Concept

I have created this simple algorithm that generates two different regression functions of the confirmed cases in Tunisia. The data is imported from a subreddit. The first regression function is exponential which predicts the highest possible infection growth. The second one is logistic which predicts the minimum infection growth. I have used also the predefined Interpolation function to generate an Extrapolated function that gives an estimated number of cases on a given day. The three functions give an interval that predicts the number of cases. More parameters and modifications are required.

d=ToExpression[ StringExtract[Import["https://www.reddit.com/r/coronavirustunisia/comments/fjmd12/\cases_in_order/"], 40]];
f = GeneralizedLinearModelFit[d, x, x, ExponentialFamily -> "Poisson"];
i = Interpolation[d];
c0 = Max[d];
logistic = NonlinearModelFit[d, c/(1 + a*Exp[-b*x]), {a, {b, 0.1}, {c, c0}}, x];
  NonlinearModelFit[d, c/(1 + a*Exp[-b*x]), {a, {b, 0.1}, {c, c0}}, x];
Off[InterpolatingFunction::dmval];
Off[Syntax::stresc];
Manipulate[Panel @

    Dynamic @
    Column[
        {Row[{Text["Estimated Cases of Covid-19 in Tunisia on the  "]}],
        Row[
        {DatePlus[Now, m - 1], " 
       ", "(", n = m + Length[d], 
       " days after the first case recorded", ")",
        "
       ",
        Button["Estimate",
            If[Round[Numerator[Normal[logistic]]/2] > n,
         Print["The estimated number of cases on the ", 
          DatePlus[Now, m - 1], " is between ", 
          If[(logistic[n]*100)/f[n] > 70, Round[logistic[n]], 
           Round[Abs[i[n]]]], " and ", Round[f[n]], "
          ", "The rate is  " s, "
          ", Style["Best case scenario : ", Green], 
          "The estimated number of unconfirmed cases ", 
          " is between ", Style[Round[logistic[n]*2.2], Underlined], 
          " and ", Style[Round[logistic[n]*3], Underlined], ".", "
          ", Style["Average case scenario : ", Gray], 
          "The estimated number of unconfirmed cases ", 
          " is between ", Style[Round[Abs[i[n]*2.2]], Underlined], 
          " and ", Style[Round[Abs[i[n]*3]], Underlined], ".", "
          ", Style["Worst case scenario : ", Red], 
          "The estimated number of unconfirmed cases ", 
          " is between ", Style[Round[f[n]*2.2], Underlined], " and ",
           Style[Round[f[n]*3], Underlined], ".", "
          ", "The accuracy is ", (logistic[n]*100)/f[n], " %" , " (", 
          If[(logistic[n]*100)/f[n] > 50, 
           msg = Panel["accurate", Background -> LightGreen], 
           msg = Panel["not accurate", Background -> LightRed]], ").",
           "
          ",
            Column[
            {Show[Plot[Normal[f], {x, 0, n}], 
             p = ListPlot[d, PlotStyle -> Red], 
             Plot[Abs[i[\[FormalX]]], {\[FormalX], 1, n}, 
              PlotStyle -> Dashed], 
             Plot[Normal[logistic], {x, 0, n}, PlotStyle -> Pink], 
             ImageSize -> Medium]
            }, s = Panel["increasing", Background -> LightRed]]],
         Print["The estimated number of cases on the ", 
          DatePlus[Now, m - 1], " is between ", 
          If[(logistic[n]*100)/f[n] > 70, Round[logistic[n]], 
           Round[Abs[i[n]]]], " and ", Round[f[n]], "
          ", "The rate is ", s, "
          ", Style["Best case scenario : ", Green], 
          "The estimated number of unconfirmed cases ", 
          " is between ", Style[Round[logistic[n]*2.2], Underlined], 
          " and ", Style[Round[logistic[n]*3], Underlined], ".", "
          ", Style["Average case scenario : ", Gray], 
          "The estimated number of unconfirmed cases ", 
          " is between ", Style[Round[Abs[i[n]*2.2]], Underlined], 
          " and ", Style[Round[Abs[i[n]*3]], Underlined], ".", "
          ", Style["Worst case scenario : ", Red], 
          "The estimated number of unconfirmed cases ", 
          " is between ", Style[Round[f[n]*2.2], Underlined], " and ",
           Style[Round[f[n]*3], Underlined], ".", "
          ",
            Column[
            {Show[Plot[Normal[f], {x, 0, n}], 
             p = ListPlot[d, PlotStyle -> Red], 
             Plot[Abs[i[\[FormalX]]], {\[FormalX], 1, n}, 
              PlotStyle -> Dashed], 
             Plot[Normal[logistic], {x, 0, n}, PlotStyle -> Pink], 
             ImageSize -> Medium]
            }, s = Panel["decreasing", Background -> LightGreen]], "
          ", "The accuracy is ", (logistic[n]*100)/f[n], " %" , " (", 
          If[(logistic[n]*100)/f[n] > 50, 
           msg = Panel["accurate", Background -> LightGreen], 
           msg = Panel["not accurate", Background -> LightRed]], ").",
           "
          "]],

            Method -> "Queued"]}]}], {m, 1, 30, 1}, 
 SaveDefinitions -> True]

Attachments:

COVID19CasesPred...nb