Malaria in Haiti. Still a challenge. An overall increase of malaria incidence was reported in Haiti in 2010 as compared to 2009 and, a trending decline from 2010 to 2018 (Fig. 2). Curiously, the number of malaria cases estimated by the WHO in the 2009–2018 period is higher than that reported by the MSPP (Table 2). Nevertheless, both the MSPP and WHO data showed a decrease in malaria incidence from 2011 as compared to 2010, while the MSPP data showed a small increase in 2012 contrasting with the decline recorded by the WHO. Additionally, the number of malaria cases reported by the MSPP decreased in 2013, while they increased according to WHO.
A considerable difference between malaria cases reported in 2009 and 2010 by the MSPP and the WHO was detected (Fig. 2). The data of both institutions overlap between 2011 and 2018 (post-earthquake period), with the exception of 2013, when values deviate slightly. Therefore, the conflicting values for the first two years of the series may be due to the different Haitian sources of primary data. Even before the 2010 earthquake, Haiti faced socioeconomic problems [28], which inevitably affected the country's health system. In 2010, in response to the earthquake, the MSPP in collaboration with the CDC and various NGOs, established a surveillance system for infectious diseases including malaria [29]. The incongruity of MSPP data with those from WHO between 2009 and 2010 may be related to deficiencies in the epidemiological surveillance system prior to the support of CDC and NGOs. This may interfere with data collection and updating of the official MSPP database. Boncy and collaborators [16] pointed out some difficulties in the delivery of monthly reports of laboratory results to the central level of the MSPP and the lack of communication from the central to the local structures in Haiti.
Improving malaria data collection in Haiti. It should be noted that malaria data after the 2010 earthquake in Haiti is more robust. The reduction in conflicting data from 2011 is probably due to the MSPP’s actions in collaboration with their partners in the days and months following the earthquake. Although apparently conflicting, data from WHO and MSPP showed the same trend of malaria in Haiti during the ten years studied. In other words, malaria declined during the 2009–2018 period with little variation since 2011 (Fig. 2).
Malaria in the different departments/ regions of Haiti. Challenges and suggestions. Our analysis suggests that Grand’Anse Department has always been one of the highest malaria-burden areas of Haiti, and malaria cases were probably underreported in the years prior to 2014. Te underreporting of malaria cases in Grand’Anse may be related to the difficulty of access by land route to malaria foci in the municipalities of the department who presents rugged terrain [30]. Consequently, Grand’Anse and its spread and remote municipalities remain isolated. This problem results in particularly difficult and expensive access to health care, particularly in locations of high malaria burden [31], where people must walk hours to access medical care [32]. Lack of access to health facilities can be a discouraging factor, and may lead residents to use self-medication as the first alternative. It is worth noting that in Haiti, a country where the sale of drugs is not regulated, anyone can buy any drug from informal street drug vendors or in informal pharmacies without a doctor's prescription. In any case, apparently the surveillance and case records of malaria in this department in the analyzed period were more effective and realistic than in the others, for several reasons such as a major scale-up community case management such as diagnostic testing deploying RDTs and reporting thanks to the financial support provided by a global fund in 2012 to fight against AIDS, tuberculosis and malaria in Haiti [32, 33]. In addition, Haiti received technical supports from some international malaria actors such as the CDC Foundation and Malaria Zero to implement active research on malaria in the Grand’Anse Department from 2014. Probably, the significant decrease in malaria records in the Sud Department in 2014 and 2015 may be attributed to an underreporting of cases in this department in consequence of this special investment in the neighboring Grand’Anse during the same period 2014–2015.
No work has been published exploring on why Sud Department is a malaria-prone endemic area. However, some ecological determinants may hypothetically explain the fact that Sud presents high malaria endemicity, as observed in the years prior to the passage of Hurricane Matthew in October 2016, that is, since the beginning of the series in 2009. According to MSPP [34], Sud is considered to be one of the departments where the highest number of malaria cases has always been registered. The southern department is mainly made up of plains located along the coast. The hydrographic network of the Sud is dense because it is made up of 69 rivers, 250 springs, 20 ponds, one lake and 11lagoons [34], what favors the formation of larval habitats of anophelines. This large plain faces the green Massif de la Hotte which favors the precipitation and infiltration of rainwater.
