La espiral y el abismo en Amuleto

4.2.1. Introduction:

Malaria is one of the priority health problems in the Yemen Republic. Sixty per cent of the total population lives in areas at risk of malaria. Reports indicate that malaria has increased in recent years. In 1992 it was estimated that the true incidence was around 500 000 cases (National Malaria Control Programme, 1992). Outbreaks with malaria deaths were reported in 1992 from several govemorates including the

mountainous areas (WHO, 1996b). In 1998, it was estimated that 1.5-2 million people are suffered from malaria annually (National Malaria Control Programme, 1999).

4.2.2. Epidemiology o f malaria in the Yemen Republic:

Malaria endemicity varies with the topographical features of the country. In the coastal plain area (Tihama region) malaria is hypoendemic to mesoendemic and the spleen rate which is the prevelance of splenomegaly in children aged between two and nine years (Granham, 1966) is up to 25%. Hot seasons are not generally favorable for malaria transmission while the less hot seasons (October through April) are more favorable for transmission in this area. The endemicity is generally higher in the foothills where the plain coastal areas meet mountains. Pockets of mesoendemicity and hyperendemicity may be found here with the spleen rate up to 67% and malaria transmission seems to be relatively prolonged in this type of area. Malaria endemicity is considered to be hypoendemic in the highlands with the spleen rate up to 9%. The warmer season (May through September) is more suitable for malaria transmission in

this region. Malaria has been considered to be sporadic in the desert area sloping to the Empty quarter (Rub Al Khaly). Malaria is hyepemdemic in Sokotra island where the spleen rate of 60% has been reported (Thuriaux, 1971; National Malaria Control Programme ,1993a).

Ninety to 97% of malarial infections are due to P. falciparum (WHO, 1996b). Anopheles arabiensis is the principal vector and A. culicifacies is suspected to be a secondary vector in Sokotra island (National Malaria Control Programme, 1993b). Other Anopheline species such as A. sergentil, A. cinereus, A. rhodesiensis and A. d ’thali have been reported also.

The vector mosquitoes are present in rural as well as in urban areas. Water courses along wadi (river valleys) are natural breeding places of A. arabiensis. However, the mosquito has adapted to breed in man-made water collections, such as irrigation canals, household water containers (e.g. cement tanks, clay pots, barrels etc.) and waste water collections near water-pumps (National Malaria Control Programme, 1991).

The country is prone to periodic malaria outbreaks with considerable morbidity and some mortality. Outbreaks following heavy or prolonged rainfall and flooding in otherwise dry areas are common, particularly in southern govemorates and mountainous areas (National Malaria Control Programme, 1993a).

4.2.3. Present malaria situation in the Yemen Republic:

In the Yemen the prevalence of malaria have increased in last 10 years and the prevalence was the highest ever recorded. In 1990 110,000 cases were confirmed and the slide positivity rate (SPR) was 14% compared with 4.6% in 1985 (National Malaria Control Programme, 1993b). In 1994 malaria came only after gastroenteritis in the incidence of reported infectious diseases when 158,935 cases were reported and the SPR went up to 23% (MOPH, 1994). However, it should be noticed that data given above were collected from a selected number of health facilities, mainly in cities, and reports were often incomplete. The data do not represent the whole country nor a part of the country all the year round. At best the data come from approximately 50% of the country. However, they do indicate a trend in malaria incidence.

The increase of malaria cases in the recent years has been attributed to several factors: an increase in rainfall and man-made breeding sites, a decrease in anti-malaria

activities due to financial constraints, an increase in the movement of the population, and an increase in people seeking diagnosis and treatment are the main contributors.

4.2.4. Malaria control in the Yemen Republic:

The National Malaria Control Programme (NMCP) was established in the northern govemorates (previously known as the North Yemen) in 1978, and much earlier in the South Yemen. The main goals are to support and strengthen malaria control

throughout the country. The main antimalarial activities are DDT spraying, larviciding, and passive and active case detection and treatment.

DDT spraying in houses was carried out in the seventies and early eighties with fairly good results but it was stopped in late eighties as it could not be sustained for financial and logistical reasons. Larviciding using organophosphorus insecticide(Temphos) was initiated in the eighties in high malaria risk areas where more than 300,000 people benefited, but was stopped in 1992 due to financial constraints. Diagnosis and treatment of malaria have been carried out by all levels of health services. However diagnosis is mainly on clinical criteria and microscopical examination of blood smears is only carried out by hospitals or main health centres (National Malaria Control Programme, 1992).

Chloroquine continues to be the first line antimalarial drug although resistance is an increasing problem. The evidence obtained to date indicates that the problem of chloroquine resistance is a real one. The proportion of resistant cases among subjects tested varies from 5% to 19% and is higher in the southern part of Tihama (National Malaria Control Programme, 1993b). WHO (1996b) reported that simplified in vivo tests carried out in 1992 showed chloroquine resistance (R-I and R-II) in 12% of cases. Chloroquine resistance has not been recorded in the southern govemorates so far (National Malaria Control Programme, 1993b).

The main limitation of the NMCP in the battle against malaria, besides the financial constraints, is a shortage of trained technical personnel such as epidemiologists, entomologists, parasitologists and operational specialists) who can evaluate, monitor, train and coordinate antimalarial activities in the country.