Morbidity and mortality weekly report, Vol. 20, no. 50, For week ending December 18, 1971

Table 1. Cases of specified notifiable diseases: United States -- Table 2. Notifiable diseases of low frequency -- Table 3. Cases of specified notifiable diseases: United States for weeks ended December 18, 1971 and December 19, 1970 (50th week) -- Table 4. Deaths in 122 United States cities for week ended December 18, 1971Epidemiological notes and reports: Primary amebic meningoencephalitis - Pennsylvania -- Wound botulism - NebraskaCurrent trends: Influenza - USAInternational notes: Smallpox surveillance summary - Worldwide and South AmericaTable 1. Cases of smallpox - South America, 1967-1971Figure 1. Smallpox incidence - South America, 1967-197