CHAI and collaborators [1] have described the high risk of malaria transmission along the coast of Haiti. Malaria is mostly distributed along the coasts of the southern region of the country where are located both the Sud and Grand'Anse departments [35]. This coastal distribution of malaria is mainly related to the main anopheline vector bioecology, besides low local socioeconomic conditions. An. Albimanus has been described as essentially a coastal mosquito and often found in brackish water [36]. This species of anopheline is also considered a lowland mosquito [37] that breeds in a wide variety of sunny breeding sites at altitudes below 400 m [38]. Therefore, in the, there are very favorable ecological conditions for malaria transmission.
The occurrence of Hurricane Matthew in October 2016 may be considered the cause of the increase in malaria records in 2016 compared to 2015. Hurricane Matthew, which is a Category 5 Atlantic hurricane (maximum on the Saffir-Simpson scale), with winds reaching up to 260 km/h, caused catastrophic damage and a humanitarian crisis in Haiti. Haiti's departments most affected by this hurricane were Grand'Anse and Sud. Indeed, the after-effects of Matthew are likely to have included: displaced human populations, environmental changes, flooding that increased the number of malaria vector larval habitats, high exposure to mosquitoes and overcrowded human shelters. These changes in human conditions and in the environment may have facilitated the occurrence and transmission of vector-borne diseases. Even if the population of Anophelines may have temporarily decreased in numbers right after a hurricane, these conditions favored its subsequent proliferation. Actually, malaria cases have also increased after Hurricane Jeanne in Haiti in 2004 and Hurricane Flora in 1963 39, 40]).
The majority of the communes where malaria cases are notified in the Ouest Department are urbanized areas and 2/3 of the Haitian population live there. Port-au-Prince, the capital of Haiti is located in Ouest. The department has also recorded high malaria incidence in Haiti, with its municipalities accounting for 53% of malaria cases reported between 2012 and 2014 [41]. This data though, seems to be misleading. Patients travel long distances to receive better health care and malaria cases’ reports are based on the health unit location where the diagnosis occurred not where the patient lives [42].
To estimates malaria risk at the department level in this study we have used API. The results showed that malaria occurs in all departments of Haiti with a degree of risk ranging from low (0.02 to 7.71) to medium (10.68 to 23.38) (Table 2). It is known that API is influenced by the size of the population, which grows each year, regardless whether the number of cases increases [43]. Therefore, a given area may have a very low API even with high number of cases, and vice versa. For example, in 2011 Ouest Department had an API of 1.89 with a total of 8,869 cases. Since in the same year, the Department Nord-Est presented an API of 10.68 with 2124 representing 6% of the total cases for the ten departments. In 2011, the population of the Ouest Department and that of the Nord-Est department were estimated at 3,783,586 and 383,653 respectively. The population of Nord-Est department represented only 10.14% of the population of Ouest. Hence, the increase and decrease of the API value depends on the denominator that is the population size at a given time; that is; the larger the population, the lower the API will be, and vice versa.
Malaria control efforts in Haiti. Despite the objective set by Haiti and DR to eliminate malaria on the island of Hispaniola until 2020 was not achieved, an overall trending decline in the number of malaria cases in Haiti in the last years was recorded. Due to Haiti’s efforts to reduce the malaria burden over the past decade prior 2019, the number of malaria cases considerably dropped in the country from 2010 to 2018. Access to early diagnosis and treatment is one of the most important strategies for malaria control and elimination. This includes two components: 1) the patient must seek care, as soon as possible when sick; 2) health facilities with diagnosis and adequate treatment within easy access to the patient must be available [44]. Consequently, progress has been seen in improving access to malaria diagnosis and treatment in Haiti over the last years.
