Table 5.

Research questions of common interest across the ICEMR network at urban sites in South America, Asia, and sub-Saharan Africa

Evaluation of malaria in urban areas	Malaria in urban areas ranges from foci of intense transmission to obvious importations in travelers returning from highly endemic areas
	Because the intensity of transmission is typically lower in urban than rural areas, proof of urban malaria transmission is uncommon
	This inadvertently means that the term “urban malaria” is often applied empirically to all persons whose malaria was diagnosed in urban areas
	Although difficult, the proof of transmission (or the lack of transmission) in urban areas is an essential priority for malarial control
	This is because proof of transmission simultaneously provides both new information and potential malaria control strategies
Descriptive epidemiology	What are the age distributions of malarial infection (parasitemia, positive smears) and disease (uncomplicated and complicated/severe malaria)?
	Is there evidence that children, adults, or others are protected from (or at increased risk of) infection or disease?
Seasonality	Does the prevalence of infection (parasitemia) decrease during the dry season and increase with the return of seasonal rains?
	How are seasonal patterns such as rainfall related to the incidence of disease?
	When does the incidence of malarial disease peak in relation to the intensity of transmission and the peak prevalence of infection?
Length of residence	The effects of prolonged residence in this or other malaria-endemic areas
	Do persons who have lived in this or other malaria-endemic areas for ≥ 10 years acquire either the semi-immune state (protection against serious disease) or sterile immunity (protection against both infection and disease)?
Entomologic factors	What vectors are present at different study sites during the different times (seasons) of the year?
	How do their biting rates and EIRs relate to the frequency of human infection and disease?
	Are these characteristics in more urban settings similar to or different from what has been found in rural areas?
Complex malaria	Why are infections with more than one parasite genotype most common with Plasmodium falciparum in sub-Saharan Africa?
	Conversely, why are infections with more than one parasite species (e.g., P. falciparum and Plasmodium vivax) more common in India, other parts of Asia, and South America?
	Why are Plasmodium ovale and Plasmodium malariae infections much less common than P. falciparum in Africa?

EIRs = entomologic inoculation rates; ICEMR = International Centers of Excellence for Malaria Research.