Draft of a Plan for Malaria Control in the Lower Jaguaribe Region: State of Ceara
This is a transcript of a report sent by de Souza Pinto to Soper describing the 1938-1939 epidemic in Brazil and recommending
immediate action to contain it.
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5 (531,698 Bytes)
1938-06 (June 1938)
de Souza Pinto, G.
Courtesy of Fred L. Soper.
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Medical Subject Headings (MeSH):
Fighting Yellow Fever and Malaria in Brazil, 1928-1942
Malaria Control In The Lower Jaguaribe Region (State of Ceara)
A serious outbreak of malaria occurred, a year ago, in the neighborhood of the town of Aracati, reaching several points on
the coast and along the banks of the Jaguaribe River. Here the epidemic started and extended to several localities on the
Jaguaribe River, decimating the population of that region.
Extent And Character Of The Epidemic
The extent and seriousness of this malaria outbreak cannot yet be gauged. The infected zones offer a deeply impressive sight.
For example, practically the entire counties of Uniao and Russas are attacked. In these districts we find more than 90% of
the population ill, the area embraced including towns, villages, fazendas, large and small properties.
It is desolating that despite the favorable weather conditions of last winter no improvement can be recorded in this zone,
which is one of the richest, if not the richest, of the State of Ceara. All over this region one sees magnificent carnauba
trees, extensive cotton and cereal plantations, cattle, etc., but all lacking attention due to shortage of labor.
Grave clinical form of the disease and the case fatality show the seriousness of the situation.
In the Aracati region a noticeable decline of the epidemic is recorded, but in the neighboring districts the disease is extending
rapidly. Besides the Uniao and Russas counties, already mentioned, the outbreak has reached Limoeiro and Morada Nova counties.
The center of the first zone has been but slightly affected but is now seriously threatened. In the latter zone, however,
many cases are now being reported.
The local authorities estimate the total number of malaria cases in the entire region at about 60,000. This may be an exaggeration,
but we would probably be right in stating the figure to be from 40,000 to 45,000. Case fatality is much higher than has ever
been observed previously and which, as a rule, was 1% in chronic cases. In acute cases deaths rarely ever occur, except in
the pernicious type. In the present epidemic the case fatality runs from 15-25%. In normal times the number of deaths in
the town of Russas does not exceed 200 a year, which is less than one per day. Last May, however, 327 deaths occurred, which
gives an average of more or less 11 per day. Including the deaths which occurred in the whole of the county, this figure
will total about 400. The total number for the whole region affected by the epidemic is estimated at 800.
Case Of Gravity Of Situation
In 1930, in Natal, Rio Grande do Norte, the presence of a species of Anopheles of the genus "Mysomyia" was discovered,
which up to then had never been found in South America. This fact greatly surprised the eminent entomologist R. C. Shannon,
who verified that this mosquito was the "Anopheles costalis", or "Anopheles gambias", an African species,
and the most dangerous transmitter of malaria on the Black Continent. (1) Soon after this discovery an extensive outbreak
of a fever epidemic of extreme gravity and high mortality occurred in Natal and some districts on the coast of Rio Grande
do Norte. At that time, when we took over the direction of the health services of that State, we confirmed Shannon's
observation that the epidemic was caused by transmission through this insect which unfortunately had been brought into our
country by the fast French destroyers which transported the correspondence of the "Air France" between Dakar and Natal,
a voyage of only four days. (2)
We tenaciously fought against this enemy and succeeded in dominating it in Natal, Ceara-Mirim and other points, but we could
not complete the work and urgently called the Government's attention to the great danger threatening Brazil by the invasion
of this mosquito. In public conferences and various publications we pointed out the danger of this disease extending to neighboring
States, including Ceara, which State would inevitably be one of the first victims. These statements were made in October
1931 and repeated in an interview granted to the "Correio do Ceara", in November of that year.
This African mosquito is an extremely dangerous malaria vector. Research work by dissection showed percentages never before
observed in other species. In specimens from Natal, Davis found 62.8% infected stomachs and 30.2% salivaery glands. We continued
research work in 162 specimens from Taipu and 235 from Sao Goncalo, and obtained the following results:
Total dissections: 397
With cocysts on the stomach: 284, or 71.5%
With sporozoites in the salivary glands: 112, or 28.2%
This suffices to show the capacity of malaria propagation of this culicidas and the elevated hematozoic virulence which develops
in it easily and exuberantly in conditions favorable for its growth.
The importation into Brazil of this sinister insect represents one of the greatest misfortunes that could overcome our country,
unless we take immediate and energetic measures, not sparing effort expense.
According to an estimate made a long time ago, there exist in Brazil about 8 million malaria patients, but if "costalis"
continues to spread over the country, in half a century only the ruins of our race will remain.
For the past seven years we have been fighting this mosquito and for the time being we have confirmed its activities to the
States of Rio Grande do Norte and Ceara. There is still time to save the nation from the peril of this deadly malaria vector.