The use of bednets for malaria control in Haiti. The use of insecticide-treated nets (ITNs) is currently the most effective means of individual protection against malaria. ITNs have been implemented since 2010 in almost all the endemic areas of Haiti [45]. In the same context, approximately 800 thousand ITNs were distributed by The Menthor Initiative in collaboration with UNICEF from October to December 2010 [46, 35]. More than 350 thousand families in four departments of the country have benefited. In the same period, thousands of other mosquito nets were distributed by the Haitian Red Cross [47]. Subsequently, 2 million long-lasting insecticidal nets (LLINs) were distributed in Haiti by PSI in 2012. This resulted in that for the first time in the Americas it was reported that a higher number of people were protected by ITNs than by indoor residual spraying (IRS), the most common method used for malaria vector control [31]. Additionally, the Global Fund to fight AIDS, Tuberculosis and Malaria subsidized more than 400,000 mosquito nets in Haiti in December 2016 [48]. ITNs ensure individual protection by helping to limit contact between the individual and vector, as it is one of the best strategies against malaria. According to the WHO, a coverage rate with impregnated mosquito nets above 80% reduces infant and juvenile mortality by about 25% and guarantees effective protection of more than 60% against parasitemia [49]. Therefore, considering the reduction in the number of cases between 2011 and 2018, it can be said that, probably, there was an effect of the mosquito nets distribution campaigns in the reduction of malaria cases that we analyzed in the country.
The outstanding departments for malaria reduction in Haiti. While only three departments reported over 80% of all malaria cases in Haiti from 2016 to 2018, five departments (Nord, Nord-Est, Nord-Ouest, Sud-Est and Centre) showed together less than 7% of malaria cases, the smallest proportion of cases, during the period 2009–2018. In terms of reducing malaria cases over the period 2009–2018, the most outstanding departments for malaria reduction of Haiti were: Nord, Nord-Est, and Sud-Est.
Nord-Est is one of the departments of Haiti where malaria was a major concern in the years prior to 2014. Due to the binational project between Haiti and Dominican Republic, covering the border communities of Ouanaminthe (a municipality of Nord-Est Department) and Dajabon (a municipality in the Dominican Republic) [17], malaria cases in Nord-Est dropped from 3,888 in 2010 to 87 cases in 2016, a reduction of 97.76% (Table 2).
Similar observation is made for the Nord Department where a total of 14,952 malaria cases between 2009 and 2013 dropped to 942 malaria cases between 2014 and 2018, which represents only 6.3% of the total of case (more than 15 times lower). Therefore, Nord Department showed the greatest reduction in malaria incidence (almost 99%) among all departments of Haiti, when we compared 2018 with 2009. There was no work in the literature reporting the actions taken in that department to justify this important decrease. However, there is a hypothesis that the actions carried out within the framework of the binational project were extended to the Nord Department. Nord and Nord-Est Departments are close one to another. The distance between Limonade (a town in the Nord) and Ferrier (a town in the Nord-Est) is 36.29 km according to this website: https://distancecalculator.globefeed.com/Haiti_Distance_Calculator.asp. Accessed on 22 April 2020.
For decades, Sud-Est Department has been the area with the lowest malaria burden in Haiti. Over the period 2009–2018, the largest number of cases reported in that department was only 989 cases in 2010, the year in which malaria had a significant rise in the country. A study carried out by Raccurt and collaborators [50] has shown that malaria occurs in the form of heterogeneous foci in the coastal areas of Sud Department with strong variations in the carrying rates of the gametocyte and/or trophozoite forms of P. falciparum from one locality to the other.
