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Tanzania's President is Blaming the Sharp Rise of Coronavirus Cases on Faulty Testing Kits (qz.com) 76

In just a month, Tanzania went from having only 20 coronavirus cases recorded to 480 cases, an alarming increase which puts the country with the highest number of cases in East Africa. However, the country's president John Magufuli is convinced the number may be exaggerated due to technical hiccups with the imported testing kits. From a report: Magufuli, who holds a doctorate in chemistry, said the testers had randomly obtained several non-human samples on animals and fruits which included a sheep, a goat and a pawpaw and the results came out positive. The samples were given human names and ages and were submitted to the country's National Referral Laboratory to test for coronavirus without the lab technicians knowing the true identity of the samples. This apparently prompted Magufuli to believe some people who were tested positive for Covid-19 might not have contracted the novel virus after all.

"I have always raised my suspicions about how our national lab has been conducting the Covid-19 cases," he said at an event in Chato in northern-western Tanzania. The president, who has ordered a probe into the country's testing protocols, insinuated possible interference by unnamed saboteurs. But Tanzania has long been criticized by public health experts for enabling a more relaxed approach to the pandemic compared to the strict lockdowns and restrictions in neighboring East African countries. Instead Magufuli has asked Tanzanians to pray away the virus and left places of worship open since the Covid-19 outbreak began.

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Tanzania's President is Blaming the Sharp Rise of Coronavirus Cases on Faulty Testing Kits

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  • The best tests available have a "false positive" rate that's too high, and not all tests a "best"...some of the good ones have a false value rate as high as 30%, but I don't remember whether that was false positive or false negative.

    Then there's the question of the quality of the lab that's processing the test....

    He could be right.

    • by smooth wombat ( 796938 ) on Wednesday May 06, 2020 @12:33PM (#60028746) Journal
      According to this article [cnn.com], 12 antibody tests have high false positive results. From the article:

      Of the 12 antibody tests that were studied by the COVID-19 Testing Project, one of the tests gave false positives more than 15% of the time, or in about one out of seven samples. Three other tests gave false positives more than 10% of the time.

      "That's terrible. That's really terrible," said Dr. Caryn Bern, one of the authors of the study that looked at the 12 tests.

      She said while it's unrealistic to think all tests will be 100% accurate all the time, their false positive rates should be 5% or lower, or ideally 2% or lower.

      • Indeed!

        Bad metrics can be worse than having no metrics.

        testing definitely needs to be better because it is impossible to know how many deaths are being missed or are being counted when they should not be.

        Our reactions to this have to be based on good data not bad!

        • I'll take bad metrics if I'm at least aware of how bad they might be over none at all. A number with wide error bars is still better than none at all.

          The only problem with bad metrics are the fools who ignore all of that other information outside of the number itself or the pernicious bastards who see the number as the means to an end for their own agendas.

          In the real world we don't have perfect tests or anywhere near enough of them, so it's better for us to learn how to operate with data that's not a
          • Exactly, if the error rate is 10% but he's seeing a logarithmic increase is positive tests then that still indicates a big increase in infection.
            • And what if the error rate of real tests is 10%, and the lab isn't actually testing anybody, they're just looking up the expected rates of positive/negative and cooking the results?

              Also, if you understand how testing works, you're dealing with growing different proteins in various proportions, and testing the results. False positives are expected because you have an analog range of actual results, and you have to output a digital answer; positive or negative.

              A fruit does not have the same proteins, and in m

              • The tests (at least in the UK) for does the patient have it now look for matching virus RNA. Proteins have nothing to do with it. The antibody tests are different but they are looking for antibodies.

                • The tests (at least in the UK) for does the patient have it now look for matching virus RNA. Proteins have nothing to do with it.

                  Now ask your digital assistant, "what is RNA?"

                  And just to cover our bases, then ask, "What is an antibody?"

              • by HiThere ( 15173 )

                IIUC, the process of evaluation of the test samples is finicky, and subject to trace contaminants. Reusing testing tubes can be enough to give really bad results.

          • by ceoyoyo ( 59147 )

            The real problem of bad metrics in the current sitation is even worse: people who take a single result as true. Things like immunity passports rely on very, very low false positive (or negative for viral tests) results because they require the test to be reliable in individual cases.

