Table 3. Seasonality of human infectious diseases (continued from Tables 1 and 2).
Drivers categorized as being related to (a) vector seasonality, (b) seasonality in nonhuman animal host (i.e., livestock, other domestic animals, or wildlife), (c) seasonal climate (e.g., temperature, precipitation, etc.), (f) seasonal exposure and/or behavior and/or contact rate, (g) seasonal biotic environment (e.g., algal density in waterbodies), (h) seasonal flare-up/symptoms and/or remission/latency, (i) observed seasonal incidence with no hypotheses regarding drivers.
| Infection/disease | Type | Seasonal driver(s) | Description |
|---|---|---|---|
| Marburg | Acute | b | Seasonal incidence in bat reservoirs (in Uganda); seasonal peaks coincided with the twice-annual birthing season [46] |
| Measles | Acute | f | Elevated transmission driven by aggregation of children in school; seasonality in developing countries related to agricultural cycles [47, 48] |
| Meningococcal disease | Acute | c and h | Incidence varies seasonally in both tropical and temperate countries. Elevated incidence during the dry season (in sub-Saharan Africa). [49] |
| MERS-CoV | Acute | b | Introductions into humans are seasonal and are more frequent during the camel calving season. [50] |
| Onchocerciasis (river blindness) | Acute and chronic | a | Higher transmission potential in the rainy season when vector abundance and infection is elevated (in Nigeria) [51] |
| Pertussis | Acute | i and f* | Higher incidence June through October (in the US) [52] |
| Plague | Acute | a, b, c, f, and g | The seasonality varies among countries and is dependent on seasonality of reservoir and vector species and in some cases agricultural cycles [53] |
| Poliomyelitis | Acute | i, c*, and h* | Epidemics occurred during the summer (in the US) [6] |
| Rabies | Acute | b | Rabies is seasonal in bats, which are a source of human exposure [54] |
| RSV | Acute | i and c* | Peaks in winter months in temperate regions; less pronounced seasonality in the tropics [55] |
| Rift Valley fever | Acute | a and c | Associated with periods of heavy rainfall [56] |
| Rotavirus | Acute | i and c* | Geographical gradient in seasonality; peaks in December/January in the Southwest US and April/May in the Northeast US [57] |
| Rubella | Acute | f | Two seasonal peaks in transmission per year in Kenya; late-winter to early-summer peaks in the US [58, 59] |
| Salmonellosis | Acute | i | Increased number of isolates in the warm spring months (in Tunisia) [60] |
| Schistosomiasis | Chronic | b and c | Transmission is seasonal; two seasonal peaks per year (in Tanzania) [61] |
| Scrub typhus | Acute | a, c, and f | Seasonality depends on activity of vectors (i.e., chiggers) and humans. Seasonality varies geographically. Some areas (in Japan) have strong seasonal transmission, and others have relatively stable transmission [62] |
| Shigella | Acute | c | Elevated incidence in summer (in Massachusetts, US) [63] |
| Smallpox | Acute | c | Associated with dry weather [64] |
| Soil-transmitted helminth infections | Chronic | c and g | Hookworms undergo seasonal arrested development, which affects the acquisition of infection in humans; there is also seasonal acquisition of roundworm infections [65, 66] |
| Syphilis | Chronic | f | Higher incidence in summer (in China) [67] |
| Taeniasis (cysticercosis) | Chronic | b and f | Seropositivity varies seasonally in livestock, which are the source of human infection (in Romania) [68] |
| Tetanus | Acute | c and f | Peak in midsummer (in the US) [69] |
| Trachoma | Acute and chronic | a | More common in the wet season when the fly vector is most abundant (in Australia) [70] |
Since seasonal timing may differ among geographic areas, study location is indicated in parentheses.
*Indicated by author.
Abbreviations: MERS-CoV, Middle East respiratory syndrome coronavirus; RSV, Respiratory Syncytial Virus.