Table 2. Seroprevalence data by region and country, 1999–2020.
| Region/ Country | Area | Population1 | Year sample collection | Recent outbreak2 | Sample size | Seroprevalence (%) | Inapparent infection | |
|---|---|---|---|---|---|---|---|---|
| IgG | Overall IgM or IgG | (% of seropositives) | ||||||
| Africa | ||||||||
| Benin | South (Cotonou) | Pregnant women | 2006–07 | No | 352 | 36.1 | NR | NR |
| Cameroon | Northwest (3 sites, Kumbo) | Households | 2007 | Yes | 105 | 88.6 | NR | NR |
| Comoros | Comoros (Grande Comore, Ndzouani and Mwali) | Patients >15y | 2011 | No | 400 | 12.0 | NR | NR |
| Grande Comore | Households | 2005 | Yes | 331 | 26.9 | 63.1 | NR | |
| Kenya | West (Alupe) | Children aged 1-12y | 2010–11 | No | 649 | NR | 5.6 | NR |
| East (Lamu Island) | Households, individuals >1y | 2004 | Yes | 288 | 71.5 | 74.7 | NR | |
| Kenya (West—Busia and Samburu—and East—Malindi) | Individuals >17y | 2004 | Yes | 1141 | 34.0 | NR | NR | |
| West (Busia) | Individuals >5y | 2010–12 | No | 500 | 66.9 | NR | NR | |
| La Reunion | La Reunion | Pregnant women | 2006 | Yes | 888 | NR | 18.2 | NR |
| La Reunion | Households | 2006 | Yes | 2442 | 39.6 | NR | NR | |
| Madagascar | Central-East (6 sites) | Pregnant women | 2010 | Yes | 1244 | 12.4 | NR | 25 |
| Mayotte | Mayotte | Households | 2006 | Yes | 1154 | 37.2 | NR | 28 |
| Mozambique | Central-North (5 sites) | All patients | 2015–16 | No | 392 | 28.6 | NR | NR |
| Mozambique | All patients | 2009–15 | No | 895 | 17.9 | NR | NR | |
| Republic of Djibouti | Southeast (Djibouti city) | Households | 2010–11 | No | 914 | 2.6 | NR | NR |
| Rwanda | Rwanda | Blood donors | 2015 | No | 874 | 63.0 | NR | NR |
| Senegal | Northeast (5 sites) | Individuals >1y (nomadic pastoralists) | 2014 | No | 1463 | 2.7 | NR | NR |
| Southeast (Kedougou) | Households | 2012 | No | 998 | 54.0 | NR | NR | |
| Tanzania | Southwest (Kyela) | Patients >2y | 2015 | No | 132 | 10.6 | 14.4 | NR |
| Uganda | Uganda (5 sites) | Blood donors | 2006–07 | No | 1744 | 31.7 | NR | NR |
| Americas | ||||||||
| Brazil | North (Macapá, Amapá) | Blood donors | 2015 | Yes | 442 | 0.2 | NR | NR |
| Southeast (Ribeirão Preto, São Paulo) | Blood donors | 2016 | Yes | 455 | 0.0 | NR | NR | |
| Northeast (Chapada, Bahia) | Households | 2016 | Yes | 120 | 18.3 | 20.0 | 46 | |
| Northeast (2 sites, Bahia) | Households, individuals >1y | 2015 | Yes | 831 | 36.2 | 51.0 | 63 | |
| Martinique and Guadeloupe | Martinique | Blood donors | 2015 | Yes | 1004 | 41.9 | NR | NR |
| Guadeloupe | Blood donors | 2015 | Yes | 750 | 48.1 | NR | NR | |
| Mexico | Central (Puente de Ixtla, Morelos) | Households, Individuals >1y | 2016 | Yes | 387 | 29.5 | NR | 43 |
| Nicaragua | Managua | Children aged 2-14y | 2014–15 | Yes | 3362 | NR | 6.1 | 58 |
| Managua | Households, individuals ≥15y | 2015 | Yes | 848 | NR | 13.1 | 65 | |
| Nicaragua (39 sites) | Households, individuals >2y | 2015 | Yes | 11280 | NR | 32.8 | 19 | |
| Saint Martin | Saint Martin | All patients | 2014 | Yes | 203 | 17.7 | 20.7 | 41 |
| Asia | ||||||||
| India | South (Chennai, Tamil Nadu) | Households, individuals >4y | 2011 | Yes | 1010 | 43.5 | NR | 60 |
| West (Sholapur, Maharashtra) | Households | 2006 | Yes | 1192 | 30.4 | NR | NR | |
| South (Kerala) | Households, individuals >13y | 2009 | Yes | 381 | 68.0 | NR | 13 | |
| Iraq | South (Nasiriyah) | Individuals >13y, patients >9y | 2012–13 | No | 399 | 0.5 | NR | NR |
| Malaysia | Central | Individuals >34y | 2008 | No | 945 | 5.9 | NR | NR |
| Qatar | Qatar | Blood donors, male ≥18y | 2013–16 | No | 200 | 3.5 | NR | NR |
| Singapore | Singapore | Individuals >17y | 2010 | Yes | 3293 | 2.2 | NR | NR |
| Thailand | Central + South | Patients >6m | 2014 | No | 835 | 26.8 | NR | NR |
| South (Songkhla) | Pregnant women | 2009–10 | Yes | 319 | 45.7 | 72.3 | NR | |
| South (Phatthalung) | Households, individuals >17y | 2010 | Yes | 507 | 61.9 | NR | 47 | |
| Europe | ||||||||
| Turkey | Central (Kirrikale, Central Anatolia) | Blood donors | 2015 | No | 500 | 0.4 | NR | NR |
| Croatia | Southwest (Adriatic Coast) | Individuals >2y | 2011–12 | No | 1008 | 0.9 | NR | NR |
| Italy | Castiglione di Cervia | Households | 2007–08 | Yes | 325 | 10.2 | NR | 18 |
| Sweden | Sweden | Blood donors | 2015 | No | 199 | 8.5 | NR | NR |
| Oceania | ||||||||
| Fiji | Fiji | Individuals >5y | 2017 | No | 320 | 12.8 | NR | NR |
| French Polynesia | Tahiti | Children (primary/ secondary school) | 2014 | No | 476 | 1.0 | NR | NR |
| French Polynesian (5 sites) | Households | 2014 | No | 196 | 3.0 | NR | NR | |
| Society Islands | Households | 2015 | Yes | 700 | 76.0 | NR | 13 | |
| Solomon Islands | Honiara and Gizo | Households | 2016 | No | 188 | 0.8 | NR | NR |
1“Households” and “all patients” includes children and adults, unless otherwise specified.
2Recent outbreak refers to studies conducted during or immediately after an outbreak.
M = Month; NR = Not reported or not clear from the study text; Y = Year