          • by tlhIngan ( 30335 )

            The problem is the error bars aren't known. You might as well say the error bar runs from 0 to 100%. The actual value may, or may not, be significant.

            Is the trend of increasing infection merely due to poorer quality test kits, or due to actual population getting infected?

            Bad metrics are fine if you're continuously testing a known sample. If you're testing the same person over and over again, then even a 20% false positive rate is fine.

            But when things like immunity passports are around, you don't want to hav

            • by HiThere ( 15173 )

              Well, "the common cold" is actually a huge raft of different viruses (possibly even some bacteria), and even a few allergies. Expecting a vaccine against that isn't reasonable. And I'm told that some people do eventually become immune after being exposed to everything currently circulating. But I'm not sure that's a reliable claim.

    • In my experience, chemists and microbiology don't mix. Sure, there are problems with false positives and who knows how good their tests or facilities are, but if you read the article, he is promoting an herbal remedy and relatively relaxed lockdowns, so I would expect that he has both an exploding number of positives and an all around problematic testing response to the pandemic.
    • Could be, but then again, TFA reads "Magufuli is now putting his trust on a herbal treatment touted as a cure for Covid-19 by the president of Madagascar Andry Rajoelina."

      After that, I consider anything Magufuli says as suspect.

      • by dgatwood ( 11270 )

        Could be, but then again, TFA reads "Magufuli is now putting his trust on a herbal treatment touted as a cure for Covid-19 by the president of Madagascar Andry Rajoelina."

        After that, I consider anything Magufuli says as suspect.

        The supposed herbal remedy involves a plant that contains an anti-malarial drug, and much like chloroquine, artemisinin reduces reproduction of DNA viruses. Unfortunately, it has not had similar success with RNA viruses, unlike chloroquine.

        On the flip side, one province in China, Hubei (whose capital is Wuhan), had an order of magnitude worse CFR for coronavirus than the rest of the country. That's also the only province that didn't provide Chinese herbal tea (this tea) to patients. Mind you, they also h

        • Unfortunately, it has not had similar success with RNA viruses, unlike chloroquine.

          If you find the time, read some news and quit peddling last month's twitter drivel. Killing more people isn't a "success" when you're talking about medicine.Trump is not a doctor!

          • by cusco ( 717999 )

            Only because they don't provide doctorates in money laundering.

          • by HiThere ( 15173 )

            Actually chloroquine has had some success in inhibiting RNA viruses. In vitro. It just required doses that are likely to be lethal in people. And some success isn't "it's a cure", it's "well, it slows it down". And in vitro means in glass, so we're talking about petri dishes, not even animal tests.

            Of course, you can get it up to "stops the virus dead in its tracks", but that requires using concentrations that would stop the mouse dead in its tracks. At the concentration they reported, most people would

            • by dgatwood ( 11270 )

              Correct. When I said that chloroquine had success with RNA viruses, I meant in vitro. Sorry I wasn't clear about that. Chrloroquine has, AFAIK, never been effective at inhibiting viruses in vivo — not for SARS, not for H1N1, and unsurprisingly, not for COVID-19, either. For H1N1, it even made viral replication worse.

              The points I was trying to make there were twofold:

              1. that unlike chloroquine, artemisinin doesn't even inhibit RNA viruses in vitro, much less in vivo, i.e. it seems even more imp

      • You also need to consider where this is happening. Is this a case of Africa being Africa, or an African president being an African president?

        Also, in the photo from the news story, why is the president of Tanzania shown standing in front of a podium with "Republic of Kenya" on it?

    • Comment removed based on user account deletion
      • Any assay has cutoffs. Why do you feel that this means that PCR tests are not accurate? You also use positive and negative controls that ensure that the number of cycles run is sufficient to identify positive samples while failing to falsely identify negative samples. You'd do it the same way for an ELISA, a TCID50... that's why you validate your otherwise arbitrary cutoffs.
      • "In one paper," Crowe says, "I found 37 cycles. If you didn't get enough fluorescence by 37 cycles, you are considered negative. In another paper the cutoff was 36. Thirty seven to 40 were considered "indeterminate". And if you got in that range, then you did more testing. I've only seen two papers that described what the limit was. {...} So, if you cut off at 20, everybody would be negative. If you cut off at 50, you might have everybody positive."

