The "2006 Report on the global AIDS epidemic: Executive summary" gives estimated HIV cases and estimated adult (age 15-49) cases for Sub-Saharan Africa, from 1985-2005, both estimated numbers and percentages of the population. (page 7, pdf navigator page 9). From the first listed cases in 1985, the number increased to about 25 million in 2005, including roughly 12 million adult cases. These graphs include upper and lower estimated number ranges. There are many more detailed links from the contents page of the whole report. North Africa and the Middle East are included in a chart on page 13 of Chapter 2 "Overview of the global AIDS epidemic"
The "HHS/CDC Global AIDS Program in the Southern Africa Region" quotes UNAIDS, Report of the Global AIDS Epidemic, 2004:
Number of HIV-infected individuals in Angola: 240,000
Number of HIV-infect individuals in Botswana: 350,000
Number of HIV-infected individuals in Lesotho: 320,000
Number of HIV-infected individuals in Malawi: 900,000
Number of HIV-infected individuals in Mozambique: 1.3 million
Number of HIV-infected individuals in Namibia: 210,000
Number of HIV-infected individuals in South Africa: 5.3 million
Number of HIV-infected individuals in Swaziland: 220,000
Number of HIV-infected individuals in Zambia: 920,000
Number of HIV-infected individuals in Zimbabwe: 1.8 million
For estimates on malaria, Africa Malaria Day 2006 has information on cases and estimated deaths from that disease. In his "Message from the Director", Dr. Luis G Sambo stated, "It is estimated that each year, about 60% of the 350-500 million clinical malaria episodes and over 80% of the more than 1 million deaths globally occur in African countries."
The U.S. Center for Disease Control elaborates on these figures, giving estimated ranges in its "Malaria Facts": "... An estimated 700,000-2.7 million persons die of malaria each year, 75% of them African children... In areas of Africa with high malaria transmission, an estimated 990,000 people died of malaria in 1995 – over 2700 deaths per day, or 2 deaths per minute." CDC’s "The Impact of Malaria, a Leading Cause of Death Worldwide" quotes the World Malaria Report 2005: "At the end of 2004, some 3.2 billion people lived in areas at risk of malaria transmission in 107 countries and territories...Between 350 and 500 million clinical episodes of malaria occur every year... At least one million deaths occur every year due to malaria...About 60% of the cases of malaria worldwide and more than 80% of the malaria deaths worldwide occur in Africa south of the Sahara." Given the treatments available for malaria, it would take quite a bit of research to estimate how many people in Africa have malaria at any one time. Possibly more searching in the CDC and WHO sites would get you to a reasonable guess, and possibly also Medline Plus could help, but it could well require extensive searching in PubMed. I tried a few searches there: malaria AND africa AND "time series" (6 hits), malaria AND africa AND "average number" (21 hits), and malaria AND africa AND cases AND statistics (329 hits). It might well require a lot of digging through articles (and of course finding the articles in a large research library), to get to a typical number of cases at any one time.
The key difference from HIV, as of now, is pointed out in CDC’s "Treating Malaria" FAQ’s: "What is the treatment for malaria? Malaria can be cured with prescription drugs. The type of drugs and length of treatment depend on which kind of malaria is diagnosed, where the patient was infected, the age of the patient, whether the patient is pregnant, and how severely ill the patient is at start of treatment. If I get malaria, will I have it for the rest of my life? No, not necessarily. Malaria can be treated. If the right drugs are used, people who have malaria can be cured and all the malaria parasites can be eliminated. However, the disease can persist if it is left untreated or if it is treated with the wrong drug. Some drugs are ineffective because the parasite is resistant to them. Some patients may be treated with the right drug, but at the wrong dose or for too short a period of time."