Sud-Est Department, covering an area of 2,153 km², is made up of more than 65% of very steep mountainous regions [51] including the highest mountain range in Haiti, the Massif de la Selle (2,600 m altitude). The plains, representing nearly 35% of the area of the department, are all coastal; landlocked and separated from each other by an accentuated relief. The department is also characterized by its rainfall deficits which are recorded for decades (600 mm at most) and by high risks of drought [52]. Probably the highest proportion of the population of the department lives in the mountains. As the transmission of malaria in the southern region of Haiti occurs mainly at the coastal areas [4, 35], the low incidence of malaria, historically recorded in the Sud-Est Department, is probably due to the fact that the proportion of the population of the department exposed to the risk of contracting malaria is low.
Malaria in Pregnant and Children under 5 years old. According to WHO [53], malaria is considered one of the greatest health threats to children under five and pregnant women in malaria-burden areas. In high transmission areas, the majority of malarial disease occurs in young children without acquired immunity. The most commons of the severe clinical pictures of malaria seen in children are: severe anaemia, hypoglycemia and cerebral malaria. One of the WHO recommendations for the prevention of malaria in children is the use of long-lasting insecticidal nets (LLINs). As shown in Table 3, malaria morbidity among pregnant women and U5 has been included in the MSPP statistic reports only from 2015 to 2018. The proportions of reported malaria cases among pregnant women increased significantly in 2018 in the Nord-Est Department. However, Nord-Est is one of departments with low transmission areas from 2014 to 2018. Indeed, more than half of the cases (56.44%) were among pregnant women, despite the fact that few cases were recorded in this department in 2018. The MSPP data also show that in 2018 no confirmed cases were recorded in pregnant women in the North and the Nippes.
Malaria infection during pregnancy represents substantial risks for the pregnant woman, her fetus, and the newborn child having as consequences maternal illness and low birth weight [54]. According to WHO [55], the levels of acquired immunity may increase in areas of high burden of P. falciparum malaria. In those areas, malaria is usually asymptomatic in pregnant women with the presence of parasites in the placenta. This might contribute to maternal anaemia without peripheral parasitemia. Therefore, low confirmed malaria case among pregnant women in Haiti does not mean absence of Plasmodium spp. infection among them. In other words, the low number of cases registered among pregnant women during the study period may not show the malaria trend in pregnant women in Haiti. Because of the lack of health facility and education, pregnant women, especially in rural zones, do not have the habit of doing prenatal care before the third trimester of pregnancy, unless they feel really seek (personal communication).
On the other hand, in areas of low density of malaria transmission, women of reproductive age have relatively little acquired immunity to malaria. To avoid the risk of severe malaria that can lead to miscarriage, stillbirth, and prematurity and low birth weight, all pregnant women, regardless of their gestational age, are very vulnerable to malaria [54]. As solution, the WHO recommends an intermittent preventive treatment in pregnancy (IPTp), in all areas with moderate to high malaria transmission, especially in Africa. This therapy consists of administering to pregnant women at least two doses of an antimalarial drug, currently sulphadoxine-pyrimethamine (SP), at each scheduled antenatal visit after the first trimester of pregnancy, whether or not they have symptoms malaria [54]. At the date of writing of this paper, the Ministry of Health of Haiti has no IPTp in its malaria treatment protocol and, no scientific and official data on malaria case management among pregnant women were published by the MSPP.
Infant malaria. An important cohort in Haiti. Malaria in U5 in Haiti-MUF represents an important amount in the total cases. For the period 2015–2018 MUF varied from 0.78 to 17.99% in the total Haitian population. Despite total reduction in malaria cases in 2018, MUF was higher compared to the three previous years. Results between 2015 and 2018 showed inconsistency in terms of proportion of cases by department and by year with a great variation from 5.51 to 27.16% in 2015; 0 to 22.89% in 2016; 0.27 to 17.15% in 2017 and from 0.96 to 24.89% in 2018 (Table 3). At community level, and for each municipality in Haiti, MUF risk factors linked to socio-economic and environmental factors such as type of dwelling, access to health care, parental education level, household size and bed nets use should be investigated. These factors significantly influence the odds for MUF [56].