        These things are properly tested and calibrated upstream of establishing the protocols.
        The cut-off number isn't just randomly pulled out of someone's ass, normally they should be properly checked so once a reference center starts being the reference for the region, that reference can be trusted good enough.

        My first internships during Med School's summer break were helping around [doi.org] setting up [doi.org] such tests for antibiotic resistant superbugs at the local hospital.

        So, it's quite possible that different hospitals, different States, Canada versus the US, Italy versus France are all using different cutoff sensitivity standards of the Covid test.

        They are not even using the same protocols (primers [who.int]

      • by gmack ( 197796 )

        It took me some time to discover you were talking about David Crowe. [davidcrowe.ca] Who has spent the last few decades peddling the claim that HIV doesn't lead to AIDS and that the treatments for AIDS is not actually helpful.

  • So, what's the problem? The people are positive but asymptomatic or not infected. Either way, the only thing that gets messed up are the statistics. Now this might lead to some bad political decisions like keeping public space closed down for longer than they need to be. But the decision to close businesses should be based on medical resources available. Either a high infection rate of a disease with a low rate of virulence or a low infection rate of a more lethal pathogen could lead to the same impact on h

    • Statistics are very important for setting policy.

      Tests have both clinical and social value. A modest false positive rate isn't very bad for clinical use, but if you see 10% infected when the real number is 0.1% that could cause poor decisions on social policies.

      There is unfortunately a very real trade-off between spreading the disease and keeping a country functioning.

      • by PPH ( 736903 )

        Yeah. But it's the mortality rate that matters. If you have a 0.1% infection rate and a 50% mortality rate it's the same number of deaths as a 10% infection rate and a 0.5% mortality rate. In the first case, it means that potentially half your population could die. But if the same number of people are dropping per week, the first case is indicative of the disease having a very low rate of spread in the population. What do you do? Sequester 99.9% of your population for a very long time? Or work on driving th

        • by jbengt ( 874751 )

          If you have a 0.1% infection rate and a 50% mortality rate it's the same number of deaths as a 10% infection rate and a 0.5% mortality rate.

          Whoa, those are not the same at all.
          A 10% infection rate with a 0.5% mortality rate is bad, and you need to address it, but a 0.1% infection rate with a 50% mortality rate means you better do something fast to stop the spread, or else close to half your population will soon be dead.

  • Someone cheaped out and used non-filter tips for RTPCR. And contaminated their pipettor and whatever they stuck it into.

    Rookie mistake.

  • "Instead Magufuli has asked Tanzanians to pray away the virus and left places of worship open since the Covid-19 outbreak began"

    I wonder what would happen if the death rate of those infected with the virus was above 60%. Stupidity can kill, folks.
    • Prayer or fresh camel piss. The choice is yours to make!
    • When confronted with an uncurable, often fatal, disease pandemic, keeping the public calm can prevent unnecessary deaths. As most of the world believes in God, asking them to pray does two very important things:

      1. It keeps non-religious people from assuming the government will "use science" to cure them, should they become infected. As such, it encourages sensible behavior (i.e. social distancing) in those people who have an unrealistic optimism in science's ability to save them.
      2. It communicates to reli
      • As most of the world believes in God,

        Most of the world believes in a different god to you. For all values of "god", and regardless of who you are and which god you believe in.

        Relax in the touch of the Noodly Appendage. It is less likely to be harmful than all the other religions out there.

  • The bottom line is how many people are dying?
  • In addition to encouraging the public to gather and pray away the virus, he said he will be importing a made in Madagascar organic herbal cure for COVID-19 [bbc.com] ...

  • The article doesn't mention that the tests were from China. I wonder why.......

    https://www.wionews.com/videos... [wionews.com]

  • with the corona virus...

    if you weren't infected before then your are now (the tester says to the patient), we need to quit trusting imports, test the testing kits, test everything,
  • Slashdot was one of the few places left on the internet where I could read some intelligent debate (ha-ha, but everything is relative, and there is almost always a few insightful comments in each article). Since the COVID-19 outbreak, I've seen the poorest quality posts and modding ever on this site - constant panic and fear over a virus that is completely manageable and nowhere near the plagues of humanity past. We've raised to much of a pussy, "it's ok to have anxiety" generation and sadly, I expected m

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