What Sun Lien and Hu Chunbo suspected at the same time was a rare disease called "primary amoebic meningitis".

Primary amoebic meningitis is a neuroinflammatory response caused by the free-living amoebic protozoa entering the brain through the nasal mucosa and through the olfactory nerve. Strictly speaking, the brain structures invaded by primary amoebic meningitis are not limited to the meninges. However, because the disease exhibits significant meningeal irritation, it was named "meningitis".

So far, this rare disease has been reported around the world. However, all of them are sporadic cases, and there are rare cases of mass onset. If it can be confirmed that the high-mortality meningitis that broke out in the American camp is indeed primary amoebic meningitis, then this case is definitely a major discovery that can be published in the four major journals and even "Nature" and "Science". The fact that the protozoa naegleri fowlii, which was once thought to pose a threat to a wide range of people, caused such a large-scale infection would cause a huge stir in the medical community.

However, what Sun Lien and Hu Chunbo are struggling with now is not which magazine such a case report should be published. What worries them now is the high fatality rate of this "meningitis".

A total of three cases of primary amoebic meningitis caused by Naegrea fowleri have been reported in China. The three case reports spanned more than three decades. Of those infected with the disease, two were soldiers of the people and one was a young farmer. But all three patients had one thing in common – treatment was ineffective, and their condition deteriorated rapidly before they died.

Globally, the mortality rate of primary amoebic meningitis is more than 97%. There is no cure, no proven cure. Based on this global statistical rate, one of the 28 people who fell ill in the American camp could survive and burn high incense.

Due to the low number of reported cases, physicians around the world have yet to come up with an effective treatment plan for primary amoebic meningitis. Some in vitro studies have shown that amphotericin B and gentamicin have a killing effect on the protozoa naegleri fowleri. But it is almost impossible to get these drugs to cross the brain-blood barrier and reach effective concentrations in the brain. The only promising method of drug delivery is intrathecal injection, in which the drug is infused into the patient.

The reason why it "looks promising" is also because this treatment does not increase the chances of survival for many patients. At least not all patients who survive the treatment receive this treatment.

It can be said that the current situation is not optimistic at all - even if evidence of primary amoebic meningitis is found, it is still possible that none of the 20 or so people will survive.

But once you understand why, you can at least try to save lives. That's what diagnosis is all about.

The sample sent by Sun Lien came out almost at the same time as the autopsy results from Hu Chunbo's side. The lake water contains Naegrea fowleri, and amoebic trophozoites are indeed found in the brain tissue of cadavers.

"It can be diagnosed. Sun Lien and Hu Chunbo checked the results again, and then nodded, "The source of infection is there, and the pathogen has been found, so let's treat it according to primary amoebic encephalitis." ”

Liu Tangchun, who got the diagnosis, was a little surprised, "Can you be sure? It's all primary amoebic meningitis?"

This is the only plausible explanation. And so far, the evidence is sufficient. Sun Lien took the initiative to stand up and explained to Liu Tangchun, "We don't have time to do cerebrospinal fluid smears on every patient, but when we do intrathecal injections, we can take a smear of cerebrospinal fluid by the way." ”

Ms. Iweala, who was called to hear the results, also seemed a little hesitant, "But...... The disease has always been sporadic, and since its discovery, there has never been a record of a mass outbreak. ”

"We won't be able to find a second possibility anytime soon. Hu Chunbo is very confident in his autopsy, "At least the body I examined must have died of a foramen magnum hernia caused by primary amoebic encephalitis." It is contrary to Occam's razor principle to say that so many patients with common experiences exhibit the same or very similar symptoms, and that they are not infected with primary amoebic encephalitis. ”

It is sometimes easy to make mistakes when using philosophical perspectives to guide practice. But in the current situation, Hu Chunbo's words are very convincing. At least Ms. Iweala couldn't think of any other possibility.

"Makes sense. Liu Tangchun completely changed his angle at this moment and began to help Hu Chunbo speak. He said earnestly to Ms. Iweala, "I think that in the absence of more evidence, at least we should treat according to the diagnosis of Dr. Hu and Dr. Sun." Even if other evidence is found in the course of treatment, and then the treatment method is changed? According to the available data, if there is no treatment, it will not be long before these patients who have already developed the disease will die. Intrathecal injections of high concentrations of amphotericin B may save one or two. ”

Lady Iweala was silent for a moment, then nodded, "That seems to be the only way." She said to Hu Chunbo and Sun Lien on the side, "Then treat it according to primary amoebic encephalitis." After finishing speaking, she turned to Liu Tangchun and said, "I need to report this diagnosis to the CDC, and they may still be infected in China." ”

Liu Tangchun had no objection to this request, and he also kindly asked, "Can your existing doctors be competent to treat them? If there is a shortage of manpower, I can call back the members of our medical team." ”

Intrathecal injection is a treatment that needs to be done by a doctor. At least in the country's health care system, this must be done by doctors. Both Hu Chunbo and Liu Tangchun had experience in intrathecal injections, but Sun had only withdrawn cerebrospinal fluid. Eight patients would have to be injected intrathecalally multiple times, and there would be some nervousness on the hands of people who relied on Liu Tangchun and Hu Chunbo alone.

"If you don't delay your trip, it would be best to get help from the Chinese medical team. "Of the fourteen doctors in our two medical teams, only eight of them are sick, two ......of them are from the laboratory department," she sighed, "and six left the camp last night without permission. They're supposed to be looking for you, right?"

"Yes. "Of course, Liu Tangchun has nothing to hide from this kind of thing - it's not me Liu Tangchun who poached six doctors from your medical team. "If I were you, I'd thank them a lot. If they hadn't hiked more than a dozen kilometers to ask for help last night, we probably wouldn't have known what was going on here. These twenty-eight patients did not even get a correct diagnosis. "Whether your reason for denying us access to the camp in the first place was for your own safety or to keep us away from this virulent infectious disease, which was unknown at the time, you must first remember that we are doctors, Chinese doctors who have come to Africa for humanitarian aid." No Chinese doctor will be a deserter before the epidemic, this is our professional requirement and our belief. ”

Liu Tangchun took a deep breath and said word by word, "When an unknown disease that threatens human health strikes, you can always trust Chinese doctors." ”