol stage, where 7:10 the person 7:12 who has the infection becomes highly contagious. Symptoms also are similar to 7:19 upper respiratory 7:20 tract infections, and this goes for about two weeks. Between two to eight weeks 7:28 , 7:28 the next stage is proxysmal stage, where you get essentially a worsening cough. 7:36 Eight weeks onwards is the convalescent stage, where the cough subsides, and 7:42 essentially it just 7:42 subsides with coughs here and there for weeks two months. Myocarditis is a 7:51 condition resulting 7:51 from inflammation, infection of the heart muscles. It presents with a broad 7:57 clinical spectrum of 7:58 signs and symptoms in children. MRI helps in the diagnosis of myocarditis. 8:06 The signs and symptoms include fatigue, chest pain, as well as signs of heart 8:11 failure, 8:11 because the heart is irritated and cannot pump, or pump enough blood out of the 8:17 heart. 8:17 Again, myocarditis is inflammation of the myocardium, the muscle fibers of the 8:23 heart. 8:24 The cause of myocarditis is usually secondary to a recent infection in the past 8:29 two weeks. 8:29 The initial infection could have been a respiratory or a gastrointestinal 8:34 infection, 8:35 which has disseminated and traveled to the heart to cause myocarditis. 8:39 The common agents that cause myocarditis are viruses, specifically an enterov 8:45 irus, such as 8:46 cocksacki and adenovirus. There's also another heart infection that can occur 8:53 in neonates. 8:54 Endocarditis, which is infection inflammation of the endocardium and/or hot 9:01 valves, 9:01 which typically involve thrombus formation known as vegetations. 9:05 Now, the cause of endocarditis and these vegetative growths are bacteria, 9:10 specifically streptococcus species and staphylococcus species. 9:15 Signs and symptoms are that of infection, such as fever, 9:20 diaphoresis, or sweating, fatigue, arthralgia, and/or myalgia. 9:28 Endocarditis, you essentially get inflamed heart valves, initially by the 9:34 bacteria. 9:35 The bacteria then grow in this environment, causing vegetations. 9:40 This can impair heart function and can lead to valvular heart disease. 9:47 The causative agents, again, are mainly bacteria, including staphylococcus aure 9:54 us, 9:54 group A streptococcus, and viridens streptococci. An echocardiogram and blood 10:01 cultures are useful 10:02 for diagnosis, and treatment involve antibiotic therapy empirically, followed 10:08 by targeted therapy, 10:09 once causative agent is identified. 10:12 The next infection is infant botulism. Infants develop botulism from ingestion 10:19 of 10:19 clostridium botulums spores. The sequence of events usually goes as follows. 10:25 The infant inhales or ingests clostridium botulum. This results in the signs 10:32 and symptoms, 10:33 which typically involve diminished muscle activity. This can be poor feeding, 10:40 there's lethargy 10:42 constipation, rest failure, ptosis, decreased eye movements, and just lethargy 10:48 in general 10:49 indicates diminished muscle activity. The signs and symptoms actually arise 10:55 when the bacteria produces the botulism toxin in the gastrointestinal tract, 11:01 and this causes 11:03 neuromuscular junction dysfunction, which leads to the poor muscular control 11:09 and muscular movement. 11:12 So when a muscle normally contracts, the nerves that supply the muscle releases 11:19 peptides called 11:20 acetylcholine in the synaptic cleft. The acetylcholine will then bind onto 11:26 receptors 11:27 on the muscle cells, causing the muscle to contract. In infant botulism, the 11:34 nerve 11:35 is unable to release acetylcholine because the botulum toxin inhibits acetylch 11:41 oline release 11:42 from the nerve cells. Because there is no acetylcholine being released into the 11:47 synaptic cleft, 11:48 there is no acetylcholine that can bind onto receptors on the muscle fibers, 11:53 causing no contraction 11:54 of the muscle, and so we get weakening of the muscle. Most infants require 11:59 intensive care 12:01 and many need mechanical ventilation. Median age is about four months, and this 12:08 infection is more 12:09 common among breastfed infants. Acute gastroenteritis is a clinical syndrome 12:17 often defined by increased 12:20 stool frequency with or without vomiting. Acute gastroenteritis usually lasts 12:27 one week up to two 12:28 weeks, but it can be more than two weeks. If it's more than two weeks of 12:33 diarrhea, 12:33 it is classified as persistent or chronic. Complications of acute gastroenter 12:39 itis include 12:40 dehydration and electrolyte imbalance. The signs and symptoms of acute gastro 12:47 enteritis include 12:48 headache, diarrhea, vomiting, and fever. Myalgia, and of course there's 12:53 abdominal cramps. The causes 12:55 of acute gastroenteritis can be viral or bacterial. It is most often viral. The 13:01 viral causes include 13:03 rotavirus, noravirus, or adenovirus. Adenovirus, as we mentioned earlier in 13:09 this video, can cause 13:10 myocarditis, a secondary to the gastroenteritis. Bacterial gastroenteritis, the 13:17 causes are include 13:19 chigella, salmonella, and E. coli. Bacterial causes are often more severe. 13:25 The next and final infection of the infant I want to talk about is overwhelming 13:32 viral infection. 13:33 As the name suggests, it's essentially an overwhelming response to a viral 13:38 infection. 13:39 It's most often caused by herpes simplex virus or interovirus. 13:44 Herpy simplex virus can cause life threatening or central nervous system 13:49 infection 13:50 in the newborn. Interovirus may cause myocarditis or hepatitis among neonates. 13:57 Let's look at how these microbes cause an infection. 14:02 Let's begin by looking at the herpes simplex virus. The signs and symptoms of 14:10 our herpes 14:10 simplex viral infection include lethargy, formation of skin vesicles, about 60% 14:16 of cases. 14:17 They're often a febrile and maybe have conjunctivitis. Risk factors for neon 14:24 atal herpes simplex 14:25 virus infection is having a mother with herpes simplex virus, prenatally, 14:32 are perinatally in 80% of cases or postnatally. These risk factors can 14:39 essentially lead to 14:40 a herpes simplex virus infection, which can either cause one or more of the 14:45 following. 14:46 It can cause localized skin infection as in the skin vesicles. It can cause a 14:55 mouth infection 14:56 plus minus CNS involvement and/or disseminated disease leading to the 15:02 overwhelming viral infection. 15:04 Finally, the interovirus, which can also cause the overwhelming viral infection 15:12 . 15:12 Now, interovirus infections can actually lead to a full-minute hepatitis or my 15:19 ocarditis, 15:21 which is infection of the myocardium, the heart muscle cells. Now, if it causes 15:28 myocarditis, 15:30 it often has with it encephalitis or hepatitis. The signs and symptoms include 15:36 hypotension, 15:37 jaundice due to the hepatitis, profuse bleeding, and organ failure. Again, an 15:44 overwhelming viral 15:45 infection is essentially the response the body does to a viral infection, which 15:50 can. 15:50 So those were the two main causes of overwhelming viral infection, which are 15:58 herpes simplex virus 15:59 or enterovirus. Thank you for watching.