We find it opportune to here transcribe the concluding words of our report, presented in 1931 to the then Minister of Education
and Public Health: "Summarizing, we believe that there is still time to defend ourselves and to blockade the enemy. With
the advances of preventive medicine, nothing would justify a hesitating action. Salvation will come from financial support
which the Government should designate for this purpose. The indispensable budgets for this immediate and important health
campaign will not be very heavy". (2)
Rio Grande Do Norte
The regions attacked at present in the State of Rio Grande do Norte are principally located in the Ceara-Mirim and Assu River
valleys or the Piranhas River, and to a lesser extent in the Mossoro and Apodi river valleys, though old foci are still to
be found along the banks of the Potegi River.
In the Ceara-Miram valley, the points most attacked are the Ceara-Mirim, Taipu and Baixa Verde counties; in the Assu Valley,
the river banks are completely infected, the left bank to an extension of more than 100 kilometers length by 30 wide, forming
a large stretch between the town and the coast. This zone is densely populated, with 20,000 inhabitants. Among other small
localities, we mention Nova Esperanca, Santa Luzia, Officinas, Logradouro and Canto do Mangue; on the right bank of the river
the counties of Macau, Angicos, Sant'Ana do Matto; in the Mossoro valley the counties of Areia Branca and part of Mossoro
are also infected.
It is interesting to observe the march of the "Anopheles costalis" along the coast line, successively reaching the
mouth of these rivers, and then turning to the Jaguaribe, in the State of Ceara.
Total Of Persons Affected By Malaria
The estimate of malaria cases which we present is based strictly on personal investigations and data gathered by various Federal
and State Health officials in this region.
In the counties of Ceara-Mirim, in Taipu and Baixa Verde there occurred 13,000 cases; in Assu county 20,000, in Macau 3,500,
Angicos 1,000, Sant'Ana dos Matos 9,000, Areia Branca 3,000, Mossoro 500; and in Sao Goncalo and surroundings 1,5000,
giving a total of 51,500.
This number tends to increase daily, and one can count on a monthly increase of from 6 to 8%. Certain regions which up to
now were spared will soon also be infected, as there are numerous points still free as yet from fever but already invaded
by "Anopheles costalis". Among others, we mention vast areas in the counties of Macau and Mossoro.
In Ceara, case fatality was high, but a certain variation in percentages was noted, according to the zones or regions studies.
In the counties of Areia Branca and Mossoro, the epidemic has been benign, the mortality due to malaria not surpassing 6%,
but already in Assu, the situation is becoming serious, as we find here 10% of fatal cases, and in the county of Macau the
doctor in charge of the health service reports a mortality of 13%. Mortality in the Ceara-Mirim valley oscillates between
8 and 15. Death registration in the interior is not on as efficient basis and we were therefore not able to gather accurate
data from the registrars. However, careful estimates were made by doctors and inspectors of the Service, which give the number
of fatal cases since the beginning of this year as: Ceara-Mirim, Taipu and Baixa Verde - 1,560; Assu - 2,100; - Sant'Ana
dos Matos e Angicos - 980; Macau - 440; Areia Branca and Mossoro - 210; Total 5,290. In this total are not included data
of various far distant localities.
In the Assu valley region we carefully studied the degree and distribution of enlarged spleens. The index obtained without
distinction of age was 74.2. Careful examination of 221 persons living in the localities of Santa Luzia (left river bank)
and Sacramento, on the right bank, gave the following result: Enlarged spleen - 194; spleens not palpable - 27; with spleen
no. 1 - 60; no. 2 - 50; no. 3 - 41; no. 4 - 3. Splenic index - 87.8; Ross index - 1.5; Parrot index - 131.7.
As is seens, in spite of a very high splenic index, the Ross index was relatively low, as there were very few large spleens.
On the contrary, the greater part were no. 1 spleens and while there were a number of no. 2 and 3 spleens, no. 4 spleens were
In patients examined in the Ceara-Mirim region we found a good number of no. 4 spleen. We did not cite this index as we thought
the data obtained was not sufficient. It should be noted that malaria in this region is of much earlier date than in the
1. Larvae Studies
The searches for Anopheles larvae were generally positive in the small and medium sized lakes. We found larvae of various
sizes, some of the subgenus "Nyssorhynchus" and other of the "Mysomyia costalis". Rains hampered this search
for larvae, which under more favorable conditions would have revealed more foci.
2. House Captures
In captures effected in residences, Anopheles costalis was not only found in dwellings situated in the infected zones but
also in various nearby localities which had not yet been affected by fever outbreaks. A much greater number of Anopheles
costalis were found in the evenings than during daytime. On rainy days were rarely found any in residences.
3. Night Captures
In Santa Luzia (on the left bank of the Assu river) we made mosquito captures with animal bait early in the evening, employing
a capture squad of four, using 2 horses. We did not expect positive results since we knew that costalis refuses animal blood,
and were surprised to see a great number of Anopheles feeding on the horses. In less than 15 minutes we captured 23 specimens.
Had it not been for an unexpected and heavy rain and the unrest of the horses, the number captured would have been much larger.
Examination of the anophelines we had caught showed that all were of the subjenus "Nyssorhynchus", which confirmed
our previous observations regarding A. costalis.