Disease-specific rate changes (such as for malaria or HIV/AIDS) are far more complex. Malaria rates tend to have marked seasonal variations, even in locations that have year-round parasite transmission. Therefore, the timing and frequency of community monitoring surveys are critical to obtaining valid data. Similarly, collecting community HIV data is a highly sensitive process that should be performed by or in conjunction with the relevant public health authorities. However, disease-prevention efforts (such as for malaria or HIV) should be strongly encouraged. Many projects enthusiastically participate in and support such efforts.