Please help me merge the extra cells or column. I want to get ride of the empty column without separating my table into two.
\documentclass[a4paper,12p]{report}
\begin{document}
\begin{center}
\begin{table}[h]
\centering
\caption{Initial conditions for HPAI infection in poultry only}
\small\addtolength{\tabcolsep}{-6pt}
\begin{tabular}{|*{12}{c|}}
\hline
\multicolumn{3}{|c|}{Ghana} & \multicolumn{3}{|c|}{South Africa} \\
\multicolumn{3}{|c}{H5N1, 2007} & \multicolumn{3}{|c|}{H5N8, 2017} \\ \hline \cline{1-4}
Initial condition &value & reference & Initial condition &value & reference \\ \hline
$A_e$ & 6500 & Pelletier et al (2013) & $A_e$ & 285,000 & chikwati (2017) \\ \hline
$P_I$ & 11743 & OIE(2007) & $P_I$ & 24,000 & chikwati (2017) \\ \hline
$P_N$ & \num{2.0263e+5} & OIE(2017) & $P_N$ & 400,000 & schnirrring(2017) \\ \hline
$P_s$ & 48052 & OIE(2007) & $P_s$ & 107,000 & OIE(2017) & \\ \hline
S & 406,390 & wikipedia & S & \num{4.4442e+6} & www.gov.za \\ \hline
\multicolumn{3}{|c|}{Zimbabwe} \\
\multicolumn{3}{|c|}{H5N8, 2017}\\ \hline
\cline{1-3}
Initial condition & value & reference\\ \hline
$A_e$ & 140,000 &chikwati (2017) \\ \hline
$P_I$ & 7485 & pathfinder(2017) \\ \hline
$P_N$ & \num{2e+6} & Reuters(2017) \\ \hline
$P_s$ & 19172 & pathfinder(2017)\\ \hline
S & \num{1.16706e+6} & www.Pindula.co.zw \\ \hline
\end{tabular}
\end{table}
\end{center}
\end{document}